Crawford-KC White Paper on CFRP for Blast Resistance1.187113413

8/22/2019 Crawford-KC White Paper on CFRP for Blast Resistance1.187113413

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P-05-5

Presented at the Enhancing Building Security

Seminar, March 23, 2005, Singapore

DESIGN AND IMPLEMENTATION OF PROTECTIVE TECHNOLOGIESFOR IMPROVING BLAST RESISTANCE OF BUILDINGS

John E. Crawford, Karagozian & Case, USA

Shengrui Lan, Karagozian & Case, USA

Abstract

This paper describes methods for designing and implementing protective technologies forimproving the blast resistance of buildings. A protection plan for buildings may include designingblast-resistant columns, walls, and windows; other elements of security may also play a major part,including physical security measures such as: anti-ram barriers and fencing to demarcate aprotective perimeter; features such as lighting, CCTVs, and locks to reduce clandestine activities; andoperational procedures such as patrols, special response teams, neighborhood watches, andeducation to provide heightened surveillance and vigilance. In other words, protection for a building

or facility does not begin at the entrance to the building, but is part of an overall fabric of multi-tiered,interwoven, and integrated protective procedures. Protective design is still in its infancy, especiallythe interoperability of its various parts. In this paper, we will focus on some of the protectivetechnologies developed or evaluated by K&C pertaining to the engineering of perimeter devices forenforcing standoff, techniques for adding blast/impact resistance to buildings, and methods forimplementing the engineering aspects of protection technology.

Key words: Protection, blast resistance, blast barrier, anti-ram barrier, column retrofit, protectivetechnology

1. Broad Aspects of Protective Design

This paper describes methods for designing and implementing protective technologies forimproving the blast resistance of buildings. A protection plan for buildings may include designingblast-resistant columns, walls, and windows; other elements of security may also play a major part,including physical security measures such as: anti-ram barriers and fencing to demarcate aprotective perimeter; features such as lighting, CCTVs, and locks to reduce clandestine activities;operational procedures such as patrols, special response teams, neighborhood watches, andeducation to provide heightened surveillance and vigilance; policing and intelligence authorities; andplanning and policy agencies related to siting, funding, and protective criteria and policy formulation.

In other words, protection for a building or other type of facility does not begin at its entrance, butis part of an overall fabric of multi-tiered, interwoven, and integrated protective procedures, including:

cultural, political, and operational modalities; policing and security laws; and the level of attention,funds, and skills focused on a particular protection project or issue. The multi-tiered nature ofprotection is illustrated by the graphic presented in Figure 1. As depicted, especially in the outer bluetinged tiers, protection can be viewed as a filtering and winnowing down process whereby each tier orlayer of protection offers opportunities for interdiction and discovery, while at the same time reducing


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the size and frequency of threat due to the fear of discovery and the difficulty of operating.

Figure 1 also illustrates the interrelative nature of physical security engineering (red) andpolicing/intelligence (blue) functions, which is often neglected in implementing protective technologiesfor buildings. Close coupling of these two functions can greatly enhance the effectiveness of thefunds expended. Both engineering and policing disciplines have important roles to play in ensuring

protective technologies are wisely and efficiently deployed. Both should be incorporated early in theprocess of designing a new building to achieve the desired protection without excessive costs orcompromise of esthetics or functionality.

Protective design is still in its infancy, especially the interoperability of its various parts.Perimeter security and policing functions are by far the most mature forms of protection. In contrast,technologies for building hardening are still not widely used or even known; however, resilient designconcepts are widely used (e.g., in earthquake design) and provide a ready pool of technologies foradaptation to blast-resistant design. Still rudimentary in their implementation are the concepts ofintegration and a multi-tiered defense as represented in Figure 1 and the need for appropriateresource allocation implied by the figure.

