TENSACCIAI - Rock and soil anchors

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ROCK AND SOIL ANCHORS



Cover photo: Ertan Dam, ChinaContractor: E.J.V. Impregilo-8.B-Dumez-Gtm-TornoClient: EHDC, Ertan Hydropower Development Co. Ltd.

Photo page 1: Railway Line Contuy MedioCaracas-Charallave-Cua, (Venezuela)Contractor: Trevi spa, Cesena (FC), ItalyMain Contractor: J.V. Astaldi/Impregilo/Ghella/OtaolaClient: Ferrocar



via flavio vegezio, 15 - 20149 milano (italy)phone +39 02 4300 16.1 - fax +39 0248 0107 26e-mail.: [email protected] - http://www.tensacciai.it



CONTENTS

FUNCTIONAL DESCRIPTION OF THE ANCHOR . . . . . . . . . . . . . page 4

MAIN FACTORS IN ANCHOR DESIGN . . . . . . . . . . . . . . . . . . . . . . . page 5

STRAND CHARACTERISTICS . . . . . . . . . . . . . . . . . . . . . . . . . . . . page 6

ANCHOR PROTECTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . page 7

ANCHOR HEADS “PT” SERIES . . . . . . . . . . . . . . . . . . . . . . . . . . . page 8

ANCHOR HEADS “MT” SERIES . . . . . . . . . . . . . . . . . . . . . . . . . . page 9

ANCHORS FOR TEMPORARY USE . . . . . . . . . . . . . . . . . . . . . . . page 10

ANCHORS FOR PERMANENT USE . . . . . . . . . . . . . . . . . . . . . . . page 12

STRESSING JACKS “PT” SERIES . . . . . . . . . . . . . . . . . . . . . . . . . page 18

STRESSING JACKS “MT” SERIES . . . . . . . . . . . . . . . . . . . . . . . . . page 19

HYDRAULIC PUMPS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . page 20

CYCLIC STRESSING: TENSACCIAI TAC SYSTEM . . . . . . . . . . . . page 21

EQUIPMENT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . page 22

NORMS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . page 24



For many yearsTENSACCIAI has beenactively engaged in thestudy of the applicationof post-tensioningtechnology in thegeotechnical field.

TENSACCIAI hasworked and is workingwith the mainspecialized

contractors, and hassupplied and installeda considerable numberof rock and groundanchors, of differenttypes and use, inimportant public andcivil works, in Italy andall over the world.

The acquiredexperience enables

TENSACCIAI todesign, test andproduce types of

anchors, technologiesand equipment whichhave a wideapplication as well asimportant technicaland operative results.

This result has beenobtained thanks to aconsiderable technicalresearch andcontinuous attention

to the variousproblems of the field.

All TENSACCIAIsupplies comply bothwith the standardscovering pre-stressedreinforced concrete“Technical standardsfor calculation,execution and testingof normal and pre-

stressed reinforcedconcrete structuresand for metal

structures” Lawn°1086/1971, MinistryDecree of 9.1.1996,Circular n°252AA.GG./S.T.C. of15.10.1996, and withthe “AICAPRecommendations” of1993.

TENSACCIAI ismember of APPI

(Italian Association ofPost-tensioningSystems) and of thefollowingAssociations: AICAP,AGI, ISSMFE, ISRM,CEB, FIB, IABSE, PTI.

TENSACCIAI hasobtained BureauVeritas QualityInternational

certification accordingto ISO 9001:2000standards.

Permanent anchors for the quay of Trattaroli Square, Ravenna (Italy)Contractor: Ing. Giovanni Rodio & C. spa, Casalmaiocco (LO) - (Italy)

Main Contractor: Ravenna Scarl, Rome (Italy)Client: Italian Ministry of Public Works, Rome (Italy)



FUNCTIONAL DESCRIPTION OF THE ANCHOR

4

ANCHOR HEADSAnchor heads are made of forged steel, with shape and dimensions allowing a uniformstress distribution on the structure, and a correct housing of the anchorages and wedgesystem and of the eventual protection cap of the anchor head system.

