ROCK AND SOILS 2012 – Project Work Preliminary Information – locations of boreholes and trench pits EXCERPTS from Sheard, M. J. and Bowman, G. M XXXXXXXXXXSoils, Stratigraphy and Engineering Geology...

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how can I start with calculations of bearing capacity ? I have atached a draft of the assigment and some ideas.


ROCK AND SOILS 2012 – Project Work Preliminary Information – locations of boreholes and trench pits EXCERPTS from Sheard, M. J. and Bowman, G. M. (1996). Soils, Stratigraphy and Engineering Geology of Near Surface Materials of the Adelaide Plains. Dept. Mines and Energy, Report Book 94/9, Volumes 1, 2 and 3, Adelaide (available on CD from PIRSA). Fig. 2 Generalized regional geological plan and location of cross-section X-X (Fig. 3) Fig. 49 Diagrammatic cross-section across the Adelaide Coastal Plain and lower Alluvial Plain, indicating sediment relationships Symbols and Diagrams used in AURECON Borelogs RAIL CROSSING BH112 - C South Road End BH06 South Rd End: Trench Pit TP10 South Rd End: Trench Pit TP10 SOUTH RD – BARKER INLET BH129 SOUTH RD – BARKER INLET BH131 1. TITLE: Consolidation, C Rock & Soils 2012 Supervisor: Robert L. Smith/Mizanur Rahman 1.1 Introduction (Scope) Your group is required to make estimates of consolidation settlement under the centre of embankments with and without measures to counteract the consolidation. The consolidation will proceed as construction proceeds. 1.2. Constraints Loads or pressures: The embankment will consist of good quality fill having a unit weight of 21 kN/m3. A surcharge pressure of 20 kPa at the top of the embankment may be assumed. Embankment height: 4.5 to 8.5 m Design settlement requirements: a) 50 mm of primary settlement post construction b) 50 mm of creep over 10 years 1.3. Geotechnical data The site is located midway along the Northern Connector route near a proposed overpass for rail freight. A deep borehole was made at this site (Aurecon borelog BH112) and samples have been taken of the soft layer for testing as required. 2. TITLE: Slope Stability Design of Embankments, S Rock & Soils 2012 Supervisors: Kirsty Beecham/ Don Cameron 2.1 Introduction (Scope) Your group is required to design embankments over a range of embankment heights and ground conditions. Safe batter angles are to be recommended for ranges of different heights. 2.2. Constraints Embankment height and width: the width is 16m of sealed surface (allow for shoulders) and the height ranges from 4.5 to 8.5 m. A working platform of 0.8 m thickness is to be provided at the base of the embankment, i.e. an 8.5 m high embankment consists of 7.7 m of fill and 0.8 m of working platform. The road material may be assumed to be 0.75 m thick. Loads or pressures: The embankment will consist of good quality fill having a unit weight of 20 kN/m3. The working platform will consist of clean granular material. A surcharge pressure of 20 kPa at the top of the embankment may be assumed. Design approach: Bishop’s simplified method (program GALENA) is to be applied. Design checks should be made for an earthquake acceleration of 0.12g and for a tension crack 1 m deep. Factor of Safety: 1.45 (no earthquake) and 1.3 with earthquake 2.3. Geotechnical data The embankments are to be located near the South Rd interchange and so borelogs for BH129, 131 and 006 (Aurecon) are appropriate for assessing the properties of the foundation soils. TP10 is also applicable. Typical test data for embankment material Stratum Unit weight (kN/m3) cu (kPa) u () c (kPa) () Fill 20 10 33 0 36 Working Platform 21 0 36 0 38 Road material 23 10 38 0 40 3. TITLE: Retaining Wall Design for Embankments, R Rock & Soils 2012 Supervisors: Kirsty Beecham/ Don Cameron 3.1 Introduction (Scope) Your group is required to design retaining walls over a range of embankment heights and ground conditions. 3.2. Constraints Retained height: 3.5 to 5.5 m. Loads or pressures: The backfill will consist of well-draining fill having a unit weight of 19.5 kN/m3. A surcharge pressure of 15 kPa at the top of the retaining wall may be assumed. Design approach: A factor of safety approach may be adopted provided checks on limit state approach are made (apply a mobilization factor on shear strength of 1.2). Either gravity walls or cantilevered (embedded) walls may be considered. All stability considerations must be assessed, including bearing capacity of the retaining wall footing, but excluding slope stability and structural integrity of walls. Designs must consider a water table lying 1 m below the retained ground level. 