4.6.11 Adjacent excavations
The builder shall ensure that foundations within engineered fill are not disturbed by adjacent excavations.
The Engineer should consider the influence of drainage and other service trenches on the stability of the complete works. Excavations in engineered fill may require additional trench support, even at relatively shallow depths. Health and Safety Executives’ (HSE) advice with respect to the design and management of below ground temporary works, including those for excavations, man-entry, etc must be adhered to.
The Earthworks Verification Report should identify and duly reference any constraints to excavation because of buried features, contamination or unusual ground conditions.
The minimum horizontal clearance between excavations and foundations must not be less than the depth of excavation minus the depth of the structural foundation. Particular attention is needed for excavation below the water table, where encountered.
Last updated: 2nd January 2024