大型盾构出洞区加固土体稳定性研究.pdfVIP

第4卷 第3期 地下空 间与工程学报 Vo1．4 2008年6月 Chinese Journal of Underground Space and Engineering 、 Jun．2008 大型盾构出洞区加固土体稳定性研究 吴 韬 ，韦良文 ，张庆贺 (1上海市建设工程管理有限公司，上海 200031；2同济大学地下建筑与工程系，上海 200092) 摘 要：隧道断面越大，封门拆除时加固土体所暴露的面积也越大，施工风险也就越高。 因此如何保证盾构出洞区加固土体的稳定性是隧道建设者所必须面临的挑战。重点归纳了目 前用于盾构出洞区加固土体稳定性分析的方法，包括：板块强度理论、粘性土滑移失稳理论和 土体扰动极限平衡理论。结合上海长江隧道浦东工作井工程进行理论验算和三维有限元数值 模拟。通过对比得出，抗滑移失稳通常是出洞加固中安全控制的关键，其主导因素是加固土体 的粘聚力C，采用板块强度理论计算出的加固土体厚度是偏于保守的，另外加固土体的尺寸还 要能够满足防水、防坍塌等构造上的要求。 关键词：大型盾构；出洞；加固土体；数值模拟；稳定性 中图分类号：U455．43；TB115 文献标识码：A 文章编号：1673-0836(2008)03-0477-06 Research on Stability of Reinforced Soil at Large Scale Shield Departure Area wU Tao ，WEI Liang—wen ，ZHANG Qing—he (1．Shanghai Construction Engineering Administration CO．。LTD，Shanghai 200031，China； 2．The Department ofGeotechnical Engineering ofTon~i Unemity。Shanghai 200092，China) Abstract：Larger tunnel section brings larger exposed area and higher risks when shield departs from the working shaft-SO the stability of reinforced soil in this stage is the new challenge for the work．This paper mainly studies the methods used in analysis of reinforced soil in shield departure area-which includes the block strength theory，clay soil slippage theory and soil disturbance limit equilibrium theory．Taking Shanghai Changjiang River tunnel as an ex． ample，this paper takes checking calculation and three dimensional numerical simulation for the project．By contras— ting some conclusions are drawn：the skid proofis the key point of safety control for the project and the cohesive force of reinforced soil is the dominant factor．The thickness value calculated by block strength theory is conservative．In addition