GEOTECHNICAL INVESTIGATION SUB SOIL EXPLORATION FOR THE WORK AUGMENTATION OF EXTERNAL SUPPLY AT VISAKHAPATNAM

Amount

(1) Mobilization of equipment for detailed soil investigation and shifting them location of boreholes and for in-situ tests :- Qty- 1 job 2) Boring holes 150mm dia in any type of soil, but excluding any type of rock upto a depth (as directed by Engineer-in-charge) for conducting following activities: (a) Conduct of SPT at every 1.5m interval or change of strata whichever occurs earlier (b) Collection of undisturbed soil samples (UDS) at every 1.5m interval or change of strata whichever occurs earlier (a minimum gap of 500mm shall be ensured between SPT and collection of UDS :- Qty-12 Mtr 3) Drilling holes in any type of rock (Soft/Hard) using hydraulic drilling machine within the borehole for cutting cored in rock and collection of cores of requisite size and length as per relevant IS Standards. Drilling shall continue till minimum depth of 5m into hard rock strata :-Qty 15 Mtr. 4) Conduct of following laboratory tests as per relevant Indian Standards (See IS 2720(all parts) IS 1498 and IS 3025) on soil samples collecteda. Test on distributed/ undistributed soil samples i. Visual and engineering classification. ii. Sieve analysis and hydrometer analysis iii. Atterbergs limits (liquid limit, plastic limit and shrinkage limit) iv. Specific gravity b.Test on undistrubed soil samples. i. Bulk density and moisture content. i. Unconfined compression test (on remoulded undistrubed sample). iii. Swelling pressure (on undisturbed and remoulded sample): iv. Determination of C & ɸ values using Direct shear (Drained/Undrained) (on remouleded or undisturbed sample) or Triaxial compression tests (on undisturbed or remoulded sample) or vane shear test : Qty 3 Bore hole 5) Conduct of following laboratory tests on rock samples/ cores collected from boreholes as per relevant Indian Standards (See IS 2720 (all parts) and IS 1498, IS 9143, IS 13030, IS 9221, IS 8764, IS 9179, IS 10050, IS 10082,IS 10782, IS 12608, IS 13047, IS 3025)

a) Visual Classification b) Density c) Specific gravity d) Hardness e) Slake durability f) Uniaxial compression test (both saturated and unsaturated) g) Point load strength index: h) RQD (Rock Quality Designation) :- Qty 3 bore hole 6. Chemical analysis of ground water sample collected at bottom of one borehole :- Qty 3 Each 7. Chemical analysis of soil samples one each from each strata in respect of one borehole, If different strata(s) encountered in any other borehole additional soils samples to be analysed :- Qty 3 Each Notes Composition of subsurfaces investigation report 1. General On completion of the in-site and laboratory tests, subsurface investiagtion report shall be prepared which should include geological information procedure adopted for investiagtion, field observations, labortory or tests dasta analysis, interpretation, recommendedations etc 2. Information to be provided The report shall include but not be limited to the following (a) Dimensioned Plan showing locationa and depth of in-situ tests, the co-ordinates of bore holes locations with reference to prominent pemanent features of the site duly signed by GE and Geo consultant (b) Geological informatio of the area. (c) General topography of the site, duly marking RL of the locaton of bore holes with reference to Rl of nearby pemanent featured available at site duly signed by GE and Geo Consultant. (d) Past Usage and historical data of the site, if available. Information regarding flooding of the site in the past, High flood level etc. (e) Bore-log and trail pit log duly signed by GE and Geo Consultant

f) In situ test results. (g) Plot of standard penetration test (N values both uncorrected and corrected) with depth identified areas (h) Labortory test results. (i) Summary of strata profile and 1) Calibration record including description of membrane and seath on probes, dimension of thick-walled cylinder length of flexible tubing, calibration curves/chart, temperature etc. 2) Drilling record including, borehole number, mrtjod of making borehole, log of soil type and condition, depth of water in borehole, weather and temperature. 3) Test Record: Type of test, date and time, depth of centre point of probe, volume readings at 30 s and 60 s elapsed time and corresponding pressure reasings, notes on any deviation from standard test procedure Field pressure meter, creep and air calibration curves indicating P0, Pf and Pt corrected pressure meter and creep curves indicating P0, Pf and Pt along calibration for the corrections (k) Reporting of in-situ and laboratory test results should be ina ccordance with relevant Indian Standard (l) Analysis and interpretation of Results. The following shall be included in the report (m) Analysis of test results (n) Discussion and interpretation of results analysed including basis of adopting design parameters for the substrata (o) For Shallow foundations 1) Net allowable bearing pressure considering shear, seettlement criteria as well as SPT value for Isolated footing contionus strip footing and raft foundation at depth 1.5m, 2.0m, 2.5m and 3.0m. For calculations IS: 6403 shall be used.

(3) Modulus of sub grade reaction and modulus of elasticity of substrata (4) In case of UC Sumps./ Swimming pools K valve from 0.5m to 5.0m depth d) For pile foundations: Safe load carrying capacity (compression, pull out and horizontal with free head as well as supported head pile load capacities shall be workrd out for 300, 400, 450 & 500mm for under reamed piles and for 450, 500, 550, 600, 700 & 750mm dia for end bearing piles. e) If weak soil with lesser N value as specified in Table-1 of IS 1893 (Part-1) 2016 is encountered, then evaluation of liquefaction potential shall be assessed and remedial actions to be adopted shall be specified. (f) Suitability of the soil for backfilling around foundations/ filling under floors. (g) Susceptibility of sub soil strata to liquefaction, if any, in the event of dynamic loading and reqisite remedial measures. (h) Remedial measures against the presence of harmful chemicals in the sub-soil/ grolund water. (i) Remedial measures for foundation footings, plinth beams and filling under floors in case of meeting expensive soil. 5.The Soil investigation report should be vetted by any IIT/ NIT/ Andhra University. 6. CD containing video evidence of depth of each borehole & machinery deployed at site be kept in record

Sri Sehhasayana Consultancy