FREE LENGTHIt represents, in the length, the part of the anchor between the bond and the anchor

head, in which the tension element undergoes its lengthening during tensioning operations;in this zone strands are protected in a sheath, having also the purpose to protect themagainst corrosion and stray currents.

BOND LENGTHThis is the part of the anchor transmitting the tensile stresses to the ground by meansof cement grout, assuring adherence between the tension elements and the borehole.To increase their cement-steel adherence, strands are suitably shaped, by means ofspacers, in a sinusoidal form with loops and knots.To make easier the anchor insertioninto the borehole, its head is connected to an ogive, shaped to overcome the friction ofthe hole outline during threading phase.

anchorhead free length bond length



MAIN FACTORS IN ANCHOR DESIGN

5

CALCULATION OF ANCHOR CAPACITYCalculation can be:• of geotechnical type

• of structural type

CALCULATION OF TECHNICAL AND GEOMETRICAL CHARCTERISTICSParameters to be fixed are:• bond length, depending on the soil characteristics and particularly considering its cohesion

and adherence index, generally checked by means of preliminary unslipping tests;• free length that, depending on the structure geometry, must be sufficient to overpass

the slipping surface of the ground body to be consolidated or soil layers having poorgeotechnical properties;

• degree of anchor protection depending on its useful life;• type of anchor heads depending on the need of tensioning checks in the time, subsequent

tensioning or releasing operations.

LIFE OF THE ANCHORDepending on its length in the time and on the environmental aggressiveness, anchors canbe classified as:• Temporary: when they are applied to temporary structures to contrast the forces that

rise during the structure erection, but that are no longer present when the work isfinished.

• Permanent: when their action is requested for an important period in the life of thestructure to which they are applied: in this case anchor protection must be total.

GROUTINGIn cohesive soils it's important to increase frictions between grouting of the ground anchor'sbody and the surrounding soil; in this case grouting is performed by means of pipes withvalves, equipped with manchettes placed at variable distance depending on soil characteristics(30, 50, 100 cm.), with the aim to have the possibility to make localized pressure groutingoperations, also in different phases, and eventually to repeat grouting after tensioning, incase of lack of adherence with the soil.



Fptk Fp0,1

mm mm2

g/m kN kN % %EN 10138 standard 15.2 140 1090 260 230 2.5 4.5

0.6" super 15.7 150 1180 279 248 2.5 4.5

ASTM A416/94 Grade 270 15.24 140 1102 260.7 221 2.5 4.5

0.6"ASTM A779/90 15.2 165 1290 300 264 2.5 4.5

compact

Elastic module = 195 ± 10 kN / mm2

n. Fp=n Fptk 0,7 Fp 0,625 Fp 0,6 Fp 0,5 Fp Fs=n Fp0,1 0,75 Fs 0,6 Fs

mm mm2 kN kN kN kN kN kN kN kN

2 15,2 280 520 364 325 312 260 460 345 276

3 15,2 420 780 546 488 468 390 690 518 414

4 15,2 560 1040 728 650 624 520 920 690 552

5 15,2 700 1300 910 813 780 650 1150 863 690

6 15,2 840 1560 1092 975 936 780 1380 1035 828

7 15,2 980 1820 1274 1138 1092 910 1610 1208 966

8 15,2 1120 2080 1456 1300 1248 1040 1840 1380 1104

9 15,2 1260 2340 1638 1463 1404 1170 2070 1553 124210 15,2 1400 2600 1820 1625 1560 1300 2300 1725 1380

2 15,7 300 558 391 349 335 279 496 372 298

3 15,7 450 837 586 523 502 419 744 558 446

4 15,7 600 1116 781 698 670 558 992 744 595

5 15,7 750 1395 977 872 837 698 1240 930 744

6 15,7 900 1674 1172 1046 1004 837 1488 1116 893

7 15,7 1050 1953 1367 1221 1172 977 1736 1302 1042

8 15,7 1200 2232 1562 1395 1339 1116 1984 1488 1190

9 15,7 1350 2511 1758 1569 1507 1256 2232 1674 1339

10 15,7 1500 2790 1953 1744 1674 1395 2480 1860 1488

Working loads shown in the table above have to be defined according to Reference Norms (EN 1537, AICAP Recommendations, BS Standards, SIAnorms, TA'95 Recommendations, etc…)

Further datas are available on request.

