泥水平衡盾构开挖面稳定性模型试验研究  

Model test research on excavation face stability of slurry balanced shield in permeable sand layers

作　　者：刘泉维[1,2] 杨忠年[3] 

机构地区：[1]北京交通大学土木建筑工程学院,北京100044 [2]青岛市市政工程管理处,山东青岛266100 [3]中国海洋大学环境科学与工程学院,山东青岛266100

出　　处：《岩土力学》2014年第8期2255-2260,共6页Rock and Soil Mechanics

摘　　要：在泥水平衡盾构施工过程中,如何确保施工安全并减少对周边环境的影响受到国内外学者的广泛关注,地层土体稳定性问题显得尤为重要,但对于砂质地层开挖面稳定性的失稳机制及其稳定性分析尚处于经验阶段。利用大尺寸模型试验,研究了不同水头高度(无水、0.9 m和1.1 m)下两种地层中开挖面主动破坏的发展模式和受力情况。试验中分析了不同水头高度对开挖面主动破坏的影响,研究结果表明:砂质土层中盾构隧道开挖面失稳时,存在土拱效应,使得地表对开挖面主动破坏的响应存在滞后效应;根据水头高度不同,可将砂质地层中开挖面主动破坏发展模式划分为无水模式、低水头模式和高水头模式;在形成泥膜和提供支护力的过程中,会在砂质土层中产生超孔隙水压力,在确定支护力时,应在静止土压力和静水压力的基础上,考虑超孔隙水压力的影响。研究结果对确定开挖面极限支护压力有重要的指导意义。In slurry balanced shield tunneling, how to ensure the safety of construction and to reduce the influence on the environment has arisen wide attention of scholars both at home and abroad. But now it is still in the stage of experience as to the instability mechanism of the slurry shield tunneling excavation and its stability analysis, especially to research on instability mechanism, judgment methods and calculation methods for the complex stratum cases. Regarding the excavation face in slurry balanced shield of the high permeable sand layers as research object, large-diameter modeling test are adopted to do systematical research on the excavation face instability features when properties of sand body and water head heights are different. The results show that：the ground settlement exits hysteresis effect, because it exists soil-arching effect at the same time of the excavation face active failure in the slurry balanced shield tunneling;the development mode of the excavation face active failure in the sandy stratum can be divided into three parts：anhydrous mode, lower water head mode and higher water head mode;it will induce excess pore water pressure during the slurry cake forming and the supporting force imposing; so that excess pore water pressure should be considered in process of the selection of supporting force. This research work has an important guiding sense to the stability of excavation face in the slurry balanced shield tunneling.

关 键 词：泥水平衡盾构 砂质地层 主动破坏 失稳发展模式 土拱效应 

分 类 号：TU434[建筑科学—岩土工程]