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2010年1月12日,位于北美板块向加勒比板块的俯冲带的海地太子港,发生了Mw7.0级地震。本次地震造成了大量的人员伤亡与巨大的财产损失,并触发了数以万计的滑坡灾害。本文主要为海地地震滑坡的野外初步考察成果。海地地震发震机制为综合逆冲与左旋走滑特征的压扭性发震机制。本次地震触发了4000—5000处滑坡,滑坡类型主要为裂隙发育、风化或扰动状态下的灰岩与玄武岩中的破碎滑动与崩塌。部分滑坡形成了滑坡坝与堰塞湖,最大的滑坡坝已经被疏通,其他的滑坡坝均不会形成严重的威胁。最后分析了将来的持续滑坡灾害,主要包括如下几个方面:(1)因滑坡产生的孤立岩块并没有滑到斜坡底部,在将来的可能的地震或降雨条件下可能会发生重新滑动:(2)滑坡后壁上面坡体裂缝,表明了将来的滑坡发生的高危险性:(3)地震滑坡形成的大量滑坡堆积物会导致下游沉积量的增加。另外,更详细的滑坡编录工作正在进行。
On January 12, 2010, an Mw7.0 earthquake struck Port-au-Prince, Haiti, on the North American plate in the subduction zone of the Caribbean Plate. The earthquake caused a large number of casualties and huge property losses, and triggered tens of thousands of landslides. This paper mainly for the first time in the field of Haiti earthquake landslides inspection results. Seismogenic mechanism of Haiti earthquake is a compression-induced seismogenic mechanism that integrates the characteristics of thrusting and strike-slip. The earthquake triggered 4000-5000 landslides. The landslide types are mainly the fractures of limestone and basaltic rock under the condition of fissure development, weathering or disturbance. Part of the landslide formed landslide dam and dammed lake, the largest of the landslide dam has been dredged, the other landslide dams will not pose a serious threat. Finally, we analyze the following persistent landslide hazards, including the following aspects: (1) The isolated rock mass caused by the landslide does not slide to the bottom of the slope, and may slide again in the future under the possible earthquake or rainfall conditions :( 2) Cracks in the slope above the rear wall of the landslide indicate the high risk of future landslides: (3) The large amount of landslide deposits formed by the earthquake landslides will lead to the increase of sediments downstream. In addition, more detailed landslide cataloging is under way.