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| 1 | Carrying out a detailed topographical/contour survey, including the marking of contours at every 3 m intervals on site, and recording all visible ground features along with the number, location, and girth size of trees (with girth more than 150 mm), complete in all respects.The survey shall be carried out using an electronic total station digital instrument with an angular accuracy of 1 to 3 seconds.Preparation of survey drawings and calculation of survey/plot area using the triangulation method on a computer with AutoCAD or other suitable software, including the supply of a CD and five sets of drawings of appropriate size, preferably on A0 size, complete as per terms and conditions and as directed by the Engineer-in-Charge. |
| 2 | Carrying out soil exploration, field testing, laboratory testing, and submission of a comprehensive soil investigation report, strictly in accordance with relevant IS codes and the directions of the Engineer-in-Charge. |
| 3 | 2. General Requirements2.1 Soil exploration shall be conducted in the presence of the Engineer-in-Charge/JE.2.2 Photographic records of soil exploration and testing shall be maintained. Photographs shall be taken along with the drilling agency staff and the concerned AGE (B/R) and JE (Civil) during exploration, and shall form an integral part of the final report.2.3 All works shall be carried out in accordance with IS 1892:2021, IS 13365 (Part 1):1998, IS 12070, IS 9211:1979, and other relevant IS codes.3. Contents of Soil Investigation ReportThe report submitted by the firm shall include, but not be limited to, the following:3.1 Levels & Site Details(a) Reduced Levels (RL) of ground level and founding level, with reference to a permanent Bench Mark (BM).(b) Location of permanent boreholes along with ground levels, clearly marked on the site/layout plan and referenced to the BM for easy identification.(c) Presence and level of the groundwater table, duly recorded in the report. |
| 4 | 3.2 Soil Testing & Analysis(a) Drilling of boreholes up to a maximum depth of 25 m or as per structural requirements, or until refusal is encountered, whichever occurs earlier, using 150 mm diameter drilling through all types of soil, excluding rock or rock-like hard strata (N ≥ 50), at locations as indicated on site.Note: The depth of exploration shall be up to 1.5 times the maximum anticipated depth of foundation.(b) Collection of disturbed and undisturbed soil samples at every 1.5 m interval.(c) Conducting Standard Penetration Tests (SPT) at every 0.5 m interval, as per relevant IS codes.The subsurface investigation report shall clearly indicate the nature and type of soil based on the analysis of disturbed and undisturbed samples. The following tests shall be carried out:(i) Grain size analysis, specific gravity, unit weight, and natural moisture content.(ii) Liquid limit, plastic limit, and swelling index.(iii) Consolidation tests to determine consolidation characteristics.(iv) Shear strength tests to determine shear parameters.(v) Chemical tests for soluble chlorides and sulphates, based on local conditions.(vi) Field tests as per Fig. 5A and Fig. 5B of IS 1892:2021.(vii) CBR values (soaked and unsoaked) and modulus of subgrade reaction (k-value) for pavement strata, as per IS 9211:1979. |
| 5 | 3.3 Rock Investigation (If Encountered)(a) In case rocky strata are encountered, the investigation shall be carried out in accordance with IS 13365 (Part 1):1998.(b) Where rock is identifiable, exploration shall extend up to 3.0 m into the rock, and tests shall include unit weight, porosity, water absorption, compressive strength, and shear strength.(c) Where rock characteristics are unknown or irregular weathering is observed, deeper investigation shall be carried out to establish the depth of sound rock.(d) Rock exploration details shall be as per IS 12070, including recommendations for Safe Bearing Capacity (SBC). |
| 6 | 3.4 Additional Report RequirementsThe report shall also include:(i) Layout of trial pits and boreholes on the proposed site plan, duly signed by the AGE (B/R) and the vetting agency.(ii) Geological information of the area.(iii) Past usage and historical data of the site, if available.(iv) Boring records as per Fig. 4A, 4B, and 4C of IS 1892:2021.(v) Soil/rock properties as per Fig. 5A and Fig. 5B of IS 1892:2021. |
| 7 | 3.5 Design Recommendations(i) Estimation of Safe Bearing Capacity (SBC) based on shear and settlement criteria for rectangular foundations of widths 1.50 m and 2.00 m, at depths of 1.50 m, 2.00 m, and 2.50 m, or at other suitable depths.(ii) Detailed calculations for SBC shall be included.(iii) Recommendations for raft foundation in case of low bearing capacity.(iv) Recommendation for the type of foundation along with SBC.(v) Recommendation for pile foundation, including pile capacity, if weak strata are encountered.(vi) Recommendations for soil improvement, if required.(vii) Assessment of the suitability of existing soil for backfilling.4. Scrutiny & ApprovalThe soil investigation report shall be scrutinized by the GE and the Engineer-in-Charge, and submitted with the counter-signatures of the AGE (B/R) and JE (Civil).Preparation of the final report and submission of test results shall be made in five copies (hard and soft copies). Please Enable Macros to View BoQ information |
