Detailed Geotechnical Investigation Study

Amount

GEOTECHNICAL INVESTIGATION Identification of utilities at borehole location, making 150mm nominal diameter bore holes at various locations in all types of soils and NX size in rock using suitable approved method of boring including local shifting, chiselling, cleaning, providing retrievable casing pipe as required or as directed (which can be reused or taken back by the Contractor), performing Standard Penetration Tests (As per IS:2131) at every 1.5m intervals and at change of strata; collection of disturbed soil samples, observations such as ground water level etc., collection of undisturbed soil samples at every 3.0m intervals or more (to be decided by Employer’s Representative) and at change of strata; collection of water samples; transportation of all the collected samples to the laboratory, complete as per specification and instructions of the Employer’s Representative, for depths below Natural Ground Level including submission of Factual Report and subsequence to submission of Geotechnical Investigation Report (all inclusive) as given below: 76 Nos. of bore holes (may change as per site conditions)

For boreholes from existing ground level to desired depth in Soil

For boreholes from soil bottom upto required depth in Rock (of any type)

Backfilling of bore holes from bottom to top immediately after completion of work or as per Engineer’s instruction with cement grout

In situ Tests in Soil

Constant/Falling head permeability tests

Collecting soil samples for chemical analysis at soil/ soil & rock interface

Collecting water samples for chemical analysis

Preparing sample by mixing the soil / crushed rock from 03 boreholes of each underground station

Lab Tests for Soils Conducting various Laboratory tests on soil UDS samples collected every 4 m interval from EGL, at any Laboratory Testing Facility accredited by NABL or any other accreditation body which operates in accordance with ISO/IEC 17011 and accreditation in compliance with ISO/IEC 17025 for testing and calibration scopes, including preparation of soil samples to determine the following properties of soil, all complete as per specifications

Bulk density, dry density and moisture content

particle size distribution with and without hydrometer grading

Atterberg Limits

Shrink- Swell limits

Specific gravity

Consolidated undrained test with pore pressure measurement triaxial test

Unconsolidated, undrained triaxial test

Consolidation Test

Chemical analysis of soil to determine the, pH, Chloride, Sulphate (From sample prepared at Item No. IN-4)

Chemical analysis of water to determine pH, Chloride, Sulphate and organic matter (From sample prepared at Item No. IN-5)

Field Tests in Rock

Pressure meter test

Packer test/Lugeon test

Lab Tests in Rock Conducting various Laboratory tests on rock samples at an NABL accredited laboratory including preparation of rock samples to determine the following properties of rock, all complete as per specifications

Unconfined compressive strength test

Point load index test

Bulk density, dry density and moisture content

Specific gravity, porosity and water absorption test

Brazilian tensile test

Cerchar abrasiveness test

Petrography Test with description of rock (especially bound and unbound quartz content) based on the evaluation of thin petrographic sections with coloured photographs (only for tunnel area)

Crosshole sessmic refraction test / MASW as oer relevant IS code / ASTM code to assess subsurface structure, thickness of layers, velocities of body waves, soil amplification factors (like Vs30) up to a depth of not less than 30 mts below the existing ground level.

Modulus Elastcity of intact Rock

Conducting in situ geophysical testing to determine the subsurface shear wave velocities along the depth not less than 30m from the existing ground level by Cross Hole Seismic Test. Cross Hole Seismic Test shall be performed by 1No of source borehole & 2Nos of receiver boreholes for determining in situ subsurface shear-wave velocity up to a depth not less than 30m from the existing ground level. Location and spacing of boreholes shall be proposed by the contractor for Engineer’s approval prior to the commencement of work.

Unique Engineering Services

Techpro Engineers Pvt. Ltd.

C E TestingCompany Pvt Ltd

Cengrs Geotechnica Pvt. Ltd.

soiltech india private limited

SKW SOIL AND SURVEY CO

Geo Designs and Research Pvt. Ltd.

VELCITI CONSULTING ENGINEERS PRIVATE LIMITED

SECON Private Limited