STRAND CHARACTERISTICS

6

This catalogue provides technical information regarding anchors manufactured with strands15.2 mm. dia. (0.6”); 15,7 mm. dia. (0,6”S) and 15,2 mm. dia. compact.In case of specific applications, where the use of different diameters is required, our Technical

Department is available for any kind of information.

Diameter SpecificationType ofstrand

Nominaldiameter

Nominalsteel area

Nominalmass

Breakingload

Specifiedcharact. 0,1%

proof load

Relaxation after 1000hours at 0.7 - 0.8

breaking load

StrandsNominaldiameter

SectionBreaking

loadYielding load

Working load withreference to Fs

Working load with reference to Fp



ANCHOR PROTECTION

7

Protection degree of a ground anchor is defined with reference to its design life and to theenvironmental aggressiveness.Protection in every part of the anchor is assured by:

- Free length:each individual strand is coated with soft corrosion protection compound (grease, wax,etc.) and contained in a polyethylene pipe (hdpe coating); in addition, an externalsheath covers the whole bundle of strands (temporary and permanent anchors).

- Bond length:cement grouting and plastic corrugated sheath (permanent anchors).

- Anchor head:it is the critical element of the system and it is the part more subject to corrosionpossibility and to transmission of stray currents; it requires a perfect sealing either inits external part or in that below the bearing plate zone.

External protection of the anchor head is assured by:

- a concrete sealing, in case it does not require any check or re-stressing in the time;- the installation of a metallic cap filled with anticorrosion soft compound.Protection below bearing plate is assured by:

an insulating system, composed of a cylindrical chamber sealed to the anchor headand of a sealing assuring tightness with the plastic sheath in the free length; afterstressing the system is filled with soft anticorrosion compound.

Schemes show the system proposed by TENSACCIAI, that can allow a further protectionto stray currents by means of the interposition, between bearing plate and anchor head, ofdielectric materials.

Cap

Anticorrosion compound

Anchor head

Bearing plate

Strand

Grouting pipe

Connection tube

Tightening joint

Hdpe coating

Cap

Anticorrosion compound

Anchoring system

Anchorplate

Strand

Grouting pipe

Connection tube

Tightening joint

Hdpe coating



A B C D E Fmm mm mm mm mm mm

2 TR 15 180 180 120 26 110 250

3 TR 15 187 200 120 30 115 250

4 TR 15 187 222 120 35 117 250

5 TR 15 208 240 135 35 122 250

6 TR 15 212 265 145 37 123 250

7 TR 15 232 290 170 39 127 300

8 TR 15 258 310 185 45 132 300

9 TR 15 284 320 220 45 135 300

10 TR 15 340 360 270 50 145 350Subject to modification Additional sizes available on request

Dimension E can be increased depending on the need to re-tension the ground anchor.

Anchorplate

ANCHOR HEADS “PT” SERIES

8

D F

A C B

E



A B C D E Fmm mm mm mm mm mm

4 MTR 15 105 53 160 x 160 250 115 50

7 MTR 15 125 55 190 x 190 250 135 60

9 MTR 15 146 58 210 x 210 300 155 60

12 MTR 15 160 63 230 x 230 300 170 60

15 MTR 15 176 63 260 x 260 350 185 60

19 MTR 15 200 80 290 x 290 350 195 60

22 MTR 15 230 86 310 x 310 400 225 70

27 MTR 15 250 93 335 x 335 400 240 70

Subject to modification Additional sizes available on request

Dimension F can be increased depending on the need to re-tension the ground anchor.Of course TENSACCIAI can manufacture tendons of high or very high capacity (tendons up to 182 strands have been manufactured!). For

tendons not foreseen in the above table and for special projects, please contact our Technical Department.

