开挖爆破荷载作用下岩质边坡稳定性分析方法研究

发布时间：2018-02-12 03:37

本文关键词： 边坡稳定安全系数开挖爆破严格Janbu法三维矢量和法动力有限元　出处：《上海交通大学》2015年硕士论文　论文类型：学位论文

【摘要】：边坡稳定性问题一直是岩土工程学界十分重视的重要研究课题之一,尤其是边坡在开挖爆破荷载作用下的稳定性问题,在矿山开采、道路工程、水利水电工程等领域的施工过程中都是不可回避的工程问题。对于开挖爆破荷载作用下岩质边坡稳定性分析方法的研究是对于边坡开挖设计和施工具有极其重要的理论意义和实际工程应用价值。本文主要研究内容如下:(1)针对极限平衡法中严格Janbu法在实际应用中存在边坡条块划分过多时安全系数计算不收敛的问题,本文基于B-样条函数具有良好的光滑性、明确的表达式以及紧凑性等特点,而且B-样条插值函数系数求解过程中容易进行矩阵计算、便于编程且计算效率高,提出了采用B-样条插值函数来拟合条间力矩,保证条间力矩一阶导数连续可导,从而使得严格Janbu法安全系数计算稳定收敛。算例分析表明,此方法是可行和合理的。(2)对爆破振动安全标准进行了探讨,分析了爆破振动和天然地震的差异,指出天然地震波加速度时程曲线频率低,幅值衰减缓慢;爆破振动波加速度时程曲线频率高,幅值衰减迅速。基于此差异性,综合考虑爆破振动相位差、幅值衰减等影响因素,在分析实测爆破振动加速度衰减规律的基础上,采用拟静力法与时程分析法相结合的方法研究了开挖爆破荷载作用下的边坡稳定性问题,给出了安全系数计算方法和分析步骤。(3)对边坡抗滑稳定矢量和法整体下滑趋势方向进行了探讨,分别分析了将滑移面上实际下滑力合力方向、极限抗滑力合力反方向、以及两者的角平分线方向作为边坡抗滑稳定整体下滑趋势方向时的安全系数计算问题。指出将边坡滑移面上各面单元的极限抗剪力的合力矢方向作为矢量和法边坡稳定整体下滑趋势方向最为合理。将动力有限元与三维矢量和法相结合,给出了爆破荷载作用下边坡三维矢量和法分析计算过程,通过对一个简单边坡的分析计算,验证了矢量和法对于爆破作用下边坡稳定性分析的可行性。(4)以黄麦岭磷矿露天边坡工程为例,根据实测的加速度时程曲线,综合考虑振动加速度衰减规律,采用本文提出的开挖爆破荷载作用下边坡稳定性分析方法和步骤计算了该边坡两个滑移面的抗滑稳定安全系数,计算结果与边坡实际稳定性情况基本吻合。
[Abstract]:Slope stability has always been one of the most important research topics in geotechnical engineering field, especially the stability of slope under excavation blasting load, mining in mines, road engineering, The research of rock slope stability analysis method under excavation blasting load is very important for slope excavation design and construction. The main contents of this paper are as follows: (1) in view of the problem that the strict Janbu method in the limit equilibrium method does not converge in the calculation of the safety factor when the slope segments are divided too much, Based on the good smoothness, definite expression and compactness of B-spline function, it is easy to calculate matrix in the process of calculating the coefficients of B-spline interpolation function, and it is easy to program and efficient. A B-spline interpolation function is proposed to fit the moment between strips to ensure the continuous derivation of the first derivative of the moment between strips, so that the safety factor of the strict Janbu method can converge stably. This method is feasible and reasonable. The safety standard of blasting vibration is discussed. The difference between blasting vibration and natural earthquake is analyzed. It is pointed out that the frequency of acceleration time history curve of natural seismic wave is low and the amplitude attenuation is slow. The frequency of the acceleration curve of blasting vibration wave is high and the amplitude attenuation is rapid. Based on this difference, considering the influence factors such as phase difference and amplitude attenuation of blasting vibration, the attenuation law of acceleration of blasting vibration is analyzed. The problem of slope stability under excavation blasting load is studied by using pseudostatic method and time-history analysis method. In this paper, the calculation method of safety factor and the analysis procedure are given. The stability vector of slope anti-slide and the direction of overall slide trend of the method are discussed. The direction of the actual force of sliding force on the slip surface and the direction of the force of ultimate anti-slip force are analyzed respectively. And the calculation of safety factor when the direction of angular bisection line is taken as the direction of overall sliding trend of slope anti-slide stability. It is pointed out that the direction of the force vector of the ultimate shear resistance of the elements on the slip surface of the slope is taken as the vector and the normal edge. The downtrend direction of slope stability is most reasonable. The dynamic finite element method is combined with the three-dimensional vector sum method. In this paper, the analysis and calculation process of three dimensional vector sum method for slope under blasting load is given, and the analysis and calculation of a simple slope are carried out. The feasibility of vector sum method for slope stability analysis under blasting action is verified. (4) taking the open pit slope of Huangmaling Phosphate Mine as an example, according to the measured acceleration time history curve, the law of vibration acceleration attenuation is considered synthetically. Using the method and procedure of slope stability analysis under excavation blasting load presented in this paper, the safety factor of slope stability of two slip planes is calculated. The calculated results are in good agreement with the actual stability of the slope.
【学位授予单位】：上海交通大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TU457

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