1.1 Papers Objective

In this paper, we will focus on some aspects of physical security related to the structural designof perimeter devices and building components for the purpose of protecting the buildings occupantsand functionality against terrorist bombs. In contrast to the protection provided in building designs fornatural hazards, protection in the context of malevolent hazards is likely to be less complete.Moreover, the quality and effectiveness with which this work is performed depends on a combinationof engineering skills and know-how, as alluded to in Figure 2, that is likely to be hard to find. Fewpractitioners of protection engineering have the prerequisite skills and knowledge necessary, whichhas greatly hampered the professions ability to adequately meet the need, as well as allowed for a lotof disjointed and poorly conceived protective engineering.

In our own practice at Karagozian & Case (K&C), it is readily apparent that without our extensiveexperience with blast/impact effects testing and using physics-based numerical models toapproximate actual blast/impact responses, we could not be regarded as one of the premierengineering consultants in blast/impact resistant design. It is paramount that a wider and deeperunderstanding of blast/impact effects (for good reason, the top circle in Figure 2) be provided to bothpractitioners and owners if physical security engineering is to be an effective component of an overallstrategy to protect society from terrorism. With this paper, we can only allude to some of the newconcepts for building protection with the hope of enhancing the awareness of owners as to the kindsof protection available. Details concerning the manner in which these designs work and the designmethodology used to implement then is too complex to expand on further in this paper.

This paper briefly describes some design concepts to improve the protection of buildings againstterrorist attacks that have both high performance and good aesthetics. Contrasts between theseconcepts and other more conventional ones are made to distinguish and highlight the featuresthought to be of most benefit for improving impact and blast resistance. Selection of designparameters for the new concepts is often based on the results from high-fidelity physics-based(HFPB) finite element models because their more sophisticated nature allows for direct simulation ofthe behaviors involved, which is a prerequisite to effectively designing blast/impact resistant devicesand components. Impact and blast tests also play an important role in this process: both validatingthe HFPB models and providing demonstrative evidence of actual behaviors. Some test results arepresented in the paper to illustrate the point. In many situations, such testing and analyses aremandatory to developing satisfactory impact and blast-resistant designs; the experience at K&C hasamply demonstrated this fact.

In this paper, we will focus on some of the protective technologies developed or evaluated by

K&C pertaining to the engineering of perimeter devices for enforcing standoff, techniques for addingblast/impact resistance to buildings, and methods for implementing the engineering aspects ofprotection technology, namely the red tinged zones of Figure 1 and the combination of engineeringskills and concepts (Figure 2) needed in producing effective protective designs.


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1.2 Protective Design for Buildings

As recently as ten years ago, some well-known blast consultants believed there was little thatcould be done to protect existing office buildings from large-scale terrorist attacks. Even for newconstruction, they believed a fortress like structure was needed or that the facility needed to be

isolated from the general public behind formidable barriers. Since then, many new concepts thatmarkedly enhanced a buildings resistance to blast and high impact loads have been introduced byseveral organizations. Many of these concepts have proven themselves in blast and impact tests,and some systems have proven highly effective at preventing injuries from car and truck bombs atstandoffs of only a few feet. Besides protection from blast and impact, these concepts have ingeneral other distinct advantages: they are not excessively costly, are neither difficult nor disruptiveto install, and do not markedly alter the buildings appearance. Also of interest are the principles thatthese concepts use since they embody a design philosophy that is demonstrably effective and readilyincorporated in building design. Moreover, the esthetics and reasonable costs of these conceptsdemonstrate that to achieve good protections, one need not abandon good looking, cost effectivedesign.

As mentioned, there are many other aspects of protective technology besides the engineering

designs presented in this paper that are important in mitigating the risks engendered by malevolentattacks on buildingsfor example, policing and physical security measures like lighting, CCTVs, andguards. The relationship between these and the design concepts described in this paper is primarilypredicated on balance, costs and perceptionsfor example, guards and fencing provide a perceivedbarrier to an attack, while anti-ram devices and blast-resistant design provide actual barriers to anattack. Both have important roles to play in the overall goal of providing buildings protection, but it isimportant to not mistake one for the other. The constant barrage of bombings in Iraq amplydemonstrates that measures like guards and fencing alone are not an adequate response to this typeof malevolent hazard. Moreover, in this case the hazard has become so common place that forgovernment facilities and checkpoints, this hazard should be included in the design process in amanner similar to that followed for common hazards, like earthquake and wind.

