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| 1 | Scope of Geotechnical Investigation work shall definitely include but shall not be limited to the following: |
| 2 | Drilling ofBore holesbelow the existing ground level upto suitable depth as per drawing or as directed by Engineer-in-charge & collecting representative disturbed and undisturbed samples (using thin wall tube sampler in cohesive soil) at 1.5m in depth intervals or every change of strata, whichever is earlier and recording Standard Penetration Test results upto refusal. |
| 3 | Boreholes shall be stabilized, whenever required, against caving of the sides and heaving of the bottom of the hole, especially where the hole is carried below the ground water level, by use of casing or by bentonite or other suitable methods. |
| 4 | The rates quoted shall also include backfilling of Boreholes digged with 1:1 cement-bentonite grout as per directions of Engineer-in-charge to make the borehole site as per the original conditions and no extra will be paid for stabilization and backfilling of boreholes. |
| 5 | Frequency of Disturbed and Undisturbed soil samples shall be at every 1.5m and 3.0m interval respectively and at every identifiable change of stratum. |
| 6 | All Samples shall be clearly labelled indicating date of sampling, bore hole or trial pit no., depth of sampling, etc. Also, arrow shall be marked pointing towards top surface of undisturbed soil sample. |
| 7 | All Samples shall be suitably packed in sturdy good quality wooden boxes using sand, saw dust, etc. all around the samples before transporting to the laboratory for testing. Sampling tubes containing undisturbed samples shall not be exposed to direct sun and shall be kept in shade covered with wet gunny bags. Precaution shall be taken to ensure that there shall not be any change in moisture content of the soil samples. |
| 8 | Each Rock core sample recovered in drilling shall be numbered serially with good quality enamel paint and arranged sequentially in core boxes from top downwards. Further, core boxes shall be conforming to IS:4078. |
| 9 | All unused and excess soil / rock samples after testing shall be retained and properly stored by contractor for three months after the end of submission of the Final Geotechnical report and thereafter shall be handed over to department as directed by Engineer-in-charge. |
| 10 | Detailed chronological record of drilling and sampling operations shall be maintained in the field log and should be submitted to department after completion of boring work at site. |
| 11 | Field log should contain at least the following information: |
| 12 | a) Reference information like borehole no., test no., location, datum, existing ground level, inclination of boring, etc. |
| 13 | b) Sample type (Disturbed / Undisturbed), number, sampler dimension, depth at start and completion of sampling, length of sampling, Core Recovery Ratio (CRR), Rock Quality Designation (RQD) and complete visual description of each sample in \"as retrieved state\" |
| 14 | c) Number of blows for each 150 mm penetration |
| 15 | d) Depth at which casing required |
| 16 | e) Ground water information |
| 17 | f) Elevation at top and bottom of borehole and top of rock |
| 18 | g) Date and time of all operations and delays with reasons |
| 19 | h) Miscellaneous information to aid interpretation of subsurface conditions |
| 20 | Final log shall be condensation of field log refined on basis of field and laboratory tests and it should present a clear, concise and accurate picture of subsurface conditions. |
| 21 | Carrying out Laboratory tests on samples collected to determine Engineering properties of Soil / Rock as directed by the Engineer-in-charge. |
| 22 | Carrying out Chemical analysis on samples of Ground water and Soil to determine Chloride content, Sulphate content, pH value including assessing their effect on concreteand indicate corrective measures. The qualitative analysis shall clearly indicate thesuitability of water for concreting asrequired by IS:456 and for human consumption. |
| 23 | Soil investigation agency shall give complete calculations for recommendations based on field and laboratory tests. For all recommendations, formulas in Indian Standards shall be used or any established literature can be consulted. |
| 24 | The criteria for determination of quality of acceptable rock / starta shall be clearly defined in manner which will assist the supervisory staff of the department at site during the progress of work. |
| 25 | Soil Investigation Agency shall study, analyse and comment on the possibility ofliquefaction of soil at the site during earthquake along with supporting calculations. |
| 26 | Location of all boreholes and field tests, along with levels of the existing ground at such locations with reference to datum as specified by Engineer-in-charge shall be established by the contractor at his own cost. |
| 27 | Making bench mark pillar(s), whatever required for the work, and maintaining them upto the completion of work shall be the responsibility of the contractor without any extra cost whatsoever. |
