Carrying out Geophysical Investigations of Vulnerable stretches on NH-717A and 717 B (Sikkim and West Bengal), Arunachal (NH-13, NH-215, NH-415, NH-513 and NH-713 A and Twang) and Mizoram (NH-502A, NH-54 and NH-108)

0 km to 500 Km assuming Guwahati (Assam) as the centre point.

500 Km to 1000 Km assuming Guwahati (Assam) as the centre

More than 1000Km assuming Guwahati (Assam) as the centre

Local Mobilization & Demobilization of tools and equipment with other accessories including manpower from one site to next consequent site of investigation where Electrical Resistivity Tomography (ERT), Seismic Refraction Tomography (SRT) and Multichannel Analysis of Surface Waves (MASW) is to be conducted.

Localised movement from one location to another location up to 20 km within the same NH or SH

Localised movement from one location to another location 20 Km to 100 km within the same NH or SH

Localised movement from one location to another location 100 Km to 300 km within the same NH or SH

Conducting Electrical Resistivity Tomography (ERT) along the road alignment at hill side, valley side or both with the maximum target depth of investigation up to 20m as per the mentioned scope of work. Preferable 2 ERT lines of 50-120 RM will be investigated at each site using: (i) Electrode spacing of 3m(maximum) will be used utilising at least 60 electrodes in each profile. (ii) Data must be collected utilizing the Dipole - Dipole protocols.

Conducting Seismic Refraction Tomography (SRT) along the road alignment at hill side, valley side or both with the maximum target depth of investigation up to 30m as per the mentioned scope of work. Preferable 2 SRT lines of 80-120 RM will be investigated at each site using: (i) Array of 24 channels geophones will be used to record seismic signals with maximum 5 m geophone to geophone spacing. (ii) The seismic spread will consist of total 7 to 9 numbers of shots with a minimum of two far shots, two end shots, two mid shots and one centre shot.

Conducting Multichannel Analysis of Surface Waves (MASW) along the road alignment at hill side, valley side or both with the maximum target depth of investigation up to 30m as per the mentioned scope of work. Preferable 2 MASW lines of 50-120 RM will be investigated at each site using: (i) Array of 24 channels geophones having natural frequency of 4.5Hz will be used to record seismic signals with maximum 2 m geophone to geophone spacing. (ii) The data will be collected in standard pattern with 6m offset and shifting the two geophones for the next shot. This process will be repeated for covering the total length of spread. (iii) Using MASW data Vs30 at each 20m interval will be given covering the total profile length.