1.0 INTRODUCTION
- This document outlines the general procedure for the construction of Stone Columns by wet top feed method by using heavy duty Depth vibrators
- Soil Improvement by vibro replacement ( Stone Columns)
2.0 Equipment
The depth vibrator VL 18 vibroprobe consists of two elements, the vibrators and the following tubes
Figure 1: General arrangement of a vibroprobe
Figure 2: General arrangement of a vibroprobe
Eccentric weights in the vibrator section, which is
approximately 3.5m to 4.1m in length, are rotated using an electric motor,
thereby generating vibrations in a horizontal plane at the tip of the
vibroprobe.
When the vibrator is operating the follower tubes
remain almost stationary due to the dampening effect of the flexible vibration
damper, or isolator. Fins on the side of the vibrator prevent rotation of the
vibroprobe in the ground and assist in transmission of compactive effort tot
the ground.
There is a range of different vibroprobes, and example specifications are shown in Table 1 below:
Manufacturer
|
Vibro
|
Machine name
|
VL18
|
Length [m]
|
10-18
|
Diameter [mm]
|
40-60
|
Motor[kW]
|
130
|
Speed [min-1]
|
20-80
|
Dyn. Force [kN]
|
300
|
Table 1: Example vibroprobe
specifications.
Typically the following
equipment would be required for a crane mounted system.
FOR STONE COLUMNS
|
|
With VL18
|
|
Crane
|
50 tons
|
Genset
|
350 KVA
|
Water Pump
|
6 to 10 bars
|
Loader
|
CAT 930 to 966
|
MISC
|
Sledge (for Genset)
|
The vibroprobe is usually
suspended from a conventional crawler crane (Figure 2) for deeper treatment
(say greater than 8m), but for treatment depths of up to about 8m the
vibroprobe may be mounted on an excavator base machine (Figure 3). A mobile
generator is used to provide power to the electric motor in the vibrator.
Figure 3: Wet Vibro Stone Column Rig for deep
treatment.
Figure 4: Wet Vibro Stone Column Rig for deep treatment.
3.0 STONE
COLUMN CONSTRUCTION
a) During penetration water is discharged at the tip of the
vibroprobe: water is carried through the follower tubes and the
vibration damper to the top of the vibrator where passageways in the
wall of the vibroprobe lead it to pipes fixed to the outside of the
vibrator. These direct the water to the tip.
Penetration to the required depth is achieved by a combination of
vibration and the jetting action of water and/or air. If only air is used,
the in situ soil is displaced sideways. Using water only, disturbed
material is also flushed out of the hole.
When the required depth is reached, the amount of water discharged
from the tip of the vibroprobe is adjested so that the water level in the
hole stays at about 1.5m above ground water table or working
platform level. This prevents the collapse of the hole.
b) During construction of the stone column, spray water and/or air
jets in the side of the follow-up tubes may be used.
The vibroprobe is lifted by between 0.5m and 1m and a small charge
of gravel or crushed aggregate is introduced into the bore which finds
its way down the annular space around the vibroprobe. The
vibroprobe is partially re-penetrated to compact the stone and is then
lifted by another 0.5m to 1m. A further charge of aggregate is then
added which is also compacted by partial re-penetration of the
vibroprobe. Radial forces produced by the vibrator force the added
material horizontally out against the in situ soil, thereby compacting
it.
The filling / compaction cycle is repeated in upward increments up to
the working platform level. During this operation, additional gravel
or stone is added to the hole but without overfilling to avoid bridging
of the gravel; thus a stone column of dense granular material
interlocking with the surrounding ground is formed
Figure 5: Construction of stone
Figure 6: Construction of stone
Figure 7: Construction of stone
Figure 8: Construction of stone
Figure 8: Vibreprobe
Figure 9: Construction of stone
Figure 10 Stone Columns Construction
Figure 11 Stone Columns Construction
4.0 QUALITY CONTROL
The design of stone columns relies on the reinforcing effect of the highly compacted stone columns
within the soil. Important design parameters used in the design are the cross section area of the stone
columns and the grid spacing of the columns. It is therefore necessary to ensure that these parameters
are achieved during installation.
The aggregate is supplied to the column location by means of a calibrated bucket to enable accurate
measurement and recording of the stone consumption of each column.
The number of buckets of aggregate used in each stone column is recorded manually on the Daily Site
Record Sheets (sample presented in Daily Report Table).
