Production of Input Motions for the Aseismic Design by Stochastic System Model

1.随机系统模型产生地震动1）考虑硬化材料等效应力应变关系的滞回本构方程，将非线性滞回土介质波动方程表示为一阶时、空变量偏微分方程。通过表示类似类型的地震微分方程，对环向概率密度函数进行积分，得到地震可靠度函数通过引入上述输入运动的随机模型，提出了非线性滞回结构的最优随机控制方法.基于地震观测资料的地震动估计：1）预测最大地震的规模估计为记录到的最大震级地震能量的两倍，2）提出了一种考虑地基非线性影响的利用结构地震加速度记录反演自由面输入运动的方法。结构相互作用通过对结构内部及周围自由面上的地震记录的分析，验证了该方法的有效性。输入运动的属性的一个例子，适用于住宅和区域空间的地震灾害的风险分析。

1. Generation of ground motions by means of stochastic system model1) The wave equation of nonlinear hysteretic soil medium is formulated as the 1st order partial differential equations for time and space variables considering the hysteretic constitutive equation of the equivalent stress and strain relationship of hardening material.2) Seismic reliability function is obtained by integrating the circumferential probability density function by representing the similar type of differential equation on earthquake input motion, hysteretic system and the damage process of the structures.3) Optimum stochastic control method is proposed for the nonlinear hysteretic structures by introducing the above-mentioned stochastic model of input motion.2. Estimation of ground motions based on the observational data of earthquakes.1) Scale of the predicted maximum earthquake is estimated as twice of the earthquake energy of maximum magnitude recorded, by introducing the modified estimation method of Gutenberg-Richter formulation.2) An inverse calculation method to presume the input motion at the free surface using the accelerograms observed in structures is devised considering the effect of nonlinear soil-structure interaction. The validity of the method is verified by applying the earthquake records observed simultaneouslyin the structure and at the surrounding free surface. An example of the property of the input motions applied to a risk analysis of earthquake hazards in residential and regional spaces is shown.