ISSN 1000-3665 CN 11-2202/P

    川藏寒区道路边坡涎流冰防治措施试验研究

    Experimental study on prevention measures of extruded ice on highway subgrade slope in Sichuan-Tibet cold region

    • 摘要: 涎流冰是川藏寒区道路工程常见病害,严重威胁道路建设及运营安全。防止地下水出露地表或者地下水位过高可减缓或消除涎流冰病害。野外调查和卫图判识表明川藏寒区涎流冰以溢流型为主。通过室内物理模拟试验研究采用含砾粗砂或卵石换填疏导地下水以及铺设防水土工布隔水对涎流冰的防治效果。试验表明:当冻结深度大于地下水位埋深时会逐渐形成涎流冰;采用含砾粗砂或卵石作为换填渗流层,加快地下水排泄,可有效减少孔隙水压力,相对于未处治边坡,涎流冰体积分别减少85.4%和93.9%,孔隙水压力分别减少46.2%和58.1%;采用防水土工布阻隔地下水,涎流冰面积减少97.5%,但孔隙压力会增加。考虑到川藏交通廊道区卵(碎)石材料充足,推荐采用渗透性良好的卵(碎)石作为换填层,加强地下水疏导,并在换填层上铺设防水土工布隔水。研究成果可为川藏地区交通道路涎流冰防治提供参考。

       

      Abstract: Extruded ice is a common disease in road engineering in Sichuan-Tibet cold region, which seriously threatens the safety of road construction and operation. Preventing groundwater from being exposed to the surface or the groundwater level being too high can slow down or eliminate the formation of extruded ice. Field investigation and satellite map identification show that extruded ice in Sichuan-Tibet cold region is mainly overflow type. The prevention effects on extruded ice of backfilling with gravelly coarse sand or pebbles to dredge groundwater and laying waterproof geotextiles are analyzed by indoor physical simulation experiments. The results show that extruded ice will gradually form when the frozen depth is lower than the depth of groundwater level. Backfilling seepage layer with gravelly coarse sand or pebbles can accelerate the discharge of groundwater and reduce the pore water pressure effectively. Compared with the untreated slope, the volume of extruded ice is reduced by 85.4% and 93.9% respectively, and the pore water pressure is reduced by 46.2% and 58.1% respectively. By blocking groundwater with waterproof geotextile, the volume of extruded ice is reduced by 97.5%, but the pore pressure will increase. Considering the sufficient pebble (or gravel) materials in Sichuan-Tibet alpine region, it is recommended to use permeable pebble (or gravel) as backfill layer to accelerate groundwater drainage and control extruded ice disease in subgrade slope. And waterproof geotextile is recommended to be laid on backfill layer. The research results can provide reference for the prevention of extruded ice in Sichuan-Tibet traffic roads.

       

    /

    返回文章
    返回