DSI-Repair_and_StrengtheningSystems_for_Repair_and_Strengthening_en_02.pdf

7/27/2019 DSI-Repair_and_StrengtheningSystems_for_Repair_and_Strengthening_en_02.pdf

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Systems and Conceptsfor Repair and Strengthening

DYWIDAG-SYSTEMS INTERNATIONAL



SI can assist you at any or all stages of a repair/

rengthening project:

nspection and condition evaluation of structurespreparation/review of the repair/strengthening schemedesign and dimensioning of the strengthening work supply and installation of high quality DYWIDAG productsexecution of the strengthening workssite supervision with quality assurancemonitoring and inspection controls.

ystems and Conceptsor Repair and Streng-hening of Bridges andther Structures

oncrete is a durable and relati-

ly maintenance-free construc-n material. Nevertheless,

pair and/or strengthening of

isting structures may become

ecessary due to

natural aging, inadequate

design, poor quality of ma-

erials, faulty construction

practices

severe environmental and

accidental influences (e.g.

overloads, vehicular impacts,

strong earthquakes, hurri-

canes, fire)changes in use (e.g. load

enhancement beyond the

original design values)

ncreased safety require-

ments.



page 5

page 5

pages 6-7, 11-13

pages 7-9

page 9

page 10

pages 11, 12

page 12

page 13

page 14

page 15

DSI and DYWIDAG have more than thirty years of experience in the fieldof repair and strengthening works.

Alongside traditional methods and systems, special repair and streng-thening techniques have been developed and applied with success.

For your repair or strengthening project you can use the following wellproven DYWIDAG systems:

vacuum grouting

cathodic protection

short bar tendons, strandtendons

external bar and strandtendons, ground anchors

bar tendons, GEWI ® bars

GEWI ® bars, bar tendons,stay cables

bar and strand tendons

bar tendons, GEWI ® piles

rock anchors

ground anchors, GEWI ® piles

lifting system usingprestressing bars

restoring corrosion protec-tion of prestressing steel

restoring corrosion protectionof ordinary reinforcement

improving interaction betweenold and new concrete

strengthening of bridges

strengthening of historicbuildings

modification/expansion ofexisting structures

seismic retrofitting of bridges

seismic retrofitting ofbuildings

stabilizing of dams

seismic retrofitting offoundations

lifting/moving of structures



Autopista del Sol, Cable Stayed Bridges, MexicoFour cable stayed bridges between Cuernavaca and Acapulco

were inspected. First a detailed inspection program with a

numerical and qualitative rating system was developed.

A detailed report on the quality and state of the main parts of each bridge, especially superstructures, pylons and stay cables as

well as recommendations on remedial measures were proposed

to the owner.

nspection and conditionvaluation of structures

he efficiency of any repair or

rengthening scheme depends

ry much on an accurate

sessment of the actual state

the structure. Testing and ins-ection methodology should be

ased on an incremental stra-

gy: the type and extent of fur-

er testing are decided as defi-

encies are uncovered.

though non-destructive testing

ethods are usually preferred,

ey should be complemented

y destructive methods as nee-

ed to obtain a clear understan-

ng of the nature, causes and

tent of the defects.

Point Beach Nuclear PowerPlant, Two Rivers,Wisconsin, USAInspection of the post-tension-

ing tendons of two containment

structures was carried out

according to the safety specifi-

cations of the US Nuclear

Regulatory C ommission. Bothvisual and physical inspection

(lift-off, detensioning and tensile

tests) were carried out on selec-

ted tendons from all tendon

groups (hoop, vertical and dome

tendons).

+ + + + DSI Services + + + +Elaboration of inspection

program and evaluationsystem, inspection, detailedreport on quality and stateof the relevant parts

4

+ + + DSI Services + + + +spection, testing, detailedeport



Restoration oCorrosion Protectio

O ne of the most important task

of civil engineers to ensure the

durability of structures is the co

rosion protection of steel ele-

ments.DSI offers efficient and advance

methods for restoring corrosion

protection of both, prestressing

and reinforcing steel.

+ + + + DSI Services + + + consultancy during assess-ment of the actual stateof the piers, elaboration of repair programme, dimen-sioning of the CP system,

supply and installation of the CP system.

cathodic protection

Restoring corrosion protec-tion of reinforcing steel

Besides the traditional corrosion

protection methods in which thecarbonised or the chloride-con-

taminated concrete is mechani-

cally removed and replaced with

new alkaline concrete, DSI has

employed a highly reliable elec-

trochemical corrosion protec-

tion method:

cathodic protection (CP ).

