基于安全稳定率的岩质边坡稳定问题研究

Research on the stability of rocky slopes based on safety stability rate

岩质边坡具有明显结构特性,不同坡体结构类型的边坡,其变形破坏特性及稳定性也不相同,现有评价岩质边坡稳定性的指标较难定量、客观地反映不同坡体结构类型岩质边坡稳定性的相对差别。为此,在边坡安全系数K概念基础上引入一个评价岩质边坡稳定性的安全度指标——岩质边坡安全稳定率γ_(K),该指标为考虑坡体结构特性时岩质边坡的安全系数与不考虑坡体结构特性时岩质边坡的安全系数的比值,是表征岩质边坡稳定性的相对指标。基于有限元强度折减法对3类基本结构面岩质边坡与9类典型坡体结构的岩质边坡安全稳定率计算分析发现:I类结构面边坡的安全稳定率最低,III类结构面边坡的安全稳定率最高;不同坡体结构的岩质边坡安全稳定率在一定范围内变动,其分布规律与实际岩质边坡稳定性分类结果基本一致。上述研究成果表明,安全稳定率γ_(K)不仅能够客观反映结构面对岩质边坡稳定性的影响,而且能够定量反映不同坡体结构类型岩质边坡稳定性的相对差别;安全稳定率可作为一种全新的反映坡体结构特性对岩质边坡稳定性影响的量化指标,用于评判不同坡体结构类型的岩质边坡稳定性。

The rocky slope has obvious structural characteristics,and the deformation and failure characteristics and stability of slopes of different slope structure types are also different.The existing indexes for evaluating the stability of rock slopes are difficult to reflect the relative difference of the stability of rock slopes of different slope structure types quantitatively and objectively.Therefore,based on the concept of slope safety factorγ_(K),this paper introduces a safety index for evaluating the stability of rock slope,safety stability rateγ_(K),which is the ratio of the safety factor of rock slope when the structural characteristics of slope are considered to that of rock slope when the structural characteristics of slope are not considered,and is a relative index to characterize the stability of rock slope.Based on the finite element strength reduction method,the safety stability ratio of three types of basic structural plane rock slopes and nine types of typical slope structures is calculated and analyzed.The safety stability rate of Class I structural plane slope is the lowest,and that of Class III structural plane slope is the highest.The safety stability rate of rock slopes with different slope structures varies within a certain range,and its distribution rules are basically consistent with the actual classification results of rock slope stability.The above research results show that the safety stability rateγ_(K)can not only objectively reflect the influence of structure on the stability of rock slopes,but also quantitatively reflect the relative difference of the stability of rock slopes with different slope structure types.The safety stability rate can be used as a new quantitative index to reflect the influence of slope structure characteristics on the stability of rock slopes,and can be used to evaluate the stability of rock slopes of different slope structure types.