2. Key Features of High Performance Concepts

A partial list of high performance occupant protection systems related to blast and impact loadsis provided in Table 1. One key feature common among these high performance concepts is theirreliance on ductile, plastic behavior to achieve maximum protection with minimal material and cost.Making ductility a key feature of a design is a well trod approach for protecting equipment for shocks,preventing seismic damage to buildings, and in designing hardened military facilities; but it is not wellunderstood by many blast consultants, who often seem focused on using brute strength to resist whatare often very large forces. Unfortunately, strength concepts are often grossly inefficient and out ofkeeping with traditional architecture schemes and cost a lot to install, especially in existing buildings.Moreover, the ability of these high performance concepts to perform their job with a minimum amountof material often results in less disruption to the facilitys operations and estheticsthey tend to fit in

nicely.

A second key feature of high performance protection systems is their consideration of shockrelated behaviors, that is, responses that are directly coupled to the intensity of the load. As the ratioof impulse to system mass (i.e., I/m) becomes large, particular attention must be paid to supportdesign. This is a general phenomenon that occurs in many kinds of conventional structures (e.g., inreinforced concrete slabs [1]) and other devices where a shock load must be accommodated by thesystemthat is, the system in the vicinity of its anchorage/supports/etc. must accommodate largedifferences in early time motions. Otherwise, plastic response and ductility give way to tearing andbreaching behaviors leading to premature system failures. It is important to design away from thesebrittle response modes, which may be accomplished by tuning the initial stiffnesses or employingductility and/or traditional shock isolation concepts, especially near supports.

A third feature of this class of protection devices is their use of non-standard building materials orstandard materials in non-standard ways; for example, synthetic fabrics like Kevlar

, E-Glass, and

carbon; polymers, such as rigid polyurethane foam and spray on polyurea; the use of adhesives andshock isolation for anchorage and bonding. Or the use of sheet metal attached to metal studs (i.e.,


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steel plate shear walls, SPSW) to provide blast resistance partition walls. These systems also useexisting materials and design concepts, like reinforced concrete and steel, but in more efficient andeffective ways. For example, ensuring that sufficient ties are included in reinforced concrete (RC)columns for them to achieve their full ductile moment capacity.

Finally, and perhaps of most importance in blast protection since it is so often neglected in

protective designsis the notion that were the actual blast load larger than the design load that thesesystems would have substantial reserve capacity and that were they to fail, their presence would notsubstantially increase the risks over those present if no protection had been added. All too often,especially for windows, protective systems are designed for what is a relatively low level of protection,the implication being that many of them would fail in any actual event. What is not considered in thissituation is that were such an event to occur and the system (e.g., window) fail, would the risks begreater than those that would be present had no blast resistance been employed. This is not a simpleissue to address; for example, the daylight application of Mylar (an anti-shatter film) as a prophylacticagainst laceration injuries from window shards is likely one of those situations where the increase inblunt trauma risk outweighs any benefit in reducing laceration injuries except in those cases wherethe window is likely to break safe or be significantly overloaded, which was the conclusion in arecent paper [2].

3. New Design Concepts

Recently, ASCE published a book [3] describing general design approaches for hardening ofconventional buildings to resist terrorist bombs, a couple of these are listed in Table 2. The retrofitconcepts described in Table 2 have little in common with the high performance concepts described inTable 1; in fact, both of the concepts listed in Table 2 may actually increase the risks. In contrast tothe concepts presented in Table 2, a central purpose of the new concepts is prevention of shearfailure and other similarly brittle response modes. These concepts (Table 1) often utilize materials,design strategies, and ductilities substantially different from those related to the more conventionalretrofit concepts of Table 2.

