成兰铁路松潘隧道入口红花屯古滑坡发育特征与稳定性分析

发布时间：2018-05-25 09:35

本文选题：成兰铁路 + 古滑坡　；参考：《地质力学学报》2017年05期

【摘要】：成兰铁路地处南北地震带中段,在内外动力耦合作用下,铁路沿线发育一系列大型—巨型古滑坡及存在古滑坡复活现象,给铁路工程规划建设造成极大危害。野外调查表明,规划建设中的成兰铁路松潘隧道入口位于红花屯古滑坡的坡脚部位,在强降雨和人类工程活动等作用下,该古滑坡近年来已发生局部复活并对铁路和下方居民区造成重大威胁。本文在野外调查的基础上,对红花屯古滑坡开展了原位大型直剪试验和稳定性模拟分析。研究表明:天然工况下,组成红花屯滑坡的碎石土抗剪强度较高,与其碎石含量呈显著的相关性,随着含石量的增加,碎石土的粘聚力有降低趋势,而内摩擦角有升高趋势。基于FLAC~(3D)数值模拟结果表明,在天然状态下,红花屯古滑坡的总体稳定性较好,铁路开挖坡脚改变了坡体的局部应力状态,在强降雨作用下,雨水进一步弱化滑体力学强度,古滑坡体变形量变大;在滑坡采取抗滑桩、格构锚等治理后,滑坡变形得到了有效控制。该滑坡在干湿循环、地震和人类工程活动等作用下,有可能进一步发生失稳,影响铁路隧道安全和坡体下方居民区,应加强群测群防和稳定性监测。
[Abstract]:Cheng-lan railway is located in the middle part of the north-south seismic belt. Under the action of internal and external dynamic coupling, a series of large-scale and giant ancient landslides are developed along the railway line and there exists the phenomenon of ancient landslide resurrection, which causes great harm to railway engineering planning and construction. Field investigation shows that the Songpan Tunnel entrance of Cheng-Lan Railway is located at the foot of the slope of the Honghuatun landslide, under the influence of heavy rainfall and human engineering activities. The ancient landslide has been partially revived in recent years and poses a major threat to railways and lower residential areas. On the basis of field investigation, the in situ direct shear test and stability simulation of Honghuatun landslide are carried out in this paper. The results show that the shear strength of the stone soil composed of Honghuatun landslide is relatively high under natural conditions, which is significantly correlated with the content of crushed stone. With the increase of stone content, the cohesive force of stone soil decreases and the angle of internal friction increases. The numerical simulation results based on FLACX / 3D show that the overall stability of Honghuatun landslide is good in natural condition, the slope foot of railway excavation changes the local stress state of slope body, and the Rain Water further weakens the strength of sliding mechanics under the action of heavy rainfall. The deformation of ancient landslide has become larger, and the landslide deformation has been effectively controlled after the landslide is treated by anti-slide pile and lattice anchor. Under the action of dry and wet circulation, earthquake and human engineering activities, the landslide may be unstable further, which will affect the safety of railway tunnel and the residential area below the slope body, so it is necessary to strengthen the group survey group prevention and stability monitoring.
【作者单位】：中国地质科学院地质力学研究所;中国地质大学(北京)工程技术学院;国土资源部新构造运动与地质灾害重点实验室;
【基金】：中国地质调查局项目(DD20160271) 国家自然科学基金项目(41402321)
【分类号】：P642.22;U452.11

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