20 Excavacion y Construccion de Muros Pantalla Con Pilotes Secantes_Claudio Asioli

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Bienvenidos

Welcome

Bem-vindos

Bienvenue

Benvenuti

Willkommen

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Las informaciones y conceptos expresados en esta conferencia se hacen

con el propósito de divulgar e informar de manera general sobre los

temas relacionados con el concreto.

ASOCRETO no es ni pretende ser asesor de proyectos específicos.

Cualquier duda en relación con obras específicas debe ser consultada por

el interesado con los diseñadores e interventores de la respectiva obra.

El uso que se haga de las informaciones y conceptos aquí expresados no

conllevan responsabilidad alguna para ASOCRETO ni para los

conferencistas, ya que debe ser utilizada por personas idóneas bajo su

responsabilidad y criterio. Esta información no sustituye las funciones y

obligaciones de las personas contractualmente responsables de la

concepción, ejecución y vigilancia de los respectivos proyectos. Los

conceptos expresados no son asesoría para una obra en particular.

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DURANTE LAS PRESENTACIONES MANTENGA LOS EQUIPOS DE COMUNICACIÓN EN SILENCIO

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SALIDA DE EMERGENCIA

RUTA EVACUACION

USTED ESTA AQUI

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Claudio AsioliGRUPO TREVI

ITALIA

CIMENTACIONES

EXCAVACIÓN Y CONSTRUCCIÓN DE MUROS PANTALLA CON PILOTES SECANTES Y SISTEMA DE HIDROFRESADO

Gracias al apoyo de:

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Presentation bullet points

Different construction methods and features for Retaining Wall

and Cut-Off Wall executed by:

Diaphragm Wall by Grab (Mechanical or Hydraulic)

Diaphragm Wall by Hydromill

Cased Secant Piles

Reverse Circulation Drilling System

TREVI experiences concerning to:

Metro and Railway Stations

Building Basements and underground Car-Parks

Circular Shafts

Cut-Off for Dams Rehabilitation

Confinement of Polluted Site

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History

TREVI was established in

1957 in Cesena – Italy.

Thanks to its continuous

improvement, studies,

innovation, experience,

quality and research of

new technologies

Trevi has became aleader company in thefield of geotechnical andspecial foundationEngineering.

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TREVI DivisionSOILMEC Division DRILLMEC Division PETREVEN Division

VENEZUELA

Trevi Cimentaciones

U.S.A.

Trevi Icos Corporation (Boston)

Trevi Icos South Inc.

MOZAMBIQUE

Profuro Lda

NIGERIA

Trevi Foundations

U.A.E.

Swissboring

OMAN

Swissboring

GERMANY

Spezialtiefbau GmbH

SWEDEN

Hercules Trevi Foundations A.B.

ITALY

Trevi S.p.A. (Cesena)

RCT S.r.l. (Milano)

HONG KONG

Trevi Construction

JAPAN

Soilmec Japan

CHINA

Repr. Office

HONG KONG

Soilmec H.K. Ltd

SINGAPORE

Soilmec Far East Ltd

ITALY

Soilmec S.p.A. (Cesena)

PSM S.r.l. (Treviso)

RUSSIA

Moscow Repr. Office

ITALY (Piacenza)

Drillmec S.p.A.

Edra S.r.l.

U.S.A.

Drillmec Inc.

ARGENTINA

Pilotes Trevi

COLOMBIA

Petreven

CANADA

Trevi Foundations

Canada Inc.

QATAR

Swissboring

IRAN

Trevi Iran Branch

NEW ZEALAND

Trevi Construction

FRANCE

Soilmec France

PERU

Petreven

UK

Soilmec Ltd

AUSTRIA

Trevi Branch

VENEZUELA

Petreven

ARGENTINA

Petreven UTE ALGERIA

Trevi Algerie

INDIA

Soilmec India

PHILIPPINES

Trevi Philippines Inc.

U.S.A.

Soilmec North America

GERMANY

Soilmec DeutschlandDUBAI – U.A.E.

Soilmec Emirates LLC

Soilmec Gulf FZCO

TURKEY

Trevi Insaat Ve

SUDAN

Drillmec Engineering Sudan

PANAMA

Trevi - Galante

ANGOLA

Trevi Angola

EGYPT

Soilmec Misr S.A.E.

SAUDI ARABIA

Soilmec Arabia LLC

AUSTRALIA

Soilmec Australia

COLOMBIA

Galante SAU.S.A.

Watson

SAUDI ARABIA

Trevi Saudi Arabia

U.A.E.

SoilArabContractor

BRASIL

Soilmec Brasil

Global Presence

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837624.4

497.7

20052006

2009

2007

1.069

2008

1.035

Evolution of Total Revenuesin millions of euro

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EMPLOYEES

2004

2005

2006

2007

2008

3.238

3.5774.218

5.400

5.000

Covering more than 35 different ethnic groups

2009

6.200

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Recent acquisitions:

-1997 I.C.O.S. Boston, a leader company in the field of

special foundations in the North American market.

-1999 SWISSBORING which operate in the U.A.E., Oman

and Qatar .

-2005 RODIO S.p.A., the oldest Italian company specialized in

the field of special foundation founded in the 1921.

-2009 GALANTE S.A., that operates in South and Central

America market such as Colombia, Peru, Panama and

Dominican Republic.

-2009 ARABIAN SOIL CONTRACTOR Ltd., located in

Saudi Arabia.

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Main Executed ProjectsFoundations & Soil Consolidations

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MARINE WORKS

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TRANSPORT AND COMMUNICATION LINES

“Central Artery”

Boston (United States)

“Raticosa Tunnel” High Speed Railway System

Bologna (Italy)

Diaphragm Walls forCut & Cover Tunnels

Fiberglass pre-consolidation,Excavation & Internal Lining

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FOUNDATIONS FOR CIVIL& INDUSTRIAL BUILDINGS

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RESTORATION WORKS OF ARTISTIC MASTERPIECES

Underexcavation of the Pisa Tower

Pisa (Italy)

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DAMS REHABILITATIONNew Orleans - USA

W.F. George Dam – USA

Arapuni Dam - New Zealand

Tuttle Creek Dam - USA

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NEW DAMS CONSTRUCTION

Diavik Mine Dam - Canada

Piedra de Aquila Dam - Argentina

Yaciretà Dam - Argentina

Ertan Dam - China

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ENVIRONMENTAL PROTECTION WORKS

Ex-industrial area in Avigliana - Turin (Italy)

Enichem Plant - Priolo (Italy) Acna Chemical Plant - Cengio (Italy)

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1st Part

Construction methods and features forRetaining Walls and Cut-Off Walls

Diaphragm Wall by Grabs (Mechanical or Hydraulic)


Cased Secant Piles


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European Code EN 1538, define the following two types:

Retaining walls: usually made to support an excavation in

the ground. They include:

cast in situ concrete diaphragm walls;

pre-cast concrete diaphragm walls;

reinforced slurry walls.

