METHOD STATEMENT

FOR
GEO TECHNICAL INVESTIGATION
1. PURPOSE
This document sets out the Work Method Statement for Geo Technical investigation detailing the location, depth &
the procedure to carry out the works in planned and systematic manner.

2. SCOPE
To set out the requirements for Geo technical investigation works for MMRDA/9/MMRP/CA48 Project to meet all the
contract requirements and JKIL standards for work operation, safety, quality and environmental compliance. This
Method Statement applies to the Stations, This includes the following.
• Preliminary site characterization
• Actual field test holes, sampling and laboratory testing.
• Assessment of the information collected and presenting it in recognized form
• Recommendation

3. RESPONSIBILITIES
• The MS shall be followed by all personnel involved in the Geo Technical investigation activity. This MS may
be adjusted to suit adverse site conditions subject to approval of ,JKIL geotech incharge.
• Organization chart for the scope of this document is attached as attachment-01.
• Action may be delegated, but responsibilities shall not be delegated.
• Use of word 'shall' with in this document indicates a mandatory requirement.
• Use of word 'should' within this document indicates a preferred requirement.
• Detailed responsibilities are set out in:
• o Project Quality Management Plan
• o ITPs
• o Risk Assessment

3.1 Project Leader

• The approval of this MS
• Overall scope of work.
• Coordination of personnel and equipment to ensure continuous program of works during execution.
• Receiving daily progress reports and distributing to Client's approved representative and JKIL Management, and
ensuring prompt action to any matter highlighted in the same.

3.2 Station Manager

Implementation of this MS.

• Safety to personnel, incident reporting and implementation of the Safety Management Plan and Safety
Management System.
• Ensuring that the works are carried out in accordance with approved permits and MS.
• Ensuring that all personnel are fully aware of their duties and responsibilities.
• Liaising with Client's approved representative during the operations and during MS change, contingency operations
or mitigation works.
3.3 Site Engineer / Geotech site incharge
• Ensuring work is executed in accordance with approved MS and specifications.
• Ensuring that all data is recorded in accordance with this document.
• Ensuring all required as built data are recorded.
• Providing any information and field calculations that may be required during the work.

4. DEFINITIONS
. For the purpose of this document the term:

 JKIL : Contractor
 QA : Quality Assurance (applies essentially to process)
 QC : Quality Control (applies essentially to works and products)
 ITP : Inspection& Test Plan-A document that sums up all the information related
to inspections, measurements and tests to be carried out during execution of work in scope. For the
scope, the term ITP is used.
 Shall : Mandatory Requirement
 Should : Recommended Practice
 SHEVC : SHE verification checklist

5. REFERENCES
: Contractor : Quality Assurance (applies essentially to process) : Quality Control (applies essentially to works and products)
: Inspection& Test Plan-A document that sums up all the information related to inspections, measurements and tests to be
carried out during execution of work in scope. For the scope, the term ITP is used.
: Mandatory Requirement : Recommended Practice : SHE verification checklist

• Applicable Specifications -refer to Attachment 1

• Applicable Project Procedures -refer to Attachment 1

• Applicable Project MSs -refer to Attachment 1

• Applicable Drawings & Sketches -refer to Attachment 2

6. GEOTECHNICAL INVESTIGATION METHODOLOGY:

Geotechnical investigation shall be performed according to the following Sequence:

6. 1. Marking ofdetails:

Survey team shall mark the details like TBM path, reduced level (RL), chainage etc as required for the
Geotechnical survey team to identify and record the location and details for sampling.
6.2. Mobilization ofresources:

Geotechnical investigation teams (1. Shriprakash Techoformulators Pvt. Ltd. And 2. Soil Engioneering
consultants) shall mobilize necessary team and equipment for the scope. Survey team shall mark the details
like TBM path, reduced level (RL), chainage etc as required for the Geotechnical survey team to identify and
record the location and details for sampling.

6.3. Number and Disposition of Trial Pits and Borings:

The disposition and spacing of the trial pits and borings should be such as to reveal any major changes in
thickness, depth or properties of the strata over the base area of the structure and its immediate surroundings.
The number and spacing of bore holes or trial pits will depend upon the extent of the site and the nature of
structures coming on it. Tentative bore hole locations has been identified and attached as attachment -2.

6.4. Depth ofExploration:

The depth of exploration required depends on the type of proposed structure, its total weight, the size, shape
and disposition of the loaded areas, soil profile, and the physical properties of the soil that constitutes each
individual stratum. Normally, it should be one and a half times the width of the footing below foundation level. In
certain cases, it may be necessary to take at least one bore hole or cone test or both to twice the width of the
foundation. If a number of loaded areas are in close proximity the effect of each is additive. In such cases, the
whole of the area may be considered as loaded and exploration should be carried out up to one and a half
times the lower dimension. In weak soils, the exploration should be continued to a depth at which the loads can
be carried by .the stratum in question without undesirable settlement and shear failure. In any case, the depth
to which seasonal variations affect the soil should be regarded as the minimum depth for the exploration of
sites. But where industrial processes affect the soil characteristics this depth may be more.