Many of the concepts listed in Table 1 are depicted in Figures 3 to 20 and documented inReferences 4 to 23. In some cases, window and wall retrofit schemes may be combined, as shown inFigures 4 and 6. Many of the systems rely on the remarkable properties of synthetic fabrics andpolymers to provide the flexibility, stiffness, and ductility needed to effectively mitigate the effects ofclose-in large vehicle bombs.

4. Appearance Issues

For many civilian buildings, especially the important ones that may be likely targets of terroristsbombs, esthetics are an important consideration. In this situation, it is paramount that blast protectionschemes avoid giving a fortress like appearance. They should not promote an unfriendly and closedatmosphere or force unnecessary compromises in the architects vision of the facility.

There is nothing inherently ugly about blast-resistant design. J ust as in many other designefforts, esthetics is often a by-product of good design. Many of the design concepts listed in Table 1lend themselves to unintrusive installation; they illustrate that ugly is not an integral part of blastresistance. Moreover, many of these designs can be installed so that the user of the facility iscompletely unaware of them.

5. Effectively Addressing Building and Occupant Protection

To effectively address building/occupant protection will require development of a range of highperformance designs because many situations are going to involve existing buildings that are oftensituated such that there is little standoff to be had or that must adhere to conditions/regulations that

inhibit using blast protection devices along the sites perimeter.

Unfortunately, there has been little incentive for manufacturing companies or venture capitaliststo put together markedly better products to combat terrorist threats because the market for advancedblast-resistant products is still exceedingly small. Moreover, it may not be sufficient to have great


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designs and good esthetics; they are likely to need to be approved/accepted/validated, which is aprocess that nearly all approval authorities are unable to perform. This lack of process is largelyresponsible for why we dont have better protection, or even better know-how in addressing blastprotection more effectively. Government authorities must get a lot more knowledgeable if good blast-resistant designs are to be put in place.

The incentive for industry to develop more effective products, especially for the high levels ofprotection, just has not been there. This is due partly to the high cost of validating these concepts,which usually requires blast tests often at full scale, and a relatively extensive design effort. Many ofthe concepts cannot be patent protected; or if they are, the government is less interested in helpingbring them to market, both of which act as roadblocks to privately developing the needed technology.

It takes time, skillful engineering, and a knowledgeable manufacturing/marketing organization tobring these concepts to production and market. Then it requires a desire and an awareness/belief ofits usefulness on the part of owners and government policy makers, who themselves are not likely tobe up to speed on the latest and greatest, to give the concept/product a chance at making itcommercially. Finally, the typically larger threats applicable to US facilities means that the programsin other countries are of marginal benefit, not a great recipe for major advances in technology.

However, for many countries, the US protective design programs should be of great interest sincethey are likely to provide systems that are more than adequate. Moreover, this data will be highlyuseful in assessing the risks to existing buildings from terrorists bombs.

Maybe its time to try another model. In the past, many partnerships between government andindustry have been forged to speed product development where industry alone lacks resources ordirection. Maybe some version of that is needed now if we are to make the leap forward that appearsto be needed in addressing the terrorist threat to buildings and their occupants.

The inherent problem with producing high performance impact- and blast-resistant devices andretrofit designs for existing facilities is primarily organizational. The problem is exacerbated by thenewness of the effort, lack of skill among most designers, insufficient funds, a general lack ofknowledge among those buying such products and services of what can be done, and a test bedhaving sufficient availability and general purpose to effectively certify and evaluate blast-resistantconcepts and products. High performance designs invariability require advanced analytic skills alongwith good design sense specifically related to blast and impact effects. In the engineering communitywe have the requisite knowledge as individuals, but few groups have all of the requisite skills orresources.

Now would seem the time for us to reorganize our efforts as a community and more effectivelyaddress blast and impact protection, letting us put our best technological foot forward.

