非构造作用缓倾岩层高侧压系数成因分析

一般认为高侧压系数是由构造作用所致，实践表明，在一些非构造作用岩层中也存在高侧压系数现象。依托浩吉铁路如意隧道工程，采用剥蚀卸荷模型对非构造作用缓倾岩层高侧压系数现象进行解释；采用基于岩石Kaiser效应的声发射法，对如意隧道DK476附近历史最大地应力进行测试分析。通过切线交点法作图确定Kaiser效应点，测得Kaiser应力平均值为45.6 MPa。取样点历史最大埋深测算结果为1876 m，而现今埋深仅为140 m，地层剥蚀厚度高达1736 m，这是导致其现今侧压系数较高的主要原因。

Cause Analysis of High Lateral Pressure Coefficient of Gently Inclined Strata under Nontectonism

It is generally believed that the high lateral pressure coefficient is caused by tectonic action. Practice shows that there are also high lateral pressure coefficient phenomena in some non-tectonic strata. In relation to Ruyi tunnelling on Haoji railway, it uses the denudation unloading model to explain the phenomenon of high lateral pressure coefficient of non-tectonic gently inclined strata. The acoustic emission method based on Kaiser effect of rock is used to test and analyze the historical maximum geostress near DK476 of Ruyi tunnel. Kaiser effect points were determined by tangent intersection method, and the average Kaiser stress was 45.6 MPa. The historical maximum buried depth of the sampling point is 1876 m, while the present buried depth is only 140 m, and the stratum denudation thickness is as high as 1736 m, which is the main reason for the high lateral pressure coefficient.