连续振动沉桩施工环境影响数值模拟研究

Research on Numerical Simulation of Environmental Infl uence of Continuous Vibration Pile Sinking Construction

文章利用FLAC3D软件中的结构单元模拟钢管桩,通过设置接触面考虑桩土相互作用,用单元劈裂技术模拟钢管桩连续下沉,并分析了沉桩过程中桩周土体的动力响应规律。结果表明:9倍桩径范围内,地表竖向和径向速度峰值均随距离的增加而快速衰减,超过5倍桩径时,免共振沉桩施工对桩周土体造成的动力影响可降至规范建议值以下;土体深度越大,桩周孔隙水压力增量越大,同时孔隙水压力受影响区的径向范围越小;5倍桩径范围内孔隙水压力变化较快,桩周土体孔隙水压力受剧烈影响的范围在2倍桩径以内。

The structural element in FLAC3D software is used to simulate the steel pipe pile.The pile-soil interaction is considered by setting the contact surface,the continuous sinking of the steel pipe pile is simulated by the element partition technique,and the dynamic response law of the soil around the pile in the process of pile sinking is analyzed.The results show that in the range of 9 times the pile diameter,the peak value of vertical and radial velocity of the ground surface decrease rapidly with the increase of distance,when the distance is more than 5 times the pile diameter,the dynamic influence of resonance-free pile sinking construction on the soil around the pile can be reduced to below the recommended value in the code;the larger the soil depth is,the greater the pore water pressure increment around the pile is,and the smaller the radial range of the pore water pressure affected area is;the pore water pressure changes rapidly in the range of 5 times the pile diameter,and the pore water pressure of the soil around the pile is greatly affected within the range of 2 times the pile diameter.