6. Summary

An array of new blast-resistant and impact-resistant products, devices, and design concepts areunder development or have recently become available. Several were illustrated in the paper, theseinclude:

A number of blast and impact barriers that have been tested for various levels of threat.

Retrofit technologies and design procedures for reinforced concrete columns that providemarkedly improved blast and impact resistance, have been tested, and are easy to install inexisting buildings. Composite wrap (e.g., fiber reinforced polymer (FRP), carbon, Kevlar

and

E-Glass fibers) and steel jackets have proved their effectiveness in blast tests.

Design concepts were developed to improve blast and impact resistance for existing metal stud,brick, and concrete block walls, all of which are inherently weak in lateral resistance. Some of the

retrofit techniques use polymers with or without synthetic or metal fibers to achieve theircapability; sheet metal bonded to rigid polyurethane or plywood cores; and thin steel platesanchored to the floors.


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A combination of window strengthening and debris catching systems can effectively preventinjurious debris from entering the occupied spaces of a building over a range of threats. Full-scale tests of these systems indicate this approach is highly effective at stopping injurious debriseven for large close-in bombs.

In conclusion, blast resistance of new and existing buildings can markedly be enhanced with productsand concepts available today. Their design, however, requires expertise which is not widelyavailable. In addition, many more products and design techniques are likely to be created over thenext few years.

Table 1. List of some recently developed high performance technologies for improving the blastresistance of building systems.

Component Protected Description

Key Aspect of Protective System as Compared

to Conventionally Designed Counterpart

Windows & Skylights

Debris Containment

Catcher bars/cables [4] Catches window or window debris Arpel windows

Muntin with SentryGlas P lus

[7]

Failure Prevention Transparent fabric [5, 6] Uses ductility to prevent failure

Louver Uses ductility to prevent failure

In-fill Walls, Thin plate catcher system [9] Ductile catcher system Debris Prevention Metal studs [8, 9, 10] Ductile catcher system

Polyurea coatings [10, 11] Ductile reinforcement, lacks stiffness to prevent wall

damage

Rigid polyurethane panels [12] Uses stiffness and ductility to prevent failure

Kevlar

laminate [10]

Bearing Walls FRP [12] Uses combination of stiffness and ductility toprevent failure

Failure Prevention (i.e., for

Masonry Walls)

Composite panels [13, 14] E-Glass composite, bullet- and blast-resistant

Addition of internal reinforcing

[15]

Rebars are drilled into interior of wall and grouted

into supports

Reinforced ConcreteColumns

Composite wrap [16] Uses shear-dilatancy to achieve high strength and

ductility

Metal jackets [16] Tested in full-scale blast test

Steel Frame Connections SidePlate [17] Stress path continuity Cabling [18] Continuous catenary support

Site Street furniture systems [23] Esthetics with high impact resistance Blast and anti-ram walls [19, 20,

23]

Debris control, modularity, ductility at small standoff;

very high impact protection

Fabric blast shield for upper

stories of a building [22]

Protects upper floor walls/windows

Table 2. Conventional protective systems (see ASCE [3]).

System Protected Description Key Aspect of Design

One-way Masonry Walls Modify wall perimeter to support two-way

response

Change response mode and add

reinforcement, adds little to capacity and

increases likelihood of shear failure

Reinforced Concrete Columns Bolted or bonded steel plate on tensile side Add reinforcement; since does not increase

shear capacity, this may actually increase risk


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Figure 1. Depiction of the multi-tiered nature of protective technologies pertaining to protecting afacilitys functionality and occupants from terrorist attacks; integration of the functionsrepresented by these tiers, especially the policing/intelligence functions (blue tinged) withthe physical security engineering functions (red tinged), is important to achieving effective

protection.

Figure 2. Depicts interrelatedness of engineering aspects of protective design.