Cut-off walls: usually made to prevent migration of clear or

polluted groundwater or other liquids present in the ground.

They include:

slurry walls (eventually with membranes or sheet piles);

plastic concrete walls.

DIAPHRAGM WALLS CLASSIFICATION

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EU

RO

PE

AN

CO

DE

EN

15

38

DIA

PH

RA

GM

WA

LL

S C

LA

SS

IFIC

AT

ION

RE

TA

ININ

G

WA

LL

S

CU

T O

FF

PL

AS

TIC

WA

LL

SCAST IN SITU

CONCRETE DW

REINFORCED

SLURRY WALL

(WITH SELF

HARDENING

SLURRY)

PRECAST

CONCRETE DW

PLASTIC

CONCRETE

WALLS

SLURRY

WALLS

(WITH SELF

HARDENING

SLURRY)

EXCAVATION WITH

SOIL REMOVAL

IN SITU SOIL MIXING

EXCAVATION with S. R.POSSIBILITY TO INSERT

MEMBRANE, SHEET PILE

HYDROMILL

GRABS (ROPE, HYDRAULIC)

CASED SECANT PILES

SOLDIER PILE WALLS

HYDROMILL


HYDROMILL


CASED SECANT PILES

EXCAVATION WITH

SOIL REMOVAL

EXCAVATION WITH

SOIL REMOVAL

HYDROMIL


DEEP SOIL MIXING

JET-GROUTING

IN SITU SOIL MIXING

HYDROMILL


DEEP SOIL MIXING

JET-GROUTING

EXCAVATION WITH

SOIL REMOVAL

DIAPHRAGM WALLS CLASSIFICATION

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Cased Secant Piles


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Diaphragm Walls by Grab

Diaphragm walls are generally composed by rectangular shaped elements.

T shape sections can be adopted to support higher flexural stresses.

Geometrical features (i.e. trench width, depth and thickness) and ground

conditions determine the choice of correct technology and equipment.

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Primary and Secondary panels are

executed

Stop-end elements are installed in

primary panels to increase the contact

surface and improve the watertightness

of the joints

Wall‟s Construction Sequence

Panel width is equal to 2.5÷4.0 m

Thickness is equal to 40÷150 cm

Typical depth is equal to 30÷40 m

Maximum depth is equal to 50÷60 m

Vertical deviation in the range 1÷2%

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Trench Excavation

De-sanding Steel Reinf. Installation

Concrete Pouring


Construction sequence of the single element

Concrete is poured with single or multiple tremiepipes depending on the size of the panel.

Structural diaphragm walls can be reinforced bycages or steel beams.

After the excavation iscompleted, bentonite mud isrecycled through a Desanderunit, until the allowed sandcontent before concreting isachieved (usually ≤ 4%).

During the excavation apositive slurry head of 2meters above natural waterlevel has to be maintained.(bentonite, polymer or water)

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Guide walls construction

GW are very important because they represents

the „starting points‟ of all operations.

They are used to:

avoid superficial soil collapse

as a guide for an accurate positioning of panels

to support the steel cages during the concrete

hardening

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Joints

Using sacrificial plastic pipes;

Using removable stop-ends and extracting them vertically or laterally

(eventually equipped with water-stop);

Leaving steel or pre-cast concrete beam element in place.

Joints between panels is a very important point, since leakages can

occur through the joint if the joint is not formed or cleaned correctly.

Joints can be obtained in the following three different ways:

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Diaphragm Walls by Mechanical or Hydraulic Grabs

Joints - Sacrificial Plastic Pipes

Two Pipes are connected to the cage of the primary

panels.

When the secondary panel excavation is completed, a

special cleaning tooth is lowered into the opened panel to

break and clean the PVC pipe.

During the secondary panel casting, the concrete fills the

empty area and a water-tight joint is created.

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Joints – Removable Stop-Ends

Stop-ends are installed into primary panels before

concreting operations and are extracted by means of

hydraulic jacks as soon as the concrete starts to set.

When the secondary panel excavation is completed,

the concave-shaped surface of the joint is cleaned by

using a proper cleaner mounted on the grab.

Stop-ends leave grooves in the concrete of the panel

under construction.

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Joints – Water Stop

If water-stop is required, the precast concrete beam element can be adopted or

stop-end can be left in place and laterally removed after the excavation of the

adjacent panel, by means of special cleaning chisels.

The action of the chisel breaks the bond between the stop-end and concrete, the

stop-end is laterally removed with the service crane and the water-stop remains

in place.

This system can also be used with the hydromill.

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Equipment

The grabs can be:

Cable suspended, mechanical or hydraulic clamshell

Kelly-bar fully guided, hydraulic clamshell; easy to repositioning over

the trench but with limited operative depth (generally 30÷35 m)

Partially guided, hydraulic clamshell; initially guided by a telescopic

leader element and then cable suspended (Soilmec BH/GH series)

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Job Site Installation: Bentonite Plant

In narrow spaces, steel tanks can replaceordinary bentonite pits.

Three pits are generally adopted to manage

bentonite mud :

1) for the production of the fresh bentonite mud

2) for the bentonite mud ready to be sent to the

excavating panel

3) for the recycled bentonite, still to be desanded

An automatic continuous-cycle bentonite plant

can be used to prepare the fresh mud (Soilmec

BE-12/50) .

The whole plant is assembled inside a standard

20 feet container.

Two removable bentonite silos are mounted on

top of the container.

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Controls

Grabs can be fitted with electronic devices (generally slope indicators)

to control and monitor verticality deviation on 2 or 3 axis.

Ultrasonic devices (i.e. Koden), that measure the distance between a

probe lowered into the excavation and the faces of the panel, provide a

“profile” of the excavation. This method needs to stop the excavation.

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Diaphragm walls are typically exposed along most of their depth and,

especially in urban areas, there are often tight tolerances in order to

save space for the construction of the internal structure.

Cut-off walls, though not exposed, required wall continuity and

watertightness joints down to low depths.

Why is verticality important?

???


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Due to its possible vertical deviation, within a 1÷2% range, Clamshell

equipment can be considered suitable and convenient for waterproof

diaphragm walls up to 30÷40 m depth and without any rock layers or

cemented soil strata (UCS ≤ 1.0 MPa).


When depths become higher than 40 m with reduced verticality

tolerances (< 1%) and/or embedment in sound rock or hard strata is

required, an alternative technology has to be considered

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Cased Secant Piles



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Diaphragm Walls by Hydromill

The Hydromill can be considered the most advanced diaphragm walls

excavation equipment; the first models were developed in the late 80‟s.

