Throughout the whole period of the exposure of existing facilities and utility services, subcontractor shall protect the said facilities and utility services and shall ensure that, on and after backfilling or building-in, the said facilities and utility services and services are adequately supported with concrete blocks or other satisfactory means so that no damage will be caused to them. any foundations of existing buildings or roads in or alongside the excavations shall be supported by suitable braces, props or other means throughout subcontractor's operations and before backfilling, shall be permanently braced in such a manner they will not be affected by the settlement of backfill