层状岩体锚杆锚固系统荷载传递规律及其破坏模式研究

Layered rock mass has especial engineering geologic properties, such as anisotropism, nonuniformity, etc, and engineering accident is easily induced when it is acted as the engineering foundation. However, the theoretical study of anchorage in layered rock mass isn't developed at present, which fall behind with engineering application. By this project, the study on load transmission and destructive mechanism of anchorage system in layered rock mass is done by the methods of laboratory experiment, theoretical analysis and engineering application. The characteristics of load transmission and destruction of three mediums and two interfaces anchorage system in layered rock mass with different anchor install angle are found through the pull-off tests in the laboratory. The anchorage mechanical model is established, which can reflect rock mass characteristics of layered structural feature, and also consider the system characteristics of many interfaces and influence of anchor install angle, the expression of mechanical equation are achieved, and the calculation formulas of destructive criterion and pull-off ultimate loading of anchorage system in layered rock mass are given on the base of system stress analysis. The reasonableness of theoretical model is verified by its engineering application. The research results of project can provide the powerful theoretical basis and scientific proofs for the design calculation, scientific evaluation and optimization of anchorage system in layered rock mass.

层状岩体具有各向异性、非均质性等特殊的工程地质属性，以其作为工程载体，工程事故常易被引发；然而，目前针对这种特定地层条件下的锚固理论研究尚未开展，严重滞后于工程应用。本项目拟遵循室内试验、理论建模以及工程应用相结合的研究思路，以层状岩体锚杆锚固系统为研究对象，开展锚固系统荷载传递与破坏机制研究；通过室内拉拔试验，揭示层状地层条件下不同布设角度锚杆三相两界面锚固系统的荷载传递特性及破坏特征；构建能反映岩体层状结构特征、考虑系统多界面特性及锚杆布设角度影响的锚固力学模型，求解获得系统各界面力学方程表达式，并结合系统应力分析，给出层状岩体锚杆锚固系统破坏类型判别标准与拉拔极限荷载计算公式；结合工程实际，验证理论模型的合理性。本项目皆在为层状岩体锚杆锚固设计与计算、科学评价及优化提供强有力的理论基础和科学依据。

层状岩体因其特殊工程地质属性，以其作为工程载体，极易引发工程事故。本项目紧密围绕层状岩体锚杆锚固系统荷载传递规律及其破坏机制两计划要点，通过系统的理论分析、室内试验、现场试验与数值分析等研究手段，相互验证推导层状岩体锚杆及其极端特例缺陷锚杆锚固力学微分方程及其解析解，并给出迭代计算方法与求解步骤，揭示了层状岩体锚杆锚固系统界面荷载传递机制；分析了锚杆剪应力分布类型、拉拔极限荷载大小及破坏特征之间的内在关系，并给出了相关判别标准及取值方法；建立了包含层状岩体地层在内的锚杆锚固系统动力分析模型，给出了其动力控制方程的具体有限差分格式，并编程使其程序化。依托本项目发表学术论文5篇，其中SCI检索3篇，EI收录2篇；培养研究生7人次，其中博士3人次，硕士4人次；总体上完成了原定的研究目标，研究成果皆可为层状岩体锚杆锚固技术提供强有力的理论基础和科学依据。