充填节理加锚剪切强度特征及变形规律研究

Study of shear strength characteristics and deformation rules of filling and anchored joints

基于含充填节理室内剪切试验数据,利用PFC2D探讨了含充填及加锚节理的数值实现方法,建立了不同粗糙度形态的含充填节理及其加锚计算模型,对比研究了含充填节理面在加锚和无锚状态下的强度特征及其应力应变曲线特性.研究结果表明:以室内含充填节理剪切试验结果为参数标定基础,获得准确细观参数,并可应用于后续含充填节理的加锚剪切模拟,且效果较好;加锚情况下含充填节理的剪切强度相比不加锚情况具有一定程度的提高,且达到峰值强度时的应变量明显增加,但锚杆对含充填节理面抗剪强度贡献量不同;同一充填厚度下,不同粗糙度的含充填节理面加锚剪切曲线可分为三种不同的曲线形式,其对应的锚杆贡献量不同;同一粗糙度下,不同充填厚度的节理面加锚剪切行为差异较大,且存在一个临界充填厚度,此厚度下的加锚充填强度最大,且不同粗糙度的加锚节理面临界充填厚度不同.

Based on the indoor shear test data of filling joints,this paper uses the PFC2D to explore the numerical implementation method of filling and anchoring joints.By establishing the filling joints of different roughness forms and their anchoring calculation models,the strength characteristics and stress-strain curves of the filled joints under anchored and unanchored conditions were compared.Results show that based on the shear test results of indoor filling joints,the accurate microscopic parameters are obtained,which can be applied to the shear simulation of subsequent anchoring and filling joints with good results.The shear strength of anchoring and filling joint is improved to some extent compared with that without anchoring,and the shear displacement is significantly increased when the strength reaches the peak value,but the contribution of the bolt to the shear strength of the filling joint is different.Under the same filling thickness,the shear curves of anchoring and filling joint surface with different roughness can be divided into three different forms,and the corresponding bolt contribution is also different.Under the same roughness,the shear behavior of anchoring and filling joints with different filling thicknesses is quite different,namely there exists a critical filling thickness,which maximizes the strength of anchoring and filling joints under this thickness,and the critical filling thickness of joint surface with different roughness is different.