Dr Omar Hamza Foundation Engineering CE 483 2. Site Investigations Copy right reserved to Dr O....

Dr O

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Ham

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Foundation EngineeringCE 483

2. Site Investigations

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Contents– Introduction– Program of site investigation– Planning– Implementation– Reporting

CE 483 - Foundation Engineering - 2. Site Investigation

Dr O

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Ham

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3

Introduction


What is Site Investigation (SI)? Why Site Investigation? Objectives of Site Investigation

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Introduction

What is site investigation (SI)?

The design of foundations of structures (such as buildings, bridges, and dams) generally requires information about:

Structure

Ground

• Structure• Ground


5

Introduction

• Site investigation (SI) or soil exploration is the process of gathering information, within practical limits, about the stratification (layers) and engineering properties of the soils underlying the proposed construction site.

Structure

GroundSite Investigation

Bore

hole

What is site investigation (SI)?

Layers

• The principal engineering properties of interest are the strength, deformation, and permeability characteristics.

Drilling rig

6

Introduction

Why site investigation (SI)?


• Many engineering failures could have been avoided if a proper site investigation had been carried out.

Sinkhole

The site has a sinkhole risk which might have

been discovered in a proper site investigation

7

Introduction

Why site investigation (SI)?


Sophisticated theories alone will not give a safe and sound design.

• The success or failure of a foundation depends essentially on the reliability of the knowledge obtained from the site investigation.

8

Introduction

Objectives of site investigationThe knowledge about the ground of the proposed construction site is obtained by Site Investigation, and used to determine:

Suitability: of site for the proposed

construction? Type of design solution: e.g.

type of foundation:

shallow or deep.Design parameters:

such as strength,

compressibility, permeability &

other parameters

used for geotechnical

design

Ground or Ground-water

conditions: that would affect the

design and construction? e.g. expansive soil, collapsible

soil, high ground water…

Geo-materials: available on site which can be re-

used?

Effect of changes: How will the design affect adjacent properties and

the ground water?

Site

Inve

stiga

tion

9

Introduction

Objectives of site investigation

Suitability: of site for the proposed

construction? Type of design solution: e.g.

type of foundation:

shallow or deep.Design parameters:

such as strength,

compressibility, permeability &

other parameters

used for geotechnical

design

Ground or Ground-water

conditions: that would affect the

design and construction? e.g. expansive soil, collapsible

soil, high ground water…

Geo-materials: available on site which can be re-

used?

Effect of changes: How will the design affect adjacent properties and

the ground water?

Site

Inve

stiga

tion

Manage the geotechnical risk


10

Program of site investigation


Before Site Investigation The sequence of Site Investigation

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Program

Before Site Investigation• Site Investigation is usually carried out as part of Subsurface Exploratory

program. • Before conducting the Site Investigation, the program usually include: Desk

Study and Site Reconnaissance.

Desk Study Collect and review preliminary information about the site, and the structure to be built.

Site ReconnaissanceVisual inspection of the site.


12

Collecting general information about the structure, from the architectural and structural design:

Structure

Ground

Information about the Structure– Type, dimensions, and use of the structure,

and any special architectural considerations. – the load that will be transmitted by the

superstructure to the foundation system– the requirements of the local building code

(e.g. allowable settlement)

Program

Desk Study Before Site Investigation


13

Collecting general information about the ground, from already existing data such as: geological maps, seismic maps, Ariel Photography, Services records (Gas, Water, Electricity), Previous geo-environmental or geotechnical reports, … etc. at or near site.

Structure

Ground

Program

Desk Study Before Site Investigation

Information about the ground:– the geological conditions of the ground (e.g.

layers, Geological features, Ground water, Flood & Earthquake risk in the area, ..).

– the historical use of the site – if previously used as quarry, agricultural land, industrial unit with contamination issue, man-made fill/slope, etc.


14CE 483 - Foundation Engineering - 2. Site Investigation

Ariel Photograph taken for a site – shows a possible sinkhole

15

Program

Site Reconnaissance

The Site Reconnaissance is normally in the form of a walk-over survey of the site.

Before Site Investigation


What things do I need to

look for?

Engineer during Site Visit

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Program

Site ReconnaissanceImportant evidence to look for is:


1. Stratification of soil: from deep cut, such as those made for the construction of nearby highway or other projects – if any.

