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季节冻土区黄土路堑边坡经常出现的剥蚀病害,造成了严重的水土流失,污染了环境,同时也破坏了道路景观,影响了道路的正常运营。针对这一问题,在平凉至定西高速公路三处路堑边坡设置自动气象站,对黄土路堑边坡不同深度(5cm、20cm、50cm、100cm)土体的温度和含水率(体积)进行长期(2年)观测,试验(观测)发现即使在气温较低的冬天,边坡表层土体仍然存在冻融循环作用,从而引起边坡表层土体内含水率的变化。根据这一结果开展室内强度试验,发现冻融循环和由冻融循环引起的干湿循环会使原状黄土强度下降,表层土体疏松。现场观测和室内试验结果都表明冻融循环是导致季节冻土区黄土路堑边坡剥落的重要原因。此外,通过在平定高速公路的工程实践证明植被防护是一种有效的坡面防护型式。
In the permafrost region, erosion and erosion often occur in loess cut slopes, causing serious water and soil loss, polluting the environment, destroying the road landscape and affecting the normal operation of roads. In response to this problem, an automatic weather station was set up at three cutting slopes of Pingliang-Dingxi Expressway to measure the temperature and water content (volume) of loess at different depths (5cm, 20cm, 50cm, 100cm) 2 years) Observations, tests (observations) found that even in the winter with a low temperature, there is still a freeze-thaw cycle in the slope surface soil, causing changes in the moisture content of the soil in the slope surface. Based on this result, indoor strength test was carried out. It was found that the freeze-thaw cycle and the wet-dry cycle caused by the freeze-thaw cycle caused the strength of undisturbed loess to decline and the surface soil loose. Both field observations and laboratory tests show that the freeze-thaw cycle is the main reason for the flaking of the loess cut slope in the seasonally frozen region. In addition, vegetation protection is an effective type of slope protection through engineering practice at Pingding Expressway.