暗挖车站新型洞桩法成桩技术及沉降规律分析

Analysis on Construction Technology and Settlement Rule of New PBA Method for Underground Excavation Station

暗挖地铁车站洞桩法施工,由传统的上下层8导洞施工,改进为6导洞施工,再优化到单层4导洞施工,中柱及边桩施工由人工挖孔转变为机械成孔,钢管柱由人工安装转变为机械操作,受力形式由底纵梁承载转变为桩基承载,最终形成了新型洞桩法.本文以地铁16号线工程某站为基础,对新型洞桩法成桩施工技术及其特点进行介绍,并对暗挖车站施工过程中的不同阶段,不同断面的地面及管线沉降实测数据进行分析、对比和总结,以探索其沉降规律.该新型洞桩法在北京地铁的成功应用,表明新型洞桩法劳动力大量节约,施工效率显著提升,施工风险明显降低,作业环境极大改善,是一种经济实用的方法,具有推广应用价值.

From the traditional upper and lower 8 guide holes to 6 guide holes and then to 4 guide holes,the manual excavation turns into mechanical hole formation,the load bearing of bottom longitudinal beam turs into pile foundation bearing,and the steel pipe column turms into mechanical installation from manual installation,forming a new PBA hole pile method.Based on a station of Metro Line 16 project,the author introduces the construction technology and characteristics of the hole pile method,analyzes and summarizes the measured data of ground and pipeline settlement in different stages and sections in the construction process,so as to explore the settlement and deformation rules.Based on the new PBA practice,the new hole pile method saves a large number of labor,significantly improves the construction efficiency,obviously reduces the construction risk,and greatly improves the operating environment.It is an economic and practical method which would be widely used in subway.