ANCHOR HEADS “MT” SERIES

9

Adjustablewith shims

Adjustablewith nut

Anchor head

Variable

F

D

C A

B

E



ANCHORS FOR TEMPORARY USE

10

This kind of anchor is mainly required for temporary use (construction of diaphragms, bulkheads, etc.) and for use in non-aggressive soils.According to the foreseen type of grouting, anchors can be supplied either with normal hdpe

pipes, or with pipes equipped with “manchette” valves for repeated grouting.

These temporary anchors are supplied with greased and unbonded strands in thefree length (“600” type - scheme below); with smoothed hdpe sheath to protect thefree length (“601” type - scheme in the following page) or with both protections. Onrequest they can be supplied with obturator bag (“603” type).Hdpe pipes are foreseen to grout every single part (bond length, free length andeventually obturator bag).

TENSACCIAI ANCHORS “600”“601”“603”TYPE

anchor head grouting pipe

anchorage

anchor head

unbonded strand

spacer

strap

end capwall

pad

cement grout

primary grouting pipe

cap

anticorrosion compound

f r e e l e n g t h

b o n d l e n g t h



This type of anchor is provided with a 27/34 mm. dia. pipe equipped in the bond length withmanchette valves (every 1 m. or, on request, at different distances) for repeated grouting.It can be supplied with obturator bag that, once grouted, closes the hole, sealing in that waythe bond length.Primary grouting can be then performed at high pressures with considerableguarantees of tightness.This system guarantees the possibility of performing groutings at high pressures at fixedintervals, according to the distance between the valves, along the whole bond length, andto repeat them in the time.

TENSACCIAI ANCHOR “604”TYPE


anchorage

anchor head

strandseal

rigid pipe

smooth sheath

spacer

strap

end cap


cement grout

pad

wallcap

anticorrosion compoundsecondary grouting pipe

f r e e l e n g t h

b o n d l e n g t h

anchorage

anchor head

strandseal

rigid pipe

smooth sheath

spacer

strap

end cap


cement grout

pad

manchette valve

wallcap


f r e e l e n g t h

b o n d l e n g t h




ANCHORS FOR PERMANENT USE

12

In case of permanent anchors, besides a sophisticated strands protection in the free length,it is necessary that, also in the bond length, tension elements are suitably protected.It's necessary to manufacture anchors having bond length protected by plastic, dielectric andwaterproof sheaths, having quite prominent corrugated shapes, so that they can receive andretransmit steel stresses to the cement grout and to the ground.Also in that case, according to the type of grouting requested, anchors can be provided withnormal hdpe pipes or with pipes equipped with “manchettes” valves for repeated grouting.

These anchors too, like the temporary ones, can be supplied with unbonded greased strandsand/or with smooth sheath in the free length;while the bond length is protected by a corrugatedhdpe sheath.Hdpe pipes are used for grouting, one for the external and one for the internal part of thebond length; a third pipe is used to grout the free length and a fourth pipe to grout theobturator bag, when requested. For venting of the bond length and of the eventual obturatorbag, pipes 10x14 mm dia. are used.

On request, anchor “602” type can be supplied with an additional external pipe 27x34 mmdia. equipped with “manchette” valves in the bond length to perform repeated groutings.



anchorage

anchor head

strandseal

rigid pipe

smooth sheath obturator bag

external spacer

corrugated sheath

spacer

strap

ogive

internal grouting pipe


cement grout

venting pipepad

obturator bag grouting pipe

pad

wallcap


secondary grouting pipe

f r e e l e n g t h

b o n d l e n g t h




13

Like “602” and “605” type this is a permanent anchor and, like “605” one, allows repeatedgroutings.The “608” anchor type is the result of the study of a mechanism allowing repeated groutingswithout the need of the use of the packer.This choice does not offer the possibility to grout valves one by one, but it allows repeatedgroutings in sequence, by means of a special pipe, equipped with valves in the bond length,able to absorb high pressures.Grouting pipe is “U” shaped, therefore it can be easily washed and made it available for

further groutings.Even if it does not allow the typical “bond wave shape” of the classic grouting pipe equippedwith “manchettes” valves, this system allows a programmed and spread grouting, and canbe the right “compromise” in uncertain geotechnical situations.