PROTECTIVE

DESIGN

STRUCTURAL

ENGINEERING

BLAST/IMPACT

EFFECTS

RISK

ANALYSIS

PERIMETER

DEFENSE

Facility functionality

and occupants


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(a) Refinished room, showing transparent fabric blast screens covering the windows,

other retrofits are not visible.

(b) Shows application of polyurea to brick wall, anchorage for fabric screen,

and CFRP wrap for columns.

Figure 3. Transparent fabric catcher system; polyurea/FRP is applied beneath the painted wall.

Bare wall &

column

Column left bare after

spray, avoid bond ing

wall to column

Wall and 6 of floor near

wall is covered wi th 1/8

to 1/4 thick layer of

FRP or polyurea coating

Fabric anchorage placed

above the drop ceiling

Fabric blast

screen

RC column

wrapped with

CFRP


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Open

Closed

(a) Installed, horizontal louvers. (b) Attachment shown for

vertical louvers.Figure 4. Louver catcher system to prevent whole of exterior wall from entering the building.

(a) Ready for installation. (b) After testing with blast load.

Figure 5. Arpal window; example of a cable catcher system, where cables are attached to frame.

ANCHORAGE BRACKET,

ATTACHMENT TO

BUILDING

Flexible frame

Catcher

cables

Laminated glass

Cables inside

these faux

mullions


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(a) Installation. (b) Test results.

Figure 6. Cable catcher system for arresting the motion of the whole wall, as installed in a DoDfacility, cables are attached to buildings floors; windows are covered with Mylar to facilitatetheir being caught with the cables.

Figure 7. Muntin window, which was developed for the Department of State; it consists of the severalsets of structural muntins used behind a single piece of laminated glass. The muntins actmuch like a catcher system, but in this case, placed just behind the glass to providestrengthening for the glazing, preventing it from breaking free from the frame.

MuntinBlast side

of window


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(a) Application to brick wall. (b) Pretest view of test article.

(c) Results from blast test.

Figure 8. Retrofit for masonry and stud walls with Kevlarlaminate (i.e., an FRP) and sheet metalcomposites.

Metal or

FRP skin

Polyurethane

foam core

Brick

Blast

Bonded tobrick withadhesive


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(a) Depicts application of unreinforced polyurea.

(b) Depicts installation of Kevlar reinforced polyurea.

(c) Finished look of polyurea coating; appearance coat may be added to provide a finished look.

Figure 9. Polyurea coatings (homogeneous layer inch to inch thick or reinforced with meshcomposed of metal, carbon, Kevlar

, or E-Glass fabric). The fabric used has an open

weaveto allow its embedding in the polyurea during the spraying process; the increased

stiffness/strength provided by the mesh reduces deflections and increases tear resistance.

Polyurea

Brick

Polyurea

Brick


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Time = 10 ms

(a) Plot of analytic model prior to detonation of 100 kg

of TNT at 4 feet from wall.

(b) Response at time = 10 ms.

Time = 19 ms

(c) Response at time = 19 ms. (d) Results from a full scale test.

Figure 10. High capacity masonry catcher system; steel plate 1/16" to 1/8" thick that is anchored todiaphragms is placed behind wall; analytic models like those shown are used to determinedesign parameters and compute capacity, these models employ high-fidelity physicsbased simulations.

Thin steel plate

used for catching

wall debris

Steel Plate


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(a) Response of a non-

retrofitted column to nearby

blast.

(b) Response of composite

wrapped column to same load.

(c) Illustration of wrapping

process.

Figure 11. Composite retrofit of reinforced concrete columns.


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(a) Shows application of CFRP to RC column to improve its blast resistance.

(b) Finished appearance.

Figure 12. Application showing process and finished appearance of FRP wrap for enhancing blast-resistance of RC columns.


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(a) Overview. (b) Plan view.

Figure 13. SidePlate connection: post-Northridge, fully-rigid steel moment resisting connection.

Girder

Cables wiconnectioto beams

Comparison of Response With

and Without Cabling

(a) Section. (b) Results from test conducted in lab.

