基于洞顶岩体应力传递的小型采空区稳定性评价方法研究

摘要

浅埋洞穴及小型采空区稳定性受顶板岩体结构强度、侧壁稳定性及上部荷载大小等多种因素影响，在地基稳定性评价中系统考虑这些因素的影响是保证评价结果真实可靠的关键。根据岩溶洞穴及小型采空区等地下空洞的分布特征，采用基于洞顶上方岩体应力传递的力学平衡分析方法进行洞穴稳定性评价，综合考虑空洞侧壁稳定和黏聚力c值的影响，推导临界深度计算公式，探讨了相关参数的取值方法。实例计算分析结果表明，本方法综合考虑洞穴侧壁稳定和黏聚力c值对洞顶稳定性的影响，使计算结果更符合客观实际，适于对浅埋洞穴的地基稳定性评价。%The roof stability of shallow holes and small goaf are affected by many factors, including structural strength of rock mass, sidewall stability, upper load and etc. The foundation stability evaluation system in perspective of the influence of these factors is the key to ensure true and reliable evaluation. According to distribution features of karst caves, small gob and other underground cavities, mechanics equilibrium analysis based on the stress transfer of rock mass above the top of cave is adopted to evaluate the stability of cave with comprehensive consideration of the stability of side wall and the value of cohesive force. Calculation formulas for critical depth are deduced, and methods for related parameter selection are discussed further in this paper. The calculation results of project example show that this method takes into account comprehensively the stability of cave wall and cohesion values with computational results more consistent with the reality, and is suitable for stability evaluation of shallow caves.