裂隙围岩的双场耦合可靠性分析

应力场和渗流场在裂隙围岩中的耦合变化规律,是非常复杂的力学过程。运用断裂损伤力学和可靠性评价原理,可推导出裂隙围岩可靠度表达式,说明可靠度与应力分布、渗流力作用、节理分布和岩体性质的相互关系。文章利用推导的裂隙围岩可靠度表达式,在雪峰山隧道YK97 847处进行计算验证,结果表明,在裂隙围岩中,可靠度低的部位不一定在主应力方位,也不一定在隧道顶端,而是因地应力分布、渗透水压、节理分布和岩体性质等综合作用,使局部围岩可靠度相对较低,该处围岩最容易变形坍塌。此研究结果可为隧道支护施工提供参考。

An Analysis of Double-field Coupling on Rock Fracture

The law of the stress field and seepage field coupled change is a very complex mechanical process.By using fracture and damage mechanics and principle of reliability evaluation,the expression for reliability degree on rock fracture can be derived.This expression explains the relationship among reliability degree,stress distribution,effect of seepage force,fissuring distribution and properties of lithesome.The article uses this expression to calculate and verify on Xuefeng Mountain tunnel YK97 84.The result shows that the position of low reliability degree on rock fracture may not be in the direction of primary stress or the top of tunnels.Because of the combined action of stress distribution,hydraulic permeation,fissuring distribution and the properties of lithesome,the reliability degree of wall rocks may become lower,which makes the wall rocks on those regions easier to collapse and distort.