Study of stratigraphic site effect on the failure mechanism of Donghekou rockslide triggered by Wenchuan earthquake
Yin Yueping 1Wang Wenpei 1Li Bin 2Zhang Nan1Li Hongtao 3
1. China Institute of Geological Environment Monitoring, Beijing 100081, China
2. Institute of Geomechanics, Chinese Academy of Geological Sciences, Beijing 100081, China
3. Institute of Hydrogeology and Engineering Geology Techniques, CGS, Baoding 071051, China
Abstract：The microtremors were firstly carried out along the boundary of Donghekou rockslide after Wenchuan earthquake, whose spectral characteristic curves showed that the predominant frequency was within the range of 1~3Hz, and the spectral ratio maximum occurred in NS direction. Secondly, the selected central frequencies of Ricker wavelets were input into the 2-layer conceptualization elastic model as well as the homogenous one. It is found that the PGA amplification of 2-layer model are higher than the homogenous one, and the range of PGA amplification is wider when the input central frequencies are lower, and the PGA amplification with higher central frequencies just concentrates on the crest and ridges of the slope. It shows that different central frequencies result in different ranges of the PGA amplification. Finally, an elastic-plastic model with the input Wenchuan acceleration records at Qingping station was used to analyze the relation between input waves of frequencies and failure process. According to the residual displacement of monitoring points, the failure time of 6.5s is determined. Meanwhile, according to high spectral values near the time of 6.5s, it shows the input wave with higher spectral values (Fourier values) will cause the rockslide. This study will help to raise awareness of the process of rockslide based on stratigraphic site effect.
地层场地效应对东河口地震滑坡发生影响研究[J]. 土木工程学报, 2016, 49(S2): 126-131.
Yin Yueping Wang Wenpei Li Bin Zhang Nan Li Hongtao. Study of stratigraphic site effect on the failure mechanism of Donghekou rockslide triggered by Wenchuan earthquake. 土木工程学报, 2016, 49(S2): 126-131.
