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; preparation)

■j storage and handling of the sheet piles | welding and cutting of steel elements t

-iving of the sheet piles'"|

Execution of sheet pile wali structures

Scope of EN 12063 Execution of special geotechnical work -sheet pile walls tolerances regarding plan position and verticality j corrections of sheet pile position during driving ) -—[installation of anchorages""} walings and struts)-

1 excavation, filling, drainage and de-watering

^extraction of sheet piles ) -j rock dowels and anchor bolts j sealing )

■jsupervision!

j Site records

— Design considerations J-

j Site records

Supervision, testing, and monitoring ]—[testing

| monitoring

-[records in connection with the execution-■] records at completion of the execution |-

Special requirements impact on the surrounding buildings and installations

-[ permeability of sheet pile walls)

Figure 15.6. Scope of EN 12063, Execution of... slieetpile walls

15.3.2 Diaphragm walls

Figure 15.7 summarizes the scope of EN 1538,7 which deals with the execution of diaphragm walls including cast-in-situ, precast concrete, and reinforced slurry walls (for retention) and slurry and plastic concrete walls (for cut-off).

Guidance is provided on the suitable characteristics for bentonite support fluid. No specific characteristics are given for polymer support fluids. Design minimum cement content of concrete for various maximum aggregate sizes is provided ranging from 350kg/m3 to 400kg/m3 for aggregate sizes of 32mm to 16mm. The water cement/ratio must not exceed 0.6. Mix design guidance is given for plastic concretes for use in cut-offs in Annex A.

A series of tables is provided which details the supervision of execution and monitoring. Tables 3 to 7 cover the requirements for: cast-in-situ concrete diaphragm walls; precast concrete diaphragm walls; reinforced slurry walls; slurry cut-off walls; plastic concrete cut-off walls.

EN 1538 provides a key diagram that defines the main parts of a diaphragm wall (panel, guide wall, and reinforcement cage) and their dimensions (panel length and thickness, depth of excavation, cut-off level, horizontal and vertical cage lengths, cage width, platform level, and casting level).

EN 1538 was published by CEN in 2000, confirmed in 2002 for a further five years, and scheduled in 2007 for revision by TC 288 following a systematic review.

15.3.3 Ground anchors

Figure 15.8 summarizes the scope of EN 1537,8 which deals with the execution of ground anchors.

The standard provides a key diagram that defines the main parts of a ground anchor, including: the anchorage point at the jack during stressing and at the anchor head in service; the bearing plate, load transfer block, and structural element; and de-bonding sleeve, tendon, and grout body.

EN 1537 defines three types of test relevant to ground anchors, the purposes of which are summarized below.

I Normative references"]—

and definitions j—

\ symbols

Terms and definitions j Information required for the execution of the work j-

specific aspects"^—Site investigation bentonite suspensions polymer solutions

[self-hardening sluiri aggregates cement water/cement ratio -}—J concrete admixtures fresh concrete •[plastic concrete or plastic mortar

"^-[supporting fluids")-

Materials

"^-[supporting fluids")-

Executii

Materials

Scope of EN 1538 Execution of special geotechnical works — diaphragm walls ion 1 -

lUi excavating panel reinforcement cage working platform guide walls supporting the sides of the excavation excavating sequence loss of supporting fluid cleaning the excavation -[forming the joints j placing the reinforcement or other elements

[concreting and trimming j

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