近岸水平场地液化侧向大变形影响因素分析

利用改进的软化模量分析方法,对近岸水平场地液化侧向大变形进行数值计算,以研究地震波波形和幅值大小、液化、竖向地震动对侧向大变形的影响。结果表明:不同的地震波作用下,即使峰值加速度相同,液化程度与侧移距离也可能有较大不同,表现了土体变形的强非线性性质,但大地震下液化导致的侧移几乎都在米的量级上;计算区域中无液化区时,岸壁侧向永久位移很小,在几公分左右,随水平峰值加速度及不同地震动输入改变不大;计算区域中有液化区时,岸壁侧向永久位移显著增大,且随输入水平峰值加速度的增大而明显增大,其机理是强地震动使液化范围加大;水平竖向两向地震动输入与单独水平地震动输入相比,前者场地液化范围增大,平均增大42%,侧移量增加,平均增加37%。

Influence factors on liquefaction-induced lateral spreading of ground near bank

The influence of inputted earthquake waves,soil property,vertical seismic motion on the liquefaction-induced lateral spreading of ground near bank is studied by using the modified soften modulus model.The results show: both the liquefied area and the displacement of the ground are quite different when the input acceleration time histories are different although the peak values of inputted acceleration are the same,but the liquefaction-induced lateral permanent displacements of the ground almost are level of meter;the displacement of bank wall is quite small,only a few centimeters,and it is changed little with the increasing of input peak acceleration when there is no liquefaction in the ground.On the contrary,the displacement of the bank wall is large and increases with the increasing of input peak acceleration when there is liquefied area in the ground.Compared with only horizontal inputing acceleration,both horizontal and vertical inputing ones make the liquefied area larger,about 42% larger on average,and as a result the permanent displacement of the bank wall is increased by an average of 37%.