A low intensity direct current

(5-20 mA/m2) is continuously

applied between the reinforce-

ment (the cathode) and a dur-

able anode (made for example

of titanium) which is embedded

into a cementitious overlay onthe old concrete surface. The

efficiency of the CP measure is

controlled through potential

measurements on the embed-

ded reference cells. This protec-

tion measure is more econo-

mical than traditional methods,

as only the mechanically dama-

ged concrete must be removed

whereas the chloride contami-

nated concrete may be left

undisturbed.

Bridges on the Brenner Highway, Austria

M any ducts in prestressed bridges of the Brenner Highwaywere checked for quality of grouting. T he detected voids

were vacuum grouted.

vacuum grouting

Restoring corrosion protec-tion of prestressing steel

Where ducts are not complete-

ly filled with cement grout, sub-

sequent grouting must be car-

ried out. T his can be accom-

plished by vacuum grouting.The advantage of this procedu-

re is that regrouting of the duct

requires only one drilled hole

for each void.

Special devices and tech-

niques have been developed

by DSI for careful drilling of

ducts to avoid damaging the

prestressing steel. T he volume

of the void is measured by

creating a vacuum, which also

sucks the grout into the void.

A comparison between the

measured volume of void andthe amount of grout consumed

provides a control measure on

the success of the operation.

Outer Noesslach Bridge, Brenner Highway, AustriaThe concrete of the 50m high piers at the buttresses of the 180 m

long arches was highly chloride contaminated up to a depth of

60mm due to twenty years of exposure to de-icing salts. C P was

applied to 1,500m2 of the concrete surface, as only this measure

did not jeopardize the load-bearing capacity and stability of thebridge. Efficiency and performance of the CP system can be mo-

nitored at any time through potential measurements.

5



In 1994 cracks were discovered

in the concrete corbelled pier

caps of the M uza line steel gir-

der viaduct. The emergency

repair scheme consisted

of placing external ø 36 mm

DY WIDA G bar tendons

(THREADBAR ® ) on both sides

of the pier cap. T hese were

anchored in steel grillages ateach end of the caps and

were supplied with DYWIDAG

double corrosion protection

system. All exposed steel parts

of the grillages were protected

by a three coat paint system.

O n selected tendons permanent

load cells were installed to mo-

nitor the prestressing forces.

MRT rapid transportationnetwork, Muza Line, Taipei,Taiwan

+ + + + DSI Services + + + +preparation of the rehabili-tation scheme, supply of steel grillages and DYWIDAGbar tendons, execution of the strengthening works.

ne of the main problemsncountered in strengthening

how to achieve compatibility

nd interaction between the

xisting structure and the

rengthening elements.

he force transfer across the

int between old and new

oncrete can be accomplished

different ways:

simple friction between sur-

faces of the existing concrete

and the prefabricated concretemember (dry joint)

simple bond between the

existing concrete surface and

the concrete of the new part

cast on site (wet joint)

the efficiency of both joints

can be considerably im-

proved through increasing

the force normal to the joint.

nteraction between the original and the newoncrete parts

This may be easily achievedby post-tensioning. For this

purpose DY WIDAG tendons

can be employed. In the case

of very short tendons, the

fine thread at the end of the

smooth bar results in an

anchorage with an extremely

small slip. In the case of short

tendons, where bond is re-

quired, bar tendons using

DYWIDAG bars (THREADBAR ® )

may be used. For longer and

curved tendons, strands offer

a solution.

trengthening of tructural Members

rengthening of structural

embers can be achieved by

replacing defective, or poor

quality material

attaching additional load-

bearing material (for example:

reinforcement, high quality

concrete, thin metallic or non-

metallic straps, post-tensioning

endons, or various combina-

ions of these methods)

redistributing action effects

hrough imposed deformation

of the structural system.



O pened in 1878, this landmark in the northern Portuguese costa

town of Viana do Castelo was designed and built by A.G . E iffel.

Strengthening of this ten span, 562 m long steel bridge with two

main truss beams of 7,5 m depth became necessary to adapt

the load-bearing capacity to modern road and railroad traffic.

However, the characteristic architecture should not be impaired

through the construction measures. The consultant decided to

install tension ties in every span. T hese run parallel to the bottom

chords and are lifted up diagonally to the top chords above the

piers. T he forces are introduced into the structure with ø 32mm

DYWID AG smooth bars. D eflection points and coupling splices

of the bars were installed very simply and economically.

Rio Lima Bridge, Viana do Castelo, Portugal

+ + + + DSI Services + + + study of the causes of thedefects, preparation of therehabilitation scheme, dimensioning of the strengtheninsystem, supply and installation of the system, final con-trol, acceptance test.

