蒙特卡洛法计算750kV输电线路绕击跳闸率的研究

利用GDS多功能三轴仪,通过控制土样应变增量比开展了饱和砂土部分排水三轴试验;利用超静孔隙水压力、有效应力路径和应力应变关系三方面的实验结果,研究了饱和砂土的渐近状态特性。研究表明,控制应变增量比为常数进行常规三轴加载时,饱和砂土的有效应力比也趋于某一常数,形成渐近状态,且渐近状态应力比随应变增量比的增大而减小。基于土的剪胀特性给出了渐近状态形成的物理机制,并给出了北京某砂土在部分排水条件下渐近状态应力比的试验结果。

Calculation of shielding failure trip-out rate for 750 kV transmission line based on Monte Carlo Method

Through GDS Multifunctional Static Triaxial Apparatus,partial drained triaxial tests on saturated sand are carried out by controlling the strain increment ratio of soil samples.Through analyzing the experimental results of excess pore pressure,effective stress paths and stress-strain relation,asymptotic properties of saturated sand are studied.Research indicates: when sand is loaded on ordinary triaxial conditions by keeping constant strain increment ratio,effective stress ratio of saturated sand also tends to be a constant and forms a asymptotic state.At the same time,the asymptotic stress ratio decreases with strain increment ratio increasing.Based on dilatancy property of soil,physics mechanisms of forming the asymptotic states are presented.Test results of asymptotic stress ratio of Beijing saturated sand under part drainage condition are given.