List of Borehole depths has been attached as attachment 1-2.

6.5. Boring in Soils:

• Shell &Auger Boring

Augers shall be of helical or post hole type and may be manually or power operated. The diameter of hole
shall be 150 mm.

Uncased holes shall be permitted only up to a depth where sides of the hole can stand unsupported. In case
sjde fall is noticed, steps shall be taken immediately to stabilize the hole by using casing pipes. While boring
through cohesion less soil below water table, water in the casing shall always be maintained at or above
water table. The auger shall be used for soft to stiff clays, shell for very stiff and hard clay and shells or sand
pumps for sandy strata attached to sectional boring rods In stiff cohesive soil it may be necessary to soak the
bore hole before any progress can be made. While boring, care shall be taken to minimize the disturbance to
the deposits below the bottom of the bore hole. Bentonite solution with water may be used as per prevailing
soil conditions to stabilize the boreholes and to recover the soil from the bottom of borehole. In-situ test
(Standard Penetration Tests) shall be conducted and undisturbed samples shall be obtained at specified
depths from the bore hole. The bore hole shall be kept clean and free from foreign matters while conducting
these operations. Water table in the bore hole shall be carefully recorded and reported. The water table in the
 bore hole shall be allowed to stabilize after depressing the water level adequately by bailing. Stability of the
borehole sides and bottom shall be ensured at all times.

• Drilling Exploratory Holes in Rock

Providing all drilling equipment and carrying out NX size core drilling using a single! double tube core barrel. .

The work shall comply with IS 1892. The format given in IS code shall be used for recording the rock-drilling,
color of wash water, nature of sediments in the wash water, loss or gain of drilling water, core run length, core
recovery & RQO (Rock Quality Designation).

Cores shall be kept in wooden boxes with compartments of exact size of the rock cores. While placing the
core samples in wooden boxes, it shall be ensured that the direction and sequence of core placement is not
altered. The core run shall be restricted to the length generally not more than 1.5m. In weak and friable rock
core run shall be reduced.

• Core Box

Each core box shall house samples not more than 6m (six meters) long.

The depth of cores below ground level shall be indicated at. about every 1.5 metres interval by writing the
depth in indelible ink on wooden spacers, which shall be inserted in their correct position in the box. Similarly
the exact depth of any change in stratum, and failure to recover the core, etc. shall be recorded.

The labeling of core samples of rock shall be done in accordance with Appendix D of IS 1892.

6.6. Field Tests:

• Standard Penetration Test

These tests shall be conducted in all types of deposits and layers at intervals as specified.

The test shall be performed on undisturbed soil by driving of the split spoon sampler by means of 63.50 kg
weight with 75 cm free fall. The number of blows required to effect each 15 cm of penetration shall be
recorded. First 15 cm drive to be considered as seating drive. The penetration resistance shall be for the last
30 cm of penetration. The procedure of standard penetration test shall be as per IS: 2131. These tests shall
be carried out at interval of 1.50 m within continuous stratum or at every change of stratum whichever is less.
The tests shall be terminated at SPT value of greater than 50 or after reaching minimum borehole depth as
defined in clause 3.1.2 above, whichever occurs earlier, subject to refusal not occurring. The samples
obtained in the split spoon sampler shall be labeled and preserved for identification tests in the laboratory.

6.7. Sampling:

• Procedure for Sampling

Before sampling operation the bottom of the bore hole will be carefully cleaned and every care will be taken to
avoid any disturbance of material to be sampled.
The following steps will be adopted to collect samples.

o For sampling the sampler will be lowered slowly to the bottom of the borehole with the help of drill rods.
o The sampling tubes will be driven into the soil by continious and rapid action, SPT driving equipment will be
used for driving the tubes. In no case the sampler will be driven further than the length provided for the
sample and it will never be driven to full length of the sample tube. Before pulling out the tube at least 5 Min
will be allowed to escape after driving the tuibe after which the tube will be turned at least for two revolution to
shear the sample at the bottom.
o The sampler will be then withdrawn smoothly so as to cause minimum disturbance to the samples.
o Upon removal of the sampling tube the total length of the sample in the tube and the length between the top
of the tube and the top of the sample in tube will be measured and recorded.
The choice of sampling tools, the methods of sampling and the procedure for taking samples shall be
in accordance with equivalent IS 1892 recommendations.
• Disturbed Soil Samples

Disturbed samples shall be carefully preserved for mechanical analysis and chemical analysis tests. The
samples shall be collected at every 1.50 m intervals
• Undisturbed Soil Samples
Samplers for recovering the undisturbed soil samples shall conform to IS: 2132. The UDS shall be collected at
3.0 m intervals using thin walled 100 mrn dia and 450 mm long open end seamless sampling tube. The tubes
shall be driven into the strata at every 3.0 m intervals. On collection of these samples the loose material shall
be removed and waxed on either side of the tube. These tubes are properly labeled with depth and Borehole
No. The sampling procedure shall conform to IS: 1892 and IS: 2132. In very soft or soft clays a piston sampler
of an approved design shall be used.