+ + + + DSI Services + + + +supply of DYWIDAG bars,accessories and corrosionprotection.

Won Hyo Bridge, Seoul,South Korea

The 1,120m long bridge over

the Han R iver was completed in

1981. Because of inaccurate

calculations of prestressing los-

ses and deflections caused by

creep and shrinkage of concrete,

additional deflections of up to

30cm occured. These resultedin 5cm to 20cm sagging at the

hinges. T he DSI rehabilitation

concept called for external ten-

dons, which on the one hand

slightly reduced deflections and

on the other strengthened the

structure. The remaining sag

could be eliminated by an addi-

tional asphalt layer. Twelve

19 x 0.6" DY WIDAG tendons

were applied in each cantilever

and anchored in new concrete

buttresses cast inside the box

girders. These were connectedto the concrete of the existing

webs of the box girder through

friction created by the means of

short ø 36mm DYWIDAG

smooth bar tendons.

external bar and strandtendons

Strengthening of bridges

Bridges of any material can be

strengthened by adding external

post-tensioning tendons.

The influence of post-tensioning

on serviceability and ultimatelimit states can be varied within

wide limits by selecting different

methods of introducing prestres-

sing forces and using various

tendon profiles.



urlington Skyway, Ontario, Canada

his 2,560 m long steel bridge built in the mid 50’s was repaired and

rengthened in order to increase the number of lanes from four to

e and to support the heavier design loads of the current codes.

he three main spans (84-151-84m) consist of a continuous truss

ch structure where the two longitudinal main trusses are connec-d by bracing bents and transverse floor trusses. These trusses

upport longitudinal deck stringers which in turn support a reinfor-

ed concrete deck. The transverse floor trusses consist of standard

ructural steel shapes riveted and bolted together. The increased

ading resulted in significant overstressing of the transverse floor

uss members. T hese trusses were strengthened by external post-

nsioning using ø 36 mm DY WIDAG bars (THREAD BA R® ) and

limited addition of new structural steel. T his method allowed a

nimal number of members to be dismantled and eliminated the

eed for strict dimensional tolerances that would be required with

e addition or replacement of truss members. The selected dra-

ed tendons were anchored in the deck slab to maximize their

fectiveness. A unique steel plate assembly was bolted to the

uss joint at the deviation point of the tendon to anchor the barsnd transfer the tendon force to the truss. The bars were protected

y a three coat zinc/vinyl paint system.

Due to deterioration the entire

superstructure of this steel-

timber composite bridge was

to be rehabilitated. The 3 single

spans of 7-18-7m consist of

standard wide flange steel

beams at 1.2m spacing.The existing transverse nail-lami-

nated timber deck was replaced

with a longitudinally laminated,

transversely prestressed timber

deck. The bridge was repaired

in two stages to maintain one

traffic lane at all times.

Transversely prestressed tim-

ber decks are stiffer and more

durable than nail-laminated

timber decks. P restressing in-

hibits relative movements be-

tween the timber laminates

and greatly improves wheelload distribution.

Cripple Creek Bridge, Highway 101, Ontario, Canada

+ + + + DSI Services + + + +supply of DYWIDAG bars(THREADBAR®), specialanchorages and tensioningequipment, installation andstressing of the post-tensio-ning system.

+ + + DSI Services + + + +upply of DYWIDAG barsTHREADBAR®) and tensio-ng equipment.

The transverse prestressing

system consists of galvanized

ø 26mm DYWIDAG bars

(THREADBAR ® ) placed at

300mm spacing. Tensioning

was repeated 1 week and 5

weeks after the initial stressingoperation, to compensate for

the large creep losses in the

timber deck system. DYWIDAG

bars (THR EADBAR ® ) easily

allow the repeated retensioning

both at the time of construc-

tion, and in the future if neces-

sary. Connecting of the tendons

between the 1st and 2nd stage

construction was accomplished

by using standard couplers.



Restoration oCorrosion Protectio

O ne of the most important task

of civil engineers to ensure the

durability of structures is the co

rosion protection of steel ele-

ments.DSI offers efficient and advance

methods for restoring corrosion

protection of both prestressing

and reinforcing steel.

1

Gänstor Bridge, Ulm,Germany

The frame legs of this two-

hinged bridge were formed by

vertical columns and inclined

prestressed ties. After 30 years

of service, cracks in the super-

structure occurred. Surveying

revealed some ungrouted ductswith corrosion of prestressing

steel. Besides repair measures

(vacuum grouting, injection of

cracks, restoration of concrete

surface and water proofing)

three strengthening options

were considered:

- strengthening by means of

external tension ties in the

form of permanent ground

anchors

- strengthening with additionalreinforced concrete and pre-

stressed concrete elements

- strengthening of the super-

structure applying external

tendons.