2. Slope: signs of slope instability include bent trees, shrinkage cracks on the ground and displaced fences or drains.

Stratification of soil Signs of slope instability

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Program

Site ReconnaissanceImportant evidence to look for is:


3. Structures: type of buildings in the area and the existence of any cracks in walls or other problems. You may need to ask local people.

Tipping settlement (often without cracks)

Differential settlement (with cracks)

Indication of possible ground-related problem


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Program

Site ReconnaissanceOther important evidence to look for is:


4. Mining: The presence of previous mining is often signs of subsidence and possibly disused mine shafts. Open cast mining is indicated by diverted streams replaced or removed fence/hedge lines.

5. Hydrogeology: Wet marshy ground, springs or seepage, ponds or streams and Wells.

6. Topography: possible existence of drainage ditches or abandoned debris or other man-made features.

7. Vegetation: may indicate the type of soil.8. Access: It is essential that access to the site can be easily obtained.

Possible problems include low overhead cables and watercourses.


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Program

The sequence of Site Investigation

• Whether investigation is preliminary or detailed, there are three important phases:

planning, implementation and reporting.

Planning

Implementation

Reporting

• In large construction projects, 2 site investigations (SI) are carried out: – Preliminary SI, followed by – Detailed SI.

• Soil exploration is a requirement for the design of foundations of any project.


Sequ

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Sequ

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Planning

Implementation

Reporting


Planning

Why planning Depth of investigation Spacing of boreholes

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Bore

hole


Planning

Why planning?

• How many borings do we need?• How deep the borings should be?

The more the better, but what about the cost?

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• Minimize cost of explorations and yet give reliable data.• Decide on quantity and quality depending on type, size and

importance of project and whether investigation is preliminary or detailed.

Planning for site investigation is required to:

• Decide on minimum depth and spacing of exploration.

Dep

th o

f Bor

ehol

eBorehole Spacing


Planning

Why planning?

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Dep

th o

f Bor

ehol

e

• In general, depth of investigation should be such that any/all strata that are likely to experience settlement or failure due to loading.

• The estimated depths can be changed during the drilling operation, depending on the subsoil encoun tered.

• To determine the approximate minimum depth of boring, engineers may use the following rules:


Planning

Depth of investigation

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1. Determine the net increase of stress, under a foundation with depth as shown in the Figure.

2. Estimate the variation of the vertical effective stress, ‘0 , with depth.

3. Determine the depth, D = D1, at which the stress increase ’ is equal to (1/10) q (q = estimated net stress on the foundation).

Determination of the minimum depth of boring

4. Determine the depth, D = D2, at which /'0 = 0.05.

5. Unless bedrock is encountered, the smaller of the two depths, D1 and D2, is the approximate minimum depth of boring required.

’0’

q

D


Planning


25

Table shows the minimum depths of borings for buildings based on the preceding rule.

Depth of Boring

Number of StoriesBuilding width

(m)

What do you notice about this table?


Planning


26

• There are no strict rules for the spacing of the boreholes. • The following table gives some general guidelines for borehole spacing. • These spacing can be increased or decreased, depending on the subsoil

condition. • If various soil strata are more or less uniform and predictable, the number of

boreholes can be reduced.

What do you notice about this table?

Type of project Spacing (m)

Planning

Spacing of boreholes

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Planning

Implementation

Reporting


Overview Boring Sampling Testing

Implementation

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Overview

Boring

Trial pits

Boreholes

Sampling

Soil Sampling

Rock Sampling

Testing

In-situ tests

Laboratory tests

The implementation phase of site investigation usually includes three important aspects:


21 3

Implementation

29

Boring

Trial pits

Boreholes

Sampling

Soil Sampling

Rock Sampling

Testing

In-situ tests

Laboratory tests


21 3

BoringImplementation

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Trial pits


• Trial pits are shallow excavations - less than 6m deep.

• The trial pit is used extensively at the surface for block sampling and detection of services prior to borehole excavation.

• For safety ALL pits below a depth of 1.2m must be supported.

BackhoePick and shovel

Depth Excavation Method

0-2m By Hand

2-4m Wheeled Back Hoe

4-6m Hydraulic Excavator

Trial Pit6m > depth


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Boreholes


1. Auger Boring2. Wash Boring 3. Rotary Drilling4. Percussion Drilling

Borehole• The right choice of method depends on:

– Ground condition: presence of hard clay, gravel, rock.

