Deep underground basements final with edits 10-14-03
pile wall
1. M SC, Civil Engineering
TUNNELING
Student name : Eng./ SALEM MOHAMMED MUSTAFA
Topic name : PILE WALL
Prof.Dr.-Ing.Yasser El-Mossallamy
2. OPEN CUT SHORED SYSTEM
Safe
No Effect Adjacent Building
Inexpensive
But Take Big Area & Passage
With respect to Vl. Element
Such as :
1. wood lagging.
2. Purlin wall
3. Sheet pile
4. PILED WALL My Topic
5. Diaphragm wall
WHY WE NEED SIDE SUPPORT SYSTEM
3. 1. Site Investigation.
2. Survey Map & Location
3. All Neighboring Structures
Information & Site Visit
4. Soil Parameters For Design
5. Statically System & Shoring
Type
6. Ground Water Control System
7. Construction Sequence
8. Load
Earth Pressure
Water Pressure
External Load
Seismic Load
……….
How To Start Design Of Shoring System
9. Start geotechnical design for
all stages
Stage 1
Stage 2
Stage …..
And take critical stage with more
safe & economic
10. Structural design
11. Drawing & details
4. good quality site investigation
program
Cost of Failure - Too High!
The subsurface exploration program
should include the following:
1. Collection of Preliminary Information
about the Structure
Type of soil in the structure
surrounding area.
2. Planning and location of the
boreholes.
Performing test boreholes.
Collecting samples at the desired
depths of the boreholes for
observation, classification, and testing.
3. Depth of Boreholes
The boring should penetrate the sand
layer (if exists) sufficiently to
determine its continuity, (especially in
pile foundations.
For deep excavation, depth of boring ≈
1.5 excavation depth.
If rock is encountered, it should be
penetrated 4 m, at least.
بالعمق الجسة عمق تحديد يتم أن ممكن
إلى اإلجهادات قيمة عنده تصل الذى0.10
التأسيس منسوب عند اإلجهادات قيمة من
Ds2 ≈ 0.1 Ds1
SITE INVESTIGATION الموقع استكشاف
5. Site Investigation Report
• Starting level of the
borehole, as related to
specific surveying level.
• Borehole log, showing
different soil layers and
depths.
• Field test results, e.g., SPT.
• Ground water table level
• Consistency of clays, and
relative density of sands, in
addition to color
• Typical Borehole Log
According A C P 202/2001
15. Piled Retaining Walls
In-situ Pile Retaining Walls Also Called
Column Piles Are Rows Of Concrete Piles
Either Cast-in Situ Pile Method Or Precast
Pile Method. Merits Of Column Piles Are
Less Noise Or Vibration Than Produced By
The Installation Of Solider Piles Or Sheet
Piles. Colum Piles Have Greater Stiffness
Than Soldier Piles Or Steel Sheet Piles.
They Avoid Excessive Bulk Excavation And
Help To Control Ground Movements.
There Are Three Distinct Bored Pile Wall
Options In Current Use: Contiguous
Wall, Secant Wall And Tangent Wall.
16. Continuous Flight Auger
CFA is a drilling
method which enables
a high drilling
performance in stable
soil. A continuous flight
auger is used as drilling
tool. After having
reached the final
depth, concrete is
injected through the
hollow stem auger
17. Continuous Flight Auger
Diameter and spacing of the piles is decided based on soil type, ground water
level and magnitude of design pressures. Large spacing is avoided as it can result in
caving of soil through gaps. CFA pile diameters range from 300mm to 1000mm. CFA
piles are considered more economical than diaphragm wall in small to medium
scale excavations due to reduction in cost and time of site operations. Besides, no
bentonite mud is needed for the excavation. Contiguous piles are suitable in
crowded urban areas, where traditional retaining methods would otherwise
encroach the adjoining properties, these piles restricts ground movements on the
backfill side. The pile is formed by first drilling into the ground with a CFA.
Cement-sand grout or concrete is then injected under pressure through the auger’s
hollow stem as it is being withdrawn. The grout or concrete pressure is maintained
during the auger withdrawal so that it assists the extraction as well as exerting a
lateral pressure on the surrounding soils. On completion of this operation, a
reinforcing cage is placed into the fluid column of grout or concrete. When CFA
pile combined with capping beams/breasting beams can show savings in cost and
time. Capping beams at the top to help equitable pressure distributions in piles.
Separate facing usually provided to improve looks. The range of soil conditions in
which CFA piles can be used are granular soils, cohesive soils, soft rocks
diaphragm beam
Or guide beam
18. Disadvantages Of Contiguous Pile Walls
Soft clays, weak organic soils are unsuitable due to
wall bulging. Hard rocks are also not suitable. The
Contiguous wall can only be used where ground
water is not a hazard or where grouting or jet
grouting is used can be used to remedy leakage
between the piles. However, some acceptable
amount of water can be collected at the base and
pumped out. The principal disadvantages of
contiguous pile walls-the gaps between piles and
the resulting problems of lack of water proofness
have been effectively overcome by interlocking or
secant piles.
