汶川小断裂带地震机理与监测建议
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摘要
龙门山断裂带全长约560 km,宽30~50 km,面积约20 000 km2,深度在40 km左右,本文将其定义为小断裂带,它是由3条主干断裂和若干个狭小断裂块体组成的小规模断裂带群。单个块体具有刚体特征,其内部缝隙、孔隙可以忽略,在挤压剪切破碎时将其假设为剪切面,块体剪切破碎或者块体间错位滑动,从而引发地震。当应力释放时,整体表现为下沉稳定,同时,与其邻近大块体接触面因卸荷而出现上、下、左、右相对滑动,从而引发余震。本文针对龙门山小断裂带卸荷前后各块体运动特征,提出监测建议。
The Longmen mountain fault belt is about 560km long,30～50 km wide and 40km deep,covering an area of approximate 20,000 km2.It is defined as a small fault zone in this paper,which is a small-scale fault group,composed of three main faults and some small fault blocks.Each single block is of rigid-body characteristics,in which the internal gaps and porosities can be ignored.They are supposed to be shear planes when extruded,and shear fractures of the block or sliding dislocation between blocks will result in an earthquake.The whole block will be sinking steadily while the stress releasing.At the same time,there will be a relative sliding between the contacted faces of these blocks by unloading,which will result in aftershocks.Based on the movement characteristics of the small-scale fault belts of Longmen Mountain before and after unloading,some suggestions for monitoring its behavior are proposed.
The Longmen mountain fault belt is about 560km long,30～50 km wide and 40km deep,covering an area of approximate 20,000 km2.It is defined as a small fault zone in this paper,which is a small-scale fault group,composed of three main faults and some small fault blocks.Each single block is of rigid-body characteristics,in which the internal gaps and porosities can be ignored.They are supposed to be shear planes when extruded,and shear fractures of the block or sliding dislocation between blocks will result in an earthquake.The whole block will be sinking steadily while the stress releasing.At the same time,there will be a relative sliding between the contacted faces of these blocks by unloading,which will result in aftershocks.Based on the movement characteristics of the small-scale fault belts of Longmen Mountain before and after unloading,some suggestions for monitoring its behavior are proposed.
引文
[1]罗志立,赵锡奎,刘树根.龙门山造山带的崛起和四川盆地形成与演化[M].成都:成都科技大学出版社,1994:195-203.
[2]马丽芳,乔秀夫,闵隆瑞,等.中国地质图集[M].北京:地质出版社,2002.
[3]付昭仁,蔡学林.变质岩区构造地质学[M].北京:地质出版社,1996:1-239.
[4]蔡学林,朱介寿,曹家敏,等.中国大陆及邻区岩石圈地壳三维结构与动力学型式[J].中国地质,2007,34(4):543-557.
[5]李智毅,杨裕云.工程地质学概论[M].武汉:中国地质大学出版社,1994:75-90.
[6]朱介寿.汶川地震的岩石圈深部结构与动力学背景[J].成都理工大学学报(自然科学版),2008,35(4):348-356.
[7]陈永奇,吴子安,吴中如.变形监测分析与预报[M].北京:测绘出版社,1998:1-100.
[2]马丽芳,乔秀夫,闵隆瑞,等.中国地质图集[M].北京:地质出版社,2002.
[3]付昭仁,蔡学林.变质岩区构造地质学[M].北京:地质出版社,1996:1-239.
[4]蔡学林,朱介寿,曹家敏,等.中国大陆及邻区岩石圈地壳三维结构与动力学型式[J].中国地质,2007,34(4):543-557.
[5]李智毅,杨裕云.工程地质学概论[M].武汉:中国地质大学出版社,1994:75-90.
[6]朱介寿.汶川地震的岩石圈深部结构与动力学背景[J].成都理工大学学报(自然科学版),2008,35(4):348-356.
[7]陈永奇,吴子安,吴中如.变形监测分析与预报[M].北京:测绘出版社,1998:1-100.
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