CECW-EG

Engineer Manual1110-2-2301

Department of the ArmyU.S. Army Corps of Engineers

Washington, DC 20314-1000

EM 1110-2-2301

30 September 1994

Engineering and Design

TEST QUARRIES AND TEST FILLS

Distribution Restriction StatementApproved for public release; distribution is

unlimited.

DEPARTMENT OF THE ARMY EM 1110-2-2301U. S. Army Corps of Engineers

CECW-EG Washington, D.C. 20314-1000

ManualNo. 1110-2-2301 30 September 1994

Engineering and DesignTEST QUARRIES AND TEST FILLS

1. Purpose. This manual establishes criteria and provides guidance for the investigations precedingtest quarries, for the development of test quarries, and for the planning and conduct of compacted test-fill programs at civil works projects.

2. Applicability. The provisions of this manual are applicable to all HQUSACE elements, majorsubordinate commands, districts, laboratories, and field operating activities having civil worksresponsibilities.

FOR THE COMMANDER:

DEPARTMENT OF THE ARMY EM 1110-2-2301U.S. Army Corps of Engineers

CECW-EG Washington, DC 20314-1000

ManualNo. 1110-2-2301 30 September 1994

Engineering and DesignTEST QUARRIES AND TEST FILLS

Table of Contents

Subject Paragraph Page Subject Paragraph Page

Chapter 1IntroductionPurpose . . . . . . . . . . . . . . . . . . . . . . . . 1-1 1-1Applicability . . . . . . . . . . . . . . . . . . . . . 1-2 1-1References . . . . . . . . . . . . . . . . . . . . . . 1-3 1-1Scope . . . . . . . . . . . . . . . . . . . . . . . . . . 1-4 1-1General Considerations . . . . . . . . . . . . . . 1-5 1-1Test Quarry Justification . . . . . . . . . . . . . 1-6 1-1

PART 1Test Quarries

Chapter 2Investigation StagesProject Development Phasesand Associated Geotechnical

Investigations . . . . . . . . . . . . . . . . . . . 2-1 2-1Reconnaissance Study Phase . . . . . . . . . . 2-2 2-1Feasibility Study Phase . . . . . . . . . . . . . . 2-3 2-1Preconstruction Engineering and

Design Phase . . . . . . . . . . . . . . . . . . . 2-4 2-1Construction Phase . . . . . . . . . . . . . . . . . 2-5 2-1Operations Phase . . . . . . . . . . . . . . . . . . 2-6 2-2

Chapter 3Regional Investigations and Site ReconnaissanceGeneral . . . . . . . . . . . . . . . . . . . . . . . . . 3-1 3-1Initial Regional Geology Studies . . . . . . . 3-2 3-1Field Reconnaissance . . . . . . . . . . . . . . . 3-3 3-1Survey of Existing Excavations . . . . . . . . 3-4 3-1

Chapter 4Field InvestigationsGeneral . . . . . . . . . . . . . . . . . . . . . . . . . 4-1 4-1Geologic Mapping . . . . . . . . . . . . . . . . . 4-2 4-1

Geophysical Investigations . . . . . . . . . . . 4-3 4-1Subsurface Explorations . . . . . . . . . . . . . 4-4 4-1

Chapter 5Laboratory TestingGeneral . . . . . . . . . . . . . . . . . . . . . . . . . 5-1 5-1Petrographic Examination . . . . . . . . . . . . 5-2 5-1Weight/Volume Properties . . . . . . . . . . . 5-3 5-1Strength Tests . . . . . . . . . . . . . . . . . . . . 5-4 5-1Rock Durability Tests . . . . . . . . . . . . . . . 5-5 5-1

Chapter 6Location and Design of Test QuarriesGeneral . . . . . . . . . . . . . . . . . . . . . . . . . 6-1 6-1Evaluation of Project Rock Production

Requirements . . . . . . . . . . . . . . . . . . . 6-2 6-1Evaluation of Potential Test Quarry

Sites . . . . . . . . . . . . . . . . . . . . . . . . . 6-3 6-1Test Quarry Layouts . . . . . . . . . . . . . . . . 6-4 6-2Gradation Measurements . . . . . . . . . . . . . 6-5 6-9Deterioration and Incipient Fracture

Examination . . . . . . . . . . . . . . . . . . . . 6-6 6-12Rock Processing . . . . . . . . . . . . . . . . . . 6-7 6-13

Chapter 7Test Quarry OperationsSupervision . . . . . . . . . . . . . . . . . . . . . . 7-1 7-1Safety Considerations . . . . . . . . . . . . . . . 7-2 7-1Modification of Design . . . . . . . . . . . . . . 7-3 7-1Blasting Plans . . . . . . . . . . . . . . . . . . . . 7-4 7-1Slope Mapping and Presplitting

Observations . . . . . . . . . . . . . . . . . . . . 7-5 7-2Rock Quality and Pre-Test Fill

Gradations . . . . . . . . . . . . . . . . . . . . . 7-6 7-3

i

EM 1110-2-230130 Sep 94

Subject Paragraph Page Subject Paragraph Page

Rock Processing Results . . . . . . . . . . . . . 7-7 7-3Report . . . . . . . . . . . . . . . . . . . . . . . . . 7-8 7-4

PART 2TEST FILLS

Chapter 8General ConsiderationsBackground . . . . . . . . . . . . . . . . . . . . . . 8-1 8-1Why a Test Fill? . . . . . . . . . . . . . . . . . . 8-2 8-1Representative Procedures . . . . . . . . . . . . 8-3 8-3Test-Fill Scheduling . . . . . . . . . . . . . . . . 8-4 8-3Flexibility . . . . . . . . . . . . . . . . . . . . . . . 8-5 8-3

Chapter 9Planning and DesignGeneral . . . . . . . . . . . . . . . . . . . . . . . . . 9-1 9-1Location of the Test Fill . . . . . . . . . . . . . 9-2 9-1Geometry . . . . . . . . . . . . . . . . . . . . . . . 9-3 9-1Test Sections or Lanes . . . . . . . . . . . . . . 9-4 9-1Equipment . . . . . . . . . . . . . . . . . . . . . . 9-5 9-2

Chapter 10Test Fill ConstructionFoundation Preparation . . . . . . . . . . . . . . 10-1 10-1Placement of Hard to Medium Rock . . . . 10-2 10-1Placement of Soft Rock . . . . . . . . . . . . . 10-3 10-4Rockfill Versus Soil . . . . . . . . . . . . . . . . 10-4 10-5Use of Water . . . . . . . . . . . . . . . . . . . . . 10-5 10-5Compaction and Compaction

Equipment . . . . . . . . . . . . . . . . . . . . . 10-6 10-6

Chapter 11Measurements and ObservationsGeneral . . . . . . . . . . . . . . . . . . . . . . . . . 11-1 11-1Densification . . . . . . . . . . . . . . . . . . . . . 11-2 11-1Gradation Tests . . . . . . . . . . . . . . . . . . . 11-3 11-4Percolation Tests . . . . . . . . . . . . . . . . . . 11-4 11-5Other Tests . . . . . . . . . . . . . . . . . . . . . . 11-5 11-9Visual Observations . . . . . . . . . . . . . . . . 11-6 11-10Inspection Trenches or Pits . . . . . . . . . . . 11-7 11-10

Chapter 12Evaluation of Test Fill ResultsGeneral . . . . . . . . . . . . . . . . . . . . . . . . . 12-1 12-1Settlement Data . . . . . . . . . . . . . . . . . . . 12-2 12-1Roller Passes . . . . . . . . . . . . . . . . . . . . . 12-3 12-1Gradation Data . . . . . . . . . . . . . . . . . . . 12-4 12-1In Situ Density Data . . . . . . . . . . . . . . . . 12-5 12-1Inspection Trench . . . . . . . . . . . . . . . . . 12-6 12-5Test Fill Report . . . . . . . . . . . . . . . . . . . 12-7 12-9

Appendix AReferences

Appendix BVibratory Roller Information

Appendix CList of Symbols

ii

EM 1110-2-230130 Sep 94

Chapter 1Introduction

1-1. Purpose

This manual establishes criteria and provides guidance forthe investigations preceding test quarries, for the develop-ment of test quarries, and for the planning and conduct ofcompacted test-fill programs at civil works projects.

1-2. Applicability

The provisions of this manual are applicable to allHQUSACE elements, major subordinate commands,districts, laboratories, and field operating activities havingcivil works responsibilities.

1-3. References

Appendix A contains a list of required and related publi-cations pertaining to this manual. Unless otherwise noted,all references are available on interlibrary loan from theResearch Library, ATTN: CEWES-IM-MI-R, U.S. ArmyEngineer Waterways Experiment Station, 3909 HallsFerry Road, Vicksburg, MS 39180-6199.

1-4. Scope

This manual is intended to be a guide for use in planningthe portions of the project geotechnical investigationsdealing with rock source materials, the design and opera-tion of a test quarry, and the design and conduct of a rocktest fill program. This manual is not intended to be atextbook on engineering geology, blasting or rock excava-tion, or the many possible variations and elements of atest fill program. Actual investigations, test quarry designand development, and test-fill specifics must, in allinstances, be tailored to individual project requirements.While the focus of the manual is upon determining themeans to produce, place, and compact rock fill materials,the portions concerning test quarries are also applicable toestablishing sources for other rock uses such as riprap orconcrete aggregate. Part 1 of the manual will address testquarries and Part 2 will treat compacted rock test fills.

