加锚岩体流变特性及锚固控制机制分析

通过室内蠕变试验和理论分析，对加锚改善岩石流变力学特性进行了研究，并探讨了锚固控制岩石流变的力学机制。采用RLJW-2000型流变试验机，对红砂岩及其加锚试件进行分级加载（100 h以上）单轴压缩试验，结果表明，加锚后岩石的流变应力阀值提高了20%～30%? c，且不同应力水平流变量均能得到一定控制，加锚使试件的长期强度增加了5%～10%? c。此外，基于整体协调变形原理，建立了加锚体流变本构方程，推导出了一维B-K模型解答，算例分析表明，锚杆密度越大，对岩石流变控制效果越好，得出锚杆等效刚度是约束岩石流变的主导因素，但从技术经济角度考虑，锚杆支护密度与岩石流变参数之间存在一个合理的匹配区间。研究结果对长期使用的岩体工程锚固支护设计提供了理论依据。

Analysis of rheological properties and control mechanism of anchored rock

By laboratory test and theoretical analysis,the rheological properties of anchored rock and controlling mechanism by anchor are studied.The results show that,non-anchored and anchored specimens’ indoor long-time(above 100 h) creep test is done by RLJW-2000 rheology tester;creep stress threshold of anchored rock is increased by about 30% c;creep deformations at different stress level stages are significantly controlled;and anchored specimen’s long-term intensity is increased by 5% to 10% c.In addition,according to the equivalent co-deformation principle,one-dimensional creep constitutive equation of anchored rock is established;the answer of anchored generalized Kelvin(B-K) model is derived.The example shows that rock rheology’s control effect gets better with increasing of bolt consistency,which can be obtained that the anchor’s equivalent stiffness is a dominant factor restraining rock rheology.But from the view of economic technology,bolt consistency and rock rheological parameters have a rational matching interval.The result provides a theoretical basis for the anchorage support design of rock engineering after long-term service.