The effects of blast damage zone thickness on rock slope stability
The effects of blast damage zone thickness on rock slope stability
复制标题
爆炸损伤区厚度对岩质边坡稳定性的影响
作者：
Huihui Zheng;Tianbin Li;Jiayi Shen;Chaoshui Xu;Hongyue Sun;Qing Lü
Hoek-Brown(HB)准则中爆破损伤区厚度T的选取在露天矿边坡设计和稳定性分析中具有重要意义。传统的边坡稳定性分析采用单一的爆破损伤值，整个岩体采用D因子，导致对边坡稳定性估计偏低。本文采用平行层模型，将岩体划分为多个平行于坡面的层，每一层施加一个递减的D值，并用极限平衡法研究了T对岩质边坡稳定性的影响。在大量参数研究的基础上，提出了爆破损伤区厚度加权因子FT来量化T对边坡安全系数(FOS)的影响.结果表明，T在边坡模型中的选取在FOS的计算中起着重要作用，特别是当T与坡高H的比值为<；1.0时.基于傅立叶变换和现有的稳定性图，提出了不同边坡几何形状和岩体性质的边坡稳定性计算模型。用数值解检验了所提出的稳定性模型的可靠性。结果表明，与基于1254组数据的数值解相比，由所提出的稳定性模型估计的FOS仅有5.6%的平均相对误差。提出的稳定性模型简单易行，可用于岩石边坡稳定性的初步评价，同时考虑了爆破破坏程度的不同。
The selection of the blast damage zone thickness T for the Hoek-Brown (HB) criterion is signifcant in open pit.slope design and stability analysis. Traditional slope stability analysis adopts a single value of blast damage.factor D for the entire rock mass, leading to the underestimation of slope stability. In this research, the parallel.layer model (PLM), in which the rock mass is divided into a number of layers parallel to the slope face with a.decreasing value of D applied to each layer, is used with the limit equilibrium method to investigate the effects of.T on the stability of rock slopes. Based on extensive parametric studies, a blast damage zone thickness weighting.factor fT is proposed to quantify the influence of T on the evaluation of the factor of safety (FOS) of given slopes..Results show that the selection of T in the slope model plays an important role in the calculation of FOS,.especially, when the ratio of T to slope height H is < 1.0. Based on fT and existing stability charts, a stability.model is proposed for the estimation of the FOS of slopes with different slope geometries and rock mass.properties. The reliability of the proposed stability model is tested against numerical solutions. The results show.that FOS estimated from the proposed stability model exhibits only 5.6% average relative discrepancy compared.with numerical solutions based on 1254 sets of data. The proposed stability model is simple and effective, and.can be used for the preliminary assessment of rock slope stability, considering the effects of different degree of.blast damages