1-5. General Considerations

An integral part of the development of large civil worksprojects is the establishment of sources of material forembankment or fill construction. Many water-retentionand water-conveyance projects require large volumes ofrock material. As a consequence, the selection of the

project site and the selection of the types of project com-ponents frequently involve the type and availability of soiland rock materials. Test quarries are especially importantwhere there are questions about the suitability and behav-ior of rock in required excavations for use in embankmentrockfill zones, for slope protection or (less frequently) forconcrete aggregate sources. Even experienced practi-tioners often cannot predict how rock obtained from anexcavation or quarry will break down upon blasting andexcavation or subsequently upon transport, placement, andcompaction in a fill operation. The most frequent troublehas occurred when the quarried material either containedmore fines or more oversized material or degraded morein transport, placement, and compaction than had beenanticipated in the design. It has sometimes been neces-sary to make major design changes because rock behaviorwas contrary to that anticipated by the designers(EM 1110-2-1911). The use of test quarries and associ-ated test fills has assisted in precluding such expensivesurprises. In addition to providing the rock materials fortest fills, test quarries have also provided the followinginformation for project design:

a. Cut slope design constraints resulting from geo-logic structural details.

b. Blasting patterns and loading and resulting rockfragmentation.

c. Suitability of quarry-run rock.

d. Required rock processing methods.

On many projects, the results of quarry tests have alsoaided prospective bidders with a much better understand-ing of required excavation methods and rock drilling andblasting characteristics. The slope development aspects ofthe test quarry development (presplitting panels and pro-duction blast stand-off distances) and geologic maps ofthe test quarry slopes have aided in the design of requiredexcavation slopes. Because of the time and cost associ-ated with rock test quarries and test fills, it is imperativethat they be carefully designed and conducted to yieldgood, useful data for the design.

1-6. Test Quarry Justification

A test quarry is not justified under all circumstances.Before recommending that a test quarry program be initi-ated, certain questions should be carefully considered todetermine if a test quarry can improve design, reduce theprobability of differing site conditions claims and savemoney during construction. If most of the following

1-1

EM 1110-2-230130 Sep 94

questions are answered in the affirmative, a test quarryprogram is probably justified.

a. Is the quantity of stone required for constructionenough to merit the cost of developing a test quarry?

b. Are the project design and rock types to beexploited so unique that the necessary stone product infor-mation is not available from other projects?

c. Are there questions with regard to the projectbeing considered which are peculiar to that project and

can only be answered with a test quarry?

d. Is a rock test fill required which can only beconstructed with rock obtained from a test quarry?

e. Are there reasons to suspect the durability and/orhandling characteristics of the rock product which make itimportant to evaluate with a test quarry?

1-2

PART 1TEST QUARRIES

EM 1110-2-230130 Sep 94

Chapter 2Investigation Stages

2-1. Project Development Phases and AssociatedGeotechnical Investigations

Table 2-1 shows civil works project development phasesand the geotechnical investigations performed duringthese phases.

ER 1110-2-1150 provides the requirements for each of theproject development phases and EM 1110-1-1804 pro-vides detailed discussions of the scope of geotechnicalinvestigations for each phase.

2-2. Reconnaissance Study Phase

A reconnaissance study is fully Federally funded and isconducted to determine whether a problem has solutionsacceptable to local interests which are in accordance withadministration policy and if planning should proceed tothe feasibility phase. The reconnaissance phase is generalin scope and the engineering effort should be assessingpotential alternatives, preparing and reviewing proposedproject plans and developing preliminary cost estimates.Detailed engineering analyses are generally not required atthis time. The level of engineering effort required for thefollowing feasibility phase is identified and its associatedcosts estimated. Regional geologic and soils studies andfield reconnaissances should be performed. In addition,an initial assessment of the hazardous and toxic waste(HTRW) potential of the study area shall be conductedduring the reconnaissance phase as outlined inER 1165-2-132. The reconnaissance is limited to12 months.

2-3. Feasibility Study Phase

The feasibility study investigates and recommends solu-tions to water resource problems and, except for single-purpose inland navigation projects, are cost shared with anon-Federal sponsor. The feasibility study is the basis forCongressional authorization. Sufficient engineering anddesign should be performed to enable refinement of proj-ect features, prepare a baseline cost estimate, develop adesign and construction schedule, and allow detaileddesign on the selected plan to begin immediately uponreceipt of preconstruction engineering and design funds.Typical feasibility studies are completed in 3 to 4 years.General Design Memoranda (GDM) are not generally

scheduled or planned. The geotechnical investigationprogram should assure that sufficient geologic and soilsinformation are acquired and analyzed to verify the proj-ect plan, support site selection, selection of structures,assessment of foundation conditions, foundation designand selection of types of foundation treatment. Explora-tions should be in sufficient detail to support projectdesign and the baseline cost estimate. Potential sourcesof concrete aggregate, earth and rock borrow, and slopeprotection material should be located and the investiga-tions necessary to prove-out and develop these sourcesidentified. If needed, further HTRW assessments areconducted during the feasibility study phase as outlined inER 1165-2-132.

2-4. Preconstruction Engineering and DesignPhase

The preconstruction engineering and design phase (PED)is an intensive effort which ends with the preparation ofthe plans and specifications (P&S) and the award of thefirst construction contract. PED costs are shared in thesame percentage as the purpose of the project. Necessarydesign memoranda (DM) are prepared and P&S are pre-pared for the first contract. Geotechnical investigationsshould be project feature specific and should validate andrefine designs and costs developed during the feasibilitystudy. Final investigations in support of development ofthe test quarry and conduct of the test fill should becompleted. If the test quarry and test fill programs are tobe accomplished by hired labor, or as contract explora-tions, they may be accomplished during the PED. If theyare to be accomplished by construction contract, P&Sshould be prepared. The PED phase generally requiresabout 2 years. HTRW activities, if any, during the PEDphase shall follow the procedures outlined inER 1165-2-132.

2-5. Construction Phase

Engineering effort during the construction phase includesfinal design efforts, preparation of remaining DMs andpreparation of P&S for subsequent construction contracts,site visits, initiation of any foundation report, developmentof Operation and Maintenance (O&M) manuals and emer-gency action plans and preparation of as-built drawings.In multi-contract projects, test quarry and test fill develop-ment may be accomplished at the beginning of the con-struction phase. HTRW activities, if any, duringconstruction, shall follow the procedures outlined inER 1165-2-132.

2-1

EM 1110-2-230130 Sep 94

Table 2-1Sequence of Geotechnical Investigations with Project Development Phases

Civil WorksProject Development Phases

GeotechnicalInvestigations

Reconnaissance Phase Development of Regional Geology andField Reconnaissance

Feasibility Phase Site Selection and Initial FieldInvestigations

Preconstruction, Engineering, and DesignPhase

Foundation and Design Investigationsand Constructibility Review

Construction Phase Quality Assurance and Post-ConstructionDocumentation Activities

Operation and Maintenance Phase Special Investigations as required

(Adapted from ER 1110-2-1150 and EM 1110-1-1804)

2-6. Operations Phase

Engineering activities during the operations phase gener-ally consist of the participation in periodic inspectionsand design and P&S preparation for major repair andrehabilitation projects.

2-2

EM 1110-2-230130 Sep 94

Chapter 3Regional Investigations and SiteReconnaissance

3-1. General

Regional geologic and site reconnaissance investigationsare made to develop the overall project geology and toscope early site investigations. The required investigationsteps are shown in Figure 3-1. Detailed guidance on theconduct of these investigations is contained in EM 1110-1-1804. Additional guidance specific to determining theprobable need for a test quarry, development of potentialtest quarry locations, and definition of necessary siteinvestigations is provided in the following paragraphs.

3-2. Initial Regional Geology Studies

The overall regional geologic model resulting from inter-agency coordination, literature surveys, and map andremote sensing studies will assist in the decisions con-cerning the most efficient and economical project compo-nents and their tentative siting. As this projectformulation proceeds, the potential need, or lack thereof,for produced rock materials will develop. During thecoordination and information survey stages, informationcan be sought concerning existing sources of rockmaterial in the region. On-line computer aided informa-tion retrieval services are readily accessible and can pro-vide detailed reference lists. Information on regional andlocal geology, etc., relevant to site selection and designmay be available from the U.S. Geological Survey. TheU.S. Bureau of Reclamation maintains data on their proj-ect quarries as a function of broad rock genesis. Addi-tional information on data sources is contained inEM 1110-1-1804. As part of the development of thegeology of the region, special attention should be paid tothe existence of regional stress fields in terms of how theymay affect potential quarry excavations and produced rockproducts. In addition to determining groundwater condi-tions for normal project purposes, their effect on potentialquarry excavations should be assessed.

3-3. Field Reconnaissance

Field reconnaissance should be made concurrent with, orimmediately following the regional geologic studies.While the field reconnaissance stage does not includedetailed studies such as geologic mapping, there are anumber of observations that can be made that will assistin the decision to employ test quarry programs and in theprobable quality of rock fill material that would be pro-duced. Rock types, as noted from existing geologic maps,literature, and remote sensing studies can be confirmed.Tentative depths of overburden and weathered rock can beestablished. Outcrop observations can provide preliminaryinformation on geologic structure and fracture frequency.Terrain conditions as they relate to tentatively selectedrequired excavations can be determined. From the infor-mation obtained during the field reconnaissances, prelimi-nary test quarry layouts can be developed, blasted rockgradations and relative amounts of rock waste can bepredicted, follow-on investigations planned and programcosts can be estimated.

