预置节理试样的力学特性及透水能力研究

Studies on mechanical characteristics and permeable capability of test specimens with pre-set joints

节理裂隙普遍存在于各种天然岩体中,其力学特性和透水能力直接关系到岩体工程质量及工程应用安全.针对按一定角度预置了不同尺寸裂隙的试样,用剪切试验和渗流试验的方法研究了其在剪切作用下的力学性质及不同剪切加载级数下含预置裂隙试样的透水能力.研究结果表明:(1)裂隙尖端的起裂角与初裂强度变化规律符合Lajtai提出的岩桥破坏理论;(2)自主研制的用于含裂隙试样透水能力测试的试验装置,原理简单、制作方便、操作容易、数据可靠,能有效地用于含节理试样的透水能力测试;(3)试验数据表明,含裂隙试样的透水能力与加载级数呈先下降后上升的非线性关系,并导出了透水系数(Kf)和加载级数(σ/σini)之间的函数关系方程.

Joints （faults） exist in all kinds of natural rock masses,of which the mechanical characteristics and permeable capability determine directly the rock mass quality and its application safety.In order to study the mechanical characteristics and permeable capability of test specimens with different dimension of pre-set joints,both shear test and seepage test had been performed in different loading and testing conditions.The results show that （1） The crack opening angle and its perforation strength change consistently with Lajtai＇s rock bridge failure rule,（2） The independently designed and made seepage test equipment possesses clear working mechanism,simple testing processor,low cost and high reliability which can be used effectively to measure the permeable capability of specimens with different pre-set joint＇s dimension,and （3） The relation between the specimen＇s permeability and the loading grade is not linear.The permeable coefficient （Kf） decreases firstly with the increase of loading level （σ/σini） then increases rapidly behind certain loading level.The function between （Kf） and （σ/σini） has been devised.