Figure 14. Section showing cable placement along exterior girder for providing continuity aroundexterior face of building.

Side

plate

Horizontal

shear plate Cover plate

Beam

Shop fillet welds

(typical throughout)

Column/beam separation

Without cable

With cable


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Fill with concrete orother materials; flat and

curved sh apes available.

Could also be used for

barrel roof

7 feet

15 feet

6 feet

8 feet

(a) Bi-Steel concept for constructing a

concrete/steel composite panel; friction welded

dowels are used to tie the system together;

PANEL thicknesses over 2 feet, 2 meters tall

by up to 40 feet long are allowed.

(b) Adler Blast Wall test setup.

(c) Posttest result for Adler Blast Wall.

Figure 15. Blast wall designs proven in blast tests.

Dowels attached to

plates with friction

welds


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(a) Basic anti-ram foundation module is composed of a steel grillage that is manufactured and brought

to the site as shown.

(b) Shows installation of modules and the concrete fill added to it.

Figure 16. New modular anti-ram system, allowing installation of an array of devices to be installedover a common anti-ram foundation; the shallow footing foundation shown requires lessthan 6-inch depth for a K-12 rating.


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(c) Finished appearance, devices shown are just slipped over the unfinished stems shown in

Figure 16b.

Figure 16. New modular anti-ram system, allowing installation of an array of devices to be installedover a common anti-ram foundation; the shallow footing foundation shown requires less

than 6-inch depth for a K-12 rating (Continued).


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(a) Different style benches may be used for street furniture.

(b) Furniture slips over anti-ram bollards; transparency shows stem inside.

Figure 17. Illustration of the use of street furniture to mask anti-ram devices.


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(c) Shows other street furniture that may be supported by the shallow footing bollard system

shown in Figure 16a.

Figure 17. Illustration of the use of street furniture to mask anti-ram devices (Continued).


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Figure 18. Photos of an actual site where the shallow footing bollard system (Figure 16a) is to be

installed.


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(a) Step 1: survey initial site conditions.

(b) Step 2: site after excavation.

Figure 19. Steps in installation process of new modular anti-ram device, which is shown in Figures 16and 17.


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(c) Step 3: installation of the units.

(d) Step 4: fill units with concrete, then replaces plaza paving.

Figure 19. Steps in installation process of new modular anti-ram device, which is shown in Figures 16and 17 (Continued).


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(e) Step 5: install street furniture.

(f) Step 6: installation completed.

Figure 19. Steps in installation process of new modular anti-ram device, which is shown in Figures 16and 17 (Continued).


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Airport Along high-speed roadway

Along street side Layered look

Figure 20. Examples of application for new shallow footing modular bollard system, which provides avariety of anti-ram capabilities.

References:

[1] Murtha, R. and J . Crawford (1981). Dynamic Shear Failure Predictions of Shallow-Buried Reinforced-Concrete Slabs,

TM No. M-51-81-04, Civil Engineering Laboratory, Port Hueneme, CA.

[2] Bogosian, D. and H. Der Avanessian, To Film Or Not To Film: Effects Of Anti-Shatter Film On Blunt Trauma Lethality

From Tempered Glass," Proceedings of the 17th International Symposium on the Military Aspects of Blast and Shock,

Las Vegas, Nevada, J une 2002.

[3] ASCE (1999), Structural Design for Physical Security, State of the Practice, American Society of Civil Engineers, Reston,

VA.

[4] Crawford, J . E. (2000). High Performance Occupant Protection Systems for Office Buildings; An Overview of New

Concepts Developed by Karagozian & Case for Mitigating Risks Engendered by Large Nearby Terrorist Bombs,

Karagozian & Case, Burbank, CA, TR-00-30.2, September, 2000.

[5] Moffett, D. (2001). Sunshade Fabric Fragment Retention Retrofit for Blast Mitigation, DS/PSD/SDI TIB # 01.03, U.S.Department of State, Bureau of Diplomatic Security, Physical Security Division.

