旋挖桩孔壁坍塌事故致灾机理探讨  

Discussion on Disaster-causing Mechanism of Hole Wall Collapses with Rotary Drilling

作　　者：陈绍清[1] 李锦兰 宋丹丹[1] 庞成武 刘金江[1] 

机构地区：[1]重庆科技学院安全工程学院,重庆401331 [2]重庆川东南地质工程勘察设计院,重庆400038

出　　处：《重庆建筑》2017年第5期24-26,共3页Chongqing Architecture

摘　　要：某房屋建筑工程基础设计为旋挖桩,施工单位采用全钢护筒护壁旋挖钻进成孔,在钢筋笼安装接长过程中,钢护筒周围地面塌陷引发孔壁坍塌事故,造成电焊作业工人伤亡。该工程场地上部为3~5年的新近填土,事故孔位置的回填土层厚度为14.2m,旋挖钻机掏碴取芯钻凿扰动,每节钢护筒外侧形成空腔,孔内动水压力改变了土层的物理力学性质,在土自重力作用下,空腔径向扩展和竖向联通后形成巨大的空洞,导致钢护筒外侧填土地层变形和破坏是孔壁坍塌事故致灾的诱因。The foundation design of a construction engineering is swivel-driven pile, and the construction unit adopts complete steel protection tubes and walls to rotary drilling hole, but in the installation process of reinforcement cages, the ground around the steel protection tubes collapse, causing the hole wall collapsed and the welding workers injured or died. The upper part of the construction site is newly filled soil of the recent three to five years, and the backfilling thickness of the incident is 14.2m. The disturbance by rotary driller makes the steel protection tubes hollow, the hydrodynamic pressure within changes the physical and mechanical properties of the soil and, under the soil gravity impacts, the radial extension and the vertical connection within the hollow center forms huge empty spaces, resulting in ground deformation and failure of exterior fill stratum of steel protection tubes, a cause of the hole wall collapse incident.

关 键 词：旋挖桩 孔壁 坍塌 致灾机理 

分 类 号：TU712.4[建筑科学—建筑技术科学]