For every column, a Daily Record Sheet will be submitted as per the sample (if needed) in the Daily
Report Table.
4.1 Compaction Point Layout Drawings
Positioning the probe at each compaction point will be done by physically pegging each point
with setting out from Grid Lines as provided by the Main Contractor
4.2 Daily Records (As Attached)
Daily records will be kept and submitted to the Engineer for information and review and the record will
consist of the following details:-
a) Date
b) Compaction Point or Stone Column Reference Number
c) Depth of Penetration
d) Vibratory Power Consumption during penetration and compaction.
e) Record depth of obstruction encountered, if any.
f) Stone consumption
5.0 FIELD QA/QC
5.1 Quality of back fill material
Prior to commencement of improvement works soil parameters for aggregate material introduced into
the static design calculation must be verified based on laboratory tests.
Grain size analysis, Proctor Test and direct Shear Test shall be performed and results will be provided
to the Geotechnical Expert for approval.
5.2 Production of Stone Columns
The specific details of each stone column constructed shall be monitored in soil improvement record
sheets including the following information:
- No. and location of column
- Start Time - Finish Time
- Top of Column (Working Level)
- Termination Depth
- Material Consumption
5.3 Large Scale Plate Load Test
One (1) large scale plate load test shall be performed on a test column outside the improvement area,
but in the vicinity of the buildings. On this behalf one test column surrounded by at least 4 columns
shall be erected in the prospected pattern (triangular grid 1.75 m * 1.75 m).
The load test shall be made on the basis on previous standard ASTM D1194, which is actually
withdrawn. However, the bearing plate shall be of pre cast reinforced concrete of dimensions 1.5m *
1.5 m. The bearing plate shall be centered over single stone column.
The load on bearing plate shall be applied using one hydraulic jack reacting against a kentledge of
concrete blocks placed over a steel platform.
The bearing plate shall be loaded gradually in 25 % equal increments. Each load shall be maintained
until the rate of settlement has subsided which is universally recognized as being less than or equal to
0.25 mm per hour. The minimum holding time however shall be 15 min. The rate of settlement
(mm/hr) shall be noted from the last two readings of each load step.
Load shall be incrementally increased to 150 % of required allowable bearing capacity. This test load
shall be held until the rate of settlement subsides to less than or equal to 0.25 mm per hour but not less
than 2 hours in order to confirm results.
After this the plate load shall be unloaded also in 25 % increments. Heave shall be monitored after each
unloading step until the rate of heave has subsided which is universally recognized as being less than or
equal to 0.25 mm per hour.
Settlement readings shall be taken at four dial gauges with a least count of 0.01 mm placed at the four
corners of the load plate. The gauges shall be placed over two reference beams placed parallel at either
side of the footing. The reference beams shall be independently supported at a distance of at least 3 m
from the center of the bearing plate.
Prior to commencement of the plate load test all equipment and gauges shall be calibrated. Drawings of
the test arrangement, calibration sheets, monitoring form sheets and description of test procedure shall
be provided to the Geotechnical Expert for approval and endorsement.
Figure 10: Plate Load Test
Figure 11: Plate Load Test
5.4 Pre-CPTs
Prior to commencement of soil improvement a number of Cone Penetration Tests (CPT) shall be
performed at the specified locations approved by consultant.
Test locations shall be evenly spread over the improvement areas. Elevation and coordinates of test
locations shall be surveyed. Test results shall be provided to the Geotechnical Expert prior to
commencement of soil improvement.
5.5 Post-CPTs
After finalization of the soil improvement a number of CPTs shall be performed in the vicinity of
the pre-CPTs. Since CPTs cannot be applied in the centre of the stone columns, it is recommended to
perform them in the vicinity of columns (at their periphery) as well as between columns. The
monitoring logs shall provide information about the location of the CPTs related to the next column.
All test results shall be provided to the Geotechnical Expert of approval.
