RITES Limited, a Public Sector Enterprise under the Ministry of Railways, invites online e-tender for Geophysical survey for proposed tunnels in connection with Abu Road–Taranga Hill new line project.
- Tender Reference Number: RITES/RCED/Geophysical/Tunnels/Abu Road-Taranga Hill/2022
- Name of Work: Geophysical survey for proposed tunnels in connection with Abu Road-Taranga Hill new line project.
- Estimated Cost: INR 28.75 Lakhs
- EMD: INR 28,750 Thousand
- Period of Completion: 45 Days
- Document Download / Sale Start Date: 30th November, 2022
- Document Download / Sale End Date: 12th December, 2022
- Bid Submission Start Date: 30th November, 2022
- Bid Submission End Date: 12th December, 2022
- Bid Opening Date: 13th December, 2022
Scope of Work:
- Geophysical investigation at the site shall be planned to understand the surface & sub-surface geology along the alignment with a view to assess the feasibility of the proposed alignment and to highlight various geotechnical problems likely to be encountered, required strength characteristics of the underlying soil/rock to provide Geo tech parameters for selecting type of foundations, design of tunnel and tunnelling methodology for Abu Road-Taranga Hill new line Project.
Seismic Refraction Survey:
- Geophysical investigation by Seismic Refraction Survey shall be undertaken by using suitable seismographs at selected locations along/across the proposed alignment.
- The seismic refraction survey will be carried out by signal enhancement technique with adequate profile lengths with suitable geophone spacing.
- Figure 1 shows the theory of seismic refraction measurements across different horizons in the subsurface. Seismic waves are being generated by a hammer/explosives and the seismic energy travels through different mediums inside the earth surface and is recorded by an array of sensors (geophones) spread along the profile line as given in figure-1.
- For deep seismic refraction survey, explosives with Electric detonators shall be used as energy source; shot holes will be drilled and loaded with optimum quantity of explosives & detonators for generating high frequency seismic signals up to the target depth of 100m or to the competent rock mass.
- The explosives shall be handled by the licensed blaster. The output of a seismograph is obtained by converting the energy of the seismic wave into electrical energy, amplified, filtered, stacked and recorded in digital SEG2 format.
- The seismic signals thus obtained shall be displayed on monitor. In addition, the automatic gain control shall take care to prevent overloading by the stronger signals to bring out the weaker signals.
- The filters will be employed on the recorded signal to obtain maximum current and voltage at certain desirable frequencies and to reject or suppress the undesirable frequencies.
- An automatic refraction analysis package shall be used to pick up the accurate time breaks for precise processing of the seismic data. The software to be used for processing of seismic data has the following features.
- Fully automatic analyses routine.
- Checks and corrects travel time curves with the modified Hagiwara’s method.
- Fully automatic velocity analysis.
- Detection of low velocity zone at the base layer.
- Fully automatic 2D Seismic Tomography with velocity and thickness.
- Checks and corrects the analysis result by forward modeling based on ray theory.
- The quality control shall be done by checking the equipment every morning to verify the accuracy of timings as well as the accuracy of energy source.
- The seismic record from each shot shall be verified in the field, as the first step of quality control. Following criteria shall be adopted to ensure the quality, bad shots are discarded and re-shooted.
- The first arrival times on each seismic record must be clean and precise.
- Not more than two (2) traces should be absent;
- No end traces should be absent, so as to obtain a good time-distance closure curve.
- The quality control shall also be established by overlapping 1 geophone for each successive spread. This overlap allows controlling the timing of the arrival at the same point from 2 different set-ups.
- Completion certificate of Similar nature of works (of value as stated in point 10 of this table) defined as Seismic Refraction Survey/ Electrical Resistivity Survey/ MASW Survey for any type of civil engineering structure within the last seven years reckoned from the scheduled date of submission of tender for works of Railways, CPWD, MES, DOT, RITES, State PWD or any other Central / State Government Undertaking, Municipal Body, Autonomous Body of Central/State Governments or Public Ltd., MNC Companies listed on Stock Exchange in India or Abroad or subsidiaries of such companies for the work.
- The bidders are requested to satisfy themselves by visiting the site to confirm about the prevalent site conditions, topography of the area, Geological formations, accessibility of the area etc. before quoting and submitting the tender to RITES.
- No claim whatsoever on the above account shall be entertained. In this context, the bidder is required to submit undertaking on Non-Judicial Stamp Paper of Rs.10/- duly attested by Notary/Magistrate as per proforma 3 attached in Tender document.
- The bidder must submit CV of 2nos. of Geophysicists with min. 3 years of experience along with the tender document.
- The bidder must submit ownership of the Seismograph along with a tender document which shall be deployed at site for execution of geophysical work. If it is found that the bidder has not submitted proof of ownership of the seismograph, their bid shall be rejected and not considered for further evaluation.
- One similar work of Minimum value of 80% of the Estimated Cost of work i.e., of (80% of ₹ 28.75 Lakhs = ₹ 23.0 Lakhs), or
- Two Similar Works each of Minimum value of 50% of the Estimated Cost of work i.e., of (50% of ₹ 28.75 Lakhs = ₹ 14.375Lakhs), or
- Three similar works each of Minimum Value of 40% of the Estimated Cost of work i.e., of (40% of ₹ 28.75 Lakhs = ₹ 11.5 Lakhs).
- A weightage of 7% (compounded annually from the date of completion of the work to the submission of the Bid) shall be given for equating the value of works of the previous years to the current year.
- Only such works shall be considered where physical completion of entire work is over or commissioning of work has been done, whichever is earlier.
- The Bidder should submit the details of such similar completed works as per the format at Proforma-1 enclosed. In support of having completed these works, the firm should submit copies of the completion certificates from the owner companies indicating the name of work, the description of work done by the bidder, the value of contract executed by the bidder, date of start, date of completion.
- Works carried out by another Contractor on behalf of the Bidder on a back to back basis will not be considered for satisfaction of the Qualification Criterion by the Bidder.
- Credential certificates issued by Government Organizations/Semi Government Organizations of Central or State Government; or by Public Sector Undertakings/ Autonomous Bodies of Central/State Government or their subsidiaries/by Public Ltd.
- Companies listed in Stock exchange in India or Abroad or subsidiaries of such companies shall only be accepted for assessing the eligibility of a Tenderer. Certificates issued by one of the aforesaid organizations as a lead member (having equity stake of 51% or more) of a Joint Venture (JV) for work executed for the JV, will also be acceptable.
- In case of PPP projects, if the bidder has executed a work for a concessionaire who is one of the aforesaid organizations, then the certificate issued by such concessionaire or by the public authority concerned, will also be acceptable.
- The cutoff date shall be calculated backwards from the last stipulated date for submission of Tender i.e., for a Tender having the last stipulated date for submission on 12.12.2022, the cutoff date shall be 13.12.2015.
- Credentials certificate issued by Govt. Organization/Semi Govt. Organizations/Public sector Undertakings/Autonomous bodies of Central /State Govt./Municipal Bodies/ MNC/Public Ltd. Cos, listed on BSE/NSE or firms having experience certificates of private Multi-National Companies (MNCs) shall only be admissible.
- The authenticity of the experience certificate issued by Cos listed on BSE/NSE and private MNC firms shall be supported by FORM 26 AS to ensure receipt of payment outlined in the completion certificates shall only be accepted for accessing the eligibility of a tenderer.
Source: RITES- Tender | Image Credit (representational): RITES