anchorage

anchor head

unbonded strand

seal

rigid pipe

smooth sheath

corrugated sheath

spacer

strap

ogive

internal grouting pipe


external spacer

manchette valve

regrouting pipe

cement grout

wallcap


f r e e l e n g t h

b o n d l e n g t h



TENSACCIAI ANCHOR "605” APS TYPE

14

During the last few years, the demand for anchors in sophisticated applications has greatlyincreased, particularly for permanent or long lasting anchors.These anchors are now subject to more severe standards and designers must be sure that

the execution is accurate, above all with regard to the durability and the sealing conditionsof the structure.Therefore, to meet customer's needs, our company has researched new materials andsystems for grouting operations, and has developed the anchor named 'APS' TENSACCIAI.The main characteristics of the 'APS' TENSACCIAI anchor are:- full protection of prestressing steel in every part of the anchor. This protection is

guaranteed by means of hdpe sheaths in smooth and corrugated form, respectivelyfor the free and the bond length, able to undergo and transmit the steel shearingstresses to the concrete and to the ground.

- the possibility to repeat grouting in the cable bond zone, both inside and outside thecorrugated sheath.

This possibility is guaranteed by means of normal "manchette" valves, of traditionaltype, for grouting inside the sheath, and by means of special valves, the “APS” valves,for grouting outside the sheath in the bond.

- further protection of strand in the free length. In fact each strand can be individuallyprotected (hdpe coated and greased) with small hdpe tubes, which wrap it tightlywithout preventing sliding, making corrosion resistance particularly effective in thezone where tensions are high and where, therefore, the vulnerability of the steel tobe attacked is maximum.


anchorage

anchor head

strandseal

rigid pipe

obturator bag

corrugated sheath

external spacer

ogive


cement grout

APS valve

venting pipe

padpad

manchette valve

smooth sheathwall

cap


f r e e l e n g t h

b o n d l e n g t h



MODALITIES FOR THE EXECUTION OF THE TENSACCIAI "APS" ANCHOR

Grouting modalities of TENSACCIAI “APS” anchor are the following:

Stage A) The anchor is delivered to the job site completely protected by means of plasticsheaths in each part and is inserted in the hole.

Stage B) If foreseen, the obturator bag is grouted by means of a manchette valve.Stage C) The bond length is grouted inside the corrugated sheath, using the correspondent

"manchette" valves. Grouting is done at low pressure by means of a 27x34 mm.dia. pipe equipped at its end with a flexible packer (device with double obturatorbag). Grouting is stopped when the cement grout flows back constantly fromthe vent tube placed at the level of the pad.

Stage D) Grouting pipe with packer is moved up to the level of the special 'APS' valvesand the bond length is grouted in the external part of the sheath. Grouting ismade at high pressure to allow a safe bond anchorage (internal sheath of the

bond length already grouted) to the ground.Stage E) Grouting is repeated through the 'APS' valves to check that the bond zone iscompletely filled.

Stage F) After curing, stressing is done.Stage G) The anchor free length is grouted by means of the correspondent "manchette"

valve.

In this way, an anchor has been made where further groutings are still possible through theAPS valves which are still available.The anchor is protected in every part and is not thereforesubject either to corrosion or stray currents (the sheath is made of dielectric material, thevalves and the ogive are made of plastic). Repeated grouting, both outside and inside thecorrugated sheath, is the best guarantee for a perfect bond making, and for the complete

filling of all the bond areas, including the corrugated gaps of the sheath, which must guaranteethe transmission of the shearing forces.The possibility to repeat grouting in the bond length, even after stressing, is a further guaranteeof being able to close eventual slits which may have occurred in the mortar, owing to thestressing forces.It has been therefore made an anchor which can give the utmost guarantees of durabilityand reliability and which, at the same time, is easy to use, as it does not weigh more thana traditional anchor, and its execution is not particularly complicated because it utilisesproven methods (such as repeated groutings and corrugated sheaths), combining them insuch a way to make their use safer and easier.