– Ground-water condition: presence of high ground-water table (GWT).

– Depth of investigation– Site access

• Boreholes may be excavated by one of these methods:


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• This is the simplest of the methods. Hand operated or power driven augers may be used.• Suitable in all soils above GWT but only in

cohesive soil below GWT.

Hand operated augers

Power driven augers

Post hole auger Helical auger

1. Auger Boring

Boreholes BoringImplementation

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• A casing is driven with a drop hammer. A hollow drill rod with chopping bit is inserted inside the casing.• Soil is loosened and removed from the

borehole using water or a drilling mud jetted under pressure.• Wash boring is a very convenient

method for soil exploration below the ground water table provided the soil is either sand, silt or clay. The method is not suitable if the soil is mixed with gravel or boulders.

2. Wash Boring



34

• In this method a heavy drilling bit is alternatively raised and dropped in such a manner that it powders the underlying materials which form a slurry with water and are removed as the boring advances.

• Possibly this is the only method for drilling in river deposits mixed with hard boulders of the quartzitic type.

3. Percussion Drilling



35

• In this method a rapidly retaining drilling bit (attached to a drilling rod) cut the soil and advance the borehole.

4. Rotary Drilling

• When soil sample is needed the drilling rod is raised and the drilling bit is replaced by a sampler.

• This method is suitable for soil and rock.

Drilling bit

Drilling rod

Rotary Head

Movement transmitter



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Boring

Trial pits

Boreholes

Sampling

Soil Sampling

Rock Sampling

Testing

In-situ tests

Laboratory tests


21 3

SamplingImplementation

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Soil sampling

Soil samples are recovered carefully, stored properly to prevent any change in physical properties, and transferred to laboratory for testing.



Samples from each type of soils are required for laboratory testing to determine the engineering properties of these soils.

• Soil Sampling equipment?• Disturbed vs Undisturbed?

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Soil Sampling equipment

There is a wide range of sampling methods such as Split-spoon, Thin-walled Tube. The choice of method depends on:

• the requirement of disturbed or undisturbed samples• Type of soil discovered at site (Gravel, Sand, Silt, Clay)

Split-spoon Sampler

Soil sampling SamplingImplementation

Soil Sample

advancement

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Soil Sampling equipment

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• Two types of soil samples can be obtained during sampling: disturbed and undisturbed.

• The most important engineering properties required for foundation design are strength, compressibility, and permeability. These tests require undisturbed samples.

• Disturbed samples can be used for determining other properties such as Moisture content, Classification & Grain size analysis, Specific Gravity, and Plasticity Limits.



Disturbed vs Undisturbed

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• It is nearly impossible to obtain a truly undisturbed sample of soil.

• The quality of an "undisturbed" sample varies widely between soil laboratories. So how is disturbance evaluated?

• Quality of samples is evaluated by calculating Area Ration AR:

Sampling tube

soil

The thicker the wall of the sampling tube, the greater the disturbance.

Outer Diameter

Inner Dia.

Good quality samples AR<10% .




42

Area Ration AR = ----------------- =

• Samples collected in Split-spoon Sampler is usually classified as “disturbed”.

What is the Area Ration?




43

• Core drilling equipment?• Core recovery parameters?

Rock samples are called “rock cores”, and they are necessary if the soundness of the rock is to be established.



Rock Sampling (Coring)

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• Coring is done with either tungsten carbide or diamond core bits.• Rock sampler is called “core

barrel” which usually has a single tube.• Double or triple tube core

barrel is used when sampling of weathered or fractured rock.

Core barrel: (a) Single-tube; (b) double-tube

(a) (b)

Inner barrelOuter barrel

Core barrel

Rock

Rock

Rock

Corin

g bi

t

Drill rod

Diamond Drill Bit

Rock core

Rock

Rock Sampling (Coring) SamplingImplementation

Core drilling equipment

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• Cores tend to break up inside the drill barrel, especially if the rock is soft or fissured. • Core recovery parameters are used to describe

the quality of core.• Length of pieces of core are used to determine:

– Core Recovery Ratio (Rr)– Rock Quality Designation (RQD)

Rock cores



Rock Sampling (Coring)


46

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• Assuming the following pieces for a given core run:

S L i=L

100%

(Core run)

Rr

( L i ≥ 10 cm )(Core run)

Recovery Ratio, Rr

Rock Quality Designation, RQD



Core recovery (lengths of intact pieces of core)

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• So Rock Quality Designation (RQD) is the percentage of rock cores that have length ≥ 10 cm over the total drill length (core run).