6.0 REFERRED DOCUMENTS
The stone column design is based on the Geotechnical Investigation Report, prepared by Soil Investigation team
Daily Report Format
Design and Specification of Self Completed Project 2010-2011
Project Name: Saline Water Conversion Corporation (SWCC) Ras az Zawer Saudi Arabia
Attachments
1 Calculation Sheets
1.1 Main Pump House
1.2 Booster Pump House
1.3 Electrical Building
2 Design Drawings
2.1 Main Pump House
2.2 Booster Pump House
2.3 Electrical Building
1 SCOPE OF SOIL IMPROVEMENT WORK
Due to unfavorable soil conditions in the foundation report it was proposed to perform
soil improvement by vibro replacement (stone columns). This procedure is required in
the area of Main Pump House and Booster Pump House between axes 25 and 29 as
well as in the area of the Electrical Building. Additionally at the pump houses stone
columns shall be installed in a widened grid beyond axes 25 in order to create a smooth
transition from the improved to the unimproved area.
This report deals with the stone column design and prospected measures for quality
assurance (QA) and quality control (QC).
2 Referred Documents
The stone column design is based on the Geotechnical Investigation Report, prepared
by Gulf Consult and the Foundation Report prepared by Ingenieuburo Duffel.
On 29 Sept. 2010 and 11 Oct.2010 Gulf Consult presented two reports dealing with
Cone Penetration Tests (CPT) which have been conducted in this area on request of
the Geotechnical Expert. The results of these CPTs have also been considered for the
stone column design.
Furthermore guide drawings from Main Pump House and Booster Pump House and
tender drawings from Electrical Building have been provided.
3 Subsoil Conditions
During the course of soil investigation a number of four different layers has been
explored which have been briefly described as follows:
Layer I: medium dense silty Sand SPT'N' values: 10≤n30≤22
Layer II: very loose Sand/ soft clayey Sand SPT'N' values: 1 ≤n30≤ 5
Layer III: dense Sand with Silt SPT'N' values: 20≤n30≤65
Layer VI: very dense Sand/very stiff fat Clay SPT'N' values: 30≥100
The layer to be improved is layer II. The bottom of this layer has been explored at 6 m
below existing ground level at time of soil investigation (EGL) at Booster Pump
House and Electrical Building and at 5 m below EGL at Main Pump House (mean
values). The groundwater level is expected at 1 m below EGL.
Prior to commencement of soil improvement the area shall be raised by appr. 1.0 m
select fill material as specified in project specification C-03. Further backfill is
required after soil improvement in order to reach the prospected foundation levels. In
this report the select fill material is called "Layer 0".
Station zero level is scheduled at 6.00 masl which is appr. 4.7 m above EGL.
All calculations are based on the assumption that the working level is 1.0 m above
EGL at time of soil investigation, i. e. around 2.3 masl.
4 Soil Improvement Design
4.1 General
Soil improvement design is carried out using the computer software called "GRETA"
provided by company GETEC. This computer software is based on the publication
"PRIEBE: The design of vibro replacement, Ground Engineering, Dec. 1995"
For given bearing pressure and existing soil conditions the computer program
GRETA calculates the suitable spacing of stone columns of specific nominal
diameter, depth and quality. The improvement factor "n2" is defined as the ratio of the
Young's modulus of improved soil versus the Young's modulus of unimproved soil.
Based on settlement calculations provided by the Geotechnical Expert in the
foundation proposal an improvement factor n2 = 3 has been postulated.
In the presented calculations a nominal diameter of stone columns of 80 cm has been
adopted. The stone columns shall be erected using well compactable crushed stone
material. For the design a shear resistance of φ' = 42.5 º has been considered for the
stone material.
Soil parameters introduced into the design calculation have been adopted from the
foundation report as follows:
γ
[k//m3]
|
γ'
[k//m3]
|
φ'
[º]
|
c'
[k//m2]
|
E
[M//
m2]
|
v
[-]
|
|
Layer 0
|
21
|
-
|
37,5
|
0
|
40
|
0,3
|
Layer I
|
21
|
12
|
32,5
|
0
|
10
|
0,33
|
Layer II
|
18
|
8
|
25
|
0
|
2
|
0,35
|
Table 1: Soil Parameters
As written in the foundation proposal the expected soil pressure of all structures is
less than the net safe bearing capacity of unimproved subsoil. The only purpose of the
soil improvement is to reduce the settlements which are within intolerable limits
without soil improvement. By this reason no calculations regarding this bearing
capacity are required in this design.
4.2 Main Pump House
Design calculation for stone columns at Main Pump House between axes 25 and 29
has been performed based on a triangular grid with distance between columns of 1.75
m and distance between rows of 1.75 m also. Nominal diameter of stone columns is
0.80 m. Calculation yields to an improvement factor n2 = 3.03.
As reported in the foundation proposal the soil improvement shall performed 3.0 m
beyond the boundary of the building area.
