Analysis on deformation of diaphragm wall joints in soft soil

Abstract

Excessive horizontal deformation of diaphragm wall joints could lead to the difficulty in pulling locked port tube out, hoisting of reinforcing cage, percolating water in joints and so on. By analysising the problem and cause of deformation in diaphragm wall joints, bringing up the deformation analytical model of locked port tube based on elastic foundation beam, researching on the example project of diaphragm walls from a subway station in soft soil. The result shows that duo to a void of 6∼8mm in the joining of locked port tube, the maximum deformation of calculated value is about 50mm lesser than monitored deformation in the practical scenarios. In order to decrease the deformation of locked port tube effectively, sands should be used as backfill in overbreaking grooves and the reasonable embedded depth of tube toe should be 1.0∼1.5m.