NUR AQILA E’ZZANY BINTI KAMARULZAMAN

NUR AZIMAH ADILA BINTI MOHD SHUKRI

SAKINAH KHALIDAH BINTI KAHARUDDIN

SITI NADIRAH BINTI JAMIL

INTRODUCTION Definition Basement:

• A basement excavation is a construction dig.

• There are several common method of excavation, in order to build basement.

• Essential that the excavation is adequately supported, and the groundwater properly controlled.

SELECTION OF EXCAVATION FOR BASEMENT CONSTRUCTION

Subsoil conditions and ground water

level

Working space requirements and site

constraints

Maintenance of the wall and support

system in permanent condition

Cost and times of construction

Local experience and available

construction plant

TYPES OF EXCAVATION

FOR BASEMENT

CONSTRUCTION

DIAPHRAGM WALL

SHEET PILE

WALL

CONTIGUOUS BORED PILES

WALL

SECANT PILES

a form of driven piling using thin interlocking

sheets of steel.

Used vibrating hammer, t-crane and crawler

drilling to establish it

suitable for sites where the space around the

excavation is insufficient for sloping back the

sides

SHEET PILE WALL

SHEET PILE WALL It consist of rolled steel sections with interlocking

edge joints

The interlocking edges allow each sheet pile to

slide into the next with relative ease.

METHODS OF CONSTRUCTION SHEET PILE

1) POSITION OF STEEL

2) INSTALLATION OF

FIRST SHEET PILE

3) INSTALLALTION OF

SECOND SHEET PILE

4) REPITATION OF

PROCESS

5) EXTENSION OF SHEET

PILE

Examples of Sheet Pile

ADVANTAGES DISADVANTAGES

Rapid installation Direct driving effect on the subsoil

Steel can be either permanent or recovered

Noisy

very economical compare with the alternative of a diaphragm wall

High capital investment if re-usage is restricted

Seal may not be perfect

Constructed by excavation in a trench which

temporarily supported by bentonite slurry.

Suitable for :

• sites where obstructions in the ground prevent sheet

piles from being driven where the occurrence of

groundwater is unfavorable for other methods of

support.

• Also suitable for sites where considerations of noise

and vibration

On reaching founding level steel reinforcement is

lowered into the trench, followed by concrete to

displace the bentonite

DIAPHRAGM WALL

METHODS OF CONSTRUCTION DIAPHRAGM WALL

2 ) Excavation of

Panel

2. EXCAVATE TRENCH

Examples of Diaphragm Wall

ADVANTAGES DISADVANTAGES

Permanent basement wall A lot of labour is needed

Scan be designed to form part of a permanent foundation

Long period of construction

Minimum vibration and noise

High cost

Can be used in restricted space

CONTIGUOUS PILE WALL

• line of bored pile installed close together or touching.

• Smaller diameter micro-pile may be installed in between each adjacent pile.

• Gaps between the micro-pile

and main piles are grouted.

METHODS OF CONSTRUCTION CONTIGUOUS BORED PILE

1). POSITION OF BORED PILE

2) INSTALLATION OF CASING

VIBRO HAMMER

3) AUGERING OF BORE PILE

4) INSTALLATION OF STEEL

CAGE

5) CONCRETING OF

BORE HOLE

6) EXTRACTION

7) REPITATION OF

PRECESS

Examples of Contiguous Bored Pile

Advantages

Disadvantages

Built-up areas where noise and vibration should be

limited

Concrete in shaft susceptible to squeezing or

necking in soft soil where conventional types are

used

In industrial complexes where access, headroom

and/or restriction on vibration may make other

methods such as steel sheet piling or diaphragm

walling less suitable

Special techniques needed for concreting in water

bearing soils

Lower cost

Concrete can be readily inspected after installation

Speed in construction for temporary and

permanent wall where drilling conditions are

conducive

Drilling a number of pile in group may cause loss of

ground and settlement of adjacent structures

Higher capacity to overcome obstruction like rock

compare to other system

Additional work are needed to form an acceptable

surface to the wall

Drilling tools can be break up boulders or other

obstructions

Lack of water tightness

Secant pile • similar to contiguous bored piles except that

they are constructed in:

- male

- female

• interlock each other.

• male piles are reinforced while the female piles are not.

• In cases where lateral pressure from the soil is excessively high, male-male secant piles may be used.

METHODS OF CONSTRUCTION SECANT PILE

1. CONSTRUCT A GUIDE

WALL

2. INSTALLATION OF STEEL

CASING

3) AUGERING OF PRIMARY

BOREHOLES

4) CONCRETING OF PRIMARY

BOREHOLES

5) AUGERING OF SECONDARY BOREHOLES

6) INSTALLATION OF STEEL

CAGE

7) CONCRETING OF

SECONDARY BOREHOLE

8) REPITATION OF PROCESS

Example Secant Pile..

