CP1494-17 A361 and A39 North Devon Link Road Geotechnical Investigation

Tender description

This Contract involves the Geotechnical Investigation into the A361 / A39 North Devon Link Road from the Borner's Bridge Junction at South Molton to the Buckleigh Road Junction near Bideford. The ground investigation will comprise the following works: • The excavation of mechanically dug trial pits to a maximum depth of 4m or refusal. • Windowless sample borehole drilled by a dynamic sampling rig to depths as given in the Procurement Documents or refusal on rockhead. This is to include in-situ Standard Penetration Testing (SPT) and undisturbed sampling. Hand-dug starter pits shall be excavated at all exploratory borehole locations. • Combine dynamic sample / rotary open hole / rotary cored boreholes to depths as given in the Procurement Documents . This is to include in-situ Standard Penetration Testing (SPT) and undisturbed sampling. Hand-dug starter pits shall be excavated at all exploratory borehole locations. • Excavation of hand-dug trial pits in sides of existing cuttings and removal of vegetation to expose underlying rock mass to facilitate kinematic analysis. • Excavation of hand dug pits at base of cutting where inaccessible to mechanical excavation/boring methods. • Installation of groundwater monitoring standpipes in boreholes to a depth specified by the supervising engineer. Monitoring standpipes shall be 19mm diameter or greater. • In-situ determination of California bearing Ratio (CBR) - to be undertaken using Dynamic Cone Penetration (DCP) equipment. The number and location of DCP tests required to provide sufficient coverage will be determined on site by the Investigation Supervisor. • Groundwater monitoring is to be conducted following the completion of site works at intervals determined by the Investigation Supervisor. All installations shall be monitored to establish the elevation of groundwater. • Geotechnical Laboratory testing on selected samples. • Environmental/Chemical Laboratory testing on selected samples. • Specific borehole requirements and Borehole location plans are detailed within the Procurement Documents. • Provide Devon County Council with a Ground Investigation Report and Interpretation Report, plus design support. The procurement documents are available for unrestricted and full direct access, free of charge, at: http://www.supplyingthesouthwest.org.uk Tenders or requests to participate must be submitted electronically via: http://www.supplyingthesouthwest.org.uk