以色列复合地层盾构土舱压力计算方法分析

Analysis on Calculation Methods for the Soil Chamber Pressure in Composite Strata Shield Tunnelling in Israel

以色列特拉维夫"红线轻轨"项目盾构隧道穿越以粉细砂、粉土质砂、库卡(砂岩)为主的复合地层,针对复合地层盾构土舱压力难以合理计算的问题,将在建盾构区间的地层组段划分为4个岩土组,在确定每个岩土组物理力学参数的基础上,将普氏理论结合欧洲规范下常用的经验法、J&S法和A&K法,对4个岩土组的土压力进行计算,并对计算结果进行了分析。分析表明:采用三种计算方法的平均值可有效避免单种方法计算土压力时的局限性,且土舱压力随地下水位高度的变化而变化,与隧道上覆土层厚度无关。通过将该方法的计算结果与实际的开舱压力进行对比,验证了采用该方法计算以色列复合地层盾构土舱压力的准确性,可为类似工程的施工参数提供借鉴和指导。

The shield tunnelling of the Red Line Light Rail project in Tel Aviv,Israel,traverses composite strata mainly composed by silty-fine sand,silty sand and sandstone.In light of the problem that it is difficult to reasonably calculate the soil chamber pressure of the shield in composite strata,the strata passed by the running tunnel are di⁃vided into four rock-soil groups,and on the basis of determining the physical and mechanical parameters of each rock-soil group,this paper combines Protodyakonov's theory with the empirical method,J&S method and A&K method commonly used in European norms to calculate the soil pressures of the four rock-soil groups,and analyzes the calculation results.The analysis shows that using the average value of the three calculation methods it can effec⁃tively avoid the limitations of calculating the soil pressure through a single method,and the soil chamber pressure varies with the height of the groundwater table but is independent of the thickness of the overburden soil layer.By comparing the calculation results of this method with the actual pressure while intervention,it verifies the accuracy of this method in calculating the soil chamber pressure of shield tunnelling in Israel composite strata,providing ref⁃erence and guidance for the construction parameters of similar projects.