摘要
传统的块体理论分析方法未考虑到非贯通结构面在施工扰动作用下可能出现连通的问题,导致搜索出的关键块体不够精准和全面。如何判断非贯通结构面是否应该连通成为了块体理论研究的一个重要课题。采用数值模拟方法计算岩体试样的贯通强度与峰值强度,并引入贯通系数变量描述贯通强度与峰值强度的比值变化。将贯通强度作为判断岩桥贯通与否的衡量指标,定量分析贯通强度与岩桥倾角、结构面摩擦系数、围压、连通率和结构面倾角之间的函数关系,即含两条非贯通结构面岩体的岩桥贯通准则。该准则可以准确判断含两条非贯通结构面岩体的岩桥是否应该连通。基于岩桥贯通准则的块体理论能够准确搜索出因岩体内部结构面扩展贯通而滑移的关键块体,使得搜索出的关键块体更加全面,更好的分析工程的稳定性。
The traditional block theory neglects the evolution of discontinuous structural planes to continuous ones induced by the effect of construction disturbance,such that the determination of key block is inaccurate.The criterion to distinguish the type of structural planes plays a significant role in the block stability analysis.Numerical simulation methodology is adopted to calculate the coalescence strength and peak strength of rock samples.A coalescence coefficient of structural planes is introduced as the ratio of the coalescence strength to the peak strength,which could potentially provide the indication of the formation of ligament.The correlation between the coalescence strength and various influencing factors such as dip angle of ligament and structural planes,friction coefficient of structural planes,lateral stress and continuity rate is analyzed quantitatively.Based on these observed relationships through analytical studies,the coalescence criterion for ligament is proposed to characterize two arbitrary discontinuous structural planes and to identify whether they can be formed as a single continuous structural plane.Incorporating coalescence criterion into block theory,the key block sliding triggered by the propagation of interior structural planes can be obtained accurately.This may provide better guidance for practical engineers to perform stability analysis.
出处
《岩土工程学报》
EI
CAS
CSCD
北大核心
2013年第8期1513-1518,共6页
Chinese Journal of Geotechnical Engineering
基金
国家自然科学基金项目(51074042
51179031)
国家自然科学基金国际合作与交流项目(51250110531)
国家重点实验室开放基金项目(SKLGP2012K009)
关键词
非贯通结构面
贯通强度
峰值强度
贯通准则
贯通系数
discontinuous structural plane
coalescence strength
peak strength
coalescence criterion
coalescence coefficient