3.3. Geotechnical data The embankments which may be retained are to be located near the South Rd interchange and so borelogs for BH129, 131 and 006 (Aurecon) are appropriate for assessing the properties of the foundation soils. TP10 is also applicable. Backfill materials for gravity walls: Stratum Unit weight (kN/m3) c (kPa) () Granular backfill, Quarry Rubble (dense) 19.5 5 40 Sand backfill (medium dense) 19.0 3 36 4. TITLE: Allowable Bearing Capacity of Spread Footings, ABC1 and ABC2 Rock & Soils 2012 Supervisor ABC1: Robert Smith/ Mizanur Rahman Supervisor ABC2: ---------/ Don Cameron 4.1 Introduction (Scope) Purpose: Your group is required to design spread footings to take proposed loads for the columns of a building and to negate potential elastic settlements. Task: A study is to be undertaken of shallow footing systems, which should include geotechnical calculations of bearing capacity and immediate settlement. Potential foundation options should be designed for short term (undrained) and long term (drained) loading. The report should discuss the suitability of shallow foundations and whether other foundation types would be more appropriate. 4.2 Constraints Loads or pressures : The following loads are all safe working loads (SWL): External columns Internal columns Vertical (Compression) = 2500 kN Vertical (Compression) = 1800 kN Lateral = 200 kN Lateral = 100 kN Factor of Safety: 3 for shallow foundation systems on the ultimate net bearing capacity. Maximum allowable differential immediate settlement: Measured either along the perimeter or from the perimeter to the centre of the building: 15 mm 4.3 Geotechnical data Borelogs ABC1: The borelog for BH112 shall apply ABC2: Borelogs for BH129, 131 and 006 (Aurecon) are appropriate for assessing the properties of the foundation soils. 5. TITLE: Design of Piles for Bridge Supports, P1 Rock & Soils 2012 Supervisor P1a: Robert Smith/ Mizanur Rahman Supervisor P1b: ----- / Don Cameron 5.1 Introduction (Scope) Purpose: Your group is required to design pile footings to take proposed loads for the support of bridges and overpasses and to meet maximum allowable elastic settlements. Task: choose a single pile type or group of piles which meets the design requirements and which is suitable for construction on the site. Downdrag may need to be countered. 5.2 Constraints Vertical Loads Utlimate vertical load, S* = 7 to 9 MN Deformation Maximum allowable settlement of the pile head shall be 15 mm. 5.3 Geotechnical data Borelogs P1a: The borelog for BH112 shall apply P1b: Borelogs for BH129, 131 and 006 (Aurecon) are appropriate for assessing the properties of the foundation soils. 6. TITLE: Design of Piles for a Building, P2 Rock & Soils 2012 Supervisor: Robert Smith/ Mizanur Rahman 6.1 Introduction (Scope) Purpose: Your group is required to design pile footings to take proposed loads for the support of building column loads and to meet maximum allowable elastic settlements. Task: choose a single pile type or group of piles which meets the design requirements and which is suitable for construction on the site. Downdrag may need to be countered. 6.2 Constraints Vertical Loads Ultimate vertical load, S* = 5 to 6 MN Lateral load Check the capacity of your design pile to take a horizontal force of X kN aft ground level. Deformation Maximum allowable settlement of the pile head shall be 10 mm. 6.3 Geotechnical data Borelogs The borelog for BH112 shall apply CIVE 3008 – Rock & Soils 6 week Project Project Report – due Friday Week 13 (20%) Student Names: Key components of this assignment Mark Comment by marker Report Structure / 3 · Executive summary; 1 page · Table of contents · Introduction · Summary of data used · Design approach · Summary · Appendices of data and calculations Report Style / 3 · Adherence to “Report Writing Style Guide” · Referencing style · Data – clearly presented? · Quality of Figures and Tables · Appendices – appropriately used? General presentation criteria / 3 · Clarity of expression · Correct grammar, spelling and punctuation · Readability for the client · Logical and well reasoned design Quality of interpretation of data (field/lab/pc) / 5 · Poor (1 marks) · Average (3 marks) · Very good (4 marks) Level of understanding / 5 · No insightful analysis (0 marks) · Average analysis (2 marks) · Excellent analysis (4 marks) · Acknowledgement of weaknesses/ possible improvements (1 mark) Draft preparation / 2
Answered Same DayDec 20, 2021

