Response of framed buildings to excavation-induced movements

This paper presents a study of the influence of frame action on the response of buildings to deformations induced by deep excavations in soft clay. Using the finite element method, a building was modelled as a framed structure adjacent to a multi-propped excavation, firstly as a frame with continuous footings and then as a frame with individual footings. The geometry, location, and structural elements forming the frame models were varied to investigate the response of various frames. Using a structural analysis, parameters representing the stiffness of the frames in reducing deflection ratios and horizontal strains were derived. The influence of the frame action on the building stiffness can be quantified using the results from the finite element models. This makes it possible to estimate building modification factors from the relevant design charts so that induced deflection ratios and horizontal strains, caused by adjacent excavation and tunnelling activities, can be calculated. The approach gives a more realistic estimate of the tensile strains for assessing the potential damage caused to buildings.