导洞—隔离桩体系工作机理研究与侧向变形分析  

Mechanism of a drift-pile system and analysis of its horizontal displacement

作　　者：姚海波[1] 王梦恕[1] 张顶立[1] 陈浩 

机构地区：[1]北京交通大学,北京100044 [2]中国铁路隧道集团第二工程处,北京100078

出　　处：《土木工程学报》2006年第4期105-109,共5页China Civil Engineering Journal

基　　金：北京市重点科技项目(D0604003040221)

摘　　要：为了精确了解导洞-隔离桩结构体系在屏蔽隧道施工所造成的环境效应过程中的受力和变形规律,基于隧道开挖所致土体变形特点的研究,分析施工过程中导洞—隔离桩结构体系的受力特点。在此基础上,由导洞内侧(近隧道侧)土体位移与土体极限状态(朗肯被动土压力状态)时土体位移的比值,修正土体侧压力系数,使计算结果更趋近于真实状态。同时,采用梁和弹性地基梁模型模拟隔离桩的受力和变形特点,将导洞的支撑作用等效为一水平支座弹簧,通过导洞受力分析,计算弹簧刚度。利用两个分解的模型,分别模拟隧道台阶法施工中上、下导坑的开挖,再组合为整体效应。计算结果表明,隔离桩挠度理论值与实测值极为接近,二者差值上部略大于下部。由此可见,所采用的分析方法和理论模型能够精确地模拟导洞—隔离桩结构体系的工作状态,可用于类似工程中结构的设计。Based on the ground deformation data, the stress serving as an underground retaining wall is studied. The ratio and displacement characteristics of a drift-pile system of soil displacement to its corresponding displacement in passive critical state is adopted to modify the coefficient of horizontal pressure so as to describe the mechanical state more accurately. The beam and beam on elastic foundation theories are employed to simulate the behavior of the drift-pile system. The drift acts like a horizontal spring, its rigidity can be calculated via static mechanical analysis. Two models are set up to simulate the excavations at the tunnel face and at the bench, respectively. The integrated results illustrate the behavior of the system. The calculation result agrees very closes to the measured data. Nevertheless the difference in the upper part of the system is a little larger than that in the lower part.

关 键 词：导洞-隔离桩 工作机理 弹性地基梁 变形分析 

分 类 号：U455.49[建筑科学—桥梁与隧道工程]