Answer To: ROCK AND SOILS 2012 – Project Work Preliminary Information – locations of boreholes and trench pits...

Robert answered on Dec 20 2021
108 Votes
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CC HH AA PP TT EE RR PP AA GG EE
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1. Introducti on. 01
2. Scope of Work 01
3. Field Investigation 02
4. Laboratory Tests 14
5. Discussion and Recommendations 15
6. Summary 23
7. Conclusi on 28
8. Appendix

Typical C a lculation for Safe Bearing Capacity
30-36
9. Appendix…

1) Tables…
37-47
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[ 1 ] INTRODUCTION :



The purpose of the investigations was to determine the sub soil stratification,
geotechnical information & safe bearing capacity of the soil, so as to provide information
that will assist the structural engineers in the design of the foundations and the relevant
works.


[ 2 ] S
COPE OF WORK :

The scope of work consisted of

A. Field Investigation :

1. Fixing borehole locations.

2. Drilling boreholes through soil and rock.

3. Conducting standard penetration test.

4. Collection of disturbed and undisturbed samples.

5. Carrying out static plate load test at specified locations.

6. Carrying out permeability test


B. Laboratory Test :

1. Determination of moisture content.

2. Grainsize distribution analysis.

3. Atterberg limits test.

4. Specific gravity work.

5. Determination of bulk and dry density..
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6. Direct shear test.

7. Traixial test.

8. Consolidation test.

9. Differential free swell test.



C. Test on Rock Samples:-

1. Density

2. Water Absorption & Porosity

3. Crushing Strength


[ 3 ] FIELD INVESTIGATION :


3.1. Boreholes :


The field work includes drilling of Twelve boreholes upto max. 30m depth at the
locations specified by client. The locations of boreholes are indicated in the layout plan
given in the Appendix of report. Rotary type drilling machine with TC bit was used for
boring. Casing pipes and bentonite slurry were used to protect the sides of boreholes,
wherever needed. The diameter of the borehole was kept 150mm & was decreased to
NX as the rock encountered.

Standard penetration tests were conducted in the soil strata at regular intervals
and “N” values noted .The samples from the split spoon samples were collected and
treated as representative samples for laboratory tests. The undisturbed samples could
not be collected due to weathered fractured rocky strata from shallow depth. Water table
levels in the boreholes were monitored and recorded and the same is given in the
respective borelogs. Details of boring with soil profile, SPT values along with sampling
details are given in the respective borelogs in the appendix of the report.
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Detail co-ordinates and the corresponding structure is given in table – 1.
Sr.
No.
Structure BH No. Co-ordinates Depth of
Boreholes
(m.)
Water Table
Depth below GL
(m.)
N E
1. Inside building area BH-1 233.019 271.0 30.0 8.0
BH-2 233.019 321.50 18.0 6.0
4. Out side common
area
BH-3 S-310 E-440 15.0 9.0
BH-4 S-310 E-640 15.0 9.0
[ 3.2 ] Collection of Samples :

(1) Undisturbed Soil Sampling in Boreholes

1.1 Undisturbed soil samples were collected in cohesive stratum to determine
engineering properties of soil in laboratory. Thin walled open drive samplers of
450 mm length and made of seamless steel were used for collection of samples in
cohesive strata. Area ratio of this sampler does not exceed 13 %. Samples were
collected by pushing the UDS tube slowly, preferably by hydraulic pressure, into
cohesive stratum to avoid disturbance to surrounding soil stratum.
Î As per 3.1.3 the strata is rocky at all borehole location hence no UDS could be is
collected.

