Study on Internal Force and Deformation of Prefabricated Caisson Sinking Process
Based on the project of the Administrative Service Center of Haicang District of Xiamen City,this paper discusses the finite element analysis method of the sinking process of the caisson by combining the monitoring results of the project.The analysis results show that the lateral movement of the shaft wall in the sinking process of the caisson construction is small,the earth pressure is close to the static earth pressure,and the influence range of the land subsidence is about 0.5 times the diameter of the caisson.Combined with the construction of an underground parking lot in the old urban district,the method of welding connection is proposed to accelerate the construction progress,and the finite element calculation parameters of welding connection are discussed by using the principle of equivalent stiffness,and the influence of surrounding buildings is considered.Through finite element analysis,it is concluded that when the caisson is located in the old residential district with surrounding buildings,the settlement on the side with buildings increases significantly.To the outer edge of the building;The influence range of surface deformation on one side of the building is twice the diameter of the caisson,in which the subsidence is manifested within 2 m,and the surface soil is uplifted beyond 2 m.One side of the building has a lateral movement to the inside of the caisson,and there is a tendency for active earth pressure.There is no lateral movement of the building side to the outside of the caisson,and the soil tends to have passive earth pressure.The vertical bending moment of a caisson structure with the building side is mainly internal tension,while the vertical bending moment of a caisson structure without the building side is external tension.The peak value of the vertical bending moment appears roughly at 2/3 of the depth.Near the upper part of the caisson,the circumferential axial force gradually decreases from the construction-free side to the construction-free side,while the circumferential axial force gradually increases from the construction-free side to the construction-free side at the lower part of the caisson.The distribution of the circumferential axial force is nearly uniform when the depth is 0.6 times.
prefabricated open caissonearth pressuredeformationstructural internal force
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