3-4. Survey of Existing Excavations

As part of the field reconnaissances, or as a separateactivity, known existing rock quarries and undergroundexcavations, such as mines and tunnels should be visitedand assessed. The USAEWES (1988) Technical Memo-randum 6-370 provides information on, and test datafrom, quarries in the local area. Information can beobtained on lithology, structure, and fabric for the same orrock types similar to those at the tentative project loca-tions. Information on produced rock gradations andamounts of rock waste can be obtained. Blasting patterns,types of explosives and blasting procedures can beassessed. Information on required processing and pro-cessing equipment (grizzlies, crushers, screens, etc.) canbe obtained. When visiting quarry operations, checksheets should be prepared and filled out to assure thatpertinent information is obtained. Items which should beincluded in such check sheets are shown in Table 3-1.

3-1

EM 1110-2-230130 Sep 94

Figure 3-1. Schematic diagram of the development of regional geology (adapted from EM 1110-1-1804)

3-2

EM 1110-2-230130 Sep 94

Table 3-1Items for Inclusion in Quarry Inspection Check Sheets

Project and quarry Blast hole drilling sizes and patterns Rock size and gradation requirementsDates of operation

Purpose of quarry Explosives used and powder factors Volumes of rock produced

Rock type with lithologic descriptions Hauling and processing equipment Records of disputes between contractorand client

Rock structure and fabric Relation of natural block sizes to rockcomminution

Rock service records

Descriptions and costs of investigations Amounts of rock waste Remarks

Lab test data

3-3

EM 1110-2-230130 Sep 94

Chapter 4Field Investigations

4-1. General

As previously shown in Table 2-1 for the feasibility phaseand the preconstruction engineering and design phase ofproject development, geotechnical field investigations maybe divided into two stages: Site Selection and InitialField Investigations, and Foundation and Design Investi-gations. The need for this division depends on theplanned size and complexity of the project. As a simplerule of thumb, if there is an envisioned need for testquarry and test fill operations, the two stages of fieldinvestigations are probably justified. Figures 4-1 and 4-2show the required investigation steps for the two investi-gations stages. Guidance specific to the layout and con-duct of the field investigations required to locate anddesign test quarry operations is provided in the followingparagraphs.

4-2. Geologic Mapping

Surface geologic maps of potential test quarry sites shouldbe prepared during the areal and site geotechnical map-ping phase of the site selection investigations. Theregional geologic maps, developed during the reconnais-sance phase, commonly will have scales of 1:62,500 orlarger. Depending on the size of the project, the areal(e.g. reservoir) geologic maps prepared during the currentinvestigations phase may have scales of between 1:12,000and 1:62,500. Structure site geologic maps would havescales of from 1:1,200 to 1:4,800. Potential test quarrysites should be mapped at scales comparable to largerscale site maps. The scales should be such that soil androck type contacts can be shown, the location and shapeof individual outcrop areas can be plotted, observed bed-ding and joint symbols can be plotted without clutteringthe map, planned surface geophysical and core boringexploration plans can be shown, and planned excavationlayouts can be shown. The outcrop mapping method isbest for this type of work. An excellent reference forthis type of mapping is Compton (1962). The geologicmap produced and accompanying test data should includea complete lithologic classification description of the rocktypes present. In addition, the degree of weathering exist-ing in the rocks at the site should be detailed.

4-3. Geophysical Investigations

Detailed guidance and information concerning the use ofexploration geophysical methods and equipment are con-tained in EM 1110-1-1802. Of specific interest in quarrysite explorations are: overburden depths, location andorientation of rock contacts, groundwater depths, seismicvelocities, and rippability. Of the available surface geo-physical exploration methods, seismic refraction, reflec-tion profiling, and electrical resistivity are relativelyeconomical and will provide the required information. Ofthe available borehole methods, up and downhole seismic,and electrical logging will provide the appropriate data.The spacing of surface seismic and electrical resistivitylines should be a function of the variability of top of rockelevations and rock-type distribution as inferred from thedetailed geologic mapping.

4-4. Subsurface Explorations

The subsurface explorations stage can be carried out con-currently with or toward the end of the surface geophysi-cal stage. Lagging behind the start of surface geophysicsallows the results of the geophysical profiling to assist inthe layout of the boreholes. Conversely, borehole infor-mation will assist in the interpretation of the geophysicaldata.

a. Core borings. For the purposes of exploring thesites of proposed rock excavations and test quarries, withrare exception, rock core borings are the most suitabledrilling method. For most investigations in hard rock,N size diamond core borings which acquire a nominal5.1 cm (2-in.) diameter core are satisfactory. For softand/or highly fractured rocks, H size (nominal 7.6 cm(3-in.) diameter cores) or 10.2 cm to 14.0 cm (4 in. to5.5 in.) diamond core borings may be necessary. As withthe spacing of surface geophysics lines, the number andspacing of exploratory borings is a function of the antici-pated rock variability. The borings should be arranged tofacilitate the preparation of geologic cross sections withthe borings at the ends of the anticipated cross sectionsoutside the planned excavation limits; interpolation ismuch less risky than extrapolation. Borings should belocated at the intersection of geophysical profiles to assistin correlation. Depending on the surface mapping results,it may be necessary to drill a number of angle holes toeliminate bias in borehole fracture surveys. Barring other

4-1

EM 1110-2-230130 Sep 94

Figure 4-1. Schematic diagram of initial and site-selection investigations (adapted from EM 1110-1-1804)

considerations, or purposes for the borings, the depths ofthe core borings should be 1.25 to 1.33 times the depth

from the ground surface to the bottom of the plannedexcavation.

4-2

EM 1110-2-230130 Sep 94

Figure 4-2. Schematic diagram for design investigations (adapted from EM 1110-1-1804)

4-3

EM 1110-2-230130 Sep 94

b. Drilling, inspection, and sampling. General guid-ance for drilling, inspection, and core logging is containedin EM 1110-1-1804. The U.S. Bureau of ReclamationEngineering Geology Field Manual (1989) and Murphy(1985) contain comprehensive information on both coreand soils logging and on rock mass descriptions. All ofthe rock descriptors recommended in the cited referencesare important to test quarry applications. Of particularimportance are weathering, presence of clay or gougeseams, and the in situ gradation. Given a rock material ofcertain hardness and density, these types of descriptorswill form the basis for estimates of waste and the need forand design of rock processing equipment. The degree ofweathering should be described according to some stan-dard such as that contained in EM 1110-1-1804. In situfracture frequency and orientation can provide the infor-mation required to calculate in situ rock block-size distri-bution. In addition, correlations have been developedbetween rock-quality designation (RQD) and mean frac-ture frequency. The general use of RQD is treated inETL 1110-1-145. When logging rock core, in addition tologging core loss and RQD, the geologist/inspector shouldnote the depth and angle (with respect to borehole axis) ofevery identifiable fracture and note its genesis (joint,bedding plane, drill break, etc.). As a practical matter,when the fracture spacing is less than 3.0 cm (0.1 ft), thatinterval of core may be logged as broken. This datawill allow the prediction of in situ rock block-size distri-butions. In addition, it will be of value for the geologist/inspector to note those parameters which are used incurrently popular rock mass classification systems such asRMR or Q systems (ASTM 1988). The use of rockmass classification systems is discussed further in Chap-ters 6 and 7. Information and guidance on sampling andsample preservation of soils and rock core are containedin EM 1110-1-1906, and ASTM Designations: D 4220(ASTM 1994a) and D 5079 (ASTM 1994b). Sample

preservation for moisture content is generally not neces-sary in hard, crystalline rocks. Such rocks generallyexhibit intact rock material porosities less than one per-cent and moisture content is inconsequential to densitiesand other parameters. In softer sedimentary or chemicalprecipitate rocks, the porosities are sufficiently great thatmoisture content does affect bulk densities and otherparameters. In these rocks, the geologist/inspector shouldselect and preserve representative samples for moisturecontent determinations.

c. Borehole examination and in-hole testing. Bore-hole examination and in-hole testing includes boreholephotography, TV and sonic imaging, borehole geophysics,hydraulic or water pressure testing, water table measure-ments, and in-hole deformation or jacking tests. Guidanceand information on these methods are contained inEM 1110-1-1802, EM 1110-1-1804, the Corps of Engi-neers Rock Testing Handbook (USAEWES 1993), and theU.S. Bureau of Reclamation Engineering Geology FieldManual (1989). The borehole geophysical methods mostpertinent to test quarry explorations have been describedin paragraph 4-3. Tests to determine in situ stresseswould be warranted only if there were indications ofabnormally high horizontal stresses which might affectexcavation slope stability and markedly affect rock break-age. For test quarry explorations, water pressure testingnormally would not be necessary. Water table measure-ments are necessary for excavation slope and dewateringdesign purposes. For test quarry explorations, boreholephotography, TV, and sonic imaging are the most impor-tant measurements. Because they provide detailed infor-mation on rock structure, these measurements will provideinput to design analyses of probable rock waste, in siturock block-size distribution, trial blast patterns and load-ing, and rock excavation slope stability calculations andslope design.

