地震地质
地震地質
지진지질
SEISMOLOGY AND GEOLOGY
2010年
1期
98-106
,共9页
孙萍%汪发武%殷跃平%吴树仁
孫萍%汪髮武%慇躍平%吳樹仁
손평%왕발무%은약평%오수인
汶川地震%高速远程滑坡%环剪试验%振动液化%剪切强度%剪切位移
汶川地震%高速遠程滑坡%環剪試驗%振動液化%剪切彊度%剪切位移
문천지진%고속원정활파%배전시험%진동액화%전절강도%전절위이
Wenchuan earthquake%rapid and long run-out landslide%ring shear test%vibration liquefaction%shear strength%shear displacement
汶川大地震触发了多处高速远程滑坡,导致了大量的人员伤亡及财产损失.其中,东河口滑坡是这次地震触发的最为典型的高速远程滑坡之一,同时也是目前备受关注、争论颇多的滑坡之一.野外调研结果表明,该滑坡的成因和动力特征主要包括震裂溃屈、水平抛射、碎屑流化和振动液化等4个方面.为了对该滑坡滑动过程中的振动液化这一动力特征进行模拟再现,在东河口滑坡体上采集了具有代表性的滑带土作为试验样品,并以该地震时的实测地震波作为动力输入,利用目前国际上最先进的DPRI环剪试验机,对滑坡滑动过程中的振动液化现象进行了一系列环剪试验研究.结果表明,地震作用过程中,发生在滑坡潜在滑面上的振动液化现象是导致高速远程滑坡产生的一个重要因素;伴随着振动液化过程,滑体的剪切强度迅速降低并产生逐渐增大的剪切位移,为高速远程滑坡的形成提供了条件.
汶川大地震觸髮瞭多處高速遠程滑坡,導緻瞭大量的人員傷亡及財產損失.其中,東河口滑坡是這次地震觸髮的最為典型的高速遠程滑坡之一,同時也是目前備受關註、爭論頗多的滑坡之一.野外調研結果錶明,該滑坡的成因和動力特徵主要包括震裂潰屈、水平拋射、碎屑流化和振動液化等4箇方麵.為瞭對該滑坡滑動過程中的振動液化這一動力特徵進行模擬再現,在東河口滑坡體上採集瞭具有代錶性的滑帶土作為試驗樣品,併以該地震時的實測地震波作為動力輸入,利用目前國際上最先進的DPRI環剪試驗機,對滑坡滑動過程中的振動液化現象進行瞭一繫列環剪試驗研究.結果錶明,地震作用過程中,髮生在滑坡潛在滑麵上的振動液化現象是導緻高速遠程滑坡產生的一箇重要因素;伴隨著振動液化過程,滑體的剪切彊度迅速降低併產生逐漸增大的剪切位移,為高速遠程滑坡的形成提供瞭條件.
문천대지진촉발료다처고속원정활파,도치료대량적인원상망급재산손실.기중,동하구활파시저차지진촉발적최위전형적고속원정활파지일,동시야시목전비수관주、쟁론파다적활파지일.야외조연결과표명,해활파적성인화동력특정주요포괄진렬궤굴、수평포사、쇄설류화화진동액화등4개방면.위료대해활파활동과정중적진동액화저일동력특정진행모의재현,재동하구활파체상채집료구유대표성적활대토작위시험양품,병이해지진시적실측지진파작위동력수입,이용목전국제상최선진적DPRI배전시험궤,대활파활동과정중적진동액화현상진행료일계렬배전시험연구.결과표명,지진작용과정중,발생재활파잠재활면상적진동액화현상시도치고속원정활파산생적일개중요인소;반수착진동액화과정,활체적전절강도신속강저병산생축점증대적전절위이,위고속원정활파적형성제공료조건.
The 2008 great Wenchuan earthquake caused multiple rapid and long run-out landslides, which resulted in a lot of deaths and property loss. Donghekou landslide,a typical rapid and long run-out landslide triggered by Wenchuan earthquake, is located in Qingchuan county, and at present, it is concerned and discussed particularly because of its complex original mechanism. Field investigations show that the original mechanisms and dynamic features mainly include the followings, for example,the shattering collapse, the horizontal slinging, the debris flow and the vibration liquefaction, etc. In order to simulate and reconstruct the vibration liquefaction, representative soils on sliding zone of Donghekou landslide were collected for soil tests. By using the advanced DPRI ring shear apparatus,a series of ring shear tests have been carried out to study the vibration liquefaction process of Donghekou landslide under the loading of real seismic waves,and some ideal results were gotten. The test results show that when the earthquake happened,the vibration liquefaction occurring on the potential sliding surface played an important role in generating the rapid and long run-out landslide. When the soils were dry, only a small displacement ( 0. 007 m ) was generated, which couldn't form a landslide with high speed and long run-out; with the vibration liquefaction, the shear strength could be decreased and a large displacement could be generated, which supplied a necessary condition for the generation of rapid and long run-out landslide.