15



Temporary anchors for retaining wall - New Building for Research and Development - Pirelli spa, Milan (Italy)Contractor: Else spa, Milan (Italy) - Client: M.C.S. (Milan Central Services), Milan (Italy)

➊1 ➋2

➌3 ➍4

➎5 ➏6

1 Pluri-anchored piling with approached anchorsfor a Trade Centre in San MarinoContractor: San Marino Strade sa, San MarinoClient: Valpharma sa, San Marino

2 Rijeka World Trade Centre (Croatia)

Contractor: Geokarst Engineering srl, Trieste (Italy)Main Contractor: World Trade Centre, Rijeka (Croatia)

Client: Geotehnika d.d., Zagreb (Croatia)

3 P.c. pilings and anchorsParking “Urbaniana University” - Gianicolo, Rome (Italy)Contractor: S.G.F. spa, Rome (Italy)

Main Contractor: Impregilo spa, Milan (Italy)Client: Università Urbaniana, Rome (Italy)

4 Anchors on pit retaining pilings

Dante Square Station of Naples Underground, (Italy)Contractor CE.S.I.F. spa, Naples (Italy)Client:Metropolitana di Napoli spa, Naples (Italy)

5 Aosta-Monte Bianco Highway - lot. 3

Contractor: Viadotti di Courmayeur scrl, Rome (Italy)Client: RAV spa (Valle d'AostaHighway Connection), Genoa (Italy)

6 Admiral Point Centre

San Marino Customs House

Contractor: GE.O.S. sa, San MarinoClient: Admiral Point Centre sa, San Marino



Consolidation works in the western slope of Castelli - Teramo (Italy)Contractor: GEO sas, L'Aquila (Italy) - Main Contractor: Consortium Castelli scrl, L'Aquila - Client: Municipality of Castelli - Teramo (Italy)

1 Modern and contemporary Art Museum

in Rovereto - Trento (Italy)Contractor: Lamaro Appalti spa, Rome (Italy)Main Contractor: Municipality of Rovereto, Trento (Italy)

Client: Province of Trento, (Italy)

2 Zambana dihedral consolidation works, Trento (Italy)Contractor: Trevi spa, Cesena (FC), (Italy)Client: Autonomous Province of Trento (Italy)

3 Setting of squares and infrastructuresof Gioia Tauro Port, Reggio Calabria (Italy)Contractor: Teknosonda srl, Lamezia Terme - Catanzaro (Italy)

Main Contractor: Todini Costruzioni Generali spa, Rome (Italy)Client: A.S.I. (Consortium for the Area of Industrial Developmentof Reggio Calabria, (Italy)

4 Toschi Avenue Parking, Parma (Italy)

Contractor: Ing. Giovanni Rodio & C. spa,Casalmaiocco - Lodi (Italy)Main Contractor: Toschi scarl, Parma (Italy)Client: Gespar spa, Parma (Italy)

17

➊1 ➋2

➌3 ➍4



STRESSING JACKS “PT” SERIES

18

TENSACCIAI manufactures 4 types of "PT" ser ies jacks (plurijacks) which differ intensioning section, weight and dimensions. All are equipped with automatic lock-off.

