德钦-中甸断裂奔子栏段精定位及铁路构造工程效应

滇藏铁路中甸至德钦段与德钦-中甸活动断裂平行展布,在奔子栏镇附近,滇藏铁路以特大桥的形式跨越金沙江和德钦-中甸断裂,其选线受德钦-中甸活动断裂的控制。本文通过地质调查和钻孔钻探相结合的形式研究德钦-中甸断裂的平面位置和活动特征,分析德钦-中甸断裂的铁路构造工程效应。研究结果表明:(1)德钦-中甸断裂奔子栏段的平面精确展布状况并不对目前规划线路中的金沙江特大桥形成工程控制,不控制选线;(2)奔子栏镇一带是德钦-中甸断裂的孕震部位,其潜在震级上限可达7~7.5级左右,震中烈度值不会低于Ⅹ度,一旦发震对铁路工程破坏性极大;(3)滇藏在经过奔子栏镇时,选线需考虑德钦-中甸断层的平面精确展布特征。

Precise localization of Benzilan Section of Deqin-Zhongdian Fault Zone and Effect of Railway Structural Engineering

Deqin-Zhongdian active fault of Yunnan-Tibet railway is located near Benzilan town. Yunnan-Tibet Railway crosses the Jinsha River and the Deqin-Zhongdian Fault in the form of a super bridge and its geological route selection is seriously influenced by the active fault. Geological investigation and drilling method are applied to study the plane location and active characteristic of the Deqin-Zhongdian fault and analyze the railway structural engineering effect of the Deqin-Zhongdian fault. The study results show:(1) the precise plane distribution of Benzilan section of Deqin-Zhongdian fault doesn t affect Jinshajiang super-large bridge engineering and doesn t control the geological route selection in the current planning route;(2) the area around Benzilan town is the seismogenic site of the Deqin-Zhongdian fault,with a potential magnitude of upper limit of about 7~7.5,and the epicenter intensity value will not be lower than X,once the earthquake happens,the engineering destructiveness is very great;(3) When the Yunnan-Tibet line passes through Benzilan town,consideration shall be given to the precise plane distribution characteristics of Deqin-Zhongdian fault in the geological route selection in Benzilan area.