After analysis of costs and effi-

ciency of each variant and theiraesthetic aspects, the variant

with permanent ground

anchors was chosen.

The San Lorenzo C athedral

was built between the 14th

and 15th centuries. A lready in

1633-1641 important consoli-dation works had been carried

out, since, because of the

weight of the roof, the columns

and the walls had diverged.

Seismic movements in 1983

caused further damage, thus

endangering the stability of the

monument. A new consolidation

and restoration project was

decided after a thorough histo-

rical survey of the original and

subsequent static behavior

of the structure. The twenty-

three timber roof trusses werereinforced by strengthening

the joints with steel plates and

bolts and by prestressing both

San Lorenzo Cathedral, Perugia, Italy

the lower tie beam and the

central king post with two twin

ø 36mm DYWIDAG bars

(THREADBAR®

) each. Thecolumn capitals showed dis-

placements of up to 26cm.

A new system of transverse

and longitudinal ties made of

DY WIDAG bars (THR EADBAR ® )

was introduced into the columns

and walls to prevent any side

displacements. T he transverse

tie members were prestressed

and tied back to the lateral

walls in order to apply to the

whole structure a system of

acting forces capable of counter-

acting the thrusts of the vaults.

DYWIDAG

BAR GROUND

ANCHOR

+ + + + DSI Services + + +

survey of damages, deter-mination of the actual loadbearing behavior, prepara-tion of the repair/streng-thening program, cost analysis, supply of ø 26mmDYWIDAG ground anchorsrealization of the repair/strengthening measures,control at commissioning.

+ + + + DSI Services + + + supply of DYWIDAG bars(THREADBAR®), rental

of equipment, technicalassistance.

bar tendons

Strengthening of historic

buildings

Degradation of ancient building

materials, prolonged exposure

to environmental influences and

uneven settlements make

strengthening of historic buil-

dings unavoidable.

Furthermore, it must be con-

sidered that many historic buil-

dings were built to a much

lower degree of safety com-

pared to similar modern struc-

tures. Strengthening measures

must be integrated into thebuilding without altering its

character and appearance.

ground anchors

Strengthening of bridges

C olumns, piers and tension ties

can be strengthened using

ground anchors.

In this case the ground anchors

act as external tendons to sup-

ply additional uplift capacity orto increase the tie force between

different parts of the structure.



antiago Bernabéu Soccer Stadium, Madrid, Spain

increase the number of seats, the roof structure had to be raised.

he existing reinforced concrete columns were strengthened and

tended. They were lengthened by 12.5 m high steel columns

th steel trusses cantilevering to 32m and anchored by ø 40 mm

EWI® bars. Six GEWI® bars were anchored in each foundation,

ur on the tension side of the columns and two in the front. T hisrangement carries the uplift forces from wind loads on the roof

hich was placed on top of the extended columns.

GrandhotelTaschenbergpalaisKempinski, Dresden,Germany

Built between 1707 and 1711,

and completely destroyed byfire in 1945, this baroque palace

is now the site of a luxury hotel.

During construction of a 4-sto-

rey underground garage, the

existing south façade, with a

total weight of approx. 1,000t,

had to be supported 18m

above the foundation level.

GEWI® bars with various dia-

meters were used as tension-

ing and securing members.

For the deep foundation of

the western wing of the palace,

GEWI

®

piles were drilledthrough the old cellar. The

bond length of the piles is

between 7 and 12m.

16th Street Bridge overI-465, Indianapolis, USA

Two new merging lanes were to

be added to the highway under

the existing bridge. Since the

bridge was only ten years old

and in excellent condition, it was

decided to modify the structure

by removing the end pier next to

the south-bound lanes and re-place it with a cable stayed sup-

port system.

For this complex modification

project, a number of DY WIDAG

systems were used. The new

2m wide transfer girder was

prestressed with ø 32 mm

DY WIDAG bar tendons

(THREADBAR ® ).

Vertical prestressing of the

deadman pier shafts was exe-

cuted with ø 36mm DYWIDAG

bar tendons (THR EADB AR ® )

placed within a void to allow for

longitudinal movements.

To anchor the footings of the

deadman piers against uplift for-ces of the stay cables ø 36 mm

DC P DY WIDAG ground anchors

were used. The stay cables

consisted of eight ø 36 mm

DY WIDAG bars (THR EADBA R ® )

inside individual steel pipes,

which were cement grouted

after stressing.