m.u. PT 150 KN PT 200 KN PT 250 KN PT 300 KN

Capacity kN 150 200 250 300

Stroke mm 100 200 200 200

Weight Kg. 16 23 23 28

Tensioning section cm2 32.80 47.20 47.20 58.32

Max. tensioning pressure bar 550 450 550 550

Max. return pressure bar 180 180 180 180

Max. locking pressure bar 165 165 165 165

Connection -- 2 tubes 2 tubes 2 tubes 2 tubes

A mm 85 100 97 110

B mm 600 1000 930 870

C mm 60 85 77 88


Ø A

Ø C

B



STRESSING JACKS “MT” SERIES

19

TENSACCIAI manufactures 8 types of “MT” series jacks (monogroup), with capacity ranging from 1000 to9000 kN. “MT” jacks have been designed and built by TENSACCIAI considering different stressing needs:minimum strand waste (300 mm.to 500 mm.), jack built-in hydraulic circuit, automatic lock-off, easy removal

and control of the wedges, jack rotation around its own axis, making it easier to place and wedge onto thetendon. The high quality of parts and materials allows this jack to be used even under the most severeoperating conditions.TENSACCIAI “MT” jacks can also be supplied in the TAC version.

Ø D

Ø C

B

A

Ø E

m.u. MT 1000 KN MT 1500 KN MT 2500 KN MT 3000 KN MT 3500 KN MT 4500 KN MT 6000 KN MT 9000 KN

Capacity kN 1000 1500 2500 3000 3500 4500 6000 9000

Stroke mm 250 250 250 250 250 250 300 250

Weight Kg. 100 180 290 350 420 600 1000 1250

Tensioning section cm2 155.51 302.18 361 400.55 492.44 725.71 879.6 1625

Max. tensioning pressure bar 600 500 700 700 700 700 700 700

Max. return pressure bar 180 180 180 180 180 180 180 180

Max. locking pressure bar 165 165 165 165 165 165 165 165

Tensioning overlength with lock-off cm. 35 37 37 38 38 45 51 52

A mm 950 930 951 984 970 1107 1237 1016

B mm 155 130 150 154 148 200 207 195

C mm 137 152 173 195 214 243.5 295.5 322

D mm 162 185 213 236 252 310 380 407

E mm 248 310 339 370 415 512.5 615 714




m.u. X90ES X90E X16ES X6E X6EX X6EY X4E X4EX X4EY

Weight Kg. 450 450 450 170 170 150 100 90 90

Power KW 10 7.5 10 5 4 4 4 4 4

Max. pressure bar 700 700 550 500 450 430 500 430 420

System MT MT PT PT PT PT PT PT PT

Oil quantity lt. 100 90 80 60 60 60 50 40 40

Connection 3 tubes 3 tubes 2 tubes 2 tubes 2 tubes 2 tubes 2 tubes 2 tubes 2 tubes

A mm 1000 1000 1000 800 800 800 760 760 760

B mm 1300 1300 1300 800 800 800 500 500 500

C mm 800 800 800 600 600 600 400 400 400

HYDRAULIC PUMPS

20

TENSACCIAI manufactures 4 types of hydraulic pumps which differ in performances anddimensions.All are equipped with hydraulic circuit for automatic lock-off.Each series has different types

in order to meet any technical requirement of the job site.


X 90 ES

X 6 E X 4 E



CYCLIC STRESSING:TENSACCIAI TAC SYSTEM

21

Cyclic stressing is the most correct system for the execution of ground or rock anchors.Thepurpose of cyclic stressing is to study during a certain time the behaviour of the bond lengthwith regard to the ground, and to test the anchor before it is considered suitable for the function

it has been designed for.By cyclic stressing the right tension applied to the anchor is determined, as the system studiedby TENSACCIAI enables to calculate separately the values of plastic (permanent) and ofelastic strains (see diagram).TENSACCIAI TAC system has been studied to perform cyclic stressing with maximum speed,safety and automaticity. It consists of the use of a hydraulic device which allows the insertionof the wedges in the jack in such a way that it does not prevent the release of stresses, asforeseen in this particular kind of stressing.

