改进的粒子群算法在断层滑动速率反演中的应用

IMPROVED PARTICLE SWARM OPTIMIZATION ALGORITHM AND ITS APPLICATION IN INVERSION OF SLIP VELOCITY OF FAULT

结合位错理论模型,基于模拟的水平位移观测值分别采用PSO算法、遗传算法以及蒙特卡罗算法对断层的三维滑动速率进行了对比计算分析,结果表明:3种算法耗时都随着反演参数的取值范围的增大而增加,且随着适应度值增大而增加;PSO算法的耗时优于其他两种算法。随后对标准PSO算法与改进后的PSO算法进行了对比计算。在模拟试验中适应度值取0.95的条件下,改进后的PSO算法比标准PSO算法耗时减少了26.50%。最后采用改进后的PSO算法对祁连山断裂带中东段的三维滑动速率进行反演。结果表明:改进后的算法比标准PSO算法耗时减少了36.34%;惯性权值的动态调整对算法的影响比较突出;祁连山断裂带中东段主要表现为左旋走滑运动,并伴有正倾滑性质。

According to the dislocation model and from the simulated observation values of horizontal displacement the three-dimensional slip rate of the fault was deduced with the PSO algorithm,the genetic algorithm and Monte-carlo algorithm respectively.The results show that the consuming time with three algorithms rises in accord with the increase of the inversion parameters range and the fitness value,but the PSO is better than the other two algorithms.At the same time the PSO and the improved PSO algorithm were compared.The results of comparison indicate that consuming time with the improved PSO is decreased by 26.50% when the fitness value is 0.95.As an example,the three-dimensional slip rate of faults was calculated in the middle and eastern segments of Qilianshan fault with PSO algorithm and improved one and the results show that the consuming time with improved PSO is decreased by 36.34% and it is verified that the factor of dynamic adjustment of the inertia weight is more prominent than the factor of mutation operation.Futhermore in the middle and eastern segments of Qilianshan fault the main movement is left-lateral strike-slip with normal dip-slip.