Abstract: The construction of ten adjacent panels of a diaphragm wall of an ultra deep excavation in Wuhan city is simulated by a three-dimensional finite difference method. The construction procedure consists of the excavation supported by slurry, concrete pouring, and concrete hardening. The excavation is simulated by the constant distributed hydrostatic pressure while the concrete pouring process adopts variable distributed hydrostatic pressure. The concrete hardening process is finished by linear elastic solid elements with variable elasticity modulus and Poisson ratio. The results of the numerical computation show good agreement with the field test data. According to the process of single jumping excavation, the pressure monitoring reveals the influence of diaphragm wall construction on stress redistribution. The earth pressure fluctuates along the retaining wall after the construction completion of the ten panels. The peak value appears in the middle of the panel, while the trough value appears around the junction of two panels. The fluctuation range is related to the depth. The differences between slurry pressure, concrete pouring pressure and earth pressure are the main reason influencing the redistribution of earth pressure. Reasonable slurry unit weight and ideal concrete pouring method are suggested to avoid disturbance of soils.

Key words: diaphragm wall, construction, stress redistribution, numerical simulation, field test