驷马山分洪道深切岭段膨胀土渠道滑坡特征分析

分析滑坡特性及其原因,可为滑坡治理提供参考。通过对驷马山分洪道深切岭段滑坡现场调查和资料归纳整理,系统分析了驷马山分洪道膨胀土渠道滑坡分布特征和产生的原因。认为滑坡具有浅层性、牵引性、长期性、反复性,滑动面为折线形,符合典型膨胀土滑坡特点;此外滑坡还具有左、右岸同时滑,背阳岸坡滑坡次数多于向阳岸坡,滑坡位置主要集中在边坡中下部,与降雨、渠道水位密切相关等特征。滑坡的主要原因是卸荷裂缝与胀缩裂缝连通形成的垂直向裂缝控制了边坡滑面的形态,认为胀缩裂缝不是边坡滑坡的主因;水的作用增大了边坡的下滑力,并使坡脚土体湿化崩解;坡顶堆弃土、干湿交替频繁、护坡防护措施失效等加剧了边坡失稳的可能。研究成果对长期运行过程中的渠道膨胀土滑坡治理有重要借鉴意义。

Characteristics Analysis of Expansive Soil Channel Landslips in Deep Cutting Ridge Section of the Simashan Floodway

Based on the field investigation and data collection of the landslip at the deep cutting ridge section of the Simashan floodway channel, the distribution characteristics and causes of landslip in expansive soil channel of Simashan floodway were systematically analyzed. The landslip has the characteristics of shallow layer, traction, long-term, repeatability and slip surface. It is in accordance with the characteristics of typical expansive soil landslides. In addition, the landslip has the same slip on the left and right banks, and the number of landslides on the back slope is more than the sunny bank slope. The landslide position is mainly concentrated in the middle and lower side of the slope, which is closely related to the rainfall and the water level of the channel. The main reason for the landslide is that the vertical crack connected by the unloading crack and the expansion and shrinkage crack controls the shape of the slide surface of the slope, which proves that the expansion and shrinkage crack is not the main cause of the landslide. Water increases the sliding force of the slope, and makes the soil of slope to humidification disintegration. The possibility of slope instability is exacerbated by the frequent dumping of soil at the top of the slope, the frequent drying and wetting and the failure of slope protection measures. The research results have important reference significance for landslide treatment of expansive soil channel during long-term operation.