摘要
运用Acutronic 661型离心机研究超前小导管注浆加固圆形隧道的塑性变形机制,试验隧道在平面应变条件下的超固结粘土中开挖,小导管采用具有一定硬度的合成树脂模拟,管间相互重叠形成拱形加固区,设置在圆形隧道拱顶。模型地表沉降采用位移传感器进行测量,地下位移则通过一种连续的图形采样分析系统获取。目的在于研究隧道建设过程中小导管注浆"拱顶加固"工艺对地表沉降和隧道稳定性的影响。在此基础上,从塑性极限分析上限法的基本原理出发,构建小导管注浆粘土隧道的垮落机制,采用解析法导出稳定率上限方程,通过该方程进一步讨论隧道埋深、土体强度、小导管注浆体对单圆形隧道稳定率上限解的影响。最后,由离心模型试验结果证实其上限解的正确性。
The influence of forepoles on the patterns of a single tunnel plastic collapse was discussed using Acutronic 661. A series of plane strain centrifuge model tests in over-consolidated clay were conducted. Tests were carried out in a circular cavity with stiff resin inclusions embedded around the tunnel vault. These inclusions simulated elements of a secant pipe or forepole arch system. An image processing system was used to measure displacements below surface level and displacement transducers at the surface level of the models. The aim of the experimental work was to study the ground response due to simulated tunnel construction and to analyse how the vault stiff inclusions affect tunnel stability. According to the principle of the upper bound theorem of plastic limit analysis, a collapse mechanism of the single circular tunnels with embedded forepoles in cohesive soil was established. An upper bound equation of stability ratio was obtained. The upper bound solutions of stability ratio under different soil cover above the tunnel, undrained shear strength at tunnel axis level and embedded forepoles range were discussed from the equation. In the end,the correctness of the upper bound solutions was proved by the results of centrifugal model tests.
出处
《土木建筑与环境工程》
CSCD
北大核心
2013年第3期25-31,共7页
Journal of Civil,Architectural & Environment Engineering
基金
国家自然科学基金(51109231)
中央高校基本科研业务费科研专项(CDJZR10200022)
关键词
离心机
注浆导管
隧道
拱顶加固
塑性极限分析
centrifuge forepoles tunnels and tunnelling vault reinforcement plastic limit analysis
