喜家湾地震黄土滑坡形成机理
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摘要
在喜家湾滑坡现场调查基础上,采集黄土斜坡的原状黄土和滑坡滑带土试样进行了室内试验,分析计算了滑坡土体震陷性和液化可能性;并结合滑坡发生前斜坡在地震作用下的稳定性分析及数值模拟,对该滑坡的形成机理进行了研究。研究表明,地震发生时,斜坡上部黄土产生震陷,结构破坏,下部泥岩面附近处于饱和状态的黄土在很短时间内产生了液化现象,坡体下滑形成震陷—液化复合型滑坡。
The Xijiawan landslide,a typical loess landslide triggered by HaiYuan Earthquake in 1920 located in XiJi county was investigated in this paper.In order to clarify the formation mechanism of Xijiawan landslide,a series of tests were conducted on the loess soils collected from the main body of slope and surface of rupture in Xijiawan landslide,the possibility of seismic subsidence and liquefaction potential were analyzed,and the works of stability analysis and numerical simulation were done.The results show that the formation mechanism of landslide is the complex of seismic subsidence–liquefaction.When the earthquake happened,the destroy of seismic subsidence occurred on the upper soil of slope.Meanwhile,the saturated loess at the vicinity of lower mudstone built up loess liquefaction instantaneously.
The Xijiawan landslide,a typical loess landslide triggered by HaiYuan Earthquake in 1920 located in XiJi county was investigated in this paper.In order to clarify the formation mechanism of Xijiawan landslide,a series of tests were conducted on the loess soils collected from the main body of slope and surface of rupture in Xijiawan landslide,the possibility of seismic subsidence and liquefaction potential were analyzed,and the works of stability analysis and numerical simulation were done.The results show that the formation mechanism of landslide is the complex of seismic subsidence–liquefaction.When the earthquake happened,the destroy of seismic subsidence occurred on the upper soil of slope.Meanwhile,the saturated loess at the vicinity of lower mudstone built up loess liquefaction instantaneously.
引文
[1]张振中.黄土地震灾害预测[M].北京:地震出版社,1999.
[2]白铭学,张苏民.高烈度地震时黄土地层的液化移动[J].工程勘探,1990(6):1-5.
[3]王兰民.黄土动力学[M].北京:地震出版社,2003.
[4]王兰民,张振中.地震时黄土震陷量的估算方法[J].自然灾害学报,1993,2(3):85-94.
[5]袁中夏,王兰民,Yasuda S,等.黄土液化机理和判别标准的再研究[J].地震工程与工程振动,2004,24(4):164-169.
[2]白铭学,张苏民.高烈度地震时黄土地层的液化移动[J].工程勘探,1990(6):1-5.
[3]王兰民.黄土动力学[M].北京:地震出版社,2003.
[4]王兰民,张振中.地震时黄土震陷量的估算方法[J].自然灾害学报,1993,2(3):85-94.
[5]袁中夏,王兰民,Yasuda S,等.黄土液化机理和判别标准的再研究[J].地震工程与工程振动,2004,24(4):164-169.