Beyond axe 25 a transition zone shall be created in order to allow an intergradation
from the improved to the unimproved area. Based on Cone Penetration Test Results it
is recommended to erect three rows of stone columns in a grid of 2.65 m * 2.65 m
beyond axe 25 and additionally three rows in a grid of 3.50 m * 3.50 m beyond axe
24. The exact location of stone columns in the transition area shall be adopted from
attachment 2.1.
Settlement calculation provided by computer program GRETA yields to overall
settlement after soil improvement of s = 33 mm. This calculated settlement is in good
accordance to settlements calculated by the Geotechnical Expert. However, it shall be
considered, that settlement calculation provided in the foundation report is more
precisely.
In the design calculation the bottom of layer II has been considered at 6.0 m below
working level. On site the foot of each individual stone column must be fixed based
on penetration ratio of the vibrator. Considering the results of Cone Penetration Tests
it is expected that the foot of stone columns will be somewhat deeper than assumed in
the calculation.
Details upon the design calculation may be adopted from attachment 1.1. The relevant
drawing is provided in attachment 2.1.
4.3 Booster Pump House
For the Booster Pump House a triangular grid with distance between columns and
distance between rows of 1.70 m each has been considered in the static design.
Calculated improvement factor is n2 = 3.13; calculated overall settlement after soil
improvement is s = 41 mm.
Beyond axe 25 a transition zone shall be created in order to allow an intergradation
from the improved to the unimproved area. Based on Cone Penetration Test Results it
is recommended to erect three rows of stone columns in a grid of 2.55 m * 2.55 m
beyond axe 25 and additionally three rows in a grid of 3.40 m * 3.40 m beyond axe
24. The exact location of stone columns in the transition area shall be adopted from
attachment 2.2.
The bottom of layers to be improved has been considered at 7.0 m below working
level. Considering the results of Cone Penetration Tests it is expected that the foot of
stone columns will be somewhat deeper than assumed in the calculation.
Further details upon the design calculation may be adopted from attachment 1.2. The
relevant drawing is provided in attachment 2.2.
Further remarks given in item 4.2 shall be considered.
4.4 Electrical Building
In the area of the Electrical Building calculation yields to the conclusion that the grid
may be widened to 2.20 m distance between rows and columns. This is caused by the
matter of fact that the foundation level of the Electrical Building is situated higher
than the foundation level of block foundations at the pump houses. Bottom of stone
columns is considered at 7.00 m below working level which is approximately 9.50 m
below foundation level.
The calculated overall settlement is s = 47 mm. The improvement factor is n2 =- 3.44.
Further details upon the design calculation may be adopted from attachment 1.3. The
relevant drawing is provided in attachment 2.3.
Further remarks given in item 4.2 shall be considered.
5 Quantities
Number of stone columns and linear meter shall be adopted from table 2.
No.of stone columns
|
Total linear meter
|
|
Main Pump House
Axes 25–29
Transition zone
|
203
27
|
1218
162
|
Booster Pump House
Axes 25–29
Transition zone
|
210
27
|
1470
189
|
Electrical Building
|
395
|
2765
|
Total
|
882
|
5804
|
Table 2: Quantities
6 Field QA/QC
6.1 Quality of back fill material
Prior to commencement of improvement works soil parameters for aggregate material
introduced into the static design calculation must be verified based on laboratory tests.
Grain size analysis, Proctor Test and direct Shear Test shall be performed and results
will be provided to the Geotechnical Expert for approval.
6.2 Production of Stone Columns
The specific details of each stone column constructed shall be monitored in soil
improvement record sheets including the following information:
- No. and location of column
- Start Time
- Finish Time
- Top of Column (Working Level)
- Termination Depth
- Material Consumption
6.3 Plate Load Test
Mentioned above
6.4 Pre-CPTs
Prior to commencement of soil improvement a number of 14 Cone Penetration Tests
(CPT) shall be performed at the following locations:
3 CPTs at Main Pump House (axe 25 - 29)
3 CPTs at Booster Pump House (axe 25 - 29)
8 CPTs at Electrical Building
Test locations shall be evenly spread over the improvement areas. Elevation and
coordinates of test locations shall be surveyed. Test results shall be provided to the
Geotechnical Expert prior to commencement of soil improvement.
