摘要
坡顶荷载是公路边坡、铁路边坡以及矿山边坡等稳定性分析中不可忽略的因素,倾倒破坏是陡倾层状岩体边坡一类主要的变形破坏形式,研究坡顶荷载作用下岩质边坡块体倾倒破坏具有重要的工程指导意义。在Goodman和Bray块体倾倒破坏极限平衡逐步分析方法的基础上,基于传递系数法,通过建立坡顶荷载作用下岩质边坡倾倒破坏地质力学模型,提出了考虑坡顶荷载作用的边坡倾倒破坏的解析分析方法,推导出了坡顶荷载作用下反倾边坡坡脚剩余下滑力和维持边坡稳定所需要的支护力的计算公式,为该类边坡的设计和支护提供了理论依据。通过算例分析,探讨了不同岩块厚度和切坡角度下坡顶荷载对剩余下滑力和滑动比例系数的影响。结果表明:对于一个给定的边坡,岩块厚度存在一个临界值,当岩块厚度小于该临界值时,坡顶荷载对剩余下滑力的影响程度要明显大于岩块厚度大于该临界值的情况;切坡角度越大,坡顶荷载对边坡稳定性的影响越显著;随着坡顶荷载的增加,滑动比例系数逐渐增大。对比分析理论解与UDEC计算的数值解,表明两种方法计算结果是一致的,相互得到了验证。
Slope-top loading is a non-negligible factor in the stability analyses of highway slope, railway slope, mine slope and so on. Toppling failure is one of typical deformation failure modes of steep stratified rock slopes. Analysis of toppling failure of rock slopes subjected to the load applied on the top has an important bearing on engineering practice. Based on the gradual analysis method of limit equilibrium propos^d by Goodman and Bray, a geomechanical model of the toppling failure of rock slopes under slope-top loads are developed and the related analysis method is proposed. Using the transfer coefficient method, a formulation is derived for calculating the residual sliding force at the toe and the supporting force required to meet the requirements of the slope stability under slope-op load, which provides a theoretical basis for the design and support of this type of slope. Two examples are introduced, in which the influence of slope-top load on the residual sliding force as well as the sliding ratio coefficient is analyzed for the cases of diverse block widths and slope cut angles. The results show that there exists a critical block width for a given slope such that when the block thickness is less than the critical value, the influence of slope-top load on the residual sliding force is more significant. The influence of slope-top load on the slope stability increases with the slope cut angle. There is a positive correlation between the sliding ratio coefficient and slope-top load. Finally, the theoretical and numerical solutions calculated by UDEC are compared and consistent results are obtained, showing the applicability of both methods.
出处
《岩土力学》
EI
CAS
CSCD
北大核心
2015年第9期2639-2647,2658,共10页
Rock and Soil Mechanics
基金
国家自然科学基金面上项目(No.11472293)
关键词
坡顶荷载
反倾边坡
倾倒破坏
剩余下滑力
滑动比例系数
slope top load
counter-tilt rock slope
toppling failure
residual sliding force
sliding ratio coefficient
