云南陇川半成岩地层滑坡的成因机制及稳定性评价  

Formation Mechanism and Stability Evaluation of A Semi-rock Landslide in Longchuan Area of Yunnan Province

作　　者：严松[1] 王运生[1] 罗永红[1] 谢春庆 潘凯 

机构地区：[1]成都理工大学地质灾害防治与地质环境保护国家重点实验室,四川成都610059 [2]西部战区空军勘察设计院,四川成都610041

出　　处：《长江大学学报（自然科学版）》2017年第21期61-68,共8页Journal of Yangtze University(Natural Science Edition)

基　　金：国家自然科学基金项目(41072231)

摘　　要：滑坡的成因机制及稳定性评价对工程和人类活动至关重要,在对云南省陇川县新建通用机场的勘察过程中发现中型不稳定老滑坡,该滑坡对拟建的重要工程安全性产生严重的影响。通过钻探、物探、遥感等手段对该滑坡进行详细勘察,发现海岗滑坡为该地区(半成岩地层)的典型滑坡,即以流水快速侵蚀,切入坡内,形成深大冲沟,然后以冲沟为临空面,发生第1次滑动,在后期强降雨诱发下以自然边坡为临空面发生第2次滑动。在地貌上表现为"肚大口小",似瓢状,命名为"瓢把子"滑坡。该类滑坡滑带区别于一般的土质或岩质滑坡,滑带为后部高陡、中部圆滑、前部平缓的折线型。通过FLAC3D计算分析滑坡稳定性表明,在地震作用下滑坡计算剖面最大位移量为12.3mm,与天然工况相比增大了7.32倍;降雨作用下滑坡剪应变集中区主要分布在斜坡堆积体与滑床接触带附近,剪应变增大了6.25倍,充分证明该类滑坡在降雨及地震作用下极不稳定。The cause mechanism and stability evaluation of landslide are very important for engineering and human activities.In the investigation of new general airport in Longchuan County of Yunnan Province,it is found that an unstable and old landslide has serious impact on the safety of the proposed project.Through drilling,geophysical prospecting and remote sensing methods to survey the landslide in detail,it is found out that Haigang landslide(strutum of semi-rock)is the typical landslide in the region,namely a rapid water erosion,cutting into the slope,forms a deep ditch,and then the ditch is used as a free surface,first sliding is induced,influenced by heavy rainfall,late the second rainfall is induced on sliding surface of natural slope.In the landform,it presents'big belly and small mouth',like a gourd,named 'gourd'landslide.This type of landslide is different from the normal soil or rock slope,and the slip zone is high and steep,the middle is smooth,and the front is flat.The stability of landslide is analyzed by FLAC3 Dcalculation,the results show that under the earthquake,the maximum capacity of its displacement profile calculation is 12.3 mm,compared with natural working condition it increases by 7.32 times;the effect of shear strain distribution of the rainfall landslide mainly concentrates in the slope accumulated areas and slide bed near the contact zone,where the shear strain increases by 6.25 times,it fully proves that this type of landslide is extremely unstable in rainfall and earthquake.

关 键 词：云南 陇川 半成岩地层 地震滑坡 形成机制 FLAC3D 

分 类 号：P642.22[天文地球—工程地质学]