• RQD may indicate the degree of jointing or fracture in a rock mass. e.g. High-quality rock has an RQD of more than 75%.

• RQD is used in rock mass classification systems and usually used in estimating support of rock tunnels.

Core recovery parameters



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Class Example

Work out Rr and RQD for the following core recovery (intact pieces), assuming the core run (advance) is 150 cm.

What is the rock mass quality based on RQD?




49

• Total core recovery L = 125 cm• Core recovery ratio:

Rr = 125/150 = 83%• On modified basis (for pieces ≥ 10cm),

95 cm are counted, thus: RQD = 95/150 = 63 %

• RQD = 50% - 75% Rock mass quality is “Fair”

Solution:




?

? = ? S L i

L100% = S L i

L

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Boring

Trial pits

Boreholes

Sampling

Soil Sampling

Rock Sampling

Testing

In-situ tests

Laboratory tests


21 3

TestingImplementation

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In-situ tests• Introduction• Groundwater measurements• Standard Penetration Test (SPT)• Cone Penetration Test (CPT)


• Plate Load Test (PLT)• Pressure-meter Test (PMT)• Flat Dilatometer Test (DMT)• Vane shear test (VST)

PLT

In Borehole

Piez

omet

er

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Introduction

Definition: • In-situ tests are carried out in the field with intrusive testing equipment. • If non-intrusive method is required, then it is better to use geophysical

methods which use geophysical waves – i.e. without excavating the ground.

Advantage of in-situ testing (against lab testing)• It avoids the problems of sample recovery and disturbance • some in-situ tests are easier to conduct than lab tests • In-situ tests can offer more detailed site coverage than lab testing.

Testing standards• American Society for Testing and Materials (ASTM)• British Standard (BS)


: In-situ tests TestingImplementation

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Groundwater measurements

Why Groundwater:• Groundwater conditions are fundamental

factors in almost all geotechnical analyses and design studies.

Types of Groundwater measurements:• Determination of groundwater levels (GWT) and

pressures. Borehole instrumented with Piezometer is used for this purpose.• Measurement of the permeability of the

subsurface materials, particularly if seepage analysis is required. The test called Pumping test.

Piezometer



Ground water level

Standpipe

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Standard Penetration Test (SPT)

• This empirical test consists of driving a split-spoon sampler, with an outside diameter of 50 mm, into the soil at the base of a borehole.

• Drivage is accomplished by a trip hammer, weighing 65 kg, falling freely through a distance of 760 mm onto the drive head, which is fitted at the top of the rods.

• The split-spoon is driven three times for a distance of 152.4 mm (6 in) into the soil at the bottom of the borehole. The number of blows required to drive (only) the last two 152.4 mm are recorded. The blow count is referred to as the SPT-N.

760 mm

152.4 mm (6 in) x 3 timesThe first one does not count

Falling Hammer

Definition

Drive head

Slit spoon



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• Relatively quick, simple, reasonably cheap, and suitable for most soils.• good correlation between SPT-N and soil properties.• provides a representative soil sample for further

testing.

Disadvantage• SPT does not typically provide continuous data• Limited applicability to soil containing cobbles and

boulders.• Samples obtained from the SPT are disturbed.• SPT N blow require correction

Advantage


Standard Penetration Test (SPT) TestingImplementation : In-situ tests

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• Corrections are normally applied to the SPT blow count (N) to account for:– Energy loss: during the test (about only 60% of energy remains)– Equipment differences: hammer, sampler, borehole diameter, rod

Corrections for energy and equipment

• The following equation is used to compensate for these factors:

(0.75-1.0)

(1.0-1.15)

(usually 0.50-0.80)

(0.8-1.0)


Usually this correction is made by the Site Investigation operator.

60%

57

Corrections for overburden pressure


CN = overburden pressure correction factor

• In granular soil (sand, gravel) the SPT blows are influenced by the effective overburden pressure at the test depth:

Many equations have been suggested for CN – see Page 86, (Das’s text book). For example:

58


Correlation between N and friction angle

• There are many equations suggested. The figure shows the correlation with the angle of shearing resistance of sand (according to Pecks, 1974).