The Hydromill system consists of three main components:

Supporting crawler crane

Milling unit (Hydromill)

Plant for mud preparation and processing

The hydromill is lowered progressively

into the trench and excavates and crushes

the soil or rock.

A submerged mud pump creates a reverse

circulation of the stabilizing fluid

(bentonite mud or water), which acts as a

transport medium to evacuate the cuttings

from the excavation and deliver them to a

mud treatment plant.

Cuttings are removed from the mud by

means of vibrating screens and/or

cyclones.

Cleaned and fresh slurry is fed back into

the trench to maintain the slurry level.

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Excavation of a shallow pre-trench,

(3÷4 m deep) necessary to activate

the submerged mud pump

Construction sequence


Typical width is equal to 2.4÷2.8 m

Thickness is in the range 65÷200 cm

Depth up to 80÷100 m

Vertical deviation in the range of 0.2÷0.4%

Suitable in all type of soil and rocks with

UCS up to 60÷80 MPa (peak 150 MPa)

Excavation of the primary panels

Drilling mud treatment

Reinforcement cage installation

Concrete pouring

Excavation of the secondary panel

Drilling mud treatment

Reinforcement cage installation

Concrete pouring

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Joints are obtained by partial overlapping between primary and

secondary panels (usually 150÷200 mm).

During the excavation of the secondary panels, the hydromill cutter

drums cut a small portion of concrete on each adjacent primary panel,

creating a rough and clean contact surface.


Concrete to Concrete Joints

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Equipment


Milling unit can be cable-suspended onto a hydraulic crane's boom orspecial equipment named “citycutter”, which can operate is small areasbelow a free height of approx 5.5 m

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Milling Unit (Hydromill)


The milling unit consists of a heavy steel frame on

which two couple of counter-rotating and

independent milling drums are mounted.

According to soil characteristics, drums with

different torque, shape and dimensions, fitted

with different teeth types, can be adopted.

Pressure on the cutter bits can be adjusted by

means of the pull-up force of the hydraulic main

winch.

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Correction in X direction can be achieved by:

Adjusting the rotation speed of the milling drums

Moving side flaps

Correction in Y direction can be achieved by:

Moving face flaps

Varying the inclination of the drums group respect

to the main hydromill frame

Correction of twisting along Z axis:

Moving face flaps

Moving separately each drum with respect to the

main hydromill frame

The hydromill allows to perform a real time control of all the excavation

parameters. The position is continuously monitored by means of sensors

installed directly on the hydromill frame, allowing the operator to take

corrective actions before deviation reaches the design tolerance.

Controls

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Advantages

The main features of Hydromill Technology can be summarized asfollows:High quality product, in terms of joint contact and panels verticality.

The concrete-to-concrete joints ensure higher shear resistance and

water-tightness;

Real time verticality monitoring and correction during excavation

allows to achieve depths up to 80÷100 meters, with a vertical tolerance

in the range of 0.2÷0.4%;

Suitable for all types of soil and rocks, with UCS values up to

60÷80 MPa ;

Mitigation of the construction impact (also in urban environment); the

level of noise and vibrations does not affect adjacent structures;

Clean site, as a result of the slurry reverse circulation system used for

the transport and removal of cuttings.

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Cased Secant Piles

Reverse Circulation Drilling System (RCDS)


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Cased Secant Piles (CSP)

The Cased Secant Piles system has been developed by Trevi Group for theexecution of secant piles to form a continuous, watertight retaining wall.

The construction sequence foreseen the execution of theprimary piles (hard or soft) and the following executionof the secondary ones (hard) with a proper overlapping.

The piles diameter ranges between 600 ÷ 1200 mm, thespacing is in the range 500 ÷ 1000 mm and depth up to27 meter (20 m fully cased).

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A continuous flight auger and an external casing are simultaneously driven into the

soil.

Once the casing is completely driven (max 20 m), it is possible to continue to drill

by means of the auger only (up to 27 m).

When boring operation are completed, the auger and the casing are extracted while

concrete is poured throughout the internal hollow pipe.

If required, only in the secondary piles, the steel reinforcement (cages, profiles or

beams) is finally lowered into the fresh concrete.

Construction sequenceof the single pile


Drilling

Concrete Pouring

Steel Cage Installation

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The execution of a guide wall is necessary in order to assure the correctplanimetric piles location and the guide of the casing at the surface.

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The excavating system is composed by:

1 powerful hydraulic rig

1 concrete pump

1 augers housed inside a casing

Augers and casing are driven by two

independent rotaries.

AUGERROTARY

CASINGROTARY

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During the drilling phase the system controls:

depth,

auger and casing rotation and advance speed,

speed/torque settings on the two rotary table.

During the concreting phase the system controls:

pressure and delivery of the concrete,

extraction speed

computed pile diameter.


Controls

In order to assure a continuous quality control and simplify the operatoractivity the Soilmec Drilling Mate System DMS, positioned inside themachine‟s cabin, controls and records the working parameters:

All the recorded data are stored in a memory card and eventually sent bye-mail and printed.

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Advantages

The CSP method can be utilized in a wide range of cohesive and

cohesion-less soils, also in presence of a water-table and without

bentonite fluid as wall support. In this way the spoil material is not

polluted by bentonite, avoiding disposal problems and extra-costs;

The technology does not produce shocks, vibrations, noise, allowing to

work in urban areas;

The minimum required equipment (the rig plus the concrete pump)

allow to minimize the job site installation plant and to operate in very

restricted areas;

The guarantee of a small deviation from the verticality, less than

0.5÷1.0%, thanks to the casing rigidity;

Suitable to drill rocks layers, with UCS value up to 30÷40 MPa (peak

up to 80 MPa).

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Cased Secant Piles



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Working Principles

This system has been mainly developed in order to drill or socket hard

rock with UCS up to 150÷200 MPa.

Holes are drilled by a cutter which crushes rock. Meantime,

compressed air provides to develop the air lift for cuttings‟ evacuation

through the drilling string.

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Equipment

Reverse Circulation System (RCDS)

Rotary Table installed at the top of a casing;

Drilling string and stabilizer (to reduce string deflection);

Drilling tool with rock cutters;

Service Crane is just adopted to move the rotary table and

the drilling string.

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Equipment


Soilmec has implemented a new

method that allows pile excavation by

drilling with traditional Kelly bars

system and switches to RCDS when

necessary, thus optimizing each

system according to the subsoil

conditions.

Weight is applied just above the drilling

tool, avoiding deflection of the drilling

string and improving verticality .

The possibility of adjusting weight on

the tool, by applying the pull-down or

adding/removing ballasts, assures a

better penetration rate.