4-4

EM 1110-2-230130 Sep 94

Chapter 5Laboratory Testing

5-1. General

As shown in Figures 4-1 and 4-2, material testing is partof both the Site Selection and the Design Investigations.In terms of timing or scheduling, laboratory materialtesting would be performed as close to concurrent withthe subsurface exploration stages as possible. EM 1110-1-1804 provides guidance and information on types of soiland rock tests for various design applications. EM 1110-2-1906, the Corps of Engineers Rock Testing Handbook(USAEWES 1993), and ASTM (1994a through 1994d) allprovide detailed information on the procedures for con-ducting tests on soil and rock materials. Rock and soilstests are informally divided into two categories: indextests to identify and classify the materials, and engineeringproperties tests to supply parameters for design analyses.The following paragraphs discuss the applicability ofselected tests for test quarry design.

5-2. Petrographic Examination

A detailed discussion of recommended practice for petro-graphic examination of rock cores is contained in theCorps of Engineers Rock Testing Handbook (USAEWES1993). Petrographic examinations are conducted todescribe, classify, and determine the relative amounts ofthe sample constituents, identify the sample lithology, todetermine the sample fabric, and to detect evidence ofrock alteration. The identification of rock constituentsand determination of fabric and micro-structural featuresassist in the recognition of properties that may influencethe engineering behavior of the rock. Complete petro-graphic examination may require the use of such proce-dures as light microscopy, x-ray diffraction, differentialthermal analysis, and infrared spectroscopy. The selectionof specific procedures should be made by an experiencedpetrographer in consultation with geologists and engineersresponsible for the design and execution of the test quarryprogram.

5-3. Weight/Volume Properties

The weight/volume and pore properties of a rock materialinclude specific gravity of solids, porosity and absorption,apparent and bulk specific gravity, moisture content, anddegree of saturation. These properties are directly impor-tant to predictions of swell or bulking and serve asindex tests relating rock strength and deformability. As ageneral rule, for test quarry design, bulk specific gravity

and absorption are the minimum weight/volume tests thatneed to be performed. If a quarry is intended to producedimension or derrick stone, absorption and adsorption mayprovide an indication of the rocks long-term resistance tofreeze-thaw and slaking. The relationships between bulkspecific gravity (Gm), absorption (AB), and porosity of therock particles (nr) are given below. The porosity hererefers to the permeable voids associated with individualrock particles and not to the porosity of a compacted massof such rocks.

(5-1)Gm

AB C

(5-2)ABB A

A

(5-3)nr

AB Gm

where

A = weight of oven-dry specimen

B = weight of saturated surface-dry specimen

C = weight of saturated surface-dry specimen inwater

5-4. Strength Tests

Unconfined compressive strength is a well known indextest relating intact rock strength and deformability. Fur-ther, it can be used with rock mass quality descriptors toinfer rock mass strength parameters (Hoek and Bray1981). Unless there are specific requirements relating torock slope design problems, there is no need to performtests such as the triaxial shear or direct shear tests. Aninexpensive and rapid test which correlates to unconfinedcompressive strength is the point load test (Bieniawski1975). This test is growing in popularity and can beperformed either in the laboratory or the field.

5-5. Rock Durability Tests

Laboratory durability tests are divided into those thatsimulate accelerated weathering and those that measurephysical properties. Accelerated weathering tests usuallyinclude wet and dry (Designation D 5313; ASTM 1994a),freeze and thaw (Designation D 5312; ASTM 1994a),sodium sulphate soundness and magnesium sulphatesoundness (Designations D 5240 and C 88; ASTM 1994aand 1994b, respectively). Physical property tests include

5-1

EM 1110-2-230130 Sep 94

absorption (Designation C 127; ASTM 1994b), LosAngeles Abrasion (Designation C 535; ASTM 1994b),and slake durability (Designation D 4644; ASTM 1994c).

5-2

EM 1110-2-230130 Sep 94

Chapter 6Location and Design of Test Quarries

6-1. General

The final location, physical size, and design of a testquarry is made using the information obtained during thereconnaissance, site selection, and initial and design inves-tigations. The development of the test quarry programand the test quarry design is an iterative process. Prelimi-nary requirements for and locations of test quarries aredeveloped during the reconnaissance phase of projectdevelopment and refined sufficiently during the feasibilityphase to provide accurate data for baseline cost estimatesand for proceeding to detailed design during the precon-struction engineering design phase. The process of locat-ing and designing the project test quarry, or test quarries,follows a logical sequence as described in the followingparagraphs.

6-2. Evaluation of Project Rock ProductionRequirements

Concurrent with the investigations required to locate anddesign a test quarry are those required to determineembankment design, including zoning and slope protectionrequirements. The need for rock-fill zones in an embank-ment arises from the overall analyses of the amounts ofdifferent types of fill materials available and the results ofcost studies of various embankment cross sections andalignments. The decision to design and construct a rock-fill embankment is made based on design safety consid-erations and on analyzing the comparative costs amongrock, earth-rock, and earth embankments and concretestructures. Guidelines on the procedures for selecting thesafest and most economical design are contained inEM 1110-2-2300. As the embankment design develops,volumes for different qualities and gradations of rockfillare determined. These are compared with the probableamounts of rock of those qualities and gradations thatdesign investigations indicate are available in requiredexcavations or in separate excavations specifically plannedto supply rock material. This process is iterated until themost economical balance between excavation and fillrequirements is obtained which will produce a safeembankment. The supply of rock reserves available forconstruction of the dam must be accurately estimated,taking into account bulking and/or shrinkage factors.These quantity estimates can be greatly improved if bulk-ing and shrinkage factors are determined during testquarry and test fill development.

6-3. Evaluation of Potential Test Quarry Sites

At this stage in the design process, required excavationand/or stand-alone quarry sites have been explored aspotential sources of construction materials. It remains toevaluate these sites and decide upon one or more testquarry locations which will provide data that are mostrepresentative of the conditions to be encountered in theproject excavation(s). The quarry or quarries should besited so that all large-volume rock types to be used inconstruction and all associated rock conditions will beassessed and tested. If the amount of a particular rocktype will be relatively small and failure to assess it willresult in errors of minor technical and economic conse-quences during construction, the time and cost of develop-ing a test quarry only to assess it may not be justified.

a. Rock type distribution considerations. The testquarry, or quarries, should sample the same rock types, inroughly the same proportionate quantities, that will beprovided from the actual project excavation(s). A projectmay be located in one rock or several depending on theareal geologic sequence (sedimentary, igneous, metamor-phic). The degree of heterogeneity will control the num-ber and location of test quarries. In a relativelyhomogeneous igneous or metamorphic crystalline rock,one test quarry of sufficient size to sample theunweathered rock may suffice. In a bedded sedimentarysequence, a large spillway excavation may be planned tocut across several rock types. Ideally, the test quarryshould be of sufficient size that it will sample this hetero-geneity and supply adequate materials for test fills. How-ever, monies available at this stage may not allow a testquarry of that size. A number of smaller test quarriesmay provide a representative blend of materials for testfills and provide representative information on rock grada-tions, waste and slope design. However, great care mustbe used in modeling of the rock conditions to be producedfrom one large excavation with a number of smaller exca-vations. As will be pointed out in paragraph 7-2b, thereare potential problems involved in not siting the testquarry within the area of the intended project borrowexcavation.

b. Geologic structure and fabric considerations.Test quarries should not be located so that they includegross or meso-scale geologic structural features such asfaults and solution cavities. Macro-scale geologic struc-ture, such as joints and bedding planes, affects both thegradation of the blasted rock mass and the stability of thequarry slopes. The regional residual stress field will havean effect on quarry slope stability and on rock

6-1

EM 1110-2-230130 Sep 94

fragmentation. The effect of the geologic structure on thedesign of the quarry slopes will be discussed below inparagraph 6-3d and its effect on the blasted rock massgradation will be discussed in paragraph 6-3c. Geologicfabric, or arrangement of the rocks mineral constituents,affects both the ease with which comminution occursunder the dynamic loads of explosives and the shape ofthe blasted rock fragments. The test quarry, or quarries,should be sized and located so that all the variations ofgeologic structure which will be encountered in the proj-ect quarry excavations will be sampled. Generally, anadequate sampling of rock fabric is obtained if the testquarry, or quarries, adequately sample all the rock typesto be encountered in the project construction situation.

c. Rock quality and gradation considerations. Aswith rock type, geologic structural and fabric consider-ations, the number and size of test quarries should beselected so that the variations in rock quality over theplanned construction quarry excavations are sampled. If,as recommended in paragraph 4-4b, sufficient data werecollected during subsurface investigations to employ theuse of a rock-mass classification system, the rock mass inthe required excavations can be divided into zones ofdifferent rock mass qualities and that zoning can assist inthe location of the test quarries. The in situ rock block-size distribution will have a great deal of influence on thegradation of the blasted rock. The degree of variation ofin situ block-size distribution can be established from thelogs of exploration core borings. There are two ways toassess this degree of variation. Mean block-size distribu-tion for pre-selected lengths of each bore hole can beestimated from RQD using the following relationship(Brady and Brown 1985).