[6] Lan, S. and J . E. Crawford, Numerical Modeling of Fabric Catcher System, Proceedings of the Sixth International

Symposium on Fibre-Reinforced Polymer (FRP) Reinforcement for Concrete Structures (FRPRC-6), Singapore,

8-10 July 2003.

[7] Amini, A. (2001). Blast-resistant Structural Muntin Window System, DS/PSP/PSD TR # 01.01, U.S. Department of

State, Bureau of Diplomatic Security, Physical Security Division.

[8] Norris, R. J . (2001). The Steel Stud Wall/Window Retrofit, A Blast Mitigation Construction System, DS/PSD/SDI

TIB # 01.01, U.S. Department of State, Bureau of Diplomatic Security, Physical Security Division.

[9] Bogosian, D. D., "Design and Assessment Methodology for Thin Steel Plate Catcher and Metal Stud Wall Systems,"

Karagozian & Case, Burbank, CA, TR-04-9, May 2004.

[10] Crawford, J . E. and P. Bong, Concepts for Reducing Risk from Terrorist Bombings at the Los Angeles International

Airport, Karagozian & Case, Burbank, CA, TR-02-6.1, May 2002.

[11] Based on work at Tyndall Air Force Base, reported by J on Porter in 1999 and 2000.

[12] Crawford, J . E. and K. B. Morrill, "Blast Resistance of Conventional Building Faades and Evaluation of Designs for

Improving It," Karagozian & Case, Burbank, CA, TR-01-41.2, November 2003.[13] Crawford, J . E. and B. W. Dunn, Development of Polyurethane Panels for Retrofitting Masonry Walls, Karagozian &

Case, Burbank, CA, TR-01-24.1, September 2001.

[14] Tuff-Core, a composite produced and developed by Atlantic Research Corp. for lining munitions containers.

[15] Crawford, J . E., J . Valancius and J . M. Ferritto, Vulnerability Assessment of and Remediation Study for the J ames A.

Walsh Federal Building, Karagozian & Case, Glendale, CATR-01-25.1, September 2001.


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[16] Crawford, J . E., L. J . Malvar, J . M. Ferritto, K. B. Morrill, B. W. Dunn, and P. Bong, Description of Design Software for

Retrofitting Reinforced Concrete Columns to Improve Their Resistance To Blast, Karagozian & Case, Burbank, CA,

TR-01-16.2, July 2003.

[17] Crawford, J . E., D. L. Houghton, B. W. Dunn and J . Karns, "Design Studies Related to the Vulnerability of Office

Buildings to Progressive Collapse Due to a Terrorist Attack," Karagozian & Case, Burbank, CA, TR-01-10.2, J uly 2001.

[18] Crawford, J . E., Peer Review of the New US Courthouse in Seattle, Washington, Pertaining to its Blast Resistant

Design, Karagozian & Case, Burbank, CA, TR-99-29.1, November 1999.

[19] Crawford, J . E., Design and Test of Adler Blast Wall, Karagozian & Case, Burbank, CA, TR-03-16.2, J une 2003.[20] British Steel Ltd (1999). Bi-Steel Design & Construction Guide, North Lincolnshire, UK.

[21] Crawford, J . E. and K. B. Morrill, Feasibility Study for the Development of Lightweight Portable Airblast Barriers,

Karagozian & Case, Burbank, CA, TR-99-12.1, August 1999.

[22] Morrill, K. B., Fabric Blast Shield for Protecting a Buildings Exterior, Karagozian & Case, Burbank, CA, TR-03-12.1,

J uly 2003.

[23] Lan, S., and J . E. Crawford, "Development of Anti-ram Barrier Systems," Proceedings of the 2nd International Conference

on Protection of Structures Against Hazards," Singapore, December 2004.

Documents

Crawford-KC White Paper on CFRP for Blast Resistance1.187113413