1.2 On removal of sampler from borehole, all wet disturbed soil is removed and
coated just molten wax to prevent loss of moisture. Samples will be clearly
labelled at top indicating job no. borehole number, sample number, date of
sampling, type of sample, depth of sample etc. Generally, unless specified
undisturbed soil samples (UDS) /core samples will be obtained at every 3.0 m
interval and at every identifiable change of soil formation.
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1.3 However where undisturbed soil samples / core samples were not collected due
to hard strata, undisturbed soil samples were replaced by standard penetration
tests or broken cores in boreholes.

(2) Transporting and Storing of Samples


2.1 All the samples were stored properly at site till they were transported to the
laboratory for the testing. Sampling tubes containing undisturbed samples were
not be exposed to direct sun and were kept in a shade covered with wet gunny
bags. These tubes were transported in a wooden box tightly fitted with taking full
care to avoid the chances of disturbance. The fit soil samples/rock samples were
photographed on receipt in the laboratory.

(3) Drilling in Rock


3.1 When rock was encountered, size of borehole was changed to Nx. (76 mm)
diameter. A double tube core barrel and Nx sized diamond bits are used for
drilling and recovering rock cores. Recovered rock cores were numbered serially
and preserved in wooden core boxes. Rock core recovery and Rock Quality
Designation (RQD) were computed for every run length drilled. Detailed core logs
of boreholes were prepared by geologist at site.


3.2 Rock classification in terms of weathering and state of fractures and strength is
carried out in the following manner. Tabulations given in below explain it briefly.
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Scale of Weathering Grades of Rock Mass (vide 4464)


Terms Description Grade I n t e r p r e t a t i o n
Fresh No visible sign of rock material
weathering; perhaps slight discoloration on
major discontinuity surfaces.
I CR > 90 %
Slightly
Weathered
Discoloration indicates weathering of rock
material and discontinuity surfaces. All the
rock material may be discoloured by
weathering.
II CR between
70 % to 90 %
Moderately
Weathered
Less than half of the rock material is
decomposed or disintegrated to a soil.
Fresh or discolored rock is present either
as a continuous framework or as core
stones.
III CR between
50 % to 70 %
Highly
Weathered
More than half of the rock material is
decomposed or disintegrated to a soil.
Fresh or discolored rock is present either
as a discontinuous framework or as core
stones
IV CR between
10 % to 50 %
Completely
Weathered
All rock material is decomposed and / or
disintegrated to soil. The original mass
structure is still largely intact.
V CR between
zero to 10 %
Residual
Soil
All rock material is converted to soil. The
mass structure and material fabric are
destroyed. There is a large change in
volume, but the soil has not been
significantly transported.
VI N > 50
3.3 It should be understood that all grades of weathering may not be seen in a
particular in site rock mass and that in some cases a particular grade may be
present to a very small extent. Distribution of the various weathering grades of
rock material in the rock mass may be related to the porosity of the rock material
and presence of open discontinuities of all types in the rock mass.


Rock quality is further measured by frequency of natural joints in rock mass. Rock
Quality Designation (RQD) is used to define state of fractures or massiveness of rock.
Following table defines the quality of rock mass.
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RELATION BETWEEN RQD AND IN -SITU R O CK QUA L ITY ( videIS :13365)

RQD CLASSIFICATION RQD (%)
Excellent 90 to 100
Good 75 to 90
Fair 50 to 75
Poor 25 to 50
Very Poor 00 to 25
Rock is also classified by strength of intact rock cores collected during drilling. Rock
unconfined compressive strength (UCS) of the rock core is used to define strength of
rock. Following table summaries classification of rock based on strength.

CLASSIFICATION OF ROCK BASED ON COMPRESSIVE STRENGTH...
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