高压旋喷桩施工对相邻既有高铁基础的影响分析

Analysis of Influence of High-Pressure Jetting Piles Construction on Adjacent Existing High-Speed Railway Foundation

为研究高压旋喷桩施工对既有高速铁路桥梁桩基础的影响,以一受高压旋喷桩施工影响而发生偏移的高铁桥墩为背景,采用ABAQUS对桥梁下部结构建模计算分析,将墩顶横向侧移的计算值与实测值进行对比,分析基桩的内力和位移,计算不同施工压力作用下桥墩的侧移量和横桥向基频的发展趋势,从动力和静力两方面评估结构现状,给出处理措施。结果表明:高压旋喷桩施工导致桥墩偏移,墩顶横向侧移的计算值与实际值较吻合,随着施工压力的增大,墩顶偏移量的增加也更快,横向基频变化不明显;基桩未出现裂缝;提出了采用应力释放孔来纠偏的处理措施。

To study the influence of construction of high-pressure jetting piles on the pile foundation of existing high-speed railway bridge,the piers of a high-speed railway bridge,which were displaced during the construction of the nearby high-pressure jetting piles,were taken as the study background.ABAQUS was used to establish the finite element model of the substructure of the bridge to conduct calculation and analysis.The calculated values of lateral displacement along the transverse direction of the piers are compared with the measured results,the internal force and displacement of the foundation piles are analyzed,and the lateral displacement amount and the developing trend of the basic frequency along the transverse bridge direction under different construction pressures are calculated.The status of the structure was estimated by dynamic and static conditions and the handling measures were given.The results indicate that the construction of the highpressure jetting piles induce displacement of piers,the calculated values of the pier-top lateral displacement along the transverse direction agree with the measured results well.As the increasing of construction pressure,the amount of pier-top displacement enhances rapidly,but the transverse basic frequency does not show apparent change.No cracks are found on the foundation piles.The handling measure of using stress dissipation holes to rectify the pier displacement is put forward.