DYWIDAG DYWIDAG

B AR G ROU ND ANCHORS

DYWIDAG

BAR STAY CA BLES

+ + + + DSI Services + + + +supply and installation ofGEWI® bars.

+ + + + DSI Services + + + +conceptual design, proposalfor construction methods

and sequence, supply ofbar tendons and bar staycables, field supervision.

GEWI ® bars, bar tendons,ar stay cables

Modification / expansion ofxisting structures

ew demands on the use of

tructures, such as new lanes

n the top or under a bridge or

dditional seats in a stadium,may require modification of the

tructural system or an exten-

on of its size.

EWI® bars and DYWIDAG bar

endons with their excellent

ond and fatigue strength

roperties are often used for

hese works.

+ + + + DSI Services + + + +supply of GEWI® bars andpiles.


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Los Angeles County, Inter-section Freeway 10,57,210,California, USA

This very large superelevated

freeway intersection required

increased bearing capacity of

the substructure to satisfy trans-

versal flexural seismic demands.

New post-tensioned transversal

pier cap beams were added on

each side and extended beyondthe ends of the existing struc-

ture. Sixteen 15x 0.6" tendons

with DYWIDAG multiplane an-

chorages (M A) were installed.

The upper tendons were con-

ducted in pairs through holes

drilled into the webs of the exis-

ting bridge girders. Large for-

ces and confined space at

some of the pier cap beams

resulted in the first time use of

DY WIDAG 37x 0.62" strand

tendons in California.

+ + + + DSI Services + + + +

supply of DYWIDAG bars(THREADBAR®), hardwareand stressing equipment.

+ + + + DSI Services + + + supply, installation, stressinand grouting of DYWIDAGmultistrand tendons.

bar tendons, strand tendons

Retrofitting of bridges

An essential seismic upgrading

measure of bridges is to avoid

the loss of support for the bea-

rings due to large relative displa-

cements between the super-

structure and the substructure.These measures should not

impede the free movement of

the structure due to temperature

variation or other effects. O ften

the existing pier cap beams

must be widened and strength-

ened and the superstructure

must be restrained to the sup-

port. Each of the following retro-

fittings made use of post-ten-

sioning tendons to increase the

stability of the structure.

Elisian Viaduct, Los Angeles, California, USA

This bridge featured an old design concept of steel girders sup-

ported by concrete pier cap beams. The new retrofit design

specified extensive use of bar tendons throughout the entire struc-

ture. The cap beam width was increased by adding new con-

crete on both sides. Transverse ø 32mm D YWIDAG bars

(THREADBAR ® ) connected new concrete to old. Steel girder

stability was increased by adding special spreader beams bolted

to the existing webs at several locations. Spreader beams pla-

ced in pairs were connected with an external restraint made

of ø 32mm bars (THREADBAR ® ).

Altamount Sidehill Viaduct,Northern California, USA

Thirteen pier cap beams of this

440m long bridge were retro-

fitted with twin-tierod groups

connecting each side of the

steel cap beam end to a new

anchoring block. T ie rods, con-

sisting of ø 36mm DYWIDAG

bars (THREADBAR ® ) placed

inside of galvanized steel pipes,

run inclined from the anchoring

block to a special steel „shoe“

bracket fixed end. After a small

post-tensioning force was

applied at the anchorages, thetie rods were cement grouted.

+ + + + DSI Services + + + +supply of DYWIDAG bars(THREADBAR®) and hard-ware.

Seismic Upgradin

Structures have to withstand

large horizontal and vertical ac-

celerations and dynamic forces

during earthquakes. T his cre-

ates special requirements on th

stiffness and load-bearing capacity of the structural members

well as on their connections.

M any existing structures must

be improved to survive future

earthquakes. In C alifornia,

following the Loma Prieta (198

and N orthridge (1994) earthqua

kes, approximately 1.300 con-

crete and steel structures nee-

ded seismic upgrading.

Cahuenga Boulevard Underpass, Los Angeles County,California

A new column was installed at the end of the pier cap beam to

support an additional 3.6 m long concrete bolster, which increasedflexural capacity. Post-tensioned strand tendons placed in parallel,

on each side of the pier cap beam, connected new concrete to the

existing box girders. A large steel bracket, attached to the bridge

web at the tendon fixed end, allowed for uniform distribution of pre

stressing forces to the entire structure.

+ + + + DSI Services + + + supply, installation, stres-sing and grouting ofDYWIDAG multistrandtendons.



Oakland City Hall, Oakland, California, USA

This historic landmark in the San Francisco Bay Area was built in

1914. Since the Loma P rieta (1989) earthquake, the steel frame

building with masonry infill has been completely rehabilitated. D ue

to the limited strength of the existing structure, the seismic isolation

concept was applied. At that time it was the tallest seismically isola-

ted building of the world.

