摘要
盾构在复合砂性土层中掘进时容易发生开挖面失稳事故,因此掘进过程中开挖面保持合理支护压力尤为重要。考虑到砂性土的摩擦特性,采用上限分析原理并建立适合复合砂性土层的三维破坏机动场模型对开挖面失稳进行分析,最终得到该类地质条件下开挖面最小支护压力计算公式。给定穿越土层参数条件下,考虑覆土层为均一土层和双层土2种工况,分析研究盾构直径,埋深比,覆土层黏聚力,覆土层内摩擦角,地表荷载和覆土层相对厚度比等因素变化对支护压力的影响。该公式为复合砂性土层下开挖面支护压力设置提供了较为精确估算方法,为类似实际工程提供重要理论依据。
The tunnel working face easily collapses when tunneling is conducted in the composited sandy soil, thus it is important to maintain the proper support pressure for the working face stability. According to the frictional characteristics of sandy soil,the upper bound analysis is applied to analyze the working face stability by using the improved 3D kenimatically admissible mechanisms, and the formula of the minimum support pressure for the working face stability is obtained. As the crossed soil is defined,the influence of the tunnel diameter,the depth ratio,the ground surface surcharge,the cohesion and the friction angle of the cover layers and the relative thickness ratio of cover layers on the support pressure is studied. This study presents an accurate estimation of support pressure for the tunnel working face stability in the composited sandy soils as well as an important theoretical reference to the similar practice projects.
出处
《岩石力学与工程学报》
EI
CAS
CSCD
北大核心
2013年第S2期3440-3447,共8页
Chinese Journal of Rock Mechanics and Engineering
关键词
土力学
复合砂性土层
掘进面稳定
上限分析
支护压力
soil mechanics
composited sandy soil
working face stability
upper bound analysis
support pressure