6.5 Post-CPTs
After finalization of the soil improvement a number of 14 CPTs shall be performed in
the vicinity of the pre-CPTs. Since CPTs cannot be applied in the centre of the stone
columns, it is recommended to perform them in the vicinity of columns (at their
periphery) as well as between columns. The monitoring logs shall provide information
about the location of the CPTs related to the next column.
All test results shall be provided to the Geotechnical Expert of approval.
7 Conclusions
With this report the design of stone columns for soil improvement at Main and
Booster Pump House (axis 25 to 29 plus transition zone) and Electrical Building is
presented. The calculation is based on information presently available. In case on any
change in design the static designer should be notified immediately.
Additionally the report gives recommendations upon quality assurance and quality
control.
The Geotechnical Expert shall be continuously informed about the further procedure
onsite. All test results shall be provided to the Geotechnical Expert for approval and
endorsement.
Program GRETA-E, Version
90422, Copyright by GEOStat
RAS AZ
ZAWR - RIYADH WTS PS1 - MAIN PUMP HOUSE ATTACHMENT
1.1
**********************************************************************************
Calculation of a foundation
********************
Kind of treatment: Vibro replacement
Single footing of 426.36 m2 (
18.70 m * 22.80 m ) on 139 column (s)
Dead pressure g 100.00 kN/m2 live
pressure q 0.00
kN/m2
Reference area 3.07
m2
Calculation Depth 23.00 m Foundation
level 0.00 m
Depth of column foot 6.00 m
Ground water table 2.00 m
Properties of installed material (below load level)
No. Top gam phi c Dia. D E Q K
[m] [kN/m3] [º] [kN/m2] [m] [MN/m2] [MN/m2] [kN/m2
1 0.00 20.00 42.50 0.00 0.80 120.0 0.0 25.0 1.00
2 1.00 20.00 42.50 0.00 0.80 120.0 0.0 25.0 1.00
3 2.00 12.00 42.50 0.00 0.80 120.0 0.0 25.0 1.00
4 2.50 12.00 42.50 0.00 0.80 120.0 0.0 25.0 1.00
5 6.00 12.00 40.00 0.00 0.00 100.0 0.0 0.0 1.00
6 23.00 12.00 40.00 0.00 0.00 100.0 0.0 0.0 1.00
Properties of soil layers (from ground level)
No. Top gam phi c ny D A-R D-R tau
[m] [kN/m3] [º] [kN/m2] [MN/m2] [kN/m2]
1 0.00 21.00 37.50 0.00 0.30 54.00 6.10 2.22 0.00
2 1.00 21.00 32.50 0.00 0.33 15.00 6.10 8.00 0.00
3 2.00 12.00 32.50 0.00 0.33 15.00 6.10 8.00 0.00
4 2.50 8.00 25.00 0.00 0.35 3.00 6.10 40.00 0.00
5 6.00 12.00 37.50 0.00 0.30 40.00 ****** 2.50 0.00
6 23.00 12.00 37.50 0.00 0.30 40.00 ****** 2.50 0.00
Top = top level of layer Dia. = column diameter
gam =
effective bulk density phi = friction angle
c = cohesion ny = Poisson's ratio
A-R = area ratio D-R = ratio of constrained moduli
D = constrained modulus E = Young's modulus
q = admissible stress at elastic deformation
(piling)
K = adopted coeff. of earth pr.
tau = skin friction
Soil improvement
(Relevant for column sections with plastic deformations only!)
The initial support of the columns is considered with K = 1
The proportional load on columns is approximated to m = 1 - 1/n
Mutual support of columns occurs at 91 % of this limited system
only
No. n0,0 n0,1 n0 d
(A/AC) n1,0
n1,1 n1 n1' fd fd' n2 n2'
1 2.09 1.81 2.07 4.54 1.58 1.43 1.57 1.20 1.07 1.00 1.57 1.20
2 2.06 1.73 2.03 0.76 1.93 1.64 1.90 1.90 1.23 1.09 2.07 2.07
3 2.06 1.73 2.03 0.76 1.93 1.64 1.90 1.90 1.36 1.09 2.07 2.07
4 2.04 1.68 2.01 0.13 2.02 1.66 1.99 1.99 1.53 1.53 3.03 3.03
5 Layer without columns!
Without depth factor With depth factor
(for failure analyses) (for settlement calculations)
No. m1 phi1 c1 D1 m2 phi2 c2 D
[º] [kN/m2] [MN/m2] [º] [kN/m2] [MN/m2]
1 0.17 38.39 0.00 64.82 0.17 38.39 0.00 64.82
2 0.47 37.58 0.00 28.53 0.52 38.00 0.00 31.03
3 0.47 37.58 0.00 28.53 0.52 38.00 0.00 31.03
4 0.50 34.60 0.00 5.96 0.67 37.52 0.00 9.10
5 Layer
without columns!