Photos/Cathead1.JPG

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Cuttings travel to the surface via the pipes, minimizing wall stability

problems in the soil;

Suitable to drill hard rocks layers, with UCS values up to 150÷200 MPa;

Diameter up to 3500 mm;

“Theoretically” no limits in depth (lifting crane capacity);

Possibility to use (sea) water as a drilling fluid which can also be

discharged into rivers or seas;

The technology does not produce shocks and vibrations;

If combined with Directional Drilling Technology (DDT), it can

guarantee a deviation from the verticality lower than 0.2%.

Advantages

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63

FeatureDiaphragm Wall

by Grab

Diaphragm Wall

by HydromillCased Secant Pile

Reverse Circulation

Drilling System

Maximum Depth 50÷60 m 100 m 27 m (20 m cased) > 200 m

Thickness 500÷1500 mm 650÷2000 mm 400÷800 mm (*) 800÷2500 mm (*)

Diameter ----- ----- 600÷1200 mm 1200÷3500 mm

Verticality 1.0÷2.0 % 0.2÷0.4 % 0.5÷1.0 % 0.2% (**)

Soil Conditions and

Rock Strength

Soil with

weakly cemented layer

(UCS = 1÷2 MPa) (***)

Soil & Rock

UCS ≤ 60÷80 MPa

(Peak UCS = 150 MPa)

Soil & Rock

UCS ≤ 30÷40 MPa

(Peak UCS = 80 MPa)

Soil & Rock

UCS ≤ 150÷200 MPa

(Peak UCS = 300 MPa)

Joint Type Stop-End (****)Concrete to Concrete

(****)Concrete to Concrete Concrete to Concrete

Joint Number 1.0 1.1 3.0÷6.0 1.5÷3.0

Drilling FluidBentonite, Polymer,

Water

Bentonite, Water

(Polymer)----- Water

Site Installation

Area200÷500 m

2300÷800 m

2 ----- 200÷500 m2

(*) Effectice thickness (depending to piles' spacing)

(**) In combination with Directional Drilling Technology

(***) Pre-drilling with auger and/or Chiselling

(****) Posibility to install Rubber Water Stop

Comparison of the Different Technologies

Cost (m2) 1.002.0-2.5 (only soil)

3.5-5.5 (20-60% rock)

1.5-2.0 (Soft-Hard)

3.0-4.0 (Hard-Hard)???

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2nd Part

Case Histories

Underground Metro Stations

Building Basements

Circular Shafts

Cut-off Wall for Dams Rehabilitation

Confinement of Polluted Areas

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Case Histories


Building Basements

Circular Shafts



Naples - Lines 1 & 6

Rome - Lines B1 & C

Algiers - Line 1 Extension B

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Naples Metro Stations – Lines 1 & 6 (2002-2010)

Garibaldi

Arco Mirelli

Università

Toledo

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Naples Metro Stations – Typical Soil Stratigraphy

More than 35 mof water pressure

Transition layer (green Tuff)

Water Table

Ground Level

31 m

2 m

Fissured weak rock (yellow Tuff)

UCS = 2 ÷ 7 MPa

Volcanic Sand (Pozzolana)

+3.00 m

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Central Rectangular Shaft (48 x 23 m)

45 m Deep

Excavated by means of the Top Down System

4 Staircases Tunnels L = 40 m

4 Station Tunnels L= 50 m

Pre-consolidated by freezing

“Garibaldi” and “Università” Stations

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Concrete Diaphragm Wall

Technique: HYDROMILL (20 m in rock and watertight joints)

“Garibaldi” and “Università” Stations

Other Main Activity

Ground Anchors below water table

Directional Drilling for freezing pipes installation

Freezing by Liquid Nitrogen and Brine for tunnels construction

Grouting for closing plugs at the end of the station‟s tunnels

Equipment: BC 30

Thickness: 1000 mm

Max d.w. depth: 50 m

Max excavation: 45 m

Over cut joint: 150 mm

Wall surface: 6.800 m2 (each Station)

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Garibaldi Station

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Garibaldi Station

Wall with freezing pipe

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Università Station

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Lateral Shaft (63 x 18 m) - 50 m Deep

Connection Tunnel

4 Station’s Tunnel L = 50 m

MontecalvarioExit

Toledo

Toledo Station

Service Tunnel L = 40 m

Pedestrian Tunnel L = 150 m

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Toledo Station


Technique: HYDROMILL (20 m in rock and watertight joints)

Other Main Activity


Directional Drilling for freezing pipes installation

Freezing by Liquid Nitrogen and Brine for tunnels construction

Grouting for closing plugs at the end of the station‟s tunnels

Equipment: Citycutter HC 03

Thickness: 1000 mm




Wall surface: 8.100 m2

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Toledo Station

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Arco Mirelli Station – Line 6 (LTR)

114 m24

m

In the deepest part T-shape D.W.

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Technique: HYDROMILL (rock strength and watertight joints)

Other Main Activity

Preliminary soil improvement to increase trench stability for T-wall

Jet grouting for break-in and break-out

Relief wells by Stone Columns

Equipment: HF 12000

Thickness: 1200 mm





9.300 m2 (T-shape )

Arco Mirelli Station

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Leg Excavation Flange Excavation


T panel excavated by two rectangular

element.

Cutters have to work in symmetric

position to control verticality.

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Rome Metro Stations – Lines B1 & C (2007-2010)

Gondar

S. Giovanni

Lodi

Mirti

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Rome Metro Stations – Soil Stratigraphy (S. Giovanni)

Very stiff silty Clay

Very dense sandy Gravel

Heterogeneous, loose Fill material

Firm silty Clay

Sandy Silt with organic material

Water pressure = 24 m

12÷17 m

0÷5 m

10 m

15÷17 m

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Rome Metro Stations – Geometry

Conventional Stations with rectangular shapeexcavated by “Top-Down” method

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EXISTIGSTATION


The most interesting station is S. Giovanni, because the new tunnels haveto underpass the existing station just between its piles foundation.

We are proposing to consolidate tunnels by freezing, working from thenew station.

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Section of tunnels with the proposed ice columns pattern

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Gondar, Lodi, Mirti, San Giovanni Stations

Other Main Activity

Jet grouting for Bottom Plug (Gondar)

Jet grouting and chemical grouting for break-in and break-out (Gondar, Mirti)

Freezing for undercrossing existing San Giovanni Station (Line C)

Equipment: BC 30 & Soilmec Tiger

Thickness: 800÷1200 mm


Max excavation: 41 m (Gondar)

Over cut joint: 150÷200 mm



Technique: HYDROMILL (Max verticality tolerance = 0.5% watertight joints and D.W. length)

86

Gondar Station

87

Gondar Station

88

Mirti Station

89

San Giovanni Station (under construction)

90

Bachdjarah 1 and Bachdjarah 2 Stations (Piles walls)

Harrach Gare and Harrach Centre Stations (D.W.)