N

Nc

Ni

∆N’

No

δk δeδ

β2

β1

δt =

Nc lt

Es As

Nc = testing forceNo = alignment forceAs = actual cross section of prestressing steelNi = ground anchor prestressing forceδt = theoretical elastic elongationδk = permanent ground anchor elongationδe = ground anchor elastic modulus

Es = steel elastic modulus∆N’ = force increaselt = theoretical free length

Testing cyclic diagram at constant force



EQUIPMENT

TECS SYSTEM (TENSIONING ELECTRONIC CONTROL SYSTEM)The control board can be connected to the electronic equipment, called TECSsystem (Tensioning Electronic Control System), which performs an instantaneousdigital reading of both pressure and elongation, during each stressing phase.The elongation is measured simultaneously, for all jacks operating on thepump, with a precision of one tenth of a mm.(0.1 mm).This system allows to obtain the average of the values and, connecting theTECS system to a plotter, to print an automatic report of tensioning andelongation data in real time.

DYNAMOMETERIt is the instrument that allows to verify the calibration of tensioning system'spressures. It is made of an aluminium box housing a digital instrumentthat performs precise pressure readings (1 bar). It is available in the 'D'version, combined with an hydraulic transducer, as a calibration dynamometerfor the 'PT' jacks. It is also available in the 'C' version, as a sample pressuregauge to be combined with an 'MT' jack to calibrate the pump-jack system.TENSACCIAI dynamometers are supplied with calibration certificateissued by an Official Laboratory.

LOAD CELLTENSACCIAI offers a wide range of thoroidal load cells duly studied forits own anchorages with capacity ranging from 200 up to 4500 kN. Theequipment is composed of a digital reader with connection wire and of athoroidal cell equipped with fitted spacers plates.The cells have following characteristics:precision class equal to 1%, max.load charge without any calibration alteration equal to 130% of the declaredcapacity, connector and wire IP55.The portable digital reader has a reading resolution of 50 kN and a LEDdisplay. It is equipped with feeding battery, battery recharger and an IP55connection wire with different lengths.



1-2 Ground anchors on a retaining wall, Monaco (France)Contractor: Lenta (France) sarl, Menton (France)Client: Nicoletti sa, Carros Cedex (France)

3 Atlante Trade Centre, San MarinoContractor: GE.O.S. sa, San MarinoClient: Consortium Atlante srl, San Marino

4 Hotel-Casino “Belle Bay Plaza”, Manila (The Philippines)Contractor: Trevi spa, Cesena (FC), (Italy)

Client: Belle Bay City Corporation (The Philippines)

5 Singkarak Hydroelectric Power Station, IndonesiaContractor: Dumez International sa, Nanterre (France)Client: Joint Operation Dumez International/ Impregilo spa/PT Istaka Karya

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NORMS

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The norms in force to which TENSACCIAI refers in organising its anchors production are thefollowing:

- EN 1537:2002 “Execution of special geotechnical works - Ground anchors” - June 2002- AICAP Recommendations: “Ancoraggi nei terreni e nelle rocce” (Italy, 1993)- PTI Recommendations for prestressed Rock and Soil Anchors (USA, 1996)- British Standard Code of Practice for Ground Anchorages - BS 8081:1989 (Great Britain, 1989)- Recommandations Eyrolles Tirants d' Ancrage T.A. 95 (France, 1995)- SIA 267:2003 Géotechnique (Switzerland, 2003).

Zambana dihedral consolidation works,Trento (Italy)Contractor:Trevi spa, Cesena (FC), (Italy)

Client: Autonomous Province of Trento (Italy)

ersilia New Hospital, Viareggio - Lucca (Italy)ontractor: Fondamenta srl, Milanient: Consortium Impregilo spa - CMB srl, (Italy)

Consolidation works in the town of Canzano - Teramo (Italy)Contractor: GEO sas, L'Aquila (Italy) - Main Contractor : Co. Petrilli, L'AquilaClient: Municipality of Canzano - Teramo (Italy)



Design: Arch. Paola Bobba - Arch. Elena Astolfoni - MilanStampa: Grafiche Saita - Milan (Italy) - 2004



Documents

TENSACCIAI - Rock and soil anchors