Special base isolators were placed under each building column.The foundation thickness above the seismic isolators was increased

by adding new concrete around the perimeter of all footings.

The interaction between old and new concrete was improved with

ø 32mm D YWIDAG transverse bar tendons (TH READ BA R® ) that

passed through cored holes.

Designed with precast prestres-

sed girders, the structure was

under construction during the

Northridge earthquake.

A similarly designed parking

structure which collapsed

during this seismic event sho-

wed a lack of reinforcement at

shear walls. D esign engineers

decided that short post-tensio-

ned DYWIDAG bars (THR EAD-BAR ® ), placed inside holes dril-

led along existing shear walls,

would compensate for reinfor-

cing steel deficiency.

California State University, Long Beach Parking Structure,California, USA

lendale Post Office,lendale, California, USA

his historic masonry building,

erving as post office, was com-

etely rehabilitated in 1995.

ew concrete shear walls were

dded to transmit forces during

seismic event. These were

upported by ø 57mm double

orrosion protected (DC P)EWI® piles which can be loa-

ed with both tension and com-

ession forces. During instal-

tion, limited head room condi-

ns required the contractor to

se small bar sections of 3m

onnected with couplers.

+ + + + DSI Services + + + +supply of DYWIDAG bars(THREADBAR®), hardwareand equipment.

+ + + + DSI Services + + + +supply, installation, stressingand grouting of DYWIDAGbars (THREADBAR®).

+ + + + DSI Services + + + +supply of GEWI® piles andstressing equipment.

ar tendons GEWI ® piles

Retrofitting of buildings

eficient structural systems

r elements require streng-

hening to withstand future

arthquakes. DYWIDAG bar

endons, with their easy and

eliable anchorage and cou-ling systems, can be applied

o upgrade these structures.



rock anchors

Stabilizing of dams

Seismic performance of dams

may be economically improved

by adding rock anchors.

A large number of dams have

already been stabilized using

DYWIDAG multistrand anchors.

The double curvature thin arch

concrete structure was built in

the 1920’s and is approximately

64m high. Retrofitting became

necessary to prevent a possible

failure of the arch section, inwhich a separation along the

joints during a major seismic

event would occur. That was a

very real danger as, during con-

struction, the concrete cold

joints had not been properly

cleaned of laitance, resulting

in weak joints with little or no

cohesion between pour sec-

tions. T he solution was to stabi-

lize the dam by installing sixty-

two 22 x 0.62" DY WIDAG rock

anchors in the arch section

to restore monolithic action.A further 22 anchors were

installed in the left thrust block

to provide for enhanced stability

against sliding. As the anchors

were to be stressed and remain

ungrouted for a 100 days moni-

toring period, protecting the

strands against corrosion

Stewart Mountain Dam, Arizona, USA

became an extremely impor-

tant consideration. The super-

ior corrosion protection and

high bond capacity of the Flo-

Bond epoxy coated strand

provided the ideal solution forboth requirements.

Railroad Canyon Dam, Canyon Lake, California, USA

The existing dam consisted of a thin 32m high concrete arch

section supported by concrete thrust blocks and concrete gravity

wing walls. Earthquake specialists found that during M aximum

C redible Earthquake water would probably overtop parapet walls,

resulting in dam failure. For this reason each of the thrust blocks

and wing walls were raised by adding new concrete. To increase

stability, new and existing concrete was connected with anchors.

The final design included six 27x0.6" and nine 48x0.6" DY WIDA G

rock anchors with lengths up to 48 m. Flo-Fill/Flo-Bond epoxy

coated strand was used for corrosion protection reasons.

To allow for future load adjustment and long-term monitoring, spe-

cial wedge plates with external thread and load cells were used.

+ + + + DSI Services + + + +consultancy during project,planning/quality mana-gement, supply, installationand testing of DYWIDAGrock anchors.

+ + + + DSI Services + + + +Supply of DYWIDAG rock anchors, uncoiling andstressing equipment.



round anchors,GEWI ® piles

Retrofitting of foundations

n order to withstand the

ncreased loading on structures

uring a major seismic event,

Y WIDAG ground anchors

s well as GEWI

®

piles aresed to enhance bearing ca-

acity and reduce foundation

eformations.

Steel water tanks, ContraCosta County, California,USA

During a seismic event, the

tank contents will move from

side to side inducing dynamicuplifts on the tank foundations.

