节理岩体变形模量的解析方法研究

STUDY ON THE ANALYTICAL METHOD IN THE DEFORMATION MODULUS OF JOINTED ROCK MASS

岩体的变形模量是评价岩质边坡力学行为的重要参数,节理的发育分布不同,岩体的变形模量也随之变化,准确估算节理岩体变形模量显得非常重要,也是岩石力学界棘手的问题之一。本文采用叠加原理(分别考虑完整岩石和节理的变形),研究了具有围压约束条件下的节理岩体变形模量,分别提出了(a)节理两端与岩体左右两侧相交和(b)节理两端与岩体上部和左侧(或右侧)边界或下部和右侧(或左侧)边界相交两种节理岩体模型的单一和节理组变形模量的解析方法。通过与数值模拟(有限元程序)结果比较可知,本文解析式计算结果与数值分析结果误差较小,基本上都小于20%。进一步讨论了该方法的应用价值,提出了该解析方法与节理岩体强度公式结合起来,可得到节理岩体的变形破坏阈值,达到节理岩体变形破坏预测预警的目的。该解析方法为节理岩体变形模量估算提供了一定的理论基础。

The deformation modulus of rock mass is an important parameter for evaluating the mechanical behavior of rock slopes.The deformation modulus of rock mass varies with the development and distribution of joints.Accurately estimating the deformation modulus of jointed rock mass is very important and is also one of the thorny problems in the field of rock mechanics.In this paper,the deformation modulus of jointed rock mass under confining pressure is studied by adopting the superposition principle(considering the deformation of intact rock and joints separately).Analytical methods for the deformation modulus of single joint and joint group are proposed for two jointed rock mass models:(a)the two ends of the joint intersect with the left and right sides of the rock mass and(b)the two ends of the joint intersect with the upper and left(or right)boundaries or the lower and right(or left)boundaries of the rock mass.Comparing with the results of the numerical simulation(finite element program),it can be seen that the error between the analytical calculation results of this paper and the numerical analysis results is small,basically less than 20%.The application of this method is further discussed,and it is proposed that the analytical method combined with the strength formula of jointed rock mass can obtain the deformation failure threshold of jointed rock mass,which can be used to predict and provide early warning for the deformation failure of the jointed rock mass.This analytical method provides a certain theoretical basis for the estimation of the deformation modulus of jointed rock mass.