泥石流灾害对新建康定车站的影响研究

Study on Influence of Debris Flow Disaster on New Kangding Station

康定车站拟建站址位于泥石流沟口处,该沟泥石流活动性较强,成为影响铁路选线的关键因素。本文通过资料收集、遥感解译、野外调查、室内分析与计算等综合手段,对泥石流危害进行分析评价。结果表明:站址区泥石流为稀性~过渡性,容重取值在1.5~1.8 g/cm^3之间。百年一遇设计标准下(P=1%),泥石流峰值流量为250.75 m^3/s,一次最大冲出固体物质为7.7×10~4 m^3。当流域暴发P=5%以上规模泥石流时,现有排导槽(过流面积约17.5 m^2)过流面积不足。建议对泥石流采用"以拦为主,拦排结合"的治理方案,在流域内设置2~3座拦挡坝,在出山口以下堆积区修建排导槽;铁路通过沟道时,采用一桥跨越方式,桥梁跨度和净空高度要满足排泄铁路设计标准泥石流流量的要求,同时需做好桥梁跨沟上下游沟道两岸的防护措施。

The proposed site of Kangding Station is located at the mouth of debris flow gully, which has strong activity and becomes the key factor affecting railway route selection. Through data collection, remote sensing interpretation, field investigation, indoor analysis and calculation, this paper analyzes and evaluates the hazards of debris flow. The results show that: the debris flow in the station area is diluted-transitional, and the bulk density is between 1.5 and 1.8 g/cm^3. Under the a-hundred-year return perioddesign standard(P=1%), the peak flow of debris flow is 250.75 m^3/s, and the maximum total volume of 7.7×10~4 m^3. When the scale of debris flow with P=5% or more breaks out in the basin, the existing drainage channel(with a flow area of about 17.5 m^2) has insufficient flow area. It is suggested to adopt the treatment measure of "mainly blocking and combining blocking and discharging" for debris flow, set up 2~3 blocking dams in the basin, and build drainage channels in the accumulation area after the mountain pass;When the railway passes through the channel, bridge crossing shall be adopted, and the bridge span and clearance height shall be designed to meet the requirements of standard discharging the debris flow in the railway design standard. At the same time, protective measures should be taken on both sides of the upstream and downstream channels.