基于临界成拱条件的土岩复合地层中隧道深浅埋的划分

DIVISION OF DEEP AND SHALLOW TUNNELS IN SOIL-ROCK COMPOSITE STRATA BASED ON CRITICAL ARCHING CONDITION

针对土岩复合地层深浅埋划分标准存在的不足,文中以临界成拱条件为依据,研究土岩复合地层隧道的深浅埋划分标准。文中基于全断面岩层的成果,采用有限差分软件FLAC3D对土岩复合地层隧道深浅埋进行了划分,并对结果进行了回归分析。研究结果表明,土岩复合地层临界成拱埋深主要与隧道直径,土岩分界面的位置、洞室开挖后岩层的应力应变有关;土岩复合地层隧道埋深并不随岩层厚度的增加而线性减小,与压力拱的高度密切相关,土岩分界面通过影响压力拱高度进而影响隧道埋深。

This article studies the classification standard of deep and shallow buried in soil rock composite stratum based on the critical arching condition aiming at the present shortcomings.In this paper,the deep and shallow burial of the tunnel in soil-rock composite strata were classified by the finite difference software FLAC3D,then the full section rock layer were regression analyzed.The results show that the critical arch burial depth of soil-rock composite strata is mainly related to the diameter of the tunnel,the location of the soil-rock interface,and the stress-strain of the rock layer after excavation.Moreover,the tunnel burial depth of soil-rock composite strata does not decrease linearly with the increase of the rock layer thickness,but is closely related to the height of the pressure arch,finally,the soil-rock interface affects the tunnel burial depth by influencing the height of the pressure arch.