重庆库区新构造应力场及其对滑坡宏观活动规律的控制

NEOTECTONIC STRESS FIELD AND ITS IMPACT ON MACRO DEVELOPMENT OF LANDSLIDES IN CHONGQING AREA OF THE THREE GORGES RESERVOIR

基于对重庆库区的 7个地貌形态区利用 Scheidegger法研究了每个区的区域新构造应力场。重庆库区内新构造应力场主压应力方向从南向北、由西向东具有明显的旋转特性 ,这可以利用大陆板块运动理论给予解释。结合库区内典型的 5 0 0余个滑坡资料 ,融滑坡优势滑动方向与新构造应力场于一体进行相关分析。研究结果表明 ,库区内部滑坡的宏观发育不是随机的 ,与新构造应力密切相关。在库区上游 ,滑坡优势滑动方向主要沿新构造应力场的北西剪切带方向发育 ,而在下游 ,则主要沿新构造应力场的北西剪切带与主压应力方向之间发育。明确此规律 。

Based on geomorphologic features, the Chongqing area of the Three Gorges reservoir is divided into seven parts. The neotectonic stress field(NSF) in every part is identified from river system materials by Scheidegger method. NSF in Chongqing area is rotational clockwise from western region to eastern region, which results from plate movement. Comparison between slide direction and NSF is made through analyses on about 500 landslides in the area. Then it is found that the slide directions of landslides aren′t random but are consistent with NSF there. Landslides are usually developed in north west shear zone of NSF in upriver area, while landslides are typicaly developed between north west shear zone and major compression direction of NSF in downstream area. It is important to obtain the law of landslide development for the prevention of landslide.