n0 =
basic improvement factor from n0, 0 (grid) and n0, 1 (isolated col.)
d (A/AC) =
addition to the area ratio (due to column compressibility)
n1 =
reduced improvement factor from n1,0 and n1, 1 (column compressib.)
fd =
depth factor (due to overburden constraint) (fd' = reduced fd)
n2 =
fd' x n1' (n1' = reduced n1 resp. n2)
m1/2 = proportional load on columns )
phi1/2 = friction angle of compound ) attributable to n1' resp. n2'
c1/2 = cohesion of compound )
D1/2 =
constr. modulus of compound
Settlement of the single footing
at the 1.0 - fold distance of the characteristic point
(at the latest terminated at a pressure ratio of 0.80)
(at the latest terminated at a pressure ratio of 0.80)
Depth Settlement Kind of Level
of Settlement Over- Found. Press.
Improved Deformation Utiliz. Unimproved burden Pressure ratio
[m] [mm] [mm] [kN/m2] [kN/m2]
0.00 1.53 Plastic 1.83 0.0 100.0 10000.00
1.00 3.04 Plastic 6.28 21.0 98.2 4.67
2.00 1.41 Plastic 2.92 42.0 90.3 2.15
2.50 9.39 Plastic 26.68 48.0 85.1 1.77
3.50 7.87 Plastic 23.54 56.0 74.9 1.34
4.50 6.64 Plastic 20.97 64.0 66.3 1.04
5.50 2.94 Plastic 9.68 72.0 59.5 0.83
33 92
The total settlements are rounded up to full millimeters
Program GRETA-E, Version
90422, Copyright by GEOStat
RAS AZ ZAWR - RIYADH WTS PS1 - BOOSTER PUMP HOUSE ATTACHMENT
1.2
**********************************************************************************
Calculation of a foundation
********************
Kind of treatment: Vibro replacement
Single footing of 426.36 m2 (
18.70 m * 22.80 m ) on 147 column (s)
Dead pressure g 100.00 kN/m2 Live
pressure q 0.00 kN/m2
Reference area 2.90
m2
Calculation Depth 23.00 m Foundation
level 0.00 m
Depth of column foot 7.00 m
Ground water table 2.00 m
Properties of installed
material (below load level)
No. Top gam phi c Dia. D E q K
[m] [kN/m3] [º] [kN/m2] [m] [MN/m2] [MN/m2] [kN/m2]
1 0.00 20.00 42.50 0.00 0.80 120.0 0.0 25.0 1.00
2 1.00 20.00 42.50 0.00 0.80 120.0 0.0 25.0 1.00
3 2.00 12.00 42.50 0.00 0.80 120.0 0.0 25.0 1.00
4 7.00 12.00 40.00 0.00 0.00 100.0 0.0 0.0 1.00
5 23.00 12.00 40.00 0.00 0.00 100.0 0.0 0.0 1.00
Properties of soil layers (from ground level)
No. Top gam phi c ny D A-R D-R tau
[m] [kN/m3] [º] [kN/m2] [MN/m2] [kN/m2]
1 0.00 21.00 37.50 0.00 0.30 54.00 5.77 2.22 0.00
2 1.00 21.00 32.50 0.00 0.33 15.00 5.77 8.00 0.00
3 2.00 8.00 25.00 0.00 0.35 3.00 5.77 40.00 0.00
4 7.00 12.00 37.50 0.00 0.30 40.00 ****** 2.50 0.00
5 23.00 12.00 37.50 0.00 0.30 40.00 ****** 2.50 0.00
Top = top level of layer Dia. = column diameter
gam =
effective bulk density phi = friction angle
c = cohesion ny = Poisson's ratio
A-R = area ratio D-R = ratio of constrained moduli
D = constrained modulus E = Young's modulus
q = admissible stress at elastic deformation
(piling)
K = adopted coeff. of earth pr.
tau = skin friction
Soil improvement
(Relevant for column sections with plastic deformations only!)