19. Secant Pile Walls
Secant Pile Walls are formed
by constructing intersecting
piles.
Secant bored pile walls are
formed by keeping spacing of
piles less than diameter.
Secant pile walls are used to
build cut off walls for the
control of groundwater inflow
and to minimize movement in
weak and wet soils
Secant Wall constructed in
the form of hard/soft or
hard/firm and Secant Wall
Hard/hard wall. Secant
Wall-hard/soft or
hard/firm is similar to the
contiguous bored pile wall
but the gap between piles
is filled with an
unreinforced
cement/bentonite mix for
the hard/soft wall and
weak concrete for the
hard/firm wall.
21. Secant Pile Walls
Construction is carried out by installing the primary piles (A)
and then the secondary piles (B) are formed in reinforced
concrete, cutting into the primary piles , cutting into the
primary piles. Diameters can range from 500mm to
1200mm. Secant Wall Hard/hard wall construction
procedure is very similar to a hard/firm wall but in this case
the primary piles (A) are constructed in high strength
concrete and may be reinforced. The Secondary piles (B)
are cut into the concrete primary piles (A) using heavy duty
piling rigs fitted with specially designed cutting heads.
22. Tangent Pile Walls
consist of a series of drilled shafts located such that the
adjacent shafts touch each other, hence the name tangent
wall. walls and are
more effective in keeping ground water out of the excavation.
23. Continuous Flight Auger Piling (CFA Piling)
CFA Piling Is One Of The Most
Widely Adopted Piling
Techniques Due To Its Low
Impact On The Surrounding
Environment. It Is Ideal For
Use Near Any Environmentally
Sensitive Situation Including
But Not Limited To Listed
Buildings, Water Treatment
Works And Contaminated Sites.
24. Rotary Piling
Rotary Piling Allows For The
Installation Of Piles Up To Depths Of
34m And Much Larger Diameters Up
To 1.2m
Concrete Can Be Placed To Or
Below Commencement Surface
Level
Temporary Or Permanent Liners
Can Be Installed
Piles Can Be Installed Through
Particulary Stiff Or Hard Strata
Inspect The Pile Boring During
Construction
Short Rigging Up Time
25. Rotary Piling
The Rotary
Drilling
Technique
Enables The
Construction Of
Walls In
Difficult Soil
Conditions
(Hard
Cemented
Layers, Coarse
Gravel, Rock
Socketing) With
Various
Diameters And
Depth As Per
The Technical
Requirements
26. Pile Testing / QA
The pile testing regime
adopted for any site will vary
depending on the following
factors:
Quality of the site investigation
Design factor of safety
Number of piles
Consistency of the geology
Any specific contractual
requirements
27. Ground Anchors
Anchors are used to transfer
forces acting on retaining
structures to soil behind or deep
below. Anchors enable the
construction of excavation pits
without using struts during the
complete works. In this case, the
anchors are temporary.
Ground anchors are structural
elements where a grout body is
produced in the subsoil by
injecting grouting mortar around
the rear part of a steel tendon.
The grout body is connected by
way of the steel tendon and the
anchor head to the structure or
the rock section to be anchored.
28. Anchored Sheet Pile with
Free End Condition
Anchored Sheet Pile with
Fixed End Condition
Anchored Sheet Pile
29. Location of Anchor
Anchors are used to transfer the
load from the tie to the
surrounding soil. As the soil can’t
generally take tensile forces, the
anchors must be designed to
transfer the load through
compression (passive and active
earth pressure) or through skin
frictions.
“Dead Man”. It is constructed of a
heavy mass of plain concrete. It
transfers the tie force through skin
friction on the sides parallel to the
force as well as the difference
between passive and active earth
pressure on the two sides
perpendicular to the tie direction.
30. Location of Anchor
The second type, on the top right corner, and the third type on the low
left corner transfer the force mainly through the difference between
passive and active earth pressure on the two sides perpendicular to the
tie direction. The last type, which is found in the right low direction,
transfers the force through tension and compression friction piles.
31. overall stability failure Examples of limit
modes for overall stability of retaining
structures.
Rotational failure of embedded walls
Examples of limit modes for rotational
failures of embedded walls.
Failure Examples Of Retaining Structures.
32. Vertical failure of embedded
walls
Examples of limit modes for
structural failure of retaining
structures.
Failure Examples Of Retaining Structures.
Failure by pull-out of
anchors
43. بسببالمباني اساسات قرب
Support Method
For Secant Pile Wall
Consider All Loads In
Design Of Foundations
Such As ( Supporting
Of Side Support System)
44. According to structural system
Cantilever System
Single Anchor
Multi Anchor
According to Anchor system
Strut
Dead man
Tie
Pre stress anchor