提出一种基于线性预测和Z转换(linear prediction and Z-transform,LPZ)谱分析法的非高斯脉动风压模拟算法.运用Johnson变换系统实现高斯随机过程到非高斯白噪声的转换;再使用LPZ对其进行数字滤波,进而得到所需的非高斯脉动风压.采用基...提出一种基于线性预测和Z转换(linear prediction and Z-transform,LPZ)谱分析法的非高斯脉动风压模拟算法.运用Johnson变换系统实现高斯随机过程到非高斯白噪声的转换;再使用LPZ对其进行数字滤波,进而得到所需的非高斯脉动风压.采用基于LPZ谱分析法对单变量非高斯随机信号和非高斯脉动风压进行了数值模拟.通过对模拟的非高斯信号和脉动风压的统计参数(峰度和偏度)与目标统计参数,以及模拟的功率谱与目标功率谱进行比较,验证了基于LPZ谱分析法的非高斯脉动风压模拟算法的有效性.展开更多
Based on the upper bound limit analysis theorem and the shear strength reduction technique, the equation for expressing critical limit-equilibrium state was employed to define the safety factor of a given slope and it...Based on the upper bound limit analysis theorem and the shear strength reduction technique, the equation for expressing critical limit-equilibrium state was employed to define the safety factor of a given slope and its corresponding critical failure mechanism by means of the kinematical approach of limit analysis theory. The nonlinear shear strength parameters were treated as variable parameters and a kinematically admissible failure mechanism was considered for calculation schemes. The iterative optimization method was adopted to obtain the safety factors. Case study and comparative analysis show that solutions presented here agree with available predictions when nonlinear criterion reduces to linear criterion, and the validity of present method could be illuminated. From the numerical results, it can also be seen that nonlinear parameter rn, slope foot gradient ,β, height of slope H, slope top gradient a and soil bulk density γ have significant effects on the safety factor of the slope.展开更多
文摘提出一种基于线性预测和Z转换(linear prediction and Z-transform,LPZ)谱分析法的非高斯脉动风压模拟算法.运用Johnson变换系统实现高斯随机过程到非高斯白噪声的转换;再使用LPZ对其进行数字滤波,进而得到所需的非高斯脉动风压.采用基于LPZ谱分析法对单变量非高斯随机信号和非高斯脉动风压进行了数值模拟.通过对模拟的非高斯信号和脉动风压的统计参数(峰度和偏度)与目标统计参数,以及模拟的功率谱与目标功率谱进行比较,验证了基于LPZ谱分析法的非高斯脉动风压模拟算法的有效性.
基金Project(2006318802111) supported by West Traffic Construction Science and Technology of ChinaProject(2008yb004) supported by Excellent Doctorate Dissertations of Central South University, China Project(2008G032-3) supported by Key Item of Science and Technology Research of Railway Ministry of China
文摘Based on the upper bound limit analysis theorem and the shear strength reduction technique, the equation for expressing critical limit-equilibrium state was employed to define the safety factor of a given slope and its corresponding critical failure mechanism by means of the kinematical approach of limit analysis theory. The nonlinear shear strength parameters were treated as variable parameters and a kinematically admissible failure mechanism was considered for calculation schemes. The iterative optimization method was adopted to obtain the safety factors. Case study and comparative analysis show that solutions presented here agree with available predictions when nonlinear criterion reduces to linear criterion, and the validity of present method could be illuminated. From the numerical results, it can also be seen that nonlinear parameter rn, slope foot gradient ,β, height of slope H, slope top gradient a and soil bulk density γ have significant effects on the safety factor of the slope.
