锤击式沉桩法施工对既有供水隧洞结构动力响应分析

Dynamic Response Analysis of the Existing Water Supply Tunnel Structure Caused by Hammering Pile Driving Method

为分析锤击式沉桩法施工对既有供水隧洞结构的动力响应,建立了三维数值计算模型,并采用非线性时程分析法模拟了锤击式沉桩过程中既有供水隧洞结构的动力响应,并对不同桩隧距离、沉桩深度下既有供水隧道的响应规律进行了研究。结果表明:桩隧水平距离一定时,随着沉桩深度增大,隧洞正上方地表及隧洞结构的振动速度和沉降量均先增加后减小;沉桩深度一定时,随桩隧水平距离增大,隧洞正上方地表振动速度和沉降量峰值均呈减少趋势,随着桩隧水平距离增大,传递至隧洞的锤击能量被土体逐渐扩散削弱,管片的振动速度和变形量显著减小,当桩隧距离超过3倍隧洞直径后,沉桩对隧洞影响较小。

In order to analyze the dynamic response of the existing water supply tunnel structure to the hammering pile driving method,a three-dimensional numerical calculation model was established,and the dynamic response of the existing water supply tunnel structure during the hammering pile driving process was simulated using the nonlinear time history analysis method,and the response law of the existing water supply tunnel under different pile tunnel distances and pile driving depths was analyzed.The results show that when the horizontal distance of the pile tunnel is fixed,the vibration velocity and settlement of the ground and tunnel structure directly above the tunnel first increase and then decrease with the increase of pile sinking depth.When the pile sinking depth is constant,with the increase of the horizontal distance of the pile tunnel,the peak value of the ground vibration speed and settlement amount directly above the tunnel will decrease.With the increase of the horizontal distance of the pile tunnel,the hammer energy transferred to the tunnel will be gradually weakened by the soil diffusion,and the vibration speed and deformation amount of the segment will decrease significantly.When the pile tunnel distance exceeds 3 times the tunnel diameter,the pile sinking will have little impact on the tunnel.