摘要
针对内蒙古黄土泥岩接触地带界面滑坡的工程地质灾害,设计锚杆挡土墙式工程防护比尺模型试验。通过监测界面处、黄土层内不同监测点的孔隙水压力、土压力、坡面标记点位移等数据,总结黄土层内土压力场、渗流场以及坡面位移的变化规律,分析黄土泥岩界面滑移诱因及滑移机制。进而对锚杆挡土墙墙后土压力和墙体位移的变化进行监测,并以锚杆挡土墙墙体位移量来评价工程防护的效果,试验结果表明在经历了2个降雨周期后,锚杆挡土墙墙体平均位移量为5.45 mm,远小于规范中要求的挡土墙失效位移。锚杆挡土墙可以防止黄土层在坡脚处的滑移趋势,抑制黄土层内裂隙的发展,减缓界面处的位移发展,阻止并防护黄土泥岩界面滑坡的出现,是黄土泥岩界面滑坡有效且可靠的工程防护形式。
Loess-mudstone interfacial landslide is one of the most prominent landslide hazards occurred in soil-rock contacting zones. A semi-similar material physical model testing on anchor rod retaining wall was conducted to investigate the sliding mechanism of rainfall induced loess-mudstone interfacial landslides and the feasibility of engineering protection in this paper. The sliding mechanism of interface is analyzed through monitoring the pore water pressure,earth pressure and the displacement of slope surface markers along different sections of inner loess strata and interface between loess and mudstone. The variation of displacement and earth pressure behind anchor rod retaining wall were summarized. The results indicate that the average displacement of anchor rod retaining wall is 5.45 mm after the during two rainfall period,is far less than the specification requirements. This study explores the anchor rod retaining wall can effectively prevent the sliding of slope at the slope toe,restrain the development of cracks within the slope,slow down the development of interface displacement,and prevent the loess-mudstone interface landslide. It also provides the scientific guidance for the engineering prevention from geologic hazards of rainfall induced loess-mudstone interfacial landslide.
引文
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