基于修正拟动力法的岩质边坡三维稳定性分析方法及应用

Three-dimensional stability analysis approach for the rock slope based on the modified pseudo-dynamic method

岩质边坡的抗震设计是岩土工程的重要课题,其稳定性直接关系到工程安全和社会经济效益。由于岩石的非线性强度特性,岩质边坡的破坏形式和机理与土质边坡有很大的不同,需要采用不同的分析方法和设计原则。此外,地震作用是导致岩质边坡破坏的主要因素之一,其对岩质边坡的稳定性有着显著的影响。为更好地确定基于Hoek-Brown强度准则下的岩质边坡抗震设计方法,在极限分析法上限定理的框架下,基于离散化技术构建了一种更加符合实际岩石边坡失稳破坏机制的三维对数螺旋破坏预测模型。通过广义切线技术将Hoek-Brown准则的参数转化为容易计算的Mohr-Coulomb准则参数再将其嵌入到预测模型中,提出一种更加准确的岩质边坡地震稳定性分析模型。该模型可以考虑岩石的非线性强度特性,并通过修正拟动力法引入地震加速度和阻尼比参数,提高了地震作用力的预测精度。然后,将重力增加法和多元宇宙优化算法相结合,获得一种边坡临界安全系数的确定方法,实现了岩质边坡在地震作用下的三维稳定性评估。与现有研究成果对比和工程案例应用表明,此方法可以较为准确地评估岩质边坡的地震稳定性,同时也能够反映岩质边坡的失稳破坏形态和范围,在岩质边坡地震稳定性分析中具有较好的有效性和可靠性。研究成果为进一步优化岩石边坡的抗震设计方法提供了新的思路和参考。

The seismic design of rock slopes is a critical issue in geotechnical engineering,with their stability being directly connected to both engineering safety and socio-economic benefits.Owing to the nonlinear strength characteristics of rock,the failure patterns and mechanisms of rock slopes are substantially different from those of soil slopes,necessitating distinct analytical methods and design principles.Moreover,seismic forces are among the primary factors leading to the destabilization of rock slopes,exerting a significant impact on their stability.To better determine the seismic design method for rock slopes based on the Hoek-Brown strength criterion,this paper constructed a three-dimensional logarithmic spiral failure prediction model under the framework of the upper bound theorem of limit analysis,which aligned more closely with the actual failure mechanism of rock slope instability.By utilizing discretization techniques and the generalized tangent technology,the parameters of the Hoek-Brown criterion were converted into the computable parameters of the Mohr-Coulomb criterion and then integrated into the prediction model,proposing a more accurate model for the seismic stability analysis of rock slopes.This model can consider the nonlinear strength characteristics of rocks,and improve the prediction accuracy of seismic forces by introducing seismic acceleration and damping ratio parameters through the modified pseudo-dynamic method.Then,the gravity increase method and the Multi-Verse Optimizer were combined to obtain a method for determining the critical safety factor of the slope,and the 3D stability assessment of the rock slope under seismic action was realized.Compared with the existing research results and application to engineering cases,this method can more accurately evaluate the seismic stability of rock slopes,and also reflect the instability failure mode and range of rock slopes.It has good effectiveness and reliability in the seismic stability analysis of rock slopes.It provides new ideas and references for further optimizing the seismic design method of rock slopes.