| 28 | Location and depth of boreholes and field tests / areas indicated in drawings are tentative only and subject to change that may be necessary during actual execution of work as directed by Engineer-in-charge. |
| 29 | Earthwork in Boreholes shall be classified into one of the categories below and measured separately for each category. The decision of EIC regarding categorization of earthwork is binding on the contractor. |
| 30 | a) All kinds of soil: - Strata such as sand, silt, gravel, loam, clay, mud, peat, vegetable or oganic soil, shingle, river or nallah bed boulders, cobble stone, etc. and their mixtures including rock boulders of size less than 1.0m in any dimension & not more than 200 mm in any of the other two dimensions, which for excavation yields to application of picks, shovels, jumper and other ordinary digging equipments. |
| 31 | b) Soft rock: - Any rock or boulder which can be excavated by splitting with crowbars and does not require blasting, wedging or similar means for excavation such as lime stone, sand stone, hard laterite, hard conglomerate and un-reinforced cement concrete below ground level including rock boulders of size less than 1.0 m in any dimension & not more than 500 mm in any of the other two dimensions. For this type of soil, Core recovery ratio is less than or equal to 0.5 or RQD less than or equal to 25%. |
| 32 | c) Hard rock: - Any rock / boulder such as quartzite, granite, basalt, reinforced cement concrete, etc. which cannot be excavated with pick-axes, crowbars, etc. and excavation has to be carried out by chiselling, wedging, etc. For this type of soil, Core recovery ratio is more than 0.5 or RQD is more than 25%. |
| 33 | For Boring, use of chisel may be permitted in strata where SPT \"N\" value is greater than 100 blows per 300mm of penetration. |
| 34 | Department reserves the right to ask for clarification and additional information without paying additional charges. |
| 35 | Two Hard copies of Draft Geotechnical report shall be submitted for scrutiny and approval by the department and necessary changes shall be incorporated as required before submitting the Final Geotechnical report. |
| 36 | Contractor shall arrange water, electricity, lighting, etc. required for the work at their own cost. Necessary permission from statutory authority shall be obtained by the contractor. |
| 37 | The quoted rates shall be inclusive of Mobilisation of necessary equipments, instruments, tools, hoists, scaffolding, material, labour etc. to the project site including making access, cutting & filling etc., required for smooth execution and completion of geotechnical investigation. No extra amount will be paid for mobilisation of equipments, personnel, materials required for work including dismantling / removal / demobilisation of same after completion of all the field works, etc. Also, no extra charges will be paid for lead / lift, loading / unloading, handling / rehandling, stacking of materials etc. at site. |
| 38 | Contractor shall strictly abide by the local statutory regulations imposed by the Department / Police authorities regarding any equipment, operation, drainage, security, etc., wherever applicable. |
| 39 | Contractor shall follow DAE safety rules. In addition, following security regulation shall be followed strictly while movement of labourers / workers / contractor\"s personnel, etc. |
| 40 | a) Contractor shall issue I-cards to his workers deployed on regular basis. |
| 41 | b) Supervisor of contractor having photo pass can bring daily wage workers / casual workers inside premises for work. He should prepare list of such workers in duplicate. The original copy shall be handed over to the security or representative of the Engineer-in-charge at the gate and obtain endorsement on duplicate copy on a daily basis. |
| 42 | c) The Contractor\"s personnel including daily wage workers shall be in uniform with proper identification for ease in identification of such persons at unauthorised places. |
| 43 | d) The daily wage workers / casual workers employed by the contractor must wear florescence visi wear without fail during their presence inside premises. |
| 44 | e) Police Verification certificate for supervisors are to be produced as per the security requirements of the Department. |
| 45 | Regarding disposal of construction waste from site of work, the agency has to abide by the guidelines and any other regulations issued by statutory authorities in the matter from time to time and department is not responsible in any way in the matter. |
| 46 | Necessary COVID-19 protocols / guidelines shall be followed, as and when required, as per rules and regulations of Govt. of India / Maharashtra / BARC. |
| 47 | All the laboratory tests are to be conducted in NABL accredited laboratory in presence of departmental representatives. |
| 48 | The quoted rates shall be inclusive of all taxes, cess, Levy etc. |
| 49 | Refer Prebid minutes of meeting for any update. |