Artificial Tunnels with piles and D.W.

Algiers Metro - Line 1 Extension B (2007-2010)

HIGHER ZONELOWER ZONE

91

Algiers Metro – Longitudinal Soil Profile

70

60

50

40

30

20

10

0

-10

-20

Ground Elevation at 50÷60 m

Water table below final excavation level

Ground El. at 5÷25 m

Water table above

final excavation level

Upper formation: Quaternary (Dense Sand and Stiff Clay)

Lower formation: Tertiary (Very Dense Sand and Gravel, Hard Clay,

with some levels of Sandstone and Marl)

PILES WALLS DIAPHRAGM WALLS

92

“Bachdjarah 1” and “Bachdjarah 2” Stations

122 m

20

m

25

m

93

Pile Walls

Technique: BORED PILES by Auger & Bucket

Other Main Activity

Ground Anchors 882 + 770 (L = 41 km)

Berlin Wall

Jet Grouting for structural bottom plug (Bachdjarah 2)

Equipment: 3 Hydraulic Rigs Soilmec SR40

Pile diameter: 1000 mm

Spacing: 1.25/1.30 m

Max piles depth: 30 m


Number of piles: 238 + 248 = 486

Total length: 6.300+6.600 = 12.900 m


94


95


96

“Harrach Gare” Station

22 m

172 m 22 m

35 m

17

m

18 Anchors each cage 9

A

nch

ors

Levels

Lo

ng

. S

pacin

g 1

.5 m

97

Other Main Activity

1740 Ground Anchors (L = 48 km)

Berlin Wall



Technique: HYDROMILL (Rock layers, watertight joints and max verticality tolerance ≤ 0.5%)

Equipment: Citycutter HC 03

Thickness: 1000 mm





98


99


100

138 m 22

m

“Harrach Centre” Station

17

m

STEEL PROPS

14 m

101

Other Main Activity

356 Ground Anchors (L = 11 km)

Berlin Wall


Technique: HYDROMILL (D.W. length, rock and watertight joints)

Equipment: BC 30

Thickness: 1000 mm






102


103


Building Basements

Circular Shafts



Tripoli - Al Ghazala Hotel & Al Ghadafi Tower

Alassio - Partigiani Square Car Park

Malmö - Bager Plats Car Park

Manila - Yeeloofa Towers

New York - World Trade Center

Case Histories

104

Al Ghazala Hotel – Tripoli (2007-2008)Al Ghadafi Tower – Tripoli (2008-2009)

1,6 km

105

Al Ghazala Hotel & Al Ghadafi Tower – Tripoli

10 m

6 m

17 m

Calcarenite

Claystone

Recent Beach Deposits (sand)

Silty Sand weakly cemented

Calcarenite

Calcarenite (only in Al Ghadafi Tower)

Soil Stratigraphy

106


Site Layout

107


Typical Cross Sections

2 Basements

4 Basements

Al Ghazala Hotel

Al Ghadafi Tower

108


Other Main Activity


Dewatering Wells

Piles Foundations (Al Ghatafi)

Concrete Diaphragm Walls

Al Ghazala Hotel Al Ghadafi Tower

Technique: CLAMSHELL HYDROMILL

Equipment: Soilmec BH12 Citycutter MBC 30

Thickness: 600-800 mm 800 mm

Max d.w. depth: 18 m 27 m

Max excavation: 12 m 17 m

Over cut joint: stop end 150 mm

Wall surface: 7.250 m2 12.000 m2

Average Production: 108 m2/day 92 m2/day

109

Al Ghazala Hotel – Tripoli

110

Al Ghazala Hotel – Tripoli

An average of approx 10.000 m3/day of

water was discharged for 1 year by 36

electric submersible pumps (6”)

111

Al Ghadafi Tower – Tripoli

112

Al Ghadafi Tower – Tripoli

113

Partigiani Square Car Park – Alassio (2004-2006)

11

3

114

Partigiani Square Car Park – Alassio

11

4

115


Sand & Gravel

Flysh (UCS = 100 MPa)

Sand &

Gravel

Flysh

11

5

116



Technique: HYDROMILL (Rock strength up to 100 MPa)

Equipment: BC 30

Thickness: 1200 mm


Max excavation: 10.5 m



Other Main Activity

Vertical Micropiles to balance uplift water pressure

Temporary Ground Anchors

11

6

117


11

7

118


11

8

119

Bagers Plats Car Park – Malmö (2010)

Is a two basements car park close to the Central Rail Station of Malmö

and it‟s part of the Citytunnel Project.

120

Bagers Plats Car Park – Malmö70 m

10

0 m

Ste

el

Sh

ee

t P

iles

Secant Piles

121

Bagers Plats Car Park – Malmö

Sand &

Clay

Limestone with frequent

Flint thin layers (10÷30 cm)

Canal

Steel Sheet PilesWorking Platform

Secant Piles 1000 mm @ 0.8 m

8.5 m

Typical section and Soil Conditions of the area.

12.0 m

122

Equipment: Hydraulic Rigs Soilmec SR 100


Spacing: 0,80 m

Max piles depth: 12 m

Max excavation: 8.5 m

Number of piles: 215

Total length: 2.580 m

Secant Piles Wall

Technique: Bored Piles fully cased, excavated by bucket equipped with rock teeth


123


124


125

Yeeloofa Towers – Manila (2008)

New mall and two residential towers in the Chinese District in Manila.

Diaphragm walls for three basements excavation.

In this area, due to the

very bad soil condition,

excavations for basements

had never been executed.

126

Yeeloofa Towers – Manila

125 m

76 m

127


Other Main Activity

Piles Foundations with Plunge column


Technique: CLAMSHELL

Equipment: Hydraulic Grab Soilmec BH12

Crane: Soilmec SM 870

Thickness: 1200 mm



Joint: Stop-end equipped withwater stop


Average Production: 78 m2/day

128


129


130

World Trade Center – New York (2006-2007)

131

H&M Structure

East Bathtub

West Bathtub

World Trade Center – New York

280 m

0.0

Fill

Silty Clay

Granite

-20.0

-6.0

132


Technique: HYDROMILL (3÷4 m into Granite with U.C.S. up to 130 MPa)

Equipment: HF 12000

Crane: Manitowoc 12000

Thickness: 1200 mm



Over cut joint: H beam


1.000 m2 (granite)


133


Manitowoc 12000

• Hydromill Rig

• 120 Ton Crane

• 27 m Boom

Liebherr LR 1200

• Service Rig

• 275 Ton Crane

• 56 m Boom

(2) Liebherr HS 855

• Clamshell Rigs

• 110 Ton Crane

• 26 m Boom

134


135


136


Building Basements

Circular Shafts



Buenos Aires - Maldonado Shaft

Trevipark - Automated Underground Car Park

Case Histories

137

Maldonado Shaft - Buenos Aires (2009)

The shaft will be the final part of two flood

relief tunnels ( = 7 m) which will convey

the rain water of the "Arroyo Maldonado“ in

case of huge flows due to exceptional storms.