6.8. Laboratory Tests on soil samples:

List of tests intended are attached as attachment 1-3. General laboratory tests conducted for soil samples are
as follows:

• Soil Tests
o Physical parameters
Grain size analysis
Atterbergs limit
Liquid limit Plastic limit
Plasticity index
Shrinkage limit
o Shear strength parameters

Unconfined compressive strength test

Direct shear test
Tri axial test
o Consolidation test
 • Rock Tests
o Density, Moisture content and water absorption
o Spec gravity
o Uniaxial Compressive test
o Point Load test

6.9. Rock Classification:

Rock classi'fica1:ion Shall be carried out as per IS Code 11315 Part 1 to 7 in terms of weathering and state of
fractures and strength shall be carried out in the following manner.

It should be understood that all grades of weathering may not be seen in a given 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 the presence of open
discontinuities of all types in the rock mass.

'Interpretation' in above table shall be done by Author of this report based on his understanding of above table
& experience and is not a part of original table and observation of entire of rock mass instead of individual
rock pieces.

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.

6.10. Permeability Test:

Water percolation tests covered by this standard should be conducted in uncased and un grouted sections of
the drill holes. The procedure adopted consists of pumping water into the 'test section' and is therefore called
'pumping-in type'. Packers are employed for conducting these tests and depending upon the use of one packer or two
packers the methods are designated as 'single' or 'double packer' method respectively. Examination of the drill cores
and the results of water tests obtained during drilling will usually indicate whether a double packer test in any isolated
section or sections of the drill hole is required. The tests are based on measuring the amount of water accepted by
the 'test section' (of the hole) confined by a packer/packers while water is pumped into it.

The single packer method is useful where the full length of the hole cannot stand uncased/ ungrouted in soft
rocks, such as sand rock (soft sand stone), clay shale or due to highly fractured and sheared nature of the rocks or
where it is considered necessary to have permeability values side by side with drilling (for example, where multiple
aquifers are present). Where the rocks are sound and the full length of the hole can stand without casing, double
packer method may be adopted. The specific advantage of double packer method is that critical rock zones can be
tested by confining them alone with packers.

Single Packer Method -The method used for performing the water percolation tests in a section of the drill
hole using a single packer. In this method the hole should be drilled to a particular depth desirable for the test. The
core barrel should then be removed and the hole cleaned. The packer should be fixed at the desired level above the
bottom of the hole and the test performed in accordance with the procedure laid down in after performing the test the
entire assembly should be removed.
 The drilling should then be proceeding till the next test section has been drilled for performing the next test. In
this manner the entire depth should be tested side by side with the drilling.

Double Packer Method -The method used for performing the water percolation tests in a section of the drill
hole using a double packer. In this method the hole should be drilled to the final depth desired and cleaned with water
until clear water returns. Two packers connected to the ends of a perforated drill rod of a length equivalent to the test
section should be fixed in the drill hole. The bottom of the perforated rod should be plugged before the double packer
tests are proceeded with. The test may be done from bottom upwards or from top downwards. However, it is
convenient to start the tests from the bottom of the hole and then work upwards.

The tests. are recommended to be performed in 1.5 or 3 m test sections so' that the entire hole is covered,
depending upon the geological conditions; as for example in sections passing through a shear zone or a highly jointed
zone a lesser length of section should be used .The test length should not, however, be less than 5 times the
diameter of the bore hole. The test section should be confined by means of a packer or packers
Water should then be pumped into the section under pressure. Each pressure should be maintained until the
readings of water intake at intervals of 5 min show a nearly constant reading of water intake for one particular
pressure at the collar. The constant rate of water intake should be noted. It is recommended that the tests be
commenced with a low pressure at the collar and increased limited to the availability of suitable rock cover to prevent
uplift or to a maximum equivalent to H + X ( where H is the hydraulic head to which the strata would be subjected due
to contemplated structure and X is the loss due to friction) is achieved.

ATTACHMENT - 6

EQUIPMENT LIST

• Shell & Auger Rigs with Power Winch and all accessories
• Casing Pipe 6" 10
• Drilled Rod ( Standard)
• Hydraulic Drilling Mechine
• Casing Pipe Nx Size
• Barrel
• Diamond I TC bits Nx
• Core Boxes .
• Undisturbed Sampling Tube
• Split Spoon Samplers
• Drop weight