摘要
将模糊随机理论与改进的响应面模型结合求解滑坡的可靠性指标。首先,考虑到滑带土力学参数的模糊随机性,非线性程度较高,采用正态模糊隶属函数对参数样本进行模糊-随机处理,并作为优化模型的约束函数;然后,采用过无差点的改进响应面法将功能函数显式化为二阶近似函数,黏聚力和内摩擦角约束函数显式化为线性函数,基于二次规则方法,采用理性运动极限计算方法,寻找合理、有效而稳定的优化策略求解滑坡的目标功能函数;最后,采用一次二阶矩法计算滑坡的可靠性指标。改进的响应面法在迭代过程中通过中心展开点,优化过程可以收敛到精确的局部最优点,同时理性运动把每次寻优的空间缩小,在建立近似显函数展开点或构造点的邻域进行寻优,避免了优化迭代振荡、收敛速度缓慢或不收敛的缺陷,提升了优化速度并保证求解的有效性和准确性。计算方法保证了改进响应面法的精度,求得的可靠性指标考虑了参数模糊不确定性的影响,研究成果为响应法的改进并应用于滑坡工程的可靠性评价领域起到一定的推动作用。
This paper aims at proposing an improved response surface model （IRSM）, combining with the fuzzy random theory to calculate the reliability index of the landslides. First of all, considering the fuzzy randomness character of the soil mechanics parameters, the nonlinear degree is much higher, the normal fuzzy membership function is used to dispose the soil sample, and put them as constraint functions of optimization model. Then, to transfer the explicit function into second order approximation function using IRSM, the constraint function of cohesion and angle of internal friction are transferred to linear function. Based on the quadratic programming method, the rational motion limit calculation method is used to find a reasonable, effective and stable optimization strategy, so as to obtain the performance function, then using JC method to calculate the reliability index of landslides. ISRM through the center point during iteration, the optimization process can be exactly converged to the local optimal point, the optimal space is becoming narrower each time in establishing approximate explicit function expansion point or structure point, which avoiding the drawbacks of iteration vibration and slow convergence,improving the optimization speed and ensuring the effectiveness and accuracy of the results. The precision of ISRM is ensured, the reliability index is calculated considering the fuzzy uncertainty of rock-soil parameters. The research results can provide a basis for extending the application of the IRSM to the reliability evolution of landslides.
出处
《水利学报》
EI
CSCD
北大核心
2014年第5期595-606,共12页
Journal of Hydraulic Engineering
基金
国家自然科学基金资助项目(41227901)
中国科学院战略性先导科技专项B类(XDB10030300
XDB10050400)
关键词
滑坡
改进响应面法
理性运动极限
功能函数
可靠性指标
landslide
improved response surface method
rational move limit
target function
reliability index
