基于能量原理的边坡稳定概率计算

PROBABILITY CALCULATION OF SLOPE STABILITY BASED ON ENERGY PRINCIPLE

将边坡整体看成一个系统,然后从系统稳定能量原理出发,采用系统干扰能量方法作为建立边坡结构稳定可靠状态方程的准则,并给出了干扰能量的有限元计算方法。分析了边坡能量状态方程与岩土体随机参数精确的解析关系难于确定的原因,提出了采用响应面方法在验算点附近近似重构边坡干扰能量函数解析式的过程和方法。利用可靠指标的空间定义,在近似重构函数验算点求解中,引入梯度下降法,并建立验算点的梯度下降计算方法。该法无须对极限状态方程进行线性化处理,避免了由此带来的误差,提高了求解速度和精确度。最后利用能量干扰方法分析了一个土质边坡工程实例和一个岩质边坡实例在没有处理情况下的稳定可靠性,为工程的加固和处理提供了参考。

The whole slope can be regarded as a system, and a rule for stability limit-state equation of slope structure was established by systematically disturbing energy method according to energy principle of systemic stability. The calculation method-finite element method, is used to calculate the numerical value of disturbing energy. Due to complexity of slope structure, it is very difficult to obtain accurate formulas of slope structure limit-state function in which the independent variables are random parameters for geotechnical slope. The process and method of approximate analysis formulas, which reconstruct the disturbing energy function of the slope near the checking point by response surface method, are brought forward. Based on the dimensional definition of reliability degree, gradient decline method-one method of optimization, was introduced to construct the grads declining calculation method of the checking point of approximate limit-state equation that was established through response surface method. There is no need to perform limit-state equation while checking point of limit state equation was solved. The gradient declining calculation method of checking point can avoid the error that was induced by linearization of limit-state equation and can improve calculation speed as well as accuracy of checking point. Finally, the steady reliability degree about an example of terrene slope and an example of rock slope, which are not be reinforced, is analyzed. Stability reliability degree of these slopes can provide important reference to reinforcing and disposal of the project. The results show that the proposed analysis method of slope stability reliability degree has a bright application prospect.