Then the water will be pumped into the Rio

de la Plata River.

Currently, the Arroyo Maldonado is a big duct

which runs for approx 20 km below Buenos

Aires‟ streets.

138

Flood Relief Tunnels

Shaft

Arroyo Maldonado Discharge

Domestic Airport “Jorge Newbery”

Maldonado Shaft - Buenos Aires

139

35

m

Silt &

Clay

Sand

Clay

-23.0

-45.0

+4.0

-31.0

-51.0

K = 10-4 m/sec

K = 10-8 m/sec


25 primary panels +

25 secondary panels

140


Technique: HYDROMILL (Vertical Tolerance < 0.3% to guarantee circular shape and design thickness)

Equipment: Soilmec Tiger H8

Crane Soilmec SC 90

Thickness: 1200 mm



Over cut joint: 130÷290 mm



141


142


143


144

TREVIPARK (1994-2010)

The TREVIPARK, patented by TreviGroup, is an “automated undergroundcircular car parking” especially designed to be located in roads, squares,courtyards, gardens and nearby existing buildings.

A minimum of 60 up to a maximum of 96cars can be parked in the car park,respectively from 5 to 8 levels, 12 cars perfloor.

The external dimensions of the car park isabout 20 meters, with small impact onadjacent environment.

145

TREVIPARK – Shaft Structure

The C.S.P. system was especially developed for the execution of the

shafts related to the TREVIPARK realization.

Anyway, due to the soil conditions, shafts have also been carried out by

means of diaphragm walls excavated by hydraulic clamshell with round

section jaws which, in combination with the circular joints guarantees

the execution of a continuous circular wall.

106÷110 CSP

No steel reinforcement

30 Panels

146

TREVIPARK – Joint

PVC pipes, filled by gravel, are installed into the primary panel before

of the steel cage and concreting.

During the secondary panel excavation, PVC pipes are crushed and

cleaned before concreting.

147

YEAR PROJECT

No. OF

FLOORS TECNIQUE WIDTH & DEPTH

WATER

TABLE SOIL CONDITIONS QUANTITY

1994-1995Martini Park

Cesena (Italy) 2 x 6 C.S.P.

800 mm @ 0.60 m

16.5 m> 17.0 m

Fill

silty sand and gravel2 x 1800 m

1997-1998Cesena Centro Park

Cesena (Italy)8 D.W.

500 mm

25.0 m17.0 m Silt and Clay 1600 sq. m

1998-1999Piazza Fabbri Park

Cesena (Italy)7

C.S.P.

Bottom Plug

900 mm @ 0.60 m

21.5 m8.50 m

Fill

silty sand and gravel2400 m

1999-2000Barriera Park

Cesena (Italy)2 x 7 D.W.

500 mm

34.0 m15.5 m

Silt and Sand

Clay2 x 2150 sq. m

2000-2001Largo Prestinari Park

Roma (Italy)7

D.W.

Bottom Plug

500 mm

22.0 m9.0 m

Fill

Silt and Sand1400 sq. m

2001-2002Corso Cairoli Park

Torino (Italy)6 D.W.

500 mm

20.0 m12.0 m

Sand, Silt and

cemented Gravel1300 sq. m

2002-2003Piazza B. Croce Park

Brescia (Italy)6 C.S.P.

800 mm @ 0.60 m

20.0 m> 20.0 m

Sand, gravel and

peabbles2100 m

2002-2003Largo Pizzetti Park

Roma (Italy)7 C.S.P.

900 mm @ 0.67 m

21.5 m20.0 m

Fill

Silt and Sand2100 m

2002-2003Kv. Keramiken Park

Stockholm (Sweden)2 + 2 Jet Grouting

1000 mm @ 0.80 m

10.0 m4.5 m

Sand and Clay

Granite800 m

2005-2006Adda Cornagllia Park

Milano (Italy)6 C.S.P.

800 mm @ 0.60 m

22.0 m16.0 m Sand and Gravel 2300 m

2005-2006San Domenico Park

Brescia (Italy)6 C.S.P.

800 mm @ 0.60 m

19.0 m> 20.0 m

Sand, gravel and

peabbles2000 m

2007-2008Via Finelli Park

Bologna (Italy)6 D.W.

650 mm

26.0 m6.5 m Sand, Silt and Clay 1600 sq. m

2008-2009Via D'Azeglio Park

Bologna (Italy)7 D.W.

650 mm

35.0 m6.5 m Sand, Silt and Clay 2200 sq. m

TREVIPARK

Characteristics of the accomplished car parks in the last 15 years

148

TREVIPARK – Site Site dimensions are generally very small

Especially in case of Diaphragm Wall

149

TREVIPARK – Shaft Excavation Gross excavation is carried out in steps of 5 m each, since every 5 m,verticality and position of all the wall‟s elements are checked.

150

TREVIPARK – Internal structures Prefabricated boxes (or columns + slabs) are simply placed onto thebottom slab and mutually connected by steel bars.

151

TREVIPARK – Central Platform An elevator equipped with a steel rotating platform is positioned atthe shaft center.

152

TREVIPARK - Final Layout Small impact on the city environment

153


Building Basements

Circular Shafts



Alabama (USA) - W.F. George Dam

Venezuela - Borde Seco Dam

New Zealand - Arapuni Dam

Kentucky - Wolf Creek dam

Case Histories

154

W. F. George Dam – Georgia/Alabama (2002-2003)

The Walter F. George Dam spans the Chattahoochee River on theAlabama – Georgia border in the southeastern United States.

155

W. F. George Dam – Georgia/Alabama

Spillway

Navigation LockPower

House

156


The dam was built in the 1950‟s

In the last 40 years many remedial works were carried out by means

of drilling and grouting, drains, concrete cut-off walls in the two

lateral embankments, to reduce water filtrations and seepage.

Although these efforts were successful in stopping the leakages

under the embankments, they concentrated the filtration underneath

the concrete structure of the spillway, jeopardizing the stability of

the dam.

As consequence the U.S. Army Corps of Engineering decided the

construction of a 60 cm thick, 64 m deep, concrete cut-off wall

upstream the existing concrete dam to remediate once for all the

situation .

