非饱和土层厚度与充气压力对截排水效果的影响

发布时间：2018-03-20 23:49

本文选题：边坡治理　切入点：充气截排水　出处：《自然灾害学报》2017年04期 　论文类型：期刊论文

【摘要】：气驱水理论以及非饱和渗流理论已经在许多领域中得到广泛的应用,而将其应用于边坡防治领域则较少。通过向坡体后缘充入有压气体,可排除坡体中的部分地下水,形成非饱和土层,从而阻断或减小地下水流向下游潜在滑坡区,降低潜在滑坡区地下水位,提高边坡稳定性。多孔介质中气驱水理论属于多相流问题,采用有限元方法模拟研究了不同非饱和土层厚度边坡在允许充气压力下对截排水效果及地下水渗流场的影响。结果表明:地下水水层厚度和水头一定时,非饱和土层厚度越大,临界压力值越大,充气压力上限值越大,允许充气压力范围越大;坡体非饱和土层厚度一定,充气压力在允许范围内越大,截排水效果越好;截排水技术更适用于地下水埋深较浅的坡体;充气稳定后,充气区上游流速分布不均匀,充气区水流流速大幅下降,且相同充气压下非饱和土层厚度越小的坡体稳定后流速越小,充气区下游水位下降,水位线以下流速几乎不受充气和非饱和土层厚度的影响。
[Abstract]:Gas drive water theory and unsaturated seepage theory have been widely used in many fields, but they are seldom used in slope prevention. By filling the back edge of slope body with pressurized gas, some groundwater in slope body can be excluded. The unsaturated soil layer is formed, which blocks or reduces the groundwater flow to the potential landslide area downstream, reduces the underground water level in the potential landslide area, and improves the slope stability. The theory of gas-driven water in porous media is a multi-phase flow problem. Finite element method is used to simulate the effects of different unsaturated soil thickness slopes on the cutting drainage effect and groundwater seepage field under the allowable inflatable pressure. The results show that the thickness of unsaturated soil layer increases when the groundwater layer thickness and water head are constant. The larger the critical pressure, the greater the upper limit value of inflatable pressure and the larger the allowable inflatable pressure range, and the greater the inflatable pressure is within the allowable range, the better the effect of cutting and drainage is. The technique of intercepting and drainage is more suitable for slope with shallow groundwater depth. After aeration is stabilized, the velocity distribution of upstream velocity in the aerated area is uneven, and the velocity of flow in the aerated area decreases significantly. Under the same pressure, the lower the thickness of unsaturated soil is, the smaller the flow velocity is, and the lower the water level is, the lower the water level is, and the lower the velocity of water level is, it is almost independent of the thickness of aerated and unsaturated soil layers.
【作者单位】：浙江大学海洋学院;浙江大学建筑工程学院;
【基金】：国家自然科学基金(41372277) 浙江省重点研发计划(2017C03006)~~
【分类号】：P641;P642.22

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