TestingImplementation : In-situ tests

Angle of shearing resistance f’ (degree)

Cor

rect

ed S

PT N

blo

w

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The following are the recorded numbers of SPT blows required for spoon penetration of three 152.4cm (6 in) in a sand deposit:

Class example


Depth from ground surface (m) 1.5 3 4.5 6 7.5

SPT blows (blow/ 6 in) 3, 4, 5 7, 9, 10 7, 12, 11 8, 13, 14 10, 14, 15

The ground water table (GWT) is located at a depth of 4.5m. The wet unit weight of sand above GWT is 18 kN/m3, and the saturated unit weight of sand below GWT is 19.81 kN/m3.

• Draw a sketch of the foundation showing the given details of the soil.• Determine the standard penetration number (SPT-N) at each depth.• What is the corrected (SPT-N) value? (use Seed’s equation).• Determine the friction angle at depth 4m below the footing. (Use Peck’s

Equation or Chart).

Note. Assume the above SPT blows are corrected for energy and equipment.

Z, m SPT blow N60 s0’ (kPa) CN N f’

1.5 3, 4, 5 4+5=9 1.5x18 =27 0.27 1.7 15.3 35o

3 7, 9, 10 9+10=19 54 0.54

4.5 7, 12, 11 23

6 8, 13, 14 ?

7.5 10, 14, 15

60

Only the last 2 sets of blows count

Solution


g =18 kN/m3

gsat=19.8 kN/m3

2

4

Z

Corrected

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• The corrected SPT N blow can be approximately correlated to many important engineering properties of soil such as shear strength & compressibility. • This equation shows the correlation with untrained shear strength Su (or Cu)

of clay. (also with OCR = Over Consolidation Ratio).



Correlation between N and untrained shear strength

In C

lay

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• The table shows the correlation corrected SPT-N with untrained shear strength Su (or Cu) of clay (according to Terzaghi et al. 1996)



Correlation between N and untrained shear strength



Class Example

shown belowthe Figure

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Solution

Z, m N60 s0’ (kPa) Cu (kPa) s0’ (MPa) OCR

3 51.5x16.5+

1.5x(19-9.81) = 38.5100x0.29

x50.72 =92.338.5/1000=

0.03850.193x(5/

0.038)0.689 = 5.5

4.5 838.5+1.5x(16.5-

9.81) = 48.5 129.6 0.0485

6 8

7.5 9

9 10

OCRav = Cu -av =

65


Correlation between N and Relative Density Dr

• correlation between N60 and Relative Density of Granular Soil



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For Clean sand onlyGeneral

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Very loose

Loose

Medium

Dense

Correlation between N and Relative Density Dr

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Correlation between Modulus of Elasticity and Standard Penetration Number

• The modulus of elasticity of granular soils (Es) is important parameter in estimation the elastic settlement of foundation.

• An approximate estimation for Es was given by Kulhawy and Mayne (1990) as:

68

Cone Penetration Test (CPT)

• called also "Dutch cone test“ or “Static Penetration test”.• The test method consists of pushing an

instrumented cone, with the tip facing down, into the ground at a slow controlled rate.• Cone: 60 degree apex cone, Dia = 36 mm.

Definition

Cone



Measures

• Cone or Tip resistance (qc) or (qt)

• Sleeve friction (fs)

• Water Pore pressure (ub)

Friction Ratio, Fr = qc

fs

qc or qt

fs

Hydraulic push at rate 20 mm/s

Cone Rod (36 mm dia.)

• Other variables e.g. Shear wave velocity (vs)

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• Soil profile (stratigraphy): soil type identification• Estimation of geotechnical

parameters (strength, compressibility, permeability)• Evaluation of groundwater

conditions (pore pressure)• Geo-environmental:

distribution and composition of contaminants

Applications:

Sample data

Sleev

e fric

tion, f s

Tip re

sista

nce, q

c

Pore

Pressu

re, u

Clay

Clay

& S

iltSi

lty C

lay

Clay & Sand

Fricti

on Ratio , F

r

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– High in granular soil– Low in cohesive soil

– Low in granular soil– High in cohesive soil

• Friction Ratio Fr

• Point resistance qc

Soil Identification:

• However, the cone/tip (qc) and sleeve (fs) resistance increase with increasing overburden stress s0

• for accurate identification, normalization of qc & fs by overburden stress is required. Classification Chart (Robertson et al., 1983)