The initial support of the columns is considered with K = 1
The proportional load on columns is approximated to m = 1 - 1/n
Mutual support of columns occurs at 92 % of this limited system
only
No. n0,0 n0,1 n0 d
(A/AC) n1,0
n1,1 n1 n1' fd fd' n2 n2'
1 2.17 1.81 2.14 4.54 1.60 1.42 1.59 1.21 1.07 1.00 1.59 1.21
2 2.14 1.73 2.10 0.76 1.98 1.63 1.95 1.95 1.24 1.08 2.11 2.11
3 2.12 1.68 2.08 0.13 2.09 1.66 2.05 2.05 1.53 1.53 3.13 3.13
4 Layer without columns!
Without
depth factor With
depth factor
(for
failure analyses) (for
settlement calculations)
No. m1 phi1 c1 D1 m2 phi2 c2 D2
[º] [kN/m2] [MN/m2] [º] [kN/m2] [MN/m2]
1 0.17 38.43 0.00 65.44 0.17 38.43 0.00 65.44
2 0.49 37.72 0.00 29.30 0.53 38.09 0.00 31.63
3 0.51 34.87 0.00 6.15 0.68 38.69 0.00 9.39
4 Layer
without columns!
n0 =
basic improvement factor from n0, 0 (grid) and n0, 1 (isolated col.)
d (A/AC) =
addition to the area ratio (due to column compressibility)
n1 =
reduced improvement factor form n1,0 and n1, 1 (column compressib.)
fd =
depth factor (due to overburden constraint) (fd' = reduced fd)
n2 =
fd' x n1' (n1' = reduced n1 resp. n2)
m1/2 = proportional load on columns )
phi1/2 = friction angle of compound ) attributable to n1' resp. n2'
c1/2 = cohesion of compound )
D1/2 = constr. modulus of compound )
Settlement of the single footing
at the 1.0 - fold distance
of the characteristic point
(at the latest terminated at a pressure ratio of 0.65)
Depth Settlement Kind of Level
of Settlement Over- Found. Press.
Improved Deformation Utiliz. Unimproved Burden Pressure ratio
[m] [mm] [mm] [kN/m2] [kN/m2]
0.00 1.51 Plastic 1.83 0.0 100.0 10000.00
1.00 2.98 Plastic 6.28 21.0 98.2 4.67
2.00 10.06 Plastic 28.37 42.0 90.3 2.15
3.00 8.44 Plastic 25.05 50.0 79.9 1.60
4.00 7.09 Plastic 22.19 58.0 70.4 1.21
5.00 6.00 Plastic 19.90 66.0 62.7 0.95
6.00 5.14 Plastic 18.08 74.0 56.7 0.77
41 122
The total settlements are rounded up to full millimeters
Properties of installed material (below load level)
Program GRETA-E, Version
90422, Copyright by GEOStat
RAS AZ ZAWR - RIYADH WTS PS1 - Electrical Building ATTACHMENT
1.3
**********************************************************************************
Calculation of a foundation
********************
Kind of treatment: Vibro replacement
Single footing of 1885.73 m2 (
21.70 m * 86.90 m ) on 390 column (s)
Dead pressure g 100.00 kN/m2 Live
pressure q 0.00 kN/m2
Reference area 4.84
m2
Calculation Depth 23.00 m Foundation
level 0.00 m
Depth of column foot 9.50 m Depth
of column head 2.50 m
Ground water table 4.50 m
No. Top gam phi c Dia. D E q K
[m] [kN/m3] [º] [kN/m2] [m] [MN/m2] [MN/m2] [kN/m2]
1 0.00 20.00 42.50 0.00 0.00 120.0 0.0 25.0 1.00
2 2.50 20.00 42.50 0.00 0.80 120.0 0.0 25.0 1.00
3 3.50 20.00 42.50 0.00 0.80 120.0 0.0 25.0 1.00
4 4.00 20.00 42.50 0.00 0.80 120.0 0.0 25.0 1.00
5 4.50 12.00 42.50 0.00 0.80 120.0 0.0 25.0 1.00
6 9.50 12.00 40.00 0.00 0.00 100.0 0.0 0.0 1.00
7 23.00 12.00 40.00 0.00 0.00 100.0 0.0 0.0 1.00
Properties of soil layers (from ground level)
No. Top gam phi c ny D A-R D-R tau
[m] [kN/m3] [º] [kN/m2] [MN/m2] [kN/m2]
1 0.00 21.00 37.50 0.00 0.30 54.00 ****** 2.22 0.00
2 2.50 21.00 37.50 0.00 0.30 54.00 9.62 2.22 0.00
3 3.50 21.00 32.50 0.00 0.33 15.00 9.62 8.00 0.00
4 4.00 18.00 25.00 0.00 0.35 3.00 9.62 40.00 0.00
5 4.50 8.00 25.00 0.00 0.35 3.00 9.62 40.00 0.00
6 9.50 12.00 37.50 0.00 0.30 40.00 ****** 2.50 0.00
7 23.00 12.00 37.50 0.00 0.30 40.00 ****** 2.50 0.00
Top = top
level of layer Dia. = column diameter
gam =
effective bulk density phi = friction angle
c = cohesion ny = Poisson's ratio
A-R
= area ratio D-R = ratio of constrained moduli
D = constrained modulus E = Young's modulus
q = admissible stress at elastic deformation
(piling)
K = adopted coeff. of earth pr.