157


Diaphragm Walls in the two abutments

Secant Pile Wall in front of the spillway

380 m90 m100 m

Plan View of the Cut-Off

158


Diaphragm Wall in the Abutments Secant Pile in front of the Spillway6

4 m

30

m

34

m

159


Concrete Cut-Off Wall

Technique: HYDROMILL & REVERSE CIRCULATION SECANT PILES

Abutments Spillway

Technique: Hydromill Reverse Circulation

Equipment: HF12000 # 2 Wirth PBA 612

Crane: Manitowoc 12000 Manitowoc 12000

Thickness: 800 mm 1270 mm (Dia.)

Spacing: 840 mm

Max d.w. depth: 64 m (212‟) 64 m

Over cut joint: 200 mm 430 mm

Wall surface: 12.000 m2 13.200 m2

160


Site Overview

161


West Abutment East Abutment

162


Secant Piles Construction Sequence

1. Frame and Template Installation

16

2

163




2. Casing Installation into the

Template

16

3

164





Template

3. Casing Driving by Vibrator and

Hammer

16

4

165





Template


Hammer

4. Drilling Rig installation on the

casing

2 Wirth PBA 612

16

5

166





Template


Hammer


casing

5. Insertion of the Drilling String

16

6

167




Template


Hammer


casing


6. Drilling the Shaft down to the

Design Depth


16

7

168




Template


Hammer


casing



Design Depth

7. Concrete Placement


16

8

169




Template


Hammer


casing



Design Depth

7. Concrete Placement

8. Moving Casing to Next Position


ICE

16

9

170


Cut-Off Wall Construction

Primary Secant Piles Installation

Secondary Secant Piles Installation

17

0

171


“Marine“ Activity from Barge

172

Borde Seco Dam – Venezuela (2004-2006)

Borde Seco Dam

Borde Seco Dam, on the Camburito River, belongs to the UribanteCaparo Hydroelectric Network , which include 3 more dams.

Borde Seco Dam

La Vueltosa Dam

La Honda Dam

Desarrollo II

173

Borde Seco Dam – Venezuela

Spillway

174


Dam Height = 125 m

Base width = 500 m

Crest elevation = 320 m

Max water elevation = 310 m

Min water elevation = 290 m

175


The construction of Borde Seco Dam started in 1981.

In 1983, during the excavation works, a 18/20 m thick friable

calcareous sandstone layer was detected, in both abutments, between

elevations ranging from 280-310 m.

This layer represented a potential risk, due to its high permeability

that could cause its internal erosion, jeopardizing both the main earth

dam and abutments.

ARENISCA CALCAREA

ARENISCA

176


Left Abutment

Right Abutment

Spillway

The problem was solved through construction of 80 cm thick concretecut-off walls placed in the dam‟s abutments and connected to the earthdam‟s core by plastic-concrete walls

Concrete cut-off (10 MPa)

Plastic-Concrete cut-off(1.5÷4.5 MPa)

177



Technique: HYDROMILL (Sandstone, Vertical Tolerance < 0.3%)

Equipment: Citycutter HC 03 & HF 12000

Crane Linkbelt 518

Thickness: 800 mm

Max d.w. depth: 55 m (40 m average)



178


Concrete Characteristics

17

8

(1) Dry bentonite per cu.m of concrete

(*) Cylindrical samples

(**) with hydraulic gradient of 30

(***) secant at deformation 50 % of break

(****) in triaxial cell with pression of 2 kg/cm², in consolidated and drained condition, and with speed of cut V = 0.008 mm/min

179


HF 12000 in Right Abutment

180


HC 03 in the Left Abutment

181

Arapuni Dam – New Zealand (2005-2007)

The Arapuni dam is located on the Waikato river, close to Hamilton.

182

Arapuni Dam – New Zealand

The dam was completed in 1928, the total height is about 50 m.

Since the beginning, the dam has been affected by occasional under-

seepage, treated by grouting campaign. The last episode, in 2001,

convinced the owner that the dam stability was at risk.

183


The geology of the dam foundation consists of Ignimbrite volcanic rocks

28 MPa

2÷6 MPa

Inside the Ongatiti Formation there were vertical joint, filled with highlyerodible material, that were vulnerable to piping erosion and hydraulicallyconnected to the reservoir

184


At the end of an extensive study and soil investigation, 4 main

fractures underlying the dam were detected

The solution was the constructionof a concrete cut-off wall, with:

o No interruption of power station

operations (i.e. full reservoir);

o 4 discrete cut-off panels .........

o ... Constructed from the dam crest

through concrete body;

o 95 m total depth (related to thickness

of Ongatiti ignimbrite);

o Minimum panel thickness 75 mm;

o Constructed as far upstream as

possible, to reduce the uplift water

pressure beneath the dam

185


TREVI proposed to install secant piles walls, formed by 400 mm

diameter holes spaced 300 mm, drilled from the crest of the dam.

A new drilling method was developed and patented, in which the cut-

off is drilled (and concreted) in slots of subsequent holes.

Completion of discrete slots leads to completion of the total panel.

The piles length and the presence of a tunnel at the base of the dam

made it necessary to use directional drilling technology.

186


Technique: SECANT PILE WALL by Slot Pile System (SPS)

Equipment: Soilmec Hydraulic Rig R312


Spacing: 300 mm

Max d.w. depth: 95 m (up to 60 m in concrete)


Number of piles: 134 (3÷4 days/pile; 2 shifts)



187


Drilling of a precision cored

pilot hole

Drilling of subsequent holes

of the slot by guide system

Installation of a pilot-hole

former in the last hole

Slot‟s filling with concrete

by tremie method

Reaming of the pilot hole

Guide system back on

Construction Concept

188


1. Pre-drilling down to approx 5 m

Construction Sequence

189



2. Drilling of a 150 mm diameter

starter hole by directional drilling


190





3. Reaming of the starter hole to

400 mm diameter


191






400 mm diameter

4. Drilling of the following hole using

guide in adjacent hole


192






400 mm diameter



5. Completion of the slot up to 8 holes


193






400 mm diameter




6. Checking slot dimensions and

continuity across the slot


194






400 mm diameter






7. Checking joint orientation in slot

and high seepage flow through

joints


195






400 mm diameter








joints

8. Slot‟s backfilling with concrete at

carefully controlled rate

PVC Pipe filled by gravelConstruction Sequence

196






400 mm diameter








joints

8. Slot‟s backfilling with concrete at

carefully controlled rate

9. End hole is reaming to start new slot


197


As-built piles‟ position at different elevations

Flow through fissured zones into downstream area decreased by

approx 90%

198

Wolf Creek Dam – Kentucky (2009- in progress)

The Wolf Creek Dam is located on the Cumberland River in the western part of Russell Country, Kentucky

199

Wolf Creek Dam – Kentucky

Wolf Creek Dam was built inthe 50s‟

It has a concrete section andan earth section for a totallength of about 1700 m

The rock is primarily characterizedby Karstic limestone (40÷140 MPa)with caves buried under theembankment