Advantages

Disadvantages

- Provide higher degree of water

tightness

- High cost for installation

- Stronger resistance to lateral

pressure

- Ensuring complete contact of all

piles over their full length

- Can be used on small and

confined sites

- May be difficult in practice

- Suitable to built near building,

roads and other sensitive

structures

- Minimum noise and vibration

CASE STUDY

CONTRACT TITTLE Purpose to build 33 storey office tower developed by KL Sentral & MRCB for Lembaga Tabung Haji SCOPE OF WORKS 1 BLOCK OFFICE WHICH CONSISTS OF : - 3 levels of basement parking - 2 levels of Main lobbies - 5 levels of elevated car parks - 1 level of M&E Floor - 20 levels of Offices - 2 levels of Penthouse

PROJECT BRIEFING

- Location of site : KL Sentral - Located at congested area ( Putra,KTM,Erl station,shop lots building, private parking area,hotel, office building, etc ) - The land is existed flat - According to soil engineer, type of soil consist : sandy clay, silty clay, silty sand, shale and shale rock. - It was busy area – within working hours

NATURE OF SITE

METHOD STATEMENT OF

BASEMENT WORKS SURVEY STAGE - Land surveyor play their role the original ground level and set out control point SITE CLEARING - demolition of existing building – small shop building - grubbing out bushes, trees and removal soil to reduce level - After site clear - hoarding, wash trough, storage and temporary site office

CONSTRUCTION OF DIAPHRAGM WALL AND CONTIGUOUS BORED PILE - two type of retaining wall has decided by engineer – diaphragm wall and contiguous bored pile. - use existing diaphragm wall – save cost and limited space ( refer layout plan) - reason : if build new diaphragm wall, ground anchor fixed to diaphragm wall will disturbed the foundation of existing building - use contiguous bored piled - For perimeter area – did not have existing building - Bored piled : - total used : 260 nos - size : 750 mm - depth : 16 m - gap : 75 mm - use helical reinforcement - I machine can build only 2 bored pile in one day – have 4 machine at site - after completion, use concrete 200 mm thk – as skin wall + waterproofing - advantages using contig.bored pile : It is free standing – didn’t use anchor

EXCAVATION - after completion of diaphragm wall and contiguous bored pile, excavate basement. - excavate 10.00 m depth - use 1m3 bucket excavator. - ramp system – purpose of transportation – loading and unloading construction material.( refer figure 5.19 ) - the ramp will remove after excavation process. - temporary opening – entering excavation area ( refer figure 5.20 )

CONSTRUCTION TECHNOLOGY IV - BASEMENT

CONSTRUCTION BASEMENT FOUNDATION - use raft foundation as a foundation - depth : 2.75 m - size of reinforcement : 25 mm , 32 mm - concreting process – concrete + ice cube – low the temperature - reason use raft foundation : - carry a great load - soil hard material at site

View 1 raft foundation construction

View 5 Concreting of raft in progress

View 6 completion of concreting Raft foundation

CONSTRUCTIONN OF BASEMENT FRAME AND STRUCTURE

- method of construction : bottom up method ( refer figure below ) - starting by construction of basement column - start from B1 - B2 – B3 - construction including concrete, formwork , reinforcement

Construction of Basement Frame

BACKFILLING - after completion of basement frame – backfilling process - backfilling process – by stage - after completion of B3, contractor constructing B2 level – backfilling process proceed at level B3 - repeat backfilling sequence – until upper level

Backfilling the remaining excavated area

COMPLETE BASEMENT - after backfilling process –structural work for basement completely finished - proceed upper level construction – floor , wall, etc.

Complete Basement

This property is a detached Victorian house in Hampstead, which had no existing cellar, a

timber suspended floor and an existing partial lower ground floor. London Basement were

asked to carry out the construction of a basement below the house and rear and side patio’s,

creating an area of 196M² (2109 sq.ft.), with a head height of 3M below the house and 2.9M

below the patio’s.

As you will see from the artist’s rendition, the majority of the basement space was to be used

as an Art Gallery.

The property had a part timber suspended, part solid floor and our clients lived in the

property throughout the works, which took approx. 30 weeks.

Two conveyors belts were installed from the areas of excavation into the skip situated on the

road.

Initially we carried out the design and installation of the temporary works required to support

the existing building structure. This involved the installation of a series of cantilever needle

beams passing through the external walls, at critical load points, supported on temporary

compression piles placed adjacent to the external walls. This enabled us to be able to break

out the existing foundations and replace them with the new designed steel support system.

conclusion Whichever method supporting basement chosen

and any consideration will have to be given to additional measures to achieve good performance corresponding to modern consumer expectations.

Enjoy the video……..