Retaining Walls Monitoring Contract

Tender description

TII has a requirement for a specialist firm to put in place a monitoring system to assess an historic wall at the Phibsborough Luas Stop for two years. The reason for this contract is to ensure any movement of the wall does not exceed the permitted threshold. A combined monitoring system is required consisting of tilt meters, accelerometers and piezometer measurement. The system shall consist of the following installed on both the east and west retaining walls: • Triaxial tilt meters on vertically orientated beams installed at approximately 15m intervals; • Accelerometers installed at 3 locations on each wall: o 1 no. on the wall close to centre of platform o 1 no. on the wall South of North Circular Road o 1 no. on the wall North of the Cabra Road • 4 no. piezometers installed in the retained material at the locations shown on the design drawings. The system shall also incorporate still imaging cameras installed on the north and south faces of both the Cabra road bridge and the north circular road bridge. An online communications system is required to store and allow access to the monitoring data, as well as to operate alarms in the event of exceedance of thresholds of movement. The successful Tenderer shall be required to install the sensors and monitor the readings for a period of 25 months. Full details in the attached tender documents. TII are using the Open Procedure with a Pass/Fail Selection stage followed by Fixed Price Lump Sum Award stage.