200


0 1+00A 2+00A 3+00A 4+00A 5+00A1+00B2+00B3+00B4+00B5+00B5+00B

EL. 660

EL. 690

EL. 730

EL. 763

EL. 773

EL. 730

EL. 690

EL. 665

EL. 640

Flow

Axis of Dam

C.L. Roadway & Embankment Sta. 0+16B

Foundation of Toe Drain

End of Drainage Blanket

Core trench

DrainageBlanket

Bedrock

Emb

Qal

Low Plastic Clay

Entire embankment consisted of low plastic clay

The drainage blanket is 60 cm thick (judged to be inadequate or evennon-functional)

Alluvial material (clays and sands, Qal) above the Limestone bedrock wasleft in place under most of the embankment and switchyard

Typical section of the earth dam

201


Wet Areas Sinkholes

Muddy Flow

Grout Curtains

Several seepage problems developed in the dam's foundation fromthe early 1960‟s.

Remedial works were executed in 60‟s & 70‟s

202


Detail of the remedial works executed in 60‟s & 70‟s

Earth Emb

Switchyard

Grout CurtainsSwitchyard

Wall

203


In March 2004 a series of wetareas were discovered

After further investigations, for safetyreasons, in 2006 the level of the lake waslowered by 70 ft (21 m) from 750 ft el. to680 ft el. ( 50% Max Water Level)

204


New Barrier Wall

Existing Wall

In correspondence of the embankment, a new 60 cm (24”) thick cut-offwall, upstream of dam center line, has been designed

205


Section of the embankment

206


Work sequence: Technique Areas, Critical areas and general Barrier Wall

Working Platform

Staging Area

Barrier Wall Alignment

Profile of the proposed wall and work sequence

84

m

27

4‟

1200 m

207


Schematic main features of proposed works by Trevi

El. 750

El. 475

208


Top of

Rock

1. Drilling & grouting into the rock up

to 90 m


209

Top of

Rock


SC-90 + cable grab STEIN


to 90 m

2. PCEW - Pre-excavation by Clamshell

up to 40 m, 1200 mm thick


210


SC-120 + HidromillEVO 3/5 (2 units)


to 90 m



3. PCEW - Reaming up to 40 m and

excavation from 40 to 60 m by

Hydromill, 1600 mm thick


Top of

Rock

211

Top of

Rock



to 90 m






4. Concreting of the PCEW by 2 tremie

pipes ( 270 m3)


212

Top of

Rock


PSM 14GTS + PARATRACK + WASSARA HAMMER (3 units)


to 90 m







pipes ( 270 m3)

5. BW – Directional drilling up to 84 m,

200 mm diameter (8”)


213

Top of

Rock


R625 + SR-80


to 90 m







pipes ( 270 m3)



6. BW – Pile pre-drilling by auger fitted

with stinger up to 40 m, 1270 mm

diameter (50”), spacing 890 mm


214


WIRTH PBA 818 (4 units)


to 90 m







pipes ( 270 m3)






7. BW – Pile drilling by Reverse

Circulation System up to 84 m


Top of

Rock

215



to 90 m







pipes ( 270 m3)






7. BW – Pile drilling by Reverse

Circulation System up to 84 m

8. Concreting of the Barrier Wall‟s pile

by 1 tremie pipe ( 110 m3)


Top of

Rock

216


Building Basements

Circular Shafts



Cengio - Acna Chemical Plant

Case Histories

217

Acna Chemical Plant – Cengio (2003-2005)

The first ACNA plant was built at the end of the 19th century. During itsoperative 120 years, the plants produced several types of chemicalcompounds, most of them extremely polluting, that were responsible forthe heavy pollution of the uppermost alluvial strata and ground water.

218

Acna Chemical Plant – Cengio

The accomplished work represents the final phase of rehabilitation of the

site‟s polluted area, after many provisional emergency interventions

carried out in the 10/12 previous years.

The new barrier, with a length of over 2200 meters along the Bormida

River bank, completes the waterproof cut-off all around the site.

Existing cut-off

New Barrier

219


The typical section of the wall is mainly

composed of:

Two structural concrete diaphragm walls, as

foundation elements and to protect the central

slurry wall;

One plastic wall with waterproof HDPE curtains,

embedded into the impermeable marl

substratum to prevent communication between

the polluted internal water and the river water;

One draining trench, back to the wall, to collect

percolation water;

The boundary concrete wall to avoid over-

splashing of the Bormida River during possible

river‟s flooding.

The wall is also designed to resist to an

internal backfilling and a simultaneous

external dredging.MARL UCS = 25 MPa

220

Other Main Activity

Ground Anchors

Micropiles

Draining trench

Concrete and Slurry walls

Technique: HYDROMILL (Marl with UCS = 25 MPa)

Equipment: Citycutter MBC 30

Concrete Wall Plastic Wall

Thickness: 800 mm 1000 mm

Max d.w. depth: 10 m 17 m

Over cut joint: 100 mm 300 mm

Wall surface: 10.200 m2 11.800 m2


https://sp.web.trevispa.com/Trevi/Settore Italia/21323/L1 Immagini e fotografie/tipologia 5/5B zona E/2004 04 06 T5B diaframmi ca a.jpg

221


https://sp.web.trevispa.com/Trevi/Settore Italia/21323/L1 Immagini e fotografie/panoramiche/2004 02 06 panoramica (4).JPG

222


Plastic Wall

Concrete Walls

223

Acna Chemical Plant – CengioDifferent Construction Sequence

https://sp.web.trevispa.com/Trevi/Settore Italia/21323/L1 Immagini e fotografie/tipologia 3/2005 04 28 T3 opere ca b.JPG

https://sp.web.trevispa.com/Trevi/Settore Italia/21323/L1 Immagini e fotografie/tipologia 1b/2004 09 17 T1B scavi .jpg

224

Generally in any project there isn‟t “THE SOLUTION”.

Any project can be done with different systems and different

technologies which solve the problem: simple, complicated,

already tested, new, cheaper , expensive, etc....

What is important?

It‟s important to have the knowhow, experience, background,

capability and possibility to choose the solution which better

satisfies all Parties involved in the Project (Client, Designer,

Engineer, Consultant, Main Contractor,

In the field of Foundation Engineering Trevi can help You to find

this “Better Solution”.

Conclusions/Final Considerations

............ Yourself).

225

MUCHAS GRACIAS

THANKSFOR YOUR KIND

ATTENTION

20 Excavacion y Construccion de Muros Pantalla Con Pilotes Secantes_Claudio Asioli

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Transcript of 20 Excavacion y Construccion de Muros Pantalla Con Pilotes Secantes_Claudio Asioli