(6-4)RQD 100 e 0.1 (0.1 1)

where e is the exponential and is the mean number ofdiscontinuities per meter. Figure 6-1 shows the relation-ship between RQD and mean discontinuity frequency. Amore site-specific and accurate method of estimating thein situ block-size distribution is to make cumulative frac-ture frequency curves from the fracture counts on theboring logs and/or from borehole photography logs. Thiswill allow the division of the rock mass by the meanfracture spacing and variance in a manner similar to zon-ing the rock mass according to rock mass quality.

d. Rock slope design considerations. Because thetest quarries will provide the opportunity to test the proj-ect excavation slope designs, the test quarry excavation(s)should be configured to duplicate project slope

inclinations and orientations. As part of the test quarrylocation and sizing analyses, slope stability evaluationsshould be employed for trial quarry configurations. Pre-liminary evaluations of slope stability can be performedwith graphical analyses using stereographic or equal-areaprojections. An example of such an evaluation is shownin Figure 6-2. If preliminary evaluations indicate poten-tial instabilities, more detailed planar and wedge stabilityanalyses should be performed. An excellent series ofdiscussions on rock slope stability analyses is presentedby Hoek and Bray (1981). There should be sufficientslope area to test all potential presplit configurations.

6-4. Test Quarry Layouts

Test quarries should be located, if feasible, within theperimeter of the area to be used as the primary source ofrock for project construction. Reasons for this will bediscussed in paragraph 7-2b. As stated in paragraph 6-3,the quarry, or quarries, should be located so that all majorrock types and rock conditions can be tested and evalu-ated. It is presumed that, before final selection of the testquarry site(s), sufficient core borings will have beendrilled in each potential quarry location to determine ifthe desired rock type and rock conditions will be encoun-tered in the selected test quarry(ies). The layout of eachquarry must take into consideration the slope of the ter-rain, the depth of overburden and saprolite, the configura-tion of the objective strata, and accessibility to the test fillsite. Cost of the test quarry is always a consideration; thelocation and layout must achieve reasonable economy.Figures 6-3 through 6-6 are examples of single-test andmultiple-test quarry layouts, respectively.

a. Stripping requirements. It is necessary to stripall of the overburden and saprolite and haul it to a dis-posal site prior to initiation of rock excavation in the testquarry. This is important because the rock fill producedin the test quarry should not be contaminated by the over-lying materials. It is advisable to create a berm or benchon the order of 3 to 7 m (10 to 20 ft) wide between thebase of the slope through overburden and the beginning ofthe first rock excavation slope. This should be done tocontrol surface drainage and raveling of overburden intothe quarry during the continuing excavation.

b. Size and alignment. The size of the test quarryis dictated by a number of different factors. Depth to thetarget rock formation, quantity of material required fortest fills, geologic structure and side slopes, variations inrock types and rock quality, and the number of test blastsneeded are all factors which must be considered in

6-2

EM 1110-2-230130 Sep 94

Figure 6-1. Relationship between RQD and mean discontinuity frequency (after Brady and Brown1985)

designing the dimensions of the test quarry(ies). It isimportant to plan the size of the excavation larger thanthe minimum required in case it becomes necessary toexcavate the quarry deeper than the design depth.Extending an exact-sized quarry to greater depth wouldrequire re-excavating the slopes in order to maintain theirstability. This may become prohibitively expensive. Thealignment of the excavation is affected by some of thefactors that affect its size but terrain configuration

frequently controls the alignment. An example of terrain-controlled alignment is shown in Figures 6-3 through 6-5.

c. Slope and bench designs. Slope design shouldbe based upon rock slope stability analyses employingrock fracture orientations developed from the geologicinvestigations and rock shear strengths developed from theresults of laboratory testing. One purpose of the testquarry is to field test the slope design. For this reason,

6-3

EM 1110-2-230130 Sep 94

Figure 6-2. Example of a graphical slope stability evaluation of a proposed excavation (after Hoek andBray 1981)

6-4

EM 1110-2-230130 Sep 94

6-5

EM 1110-2-230130 Sep 94

6-6

EM 1110-2-230130 Sep 94

Figure 6-5. Additional sectional views of single quarry shown in Figure 6-3

several variations of the design should be tested in thequarry to prove and optimize the design. Bench design isbased upon the overall slope stability analysis and uponthe practicalities of excavation. The benches have theeffect of flattening the overall slope and improving stabil-ity. They also provide added safety by catching some of

the falling rock before it reaches the quarry floor. Thebenches can be sloped to control surface drainage and toprovide haul road access to the quarry floor. Examples ofslope and bench configurations are shown in Figures 6-3through 6-5. Quarry bench height designs should be

6-7

EM 1110-2-230130 Sep 94

Figure 6-6. Example of a multiple test quarry layout where samples from several different rock strata are requiredfor testing (after U.S. Army Engineer District, Jacksonville 1983)

6-8

EM 1110-2-230130 Sep 94

based on anticipated excavation and hauling equipmentand safety. Control of produced rock gradation is more afunction of explosive type, quantity per hole, blast-holespacing, decking of the charge, and burden than benchheight. Where practicable, setting quarry benches coinci-dent with slope berms will be efficient from a constructi-bility standpoint.

d. Presplitting patterns. The presplitting patternsdeveloped during the design phase should be tested in thetest quarry excavation. Variables in the design includehole spacing, hole size, stemming subdrilling, inclination,loading configuration, and charge weights. Hole spacingnormally ranges from 46 to 91 cm (18 to 36 in.). Thequality of the presplit slope normally decreases as thehole spacing increases, with 91 cm (36 in.) being aboutthe maximum that will produce a satisfactory slope. It isimportant to maximize suitable spacing because this willreduce the number of presplit holes required and therebyreduce drilling costs. Good drilling alignment is veryimportant to a satisfactory presplit slope cut. Alignmentrequires great care, particularly when drilling from roughor irregular surfaces. The techniques employed by thedriller also affect the resulting alignment. It is importantto specify great care in maintenance of alignment in thetest quarry contract. It is also important to optimize thebuffer zone between the presplit slope and the productionblast lifts. Too large a buffer zone will keep the produc-tion blasts from pulling completely to the presplit slopeand may result in incompletely broken rock. Too small abuffer zone will result in damage to the slope by theproduction blast. Variations of the combination of theabove variables should be tested to determine which willwork best under individual slope conditions. The basicdesigns should be furnished to the field with instructionsthat it will be modified as testing progresses and more islearned about the behavior of the rock mass. EM 1110-2-3800 provides detailed guidance on presplit design.

e. Production blasting patterns. There are numerousvariables involved with blasting patterns which affect theparticle size and gradation of the blasted rock pile. Thesevariables and combinations thereof need to be investigatedduring the test quarry development to determine whichcombinations provide the most desirable rock fragmenta-tion and gradation. Those variables that should be testedinclude: blast-hole diameter, hole spacing, powder factor,subdrilling depth, stemming type and length, type ofexplosive, loading configurations, decking, bench heights,firing delay patterns, and location of the free face (bur-den). It must be recognized that the characteristics of therock mass impose limitations on the size of the producedparticles. For instance, if rock joints occur on a repeating

frequency of 30 cm (1 ft), it will not be possible to obtainsignificant quantities of rock with intermediate dimensionsexceeding 30 cm (1 ft), no matter how the blasting patternis designed. In other words, do not attempt a blast designto create fragmentation which is impractical to achieve. Itis possible to achieve a gradation finer than the in situgradation but not coarser. With this limitation under-stood, variations in the combinations of variables shouldbe tested to develop those combinations which provide themost satisfactory rock mass fragmentation and gradation.The test quarry design should provide those patterns to betested. The contract should provide for variations as moreis learned from the initial tests. Figures 6-7 and 6-8 showexamples of variations in test blasting patterns used todevelop optimum patterns. EM 1110-2-3800 providesdetails on blast pattern design.

6-5. Gradation Measurements

There are no established standards or procedures specifi-cally directed at making gradation determinations forblasted rock to be used in compacted rock fills. The newASTM Designation D 5519-93 (ASTM 1994d) hasbecome available (but not in time to be included inASTM 1994a) for making gradation determinations forriprap and may be considered applicable. A completediscussion of gradation testing including ASTM 1994d isprovided in Part II: Test Fills. The procedures used atthe Corps of Engineers Carters, Cerrillos, and SevenOaks dam projects and described in the following para-graphs represent the typical sorts of past practices relativeto obtaining gradations for rock materials upon which theASTM standard.for riprap was based .

a. Carters Dam. The gradation measurementprocedure was to first carefully select a large representa-tive sample from the blasted rock pile. The rock wasthen processed by hand over a series of inclined screensthat separated the rock fragments into fractions of over2.5 cm (1 in.), 7.6 cm (3 in.), 15.2 cm (6 in.), and20.3 cm (8 in.). The minus 2.5-cm (1-in.) fraction wasthen processed with a Gilson shaker using a normal nestof U.S. Standard Sieves (EM 1110-2-1906). The frag-ments from that fraction of the sample which were largerthan 20.3 cm (8 in.) were individually passed through30.5-cm (12-in.), 40.6-cm (16- in.), and 61-cm (24- in.)squares in order to determine the percent passing each ofthose sizes. It is necessary to obtain progressively largerrepresentative samples for testing as the maximum particlesize increases in order for the test results to be a satisfac-tory representation (estimation) of the blasted rock grada-tion. Figure 6-9 shows the configuration of the rock