To prevent damage at the foun-

dation, high strength ø 25mm

and 32mm DC P D YWIDAG

bars (THREADBAR ® ) were

used as tie down ground an-

chors around the steel tank

perimeter.

elecommunication tower, Diepenbeck, Belgium

he consultant decided to use DY WIDAG ø 32mm bar tendons

r rehabilitation of the existing anchors at the footing of the steel

wer shaft. Since the foundation slab is supported by piles, the

nchor plates for the lower anchorages could be mounted against

e bottom side of the slab.

Los Angeles River Bridges,Long Beach, California, USA

To prevent damage to founda-

tions during seismic events,

column thickness and footing

width were increased. ø 57 mm

GEWI® piles were installed to

enhance load-bearing capacity.

Britannia Secondary School,Vancouver, BritishColumbia, Canada

In order to meet modern re-

quirements on earthquake

safety, this 70 year old building

needed to be retrofitted. T he

designer chose high capacity

ø 57mm DC P G EWI® piles.

Restricted by the low ceiling

height in the building, the 15mdeep, ø 140mm boreholes

were drilled with a track-moun-

ted hydraulic minidrilling rig.

The anchors were coupled in

sections from 2.7 m to 4 m.

The tight restrictions of 2.7 m

headroom, 0.60 m spacing at

the pile head and pile inclina-

tions of up to 40°, posed no

problem for this very flexible

installation method.

+ + + + DSI Services + + + +supply of DYWIDAG baranchors.

+ + + DSI Services + + + +upply and installation ofEWI® piles.

+ + + + DSI Services + + + +supply, installation, stressingand grouting of DYWIDAGbar tendons.

+ + + + DSI Services + + + +supply of GEWI® piles andstressing equipment.

GEWI

PILE

TANK WALL

DYWIDAG

BAR GRO UN D

AN CH O R



Marsh Mills Viaduct,Plymouth, England

Because of severe damage to

the concrete from alkali-silica

reactions, the entire structure

had to be replaced. T he new

structure, a 410m long, nine

span and 5,500 t heavy dual

carriageway road deck, was

jacked sideways 12.2 m into

position using Ø 36mm DYWI-

DAG bars (THREADBAR ® ).

Sliding was chosen as it mini-

mized traffic disruption andwas significantly cheaper than

traditional methods. T he new

deck initially carried traffic while

resting on temporary supports.

After demolition of the old via

and two abutments were built

to support the new deck. R oad

closure was limited to a week-

end – eight hours for the slide,

24 hours to allow bearing grout

to set and the remainder for

asphalting and traffic re-routing.

The merge slide was downhill

on a 2.85 % slope. Balance

between pushing and pulling

forces gave a controlled pulling

force of up to 5,700 kN . Pullingwas incremental, governed by

the jack stroke of 600mm,

enabling a rate of travel of up

to 1.8 m an hour.

bars (THREADBAR ® )

Jacked sliding

Some rehabilitation schemes

require the demolition and

rebuilding of a portion of a

structure.

A very efficient method to

achieve this is to move thestructure and then demolish it

in its relocated position. This

will result in little interruption

in the function of the remaining

structure and would allow an

early start of the reconstruction.

Another effective rehabilitation

technique is to construct the

new structure adjacent to the

one to be demolished. After

demolition is complete the

new structure may be shifted

in a very short time to its final

location.

Roof of a swimming hall, Marseille, France

Before a new roof of this swimming hall could be constructed,

the old roof had to be removed. Traditional in-situ demolishing

would have incurred very high scaffolding costs and long roof-

raising times. The DYWIDAG alternative to this method was to

disconnect the roof from its supporting columns and move it

in seven-meter long sections. O nce the butt end of the building,

had been cleared the roof was demolished. T hat proved to be

by far the quickest and most cost-effective solution.

+ + + + DSI Services + + + +device development, supply

and installation of the liftingsystem, pushing.

+ + + + DSI Services + + + supply of DYWIDAG bars(THREADBAR®).

Lifting/Moving oStructure

Lifting and moving of structures

can be advantageously used a

part of a rehabilitation scheme:

- Lifting of structures as aneasy strengthening measure

redistribution of the action

effects in a statically indeter-

minate structure is achieved

through imposed deforma-

tions (e.g. through lifting a

continuous bridge at its

supports)

- M oving of structures or por-

tions of them through jacked

sliding.

DY WIDAG bars (THR EADBA R ®

with their easy anchorage ele-ments and mechanical couplin

system are used as tension ele

ments for lifting or moving heav

and complex structures. If requ

red, DSI can assist you with the

supply of special equipment an

technical support.



