地连墙重锤成槽施工对临近变电站振动影响分析

Vibration Impact Analysis of Diaphragm Wall Hammer Grooving Construction on Nearby Power Station

地下连续墙成槽不可避免的对土层及周边建筑物产生较大影响,尤其需要采用落锤冲击成槽等重型施工工艺时,导致地层及邻近结构产生振动。本文依托于广州地区某紧邻变电站的地连墙成槽工程,利用Midas有限元分析软件,建立落锤冲击成槽的三维实体有限元模型,研究冲击荷载对临近电站桩基质点振动速度的影响,验证桩锤冲击和方锤修壁2种成槽施工方案的可行性。数值结果表明:电站桩基质点振动速度随落锤冲程的增大而增大,且竖向振动速度峰值最大;在一定冲程范围内,2种成槽施工方案均能满足规范要求。研究结果可为现场施工及类似工程提供参考。

Grooving of diaphragm wall inevitably has a great impact on soil layer and surrounding buildings,especial-ly when heavy construction technology such as drop hammer impact grooving is needed.It will cause vibration of stratum and adjacent structures.Based on the grooving project of the diaphragm wall near a power line substation in Guangzhou,a three-dimensional solid finite element model of power line substation structure and diaphragm wall grooving process were established by using Midas finite element analysis software.The influence of impact load on the vibration velocity of pile foundation in nearby power stations was studied.And the feasibility of two grooving construction schemes,pile hammer impact and square hammer,was verified.The numerical results showed that the point vibration velocity of pile foundation increases with the increase of drop height.And the peak value of vertical vibration velocity is the largest.Within a certain stroke range,the two grooving construction schemes can meet the requirements of vibration specifica-tions.The research results of this paper can provide reference for site construction and similar projects.