tau = skin friction
Soil improvement
(Relevant for column sections with plastic deformations only!)
The initial support of the columns is considered with K = 1
The proportional load on columns is approximated to m = 1 - 1/n
Mutual support of columns occurs at 94 % of this limited system
only
No. n0,0 n0,1 n0 d
(A/AC) n1,0
n1,1 n1 n1' fd fd' n2 n2'
1 Layer without columns!
2 1.65 1.65 1.65 4.54 1.43 1.43 1.43 1.13 1.45 1.00 1.43 1.13
3 1.63 1.63 1.63 0.76 1.58 1.58 1.58 1.58 1.63 1.14 1.80 1.73
4 1.62 1.62 1.62 0.13 1.61 1.61 1.61 1.61 1.78 1.78 2.86 2.86
5 1.62 1.62 1.62 0.13 1.61 1.61 1.61 1.61 2.14 2.14 3.44 3.44
6 Layer without columns!
without
depth factor with
depth factor
(for
failure analyses) (for
settlement calculations)
No. m1 phi1 c1 D1 m2 phi2 c2 D2
[º] [kN/m2] [MN/m2] [º] [kN/m2] [MN/m2]
1 Layer
without columns!
2 0.11 38.10 0.00 60.86 0.11 38.10 0.00 60.86
3 0.37 36.49 0.00 23.71 0.42 37.04 0.00 25.92
4 0.38 32.49 0.00 4.83 0.65 37.20 0.00 8.59
5 0.38 32.49 0.00 4.83 0.71 38.15 0.00 10.32
6 Layer
without columns!
n0 =
basic improvement factor from n0, 0 (grid) and n0, 1 (isolated col.)
d (A/AC) =
addition to the area ratio (due to column compressibility)
n1 =
reduced improvement factor from n1,0 and n1, 1 (column compressib.)
fd =
depth factor (due to overburden constraint) (fd' = reduced fd)
n2 =
fd' x n1' (n1' = reduced n1 resp. n2)
m1/2 = proportional load on columns )
phi1/2 = friction angle of compound ) attributable to n1' resp. n2'
c1/2 = cohesion of compound )
D1/2 = constr. modulus of compound )
Settlement of the single footing
at the 1.0 - fold distance
of the characteristic point
(at the latest terminated at a pressure ratio of 0.50)
Depth Settlement Kind of Level
of Settlement Over- Found. Press.
Improved Deformation Utiliz. unimproved burden Pressure ratio
[m] [mm] [mm] [kN/m2] [kN/m2]
0.00 1.84 1.84 0.0 100.0 10000.00
1.00 1.80 1.80 21.0 99.2 4.72
2.00 0.87 0.87 42.0 95.3 2.27
2.50 1.47 Plastic 1.66 52.5 92.5 1.76
3.50 1.65 Plastic 2.84 73.5 86.7 1.18
4.00 4.81 Plastic 13.76 84.0 83.9 1.00
4.50 8.61 Plastic 26.28 93.0 81.2 0.87
5.50 7.66 Plastic 24.79 101.0 76.5 0.76
6.50 6.83 Plastic 23.49 109.0 72.3 0.66
7.50 6.08 Plastic 22.32 117.0 68.6 0.59
8.50 5.14 Plastic 21.27 125.0 65.3 0.52
47 141
The total settlements are rounded up to full millimeters
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