This work shall consist of excavation by mechanical means in all types of soil in final line, level, grades, cross section as shown in drawings for roadways drains, shoulders, median and foundation for structures, including hauling suitable excavation materials to site for embankment and sub grade construction also disposal of unsuitable cut materials specified manner.
MoRT&H Specification clause No 301 to 303 and technical specification of contract
Excavators, Dumpers, dewatering arrangements
Line rope, lime powder, pegs etc.
Construction manager, Earth work engineer/supervisor, land surveyor, material engineer, safety supervisor, helpers
He shall be overall responsible for the activity including planning, organising the resources required to carry out the work in consultation with the project manager, implement and ensure safety requirements during the work including that of utility services. Ensures relevant test conducted and records are maintained as per the contract requirements. Coordinate with the consultant engineer in obtaining necessary approvals for the completed activity.
Deploying necessary resources at site as planned. Execute the work as per drawing and maintain quality requirements as per specification. Implement and maintain safety regulations and good housekeeping. Coordinate with the consultant staff in obtaining necessary approvals for the completed activity.
Establishing necessary reference points to carry out the work as per the level and alignment. Checking and recording the levels as completed. Coordinate with the consultant staff in obtaining approvals for the finished work.
Implement quality procedures as per plan. Ensure the materials used are meeting the specification requirement conduct the required tests as per the relevant specification and maintain all records.
Ensure that activity is being carried out safely as prescribed in the project safety plan.
The excavation shall be set out true to lines curves, grades and sections in works involving removal of existing carriage way, earthen shoulder, median, shall be excavated to the full width and to the required levels, after satisfying CBR and density requirements, as shown in drawings. After reaching to the required depth, it shall be compacted at OMC to achieve min. of 95% for embankment and 97% of MDD for sub grade.
Excavated soil shall be tested for its suitability for reuse or disposal.
The cut formation, which serves as sub grade, if found suitable, shall be loosened, graded, watered and compacted in layers in the specified manner. Any unsuitable material encountered at the sub grade level shall be removed and replaced with suitable material.
While executing excavation all adequate precautions shall be taken to prevent soil erosion and appropriate drainage measures shall be adopted to keep the site free of water stagnation.
The suitable material obtained from excavation shall be used for filling of roadway embankment, sub grade filling of existing pits in the ROW, landscaping etc. All other unsuitable materials shall be disposed of. Surplus suitable material if any shall be stacked at approved locations.
Controlled blasting shall be carried out in fixed hours as ordered by the Engineer and kept known to the public and authorities in the vicinity sufficiently in advance.
Red flags shall be displayed in all directions during blasting operations. People except those who actually light the fuse shall be prohibited from the area and all persons including workmen shall be evacuated from the flagged area at least 10 minutes before firing. A warning alarm or siren shall be sounded for this purpose. The man in-charge shall satisfy himself that all charges are exploded before allowing any workman or people to enter.
The firing of charge holes shall be done by electric detonators by using a sufficiently long fuse wire (at least 10 m) and all charge holes shall be blasted at one instance.
The explosives for blasting shall be as per permitted explosives as per procedure and requirement. The weight of charge depends upon the quantity of rock to be blasted/excavated, hardness of rock and site condition.
Stemming may be used if required, of free dry-running material, which passes through 2.8 mm sieve and retained on 1.2 mm sieve by 90%.
This shall be done to control the fly rock. Since the drill holes are loaded with less charge, sand/earth bags weighing at least 50 kg shall be kept on each charge hole to control fly rock.
All safety measures shall be as per approved EHS Plan.