0 4 1 4 6 - 1 / 1 0 . 0

9 - w e b s t

A U S T R I A

A R G E N T I N A

A U S T R A L I A

B E L G I U M

B O S N I A A N D H E R Z E G O V I N A

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C A N A D A

C H I L E

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D E N M A R K

E G Y P T

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F I N L A N D

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H O N D U R A S

H O N G K O N G

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K O R E A

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P E R U

P O L A N D

P O R T U G A L

Q A T A R

S A U D I A R A B I A

S I N G A P O R E

S O U T H A F R I C A

S P A I NS W E D E N

S W I T Z E R L A N D

T A I W A N

T H A I L A N D

T U R K E Y

U N I T E D A R A B E M I R A T E S

U N I T E D K I N G D O M

U R U G U A Y

U S A

V E N E Z U E L A

www.dywidag-systems.com

AustriaDYWIDAG-SYSTEMSINTERNATIONAL GMBHWagram 494061 Pasching/Linz, AustriaPhone +43-7229-61 04 90Fax +43-7229-61 04 980E-mail: [email protected]

DYWIDAG-SYSTEMSINTERNATIONAL GMBHTeichweg 95400 Hallein, AustriaPhone +43-6245-87 23 0

Fax +43-6245-87 23 08 0E-mail: [email protected]

Belgium and LuxembourgDYWIDAG-SYSTEMSINTERNATIONAL N.V.Industrieweg 253190 Boortmeerbeek, BelgiumPhone +32-16-60 77 60Fax +32-16-60 77 66E-mail: [email protected]

FranceDSI-Artéon

Avenue du BicentenaireZI Dagneux-BP 5005301122 Montluel Cedex, FrancePhone +33-4-78 79 27 82Fax +33-4-78 79 01 56

E-mail: [email protected]

Germany DYWIDAG-SYSTEMSINTERNATIONAL GMBHSchuetzenstrasse 2014641 Nauen, GermanyPhone +49 3321 44 18 32Fax +49 3321 44 18 18E-mail: [email protected]

DYWIDAG-SYSTEMSINTERNATIONAL GMBHMax-Planck-Ring 140764 Langenfeld, GermanyPhone +49 2173 79 02 0Fax +49 2173 79 02 20E-mail: [email protected]

DYWIDAG-SYSTEMSINTERNATIONAL GMBHGermanenstrasse 886343 Koenigsbrunn, GermanyPhone +49 8231 96 07 0Fax +49 8231 96 07 40E-mail: [email protected]

DYWIDAG-SYSTEMSINTERNATIONAL GMBHSiemensstrasse 885716 Unterschleissheim, GermanyPhone +49-89-30 90 50-100Fax +49-89-30 90 50-120E-mail: [email protected]

Italy DYWIT S.P.A.

Via Grandi, 6820017 Mazzo di Rho (Milano), ItalyPhone +39-02-93 46 87 1Fax +39-02-93 46 87 301E-mail: [email protected]

NetherlandsDYWIDAG-SYSTEMSINTERNATIONAL B.V

Veilingweg 25301 KM Zaltbommel, NetherlandsPhone +31-418-57 89 22Fax +31-418-51 30 12

E-mail: [email protected]

Norway DYWIDAG-SYSTEMSINTERNATIONAL A/SIndustrieveien 7A 1483 Skytta, NorwayPhone +47-67-06 15 60Fax +47-67-06 15 59E-mail: [email protected]

PortugalDYWIDAG-SYSTEMSINTERNATIONAL LDA Rua do Polo SulLote 1.01.1.1 – 2B1990-273 Lisbon, PortugalPhone +351-21-89 22 890Fax +351-21-89 22 899E-mail: [email protected]

SpainDYWIDAG SISTEMASCONSTRUCTIVOS, S.A.

Avenida de la Industria, 4Pol. Ind. La Cantuena28947 Fuenlabrada (MADRID), SpainPhone +34-91-642 20 72Fax +34-91-642 27 10E-mail: dywidag

@dywidag-sistemas.comwww.dywidag-sistemas.com

United KingdomDYWIDAG-SYSTEMSINTERNATIONAL LTD.Northfeld Road

Southam, WarwickshireCV47 0FG, Great BritainPhone +44-1926-81 39 80Fax +44-1926-81 38 17E-mail: [email protected]/uk

Please note:

This brochure serves basic information

purposes only. Technical data and information

provided herein shall be considered

non-binding and may be subject to change

without notice. We do not assume any liability

for losses or damages attributed to the use

of this technical data and any improper

use of our products. Should you require

further information on particular products,

please do not hesitate to contact us.

DSI-Repair_and_StrengtheningSystems_for_Repair_and_Strengthening_en_02.pdf

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