西藏G318典型地质灾害成因机制及防治对策

Genetic Mechanism of Geohazard along National Highway 318 in Tibet and Prevention Countermeasure

通过资料收集和大量现场调研得出西藏境内G318沿线发育重大地质灾害324处(段),其中崩塌162个,滑坡39个,泥石流88条,雪崩3处,河岸坍塌10段,冻土冻融22段。崩塌以节理裂隙切割型岩质崩塌、坡面堆积滑塌型和高陡阶地滚落型土质崩塌为主,滑坡以大型深厚堆积层土质滑坡和中小型风化卸荷型岩质滑坡为主,泥石流以降雨诱发型和冰湖溃决型为主。沿线地质灾害在地域上不均、地形地貌上散中有聚、地层岩性及高程上相对集中、年际上具有周期性及年内具有季节性的发育特点,且与人类工程活动有关的达67%以上。最后,提出了分期分批分级治理的防治思路和不同类型不同成因模式地质灾害的防治措施。

By data collection and field investigation along national highway 318 in Tibet,it is obtained that（1） There are 324 significant geohazard,among which there are 162 collapses,39 landslides,88 debris flows,3 avalanches,10 bank collapses,and 22 frozen soils.（2） The collapses include the joint and crack cutting type,the slope deposits slumping type,and the steep terrace pebble tumbling type;landslides include the large-scale deep deposits type and the small weathering or unloading rock type;and debris flows include the rainfall induced type and glacial lake outburst type.（3） It is shown from distribution that regional uneven,topography local focus,stratum centralization,elevation belt,interannual cycle,and years seasonal,especially above 67% is related to human engineering activities.At last,it is proposed that the prevention idea should be batches control and hierarchical governance,and the prevention countermeasures corresponding to different types and different genetic mechanisms of geohazards.