71




• Inability to penetrate through gravels and cobbles• Newer technology = less populated database

than SPT• Lack of sampling

Disadvantages:

• Borehole is not necessary• Almost continuous data (reading every 10mm)• Elimination of operator error (automated)• Reliable, repeatable test results

Advantages:

72




• In Sand: the drained friction angle

Correlation with shear strength

where: qc = the cone (tip) (point) resistance

s’0 & s0 = effective and total overburden pressure, respectively

NK = Bearing factor depends on type of cone (varies from 11-20)OCR = Over Consolidation Ratio

• In Clay: undrained shear strength cu

(Ricceri et all’s. 2002)

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Class example: Correlation with shear strength

Use equation proposed by Ricceri et all’s. 2002.

74



Solution:

Depth, m qc (MPa) s0’ (kPa) qc /s0’ f’ (Rad) f’ (deg)

1.5 2.06 1.5 x 16 =24 2060 / 24 = 85.8 0.690.69x180/

p=40o

3 4.23 48 88.1

4.5 6.01

6 8.18

7.5 9.97

9.0 12.42f’av =

f’av = Sf’ / 6Note. tan -1 is inverse tangent, the angle returned is in Radian.

75

Plate Load Test (PLT) TestingImplementation : In-situ tests

• The test essentially consists in loading a rigid steel plate at the foundation level and determining the settlement corresponding to each load increments.

• The ultimate bearing capacity is then taken as the load at which the plate starts sinking at a rapid rate.

• Plate load test is a field test to determine the ultimate bearing capacity of soil.

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Laboratory tests



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• Basic physical properties tests (Moisture content, Specific gravity, Soil Indexes, ..)

• Particle size test (sieving, Sedimentation)• Direct shear box test• Unconfined compression test• Triaxial test• Consolidation test• Permeability test• Other lab tests: Chemical test (pH,

contamination,..)


Laboratory tests


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Planning

Implementation

Reporting


Preparation of Borehole Site Investigation Report

Reporting

Sequ

ence

of S

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Reporting

Preparation of Boring Logs

Initial information: Name and address of the drilling company, Driller’s name, Job description and reference number, boring information (number, type, and location of, and date of boring).

Example of a typical boring log


Subsurface stratification: which can be obtained by visual observation of the soil brought out by auger, split-spoon sampler, and thin-walled Shelby tube sampler.

Groundwater: Elevation of water table and date observed, use of casing and mud losses, and so on

Reporting



In-situ tests: Standard penetration resistance and the depth of SPT

Samples: Number, type, and depth of soil sample collected; in case of rock coring, type of core barrel used and, for each run, the actual length of coring, length of core recovery, and RQD.

Reporting


82

The following borehole is part of a site investigation (SI) carried out over a proposed location of a bridge.

Assess the subsoil conditions and ground-water conditions based on the borehole data. In particular write about:

• Soil layers: types, description, depth…• Soil properties: shear strength properties -based on SPT.• Ground water depth

Reporting


Class example

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• When: After the completion of all of the field and laboratory work, a site investigation report is prepared.

• Why: for the use of the design office and for reference during future construction work.

• The report is also called soil exploration report or Geotechnical Factual report.

SITE

INVESTIGATION

Reporting

Site Investigation Report

What should be included in the site investigation report?


The report should contain descriptions of the followings:

• Purpose & Scope of the investigation• Site & Structure: site location, existing structures, drainage conditions,

vegetation,… and information about the structure.• Factual Details of field exploration: boreholes, samples, and testing.

For each type, quantities, method, tools should be presented.• Geological setting of the site (variation of depth and thickness of layers

as interpreted from the borings)• Subsoil and water-table conditions, (soil parameters as interpreted

from the testing results).• Design analysis & recommendations: type of foundation, allowable

bearing pressure, settlement estimation, and any special construction procedure; alternatives design solution. • Conclusions and limitations of the investigations

Reporting


Usu

ally

giv

en in

ano

ther

repo

rt(G

eote

chni

cal D

esig

n Re

port

)


The following graphical presentations must be attached to the report:

1. General map showing site location 2. A plan view of the location of the borings with

respect to the proposed structures and those nearby

3. Boring logs (including in-situ tests results and samples)

4. Laboratory test results

5. Other graphical presentations (geotechnical cross section based on the boring logs, photos of the field work and soil samples,…)

Reporting


87

Geotechnical cross section based on the boring logs

Reporting


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