6-9

EM 1110-2-230130 Sep 94

6-10

EM 1110-2-230130 Sep 94

Figure 6-8. Additional information relative to Figure 6-7

6-11

EM 1110-2-230130 Sep 94

Figure 6-9. Example configuration of a rock gradationscreening platform

gradation measurement platform used at Carters Dam.The above information was obtained verbally fromMr. C. Colwell of the South Atlantic Division Laboratory(1993).

b. Cerrillos Dam. The gradation measurement pro-cedure at Cerrillos Dam began with selection of a largesample weighing about 13.6 metric tons (30,000 lb). Thissample was then split by the quartering method to obtaina sample weighing about 2.7 megagrams or metric tons(6,000 lb). The 2.7-metric ton (6,000-lb) sample was pro-cessed by hand over 15.2-cm (6-in.), 20.3-cm (8-in.),22.9-cm (9-in.), 30.5-cm (12-in.), and 61-cm (24-in.)screens. The fraction passing the 15.2-cm (6-in.) screenwas processed through a nest of screens using theGilson shaker. The gradation was based on the percentpassing each screen size. This information was obtainedverbally from Mr. P. Davila, U.S. Army EngineerJacksonville District, Ponce (Puerto Rico) Resident Office(1993).

c. Seven Oaks Dam. Samples weighing approxi-mately 4.5 metric tons (10,000 lb) were obtained anddumped on large sheets of plastic. These materials weresorted manually in the field using 7.6-cm (3-in.) openingTyler screen and 15.2-cm (6-in.), 22.9-cm (9-in.), 30.5-cm(12-in.), and 45.7-cm (18-in.) sizing rings. The materialspassing through the screen and sizing rings were placed in2.1-cu m (55-gal) drums and weighed in the field on aplatform scale. Individual rock fragments larger than45.7 cm (18 in.) were measured in three diametricaldirections and the weights estimated based on previously

developed correlation charts. One drum of the minus7.6-cm (3-in.) material from each sample was taken to theproject laboratory for sieving and classification testing.This description was taken nearly verbatim from theU.S. Army Engineer District Los Angeles District FeatureDesign Memorandum (1992).

6-6. Deterioration and Incipient FractureExamination

Some rock formations tend to deteriorate after excavationdue to physical and/or chemical processes. This can havea very degrading effect on the rock products manufacturedfor various zones in a rock-fill dam and should be care-fully evaluated during test-quarry and test-fill construc-tion. Some conditions which lead to this type ofdeterioration are incipient fractures, bedding planes,abnormally high residual stresses, and chemically and/orphysically unstable strata such as shale and volcanic ashor tuff. Some of this deterioration may occur in stockpiles while some may occur due to the mechanical actionsof loading, hauling, placement, and compaction into thefill. It is important to identify and assess degradationduring the test-quarry and test-fill operation so that it canbe dealt with during final design and construction. Thereare several approaches to determining whether or not thisis a problem. Perhaps the simplest is to expose samplesof rock core and blasted rock to the environment for adefined period of time and measure either changes inspecimen size or weight loss. No changes would be anindication that degradation by chemical effects or weath-ering is not likely to occur in the rock fill. If changes dooccur, then more sophisticated tests are needed to evaluatethe magnitude of the problem. Petrographic analyseshave provided an indication of breakdown due to incipientfracturing. Visual observations of individual blasted rockfragments are useful in determining the presence of incipi-ent fractures or weak bedding planes. If there is an indi-cation of either chemical or physical breakdown, it isdesirable to obtain gradations of the blasted rock mass inthe test quarry, then subsequently in the stock pile andultimately in the test fills. These successive gradationswill provide information on the degree of degradationwhich occurs. In some cases, it may be necessary to testrepetitively in a stock pile to duplicate the times that acontractor is likely to stockpile materials. It is importantto note that the mechanical action of repeatedly testing thesame sample over a period of time may itself be a factorin any observed breakdown. This is discussed further inparagraph 7-6b. The blasting process often enlarges andexpands incipient fractures and planes of weakness inintact rock blocks. This process will lead to degradationof the stone during project operation. The identification

6-12

EM 1110-2-230130 Sep 94

of blast damage is very important. Both District andDivision Laboratory geologic personnel should beinvolved in the evaluation of blast damage.

6-7. Rock Processing

Rock processing is frequently called for in the design ofan earth-rockfill dam. This is particularly true for themanufacture of filter materials and materials to be placedin zones adjacent to filters. Where processing is antici-pated, it is important to process the rock being producedin the test quarry for the test fills. The decision to pro-cess for the project situation should be carefully

conceived and evaluated because rock processing, both inthe test program and in the project construction, is veryexpensive. In other words, the fewer the zones of thedam that require processing, the less expensive the damconstruction will be. The test fills should be constructedfrom rock materials that have the same characteristics asthe project material is expected to have. In order toobtain this, some processing is likely to be requiredbetween the test quarry and the test fills. This mayinvolve processing over a grizzly as diagrammed in Fig-ure 6-10 or may require a portable crushing and screeningplant to be brought to the site. Paragraph 7-7 providesfurther discussion of processing.

Figure 6-10. Flow diagram of a grizzly operation

6-13

EM 1110-2-230130 Sep 94

Chapter 7Test Quarry Operations

7-1. Supervision

A major purpose of a test quarry is to determine how rockcharacteristics and excavation variables affect the rockmaterial produced and how they affect the side slopes andbottom of the excavation. The technical aspects of thetest quarry operation are normally best supervised by ageologist experienced in rock excavation methods andprocedures. This person, the Technical Test QuarrySupervisor (TTQS) should have sufficient staff to allowcomplete oversight of the contractors operations as thework progresses. This work differs from a normal con-struction contract operation because it is an explorationand testing program with the objective of developing dataand procedures to be subsequently incorporated into proj-ect design and construction. Numerous variations ofexcavation procedures, such as ripping and blasting, withits many variables, must be tested to determine whatworks best in each different rock type. For this reason,considerable flexibility must be written into a test quarrycontract to allow the Contracting Officers Representative(COR) to exercise control of the contractors excavationprocedures, including blast hole sizes, pattern spacing,depth of hole, subdrilling, stemming, type of explosives,powder factor, and loading configuration. Loading andhauling procedures also cause considerable variation inthe rock gradation produced and are variables whichshould be within the control of the COR. A test quarrycontract should not be an end-product type but should bea method type and essentially call for the contractor tofurnish supervision, labor, materials, equipment, and sup-plies to proceed with test excavation(s) as directed bythe COR.

7-2. Safety Considerations

Safety considerations pertaining to test quarry programsare as follows:

a. Operations. Test quarries are frequently locatedin areas of very steep terrain where access is very diffi-cult. Rock excavation procedures also require operationswhich can be very dangerous unless all safety precautionsare strictly followed. A safety analysis should be per-formed before any work begins to establish any addedprecautions that may be needed beyond those set forth inEM 385-1-1.

b. Affects on test quarry location. Access to thetest quarry site is frequently a major problem because ofvery steep topography and because of the high cost ofhaul-road construction into such areas. Safety consider-ations limit the maximum grade to which haul roads maybe constructed. Because of access-road cost, the decisionis often made to locate the test quarry, not in the areawhere future construction is to take place, but in one withsimilar rock types. This may lead to test-quarry and test-fill results which are not totally applicable to the projectconstruction. This can also result in later contractorclaims and cost over-runs which are many times greaterthan if safe access roads to the planned required excava-tion area were constructed in the first place. If at allpossible, the test quarry should be sited within the limitsof the excavation area which has been selected as themain source of rock required for project construction. Ifthe costs of doing so exceed the limitations of Precon-struction Engineering and Design funding, considerationshould be given to making the test quarry and test fillcontract(s) and the access road contract the first construc-tion contract in order to transition from PED to Construc-tion General (CG) funding. This will allow adequatemonies to safely construct the test quarry in the mostappropriate location(s).

7-3. Modification of Design

As data are obtained during the progress of the test quarrydevelopment, it becomes necessary to modify the testquarry design to take into consideration new informationabout the rocks behavior that was not available at thetime of the original design. The test quarry contractspecifications should be written to permit these changes atthe direction of the COR (as discussed in paragraph 7-1).The test quarry modifications must be developed in fullcoordination between the TTQS and the designers toassure that all future needs for design information arebeing met.

7-4. Blasting Plans

Blasting plans should be required by the contract specifi-cations. These are necessary to permit the TTQS toassure that the contractors plan of operation is in accor-dance with the test-quarry design. Approval of the blast-ing plans by the COR should be required by the contract.In addition to the guidance contained in Chapter 5,detailed guidance on blasting techniques is contained inTM 5-332 and EM 1110-2-3800.

