Abstract: At present, design and construction experiences of deep and large circular shafts in soil-rock combination strata are still much insufficient.In order to ensure the safe construction of the circular shaft of78m depth and34.9m diameter in Luotian-Tiegang Reservoir water conveyance tunnel project, an elaborate three-dimensional elastic-plastic finite element numerical model was established using ABAQUS,and adjacent stratum deformation characteristics during diaphragm walls construction were studied.By comparing the measured values with the simulated results, with and without considering the stiffness weakening of diaphragm wall joints, we analyzed the impacts of the stiffness weakening of diaphragm wall joints on the deformations of the wall top, the ground, and the adjacent box culvert structure.The results showed that for the settlements of ground, the box culvert near the shaft, and the top of the diaphragm wall, the maximum average relative errors between the measured values and the numerical calculation values considering the weakening of diaphragm wall joint stiffness were10.11%,1.728% and16.49%,respectively, in good agreement with the measured values; while the maximum average relative errors between the measured values and the numerical calculation values without the joint stiffness weakening were83.02%,3.395% and139.6%,respectively, significantly different from the measured values.The results can be used as a reference for design of super deep and large-diameter shafts and diaphragm walls.