7-1

EM 1110-2-230130 Sep 94

a. Master plan. The contract specifications shouldrequire the contractor to prepare and submit for review,modification (if necessary), and approval, a master plan ofexcavation prior to initiation of any excavation. Thismaster plan should include a complete description of thecontractors proposed scheduling sequence, equipment,staffing, overburden removal and disposal/reclamationplans, drainage control, plans for ripping (if required),overall plan for each test blast, and loading and haulingprocedures. The plan should also include a description ofhis provisions for modifications and/or changes to equip-ment and procedures as required by the COR as excava-tion progresses and information is developed on which tobase such changes.

b. Individual plans. Prior to each blast, the contrac-tor should be required to furnish a detailed blasting plan.This plan should show location of bench to be blasted(with respect to the overall excavation), presplit or smoothblasting plan for side slopes, depth of excavation, burdenand free-face location, blast-hole pattern and powderfactor, blast-hole diameters, subdrill, stemming, loadingconfiguration, and delay sequence. This plan should beused by the TTQS as the basis to make any modificationsdeemed necessary to provide the desired breakage data.The contract should require approval of this plan by theCOR prior to initiation of the work in the particular testarea.

c. Blast reports. The contractor should be requiredto furnish a post-blast report which will detail any varia-tion that occurred to the individual blasting plan as fur-nished prior to the blast. Such things as misfires, underor overloaded holes, water in the holes, variations instemming, and any other observed variables should bereported. Video documentation is helpful in verifying andevaluating blast reports. Test quarry specifications can bewritten to include video documentation submittals to theTTQS. The TTQS and staff should prepare their ownreport of each blast. This should contain a description ofthe rock mass including rock type and condition,as-blasted gradations, condition of slopes, bottom configu-ration and depth of pull, location of the post-blast rockpile, slope mapping, photographic documentation of theslopes, bottom, and the rock pile before loading and haul-ing. Report conclusions should include an evaluation ofthe effectiveness of the blast in providing the design gra-dation, designed slopes, and bottom conditions. Recom-mended modifications to subsequent test blasts based onthese results should be included in the report.

7-5. Slope Mapping and PresplittingObservations

One of the purposes of a test quarry is to develop blastingprocedures which will result in safe, satisfactory perma-nent slopes. This will require the testing of differentpresplitting patterns. Different presplit hole spacingsshould be tested, usually varying from 46 cm (18 in.) to91 cm (36 in.); different slope angles, usually varyingfrom 1 vertical on 1 horizontal to 1 vertical on 0.25 hori-zontal; different loading configurations in the blast holes;and different widths of buffer zones between the presplitpatterns and the production blast holes. The results ofthese variables are affected very much by the relationshipof the orientation of rock mass structural details to theorientation of the excavation slopes. Slopes cut on oneside of the excavation may be entirely satisfactory whilethose cut on the opposite side may be unsatisfactory andeven unstable. Detailed guidance on presplitting tech-niques is contained in EM 1110-2-3800.

a. Mapping. The excavated slopes should bemapped. The conditions noted and mapped should includecut slope angle, slope height, presplit blast-hole spacing,condition of each slope segment, rock type and condition,and location and orientation of rock fractures intersectingthe slope. In addition to mapping rock fractures in theslopes, fracture spacing/frequency should also be notedalong judiciously located scan lines for comparison withsimilar information developed from the design investiga-tions and with the measured rock-pile gradations. Visiblegroundwater and surficial infiltration seepage areas shouldalso be depicted during mapping.

b. Presplitting observations. Each slope should becarefully described and reported as to its condition, takinginto account the results of the presplitting and those fac-tors such as intersecting rock fractures and rock qualitywhich affect the stability of the slope. The maintenanceof design blast-hole spacing and orientation is very impor-tant. Where these deviate from design, the results shouldbe described. Successful presplitting normally leaves ahalf-round of the individual blast hole visible in the slope.Where these are not seen, it is likely that the presplit shotwas too heavily loaded or that there was an insufficientbuffer zone between the production blast and the presplitslope. If the presplit plane between blast holes is highlyirregular, it is likely that the hole spacing was wider thanoptimum. Excessive rock fracturing behind the permanentslope line is another indication of excessive hole loading.

7-2

EM 1110-2-230130 Sep 94

By contrast, incomplete shearing of the rock betweenpresplit holes may be an indication that the holes wereunder loaded or that they were too widely spaced. Rockstructure induced (wedge or planar) slope failures mayoccur. These features should be incorporated into theslope maps and should be described for inclusion in thefinal report. Complete photo coverage of theas-excavated slopes is of considerable value in illustratingthe observation descriptions. These photographs shouldbe obtained after the slope is freshly cut and used gener-ously in the final report.

7-6. Rock Quality and Pre-Test Fill Gradations

a. Rock quality after blast. It is important to evalu-ate and describe the quality of the blasted rock existing ineach blasted area. Rock quality is a major factor of thedesign of rockfill structures and it is important to com-pare the rock quality observed from the test quarry pro-gram with the design assumptions. In addition, variationsin rock quality often become the basis for disputesbetween the contractor and the government. Because ofthe uniqueness of each site and each rock type, rock qual-ity evaluation systems should be designed on the condi-tions encountered in each test quarry program. Suchevaluation systems should include, as a minimum: rocktype, degree of weathering (unweathered, slightly weath-ered, moderately weathered, highly weathered, decom-posed, EM 1110-1-1804), potential for degradation, bothin stock piles and during fill placement and compaction(e.g., estimates of abrasion resistance, desiccation deterio-ration, incipient fractures, brittleness, softness, and physi-cal or chemical instability), and rock mass gradation.

b. Pretest fill gradations. As part of the rock massquality evaluation, it is important to develop informationon the degree of degradation that occurs during the load-ing, hauling, processing, storage, and placement of rockfill in an embankment. In order to obtain this informa-tion, it is necessary to determine the gradations that existafter blasting but before loading, hauling, placement, andcompaction. This should be done by the same procedureswhich will be used to control the gradation of fill placedin the test fills and subsequently in the embankment.Methods for obtaining mechanical gradations of rock fillwere addressed in paragraph 6-5 and will be treated inmore detail in Part 2: Test Fills. In addition to themechanical grading methods, particle size scan-line meas-urements of the blasted rock pile should be performed andtheir accuracy evaluated. If particle shape and percentageof fines allow these types of measurements, they are arapid, economical adjunct to time-consuming screen gra-dation measurements. A comparison of the initial rock

mass gradation with gradations made at subsequent stagesin the process of rock placement in test fills will providedata on which to base an appraisal of rock mass degrada-tion that can be expected during loading, hauling, andembankment construction. If there is potential for therock to deteriorate over time in a stock pile, this tooshould be evaluated. One approach is to establish teststock piles and perform initial and subsequent gradationtests and compare the results. A complication candevelop in this test because the mechanical action of thetest itself may tend to degrade the particles of the testspecimen. This must be considered in evaluating theresults. Hairline blast fractures develop in some brittlerock types. Because these fractures allow degradation ofparticle size during handling, processing, placement, com-paction, and project operation, they need to be identifiedduring this stage of test quarry development. Samples ofvarying particle size should be furnished to the appropri-ate Division Laboratory for testing to determine the pres-ence of minute blast-induced fractures.

7-7. Rock Processing Results

Frequently, rockfill embankment designs require rockprocessing that goes beyond the quarry-run gradations thatcan be produced by the rock excavation procedures in thequarry. These can include simply processing the rockover a grizzly to separate it into two or three differentsizes to the much more complex process of running therock through a crusher and vibrating screens to produce aseries of carefully controlled gradations. The more pro-cessing required, the more expensive the embankmentconstruction will likely be. In addition, it is likely thatthere will be more opportunity for disputes between thecontractor and government. If the design efforts indicatethat processing will be required during construction, it isimportant to test it during the test-quarry and test-filloperations. Otherwise, the results from the test quarryand test fill may not be indicative of the results to beobtained during final construction. The gradationsobtained from rock processing are the results of manyvariables. These include rock type, rock quality, excava-tion method, and rock crushing and screening plantdesign. It is frequently difficult for a smaller test quarryand portable processing equipment to reproduce theresults that will be obtained from a full quarry and largeproduction equipment. For these and other reasons, it isdesirable to design the embankment to require as littleprocessing as is possible and to construct the test fillswith materials that are truly representative of those thatwill be obtained from the construction production excava-tions. Rock processing results should be carefullydescribed in the Test Quarry and Test Fill Report.

7-3

EM 1110-2-230130 Sep 94

7-8. Report

The data and information developed during the test quarryconstruction should be analyzed, evaluated, and reportedin a Test Quarry and Test Fill Report. The test quarryportion of the report should contain sketches of each testblast, maps of all excavated slopes and bottoms, descrip-tions of the results of each test blast including presplitslopes, gradations of the quarry-run material produced byeach blast in each separate rock type, and conclusions andrecommendations. The report should be generously illus-trated with geologic maps and cross sections, sketches,photographs, analyses of the rock fracture orientations andfrequency/spacing revealed in the excavations and evalua-tions of the fracture orientation and spacing to slope sta-bility to the blasted rock gradations produced. A typicaloutline of the test quarry section of the report is shown in

Table 7-1. The report of the test quarry program is avery important document for use during final design andconstruction. Also, it can prove to be very valuable dur-ing the contract disputes which inevitably arise during thecomplicated construction of a large dam. The importanceof a complete, accurate, well-conceived report cannot beoveremphasized. The conclusions and recommendationssection of the report should be specific with regard to thesuitability of the rock materials for the uses to which itwill be placed. Constraints upon the suitability of thematerials must be clearly stated (e.g., shale partings in arock mass will likely lead to an eventual breakdown inparticle size). Recommendations for any special handling,processing, storage or placement methods that were devel-oped during the test quarry operation should be clearlydetailed in that section of the report.

7-4

EM 1110-2-230130 Sep 94

Table 7-1Typical Test Quarry Report Outline

1. Executive Summary

2. Introduction

3. Test Quarry Design and Objectives

a. Discussion of objectivesb. Overview of site selection criteriac. Thorough presentation of design including layout and slope stability

4. Geological Conditions in the Test Quarry

5. Description of Each Test Blast

a. Rock type and conditionb. Hole patternc. Delay patternd. Hole depths and loading designe. Explosives, detonators, and delaysf. Blasted rock mass descriptiong. Quarry-run gradationh. Laboratory test resultsi. Conclusions

6. Drilling, Loading, and Hauling Equipment and Procedures

7. Description of the Results of Each Presplit Slope Blast

a. Rock type and conditionb. Presplit hole and explosive charge configurationc. Presplit slope conditiond. Rock joint analysis and slope stabilitye. Conclusions

8. Rock Processing Results

a. Description of processing objectivesb. Description of rock processing equipmentc. Results of processing each rock type and conditiond. Gradations and particle shapese. Degradation during each stage of processingf. Laboratory test results

9. Conclusions and Recommendations

a. Conclusions including lessons learnedb. Recommendations

APPENDICES -- Laboratory Test Sheets, Boring Logs, Field Gradation Test Results, Description of Rock Processing Equipment, Photo-graphic Documentation, Etc.

7-5

PART 2TEST FILLS

EM 1110-2-230130 Sep 94

Chapter 8General Considerations

8-1. Background

The earliest rockfill dams in the U.S. were built in thesouthwest and west just before the turn of the century(Wegmann 1899). Most were of loosely dumped quarriedrock with some version of core or upstream facingincluding wooden planking, concrete, or hand-placed rockdry-wall. From thence up until the 1950s, the design andconstruction of rockfill dams were a matter of empiricism.Construction was by end-dumping over high slopes withwater sluicing in 18- to 61- m (60- to 200-ft) lifts. Thesluicing with water jets was intended to displace finesfrom between the larger particles to produce rock-to-rockcontact among the larger particles and reduce thecompressibility of the mass. However, the technique stillproduced rockfill which was relatively compressible andsubject to considerable post-construction volume change.The transition to compacted rockfill for both earth-coreand concrete-face dams occurred during the period 1955-1965 (Cooke 1984) as shown in Figure 8-1 (Cooke 1990).This transition was possible because of the advent ofheavy vibratory rollers and was particularly spurred byTerzaghis criticism of dumped rockfill for its excessivecompressibility and his recommendation of compactedrockfill in thin lifts as a means of greatly reducing it andalso allowing the use of poorer quality rock (Cooke1960). In the United States, the 136-m-high (445-ft),Corps of Engineers Cougar Dam (completed in 1964) wasthe first major earth and rockfill structure in whichvibratory rollers were used to compact the rock shells(Bertram 1973). At the time of the construction ofCougar Dam there existed practically no informationabout the construction and evaluation of compacted rock-fill so that trial and error test-fill procedures were used asthe work progressed. It is interesting to note thatTerzaghi had stated earlier that it would be impossible todetermine the properties of rockfill in the laboratory andthat only experimental fills should be used for such pur-poses. Even the most recent literature (NATO 1991),though filled with laboratory and model study informationon rockfill properties and behavior, still confirms a con-tinued reliance on test fills. Notwithstanding that state-ment, it can also be said that, in overview of thesignificant experience gained and common current prac-tices concerning rockfill, test fills may sometimes be inwider use than actually necessary. In the remaining por-tion of this Part of the manual, test fill will be spoken ofin the singular but it is not at all uncommon that morethan one test fill may be needed. The reader should have

no difficulty in recognizing the aspects of that to followwhich may dictate more than one fill.

8-2. Why a Test Fill?

The main properties of interest of compacted rockfill fallunder or relate to, shear strength, compressibility, perme-ability, and suitability of compaction equipment. Becauseof the fundamental nature of rockfill being cohesionlessand containing large particles, it is not feasible, nor is itpossible to obtain or test large undisturbed samples todetermine the pertinent properties. Furthermore, the typi-cal three-dimensional heterogeneity of rockfill and thedensities typically obtained from field compaction cannotbe replicated in reconstituted laboratory specimens inthose limited cases where very large laboratory testingequipment of high load capacity is available. Laboratorystudies of rockfill properties have been conducted ongradations containing smaller maximum particle sizes thanmost often actually placed and have, therefore, been moreakin to parameter studies to provide insights on effects ofvariations in those parameters and to provide educatedestimates of full-scale gradation behavior. In specificcase histories, such data can be applied in numericalanalyses coupled with observed embankment behavior toassess the quality of the laboratory results for predictivepurposes but the state of that art should probably be con-sidered to be in a state of relative infancy. Even the morefrequently performed versions of maximum density testshave usually involved altered gradations (scalped) ormodelled gradations (scalped/replaced or parallel) withsignificantly smaller maximum particle sizes. The profes-sion has not thoroughly established the effects of suchpractices on the numbers yielded in comparison with full-scale materials. Test fills have then often been the basisfor determining traits of the compacted rock which haveled to completely satisfactory dam embankments includingthe very highest yet constructed. If the rock is of highcompressive strength (sound rock), test fills may not evenbe necessary or adequate placement and compaction pro-cedures can be determined in the early stage of construc-tion without elaborate test fill operations. In this case, theonly tests needed are drill core samples and saturatedunconfined compressive tests which are among thosepreviously mentioned in Part 1. Cooke further states thatfor sound rock, four passes of a 9.1-Mg (10-ton) vibratoryroller upon layer thicknesses averaging about 1 m (3.3 ft)have become standard practices. Heavier rollers have notbeen found to usually offer any advantages. Since per-missible maximum particle size for sound rock can beequal to the lift thickness if the proper placement methodis used (to be discussed later), the most efficient

8-1

EM 1110-2-230130 Sep 94

Figure 8-1. Transition in practice from dumped rockfill to compacted rockfill (after Cooke 1990)

quarrying operations determined from the test quarry mayessentially dictate the lift thickness. If the available rockmaterial is of low compressive strength (say, less than55 106 Pa or 8000 psi), a test fill program is typicallynecessary. It has been previously stated in Part 1 that forsofter rock types or conditions, degradation of thematerial from the quarry through all aspects of its han-dling including loading, processing (if employed), hauling,stockpiling (if employed), placement, and compaction(whatever the combinations of lift and equipment) cannotbe confidently predicted by even the most experiencedindividuals much less the best placement/compaction

procedures. Indeed, the question sometimes exists as towhether the material will ultimately be a free-drainingrockfill after compaction or whether it will have degradedor must be made to degrade (because it will do so eventu-ally postconstruction) into a soil material and treated assuch in all aspects of design, construction, and construc-tion control. An example of material which may appearto be a rock upon quarrying but will deteriorate into a soilupon wetting (whether stockpiled or compacted in theembankment) with time are certain shales (Lutton 1977).In planning and conducting a test fill program, it shouldbe kept in mind that it can also offer considerable

8-2

EM 1110-2-230130 Sep 94

advantages in optimizing design and providing projectconstruction personnel with the opportunity to familiarizethemselves with materials and construction procedures.

8-3. Representative Procedures

A most important consideration for any test fill programis that procedures employed in constructing the test fillmust simulate, as closely as possible, feasible constructionprocedures to be used in the project fill. The achievementof this imperative objective requires some experience inthe construction of rockfill. If test-fill procedures do notclosely simulate actual construction, the value of the test-fill investment is compromised and the effort may evendo more harm than good. If experience in rockfill con-struction and its sampling/testing is seriously lacking, theuse of a test fill as a preconstruction training exercise forproject personnel may be a justified investment for soundrock and a natural advantage of test fill programs usuallyrequired for softer materials.

8-4. Test-Fill Scheduling

It has been by far the greatest preference to conduct testfills before construction begins (i.e., at some time duringthe project design stage) but there have also been cases ofprovisions made in the bid documents to allow for theirconstruction during the early phases of actual construc-tion. If the latter approach is under serious consideration,it must be based on very substantial confidence that the

items to be determined from the test fill have no potentialof altering the design of the embankment or of rejectingthe basic adequacy of the available materials. On theother hand, the advantages of a prebid test fill include:results can be used by the designer to prepare specifica-tions for rock placement and compaction (and blasting/processing if a test quarry is also conducted), the quarryface can be inspected by prospective bidders, and con-struction personnel can be trained for adequate visualobservation skills and required testing procedures. There-fore, a properly conducted prebid test fill program willmost likely result in a lower bid. A prebid fill wouldnaturally be scheduled to start at a point in the iterative-step development of the test quarry such that gradationsproduced in the test quarry and available for the test fillconstruction are deemed to be those recommended forproject construction. The decision of when to conduct atest fill, then, is one which must be based on features ofthe individual project.

8-5. Flexibility

A test fill program must be flexible. Because of naturalrock variations and unpredictable behavioral characteris-tics, it is often impossible to lay out a definite program inadvance from which there will be no deviations. Proce-dures and envisioned specifications have often beenaltered based on results of completed portions of an origi-nal program. The test fill program designers must antici-pate that possibility.

8-3

EM 1110-2-230130 Sep 94

Chapter 9Planning and Design

9-1. General

Planning and design of a test fill program should be donewith care to consider all the facets of the objectives ofsuch a typically expensive investment. The proposed pro-gram should be thoroughly reviewed to assure that allprocedures and tests are properly designated and plannedin the order of the work. There is no better guidanceavailable for laying out a program than to review thoseprograms conducted by others, particularly for Corps ofEngineer projects. This manual cannot substitute for thecareful review of the details of procedures and findings tobe found in the reports of test fills and test