| 石北啸,陈生水,韩华强,王庭博.考虑吸力变化的膨胀土边坡破坏规律分析[J].水利学报,2014,45(12): |
| 考虑吸力变化的膨胀土边坡破坏规律分析 |
| Failure law of the expansive soil slope considering the suction changes |
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| DOI： |
| 中文关键词: 膨胀土 边坡 吸力 干湿循环 |
| 英文关键词: expansive soil slope suction wetting-drying cycles |
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| 中文摘要: |
| 膨胀土边坡中吸力降低会引起强度衰减，进而引起边坡变形破坏。采用热传导传感器监测干湿循环作用下膨胀土边坡模型坡顶和坡底的基质吸力，开展膨胀土边坡基质吸力随深度和时间变化规律的室内试验，并对模型破坏过程进行了分析。试验结果表明：膨胀土边坡因膨胀干缩的反复作用产生裂缝，为雨水入渗提供通道，裂缝区土体迅速吸水，吸力骤降；非裂缝区土体雨水难以入渗，吸力降低存在明显的滞后现象。降雨后一段时间内，裂缝区土体与非裂缝区土体强度差异明显。对于填方膨胀土边坡工程，建议填筑一部分后对其先进行晾晒，促使土体吸力增长并提高土体强度；施工过程中应避免降雨水入渗，并监测坡体含水率的变化和位移情况，及时采用有效处置措施，防止发生滑坡破坏。 |
| 英文摘要: |
| By monitoring the surface and bottom matric suction of the expansive soil slope model under wetting-drying cycle with the thermal conductivity sensor， the laboratory tests were carried out on matric suction of the expansive soil slope to study the variation with the different depth and time， and the damage process of the model were analyzed. The test results show that the expansive soil slope generated cracks which provide channels for the infiltration of rainwater as the repeated swelling-shrinkage cycle， so the crack area quickly absorb water and the matric suction drop； because the rainwater is not easy to infiltrate in non-cracking area， the decrease of matric suction show obviously hysteresis. After a period of raining，the strength of soil in crack area and non-cracking area has significant differences， which reach the maximum in the second wetting. For the project of the filling expansive soil slope， we recommend that by drying the soil soon after filling a part which may promote the growth of matric suction and to improve the strength of soil mass； it should avoid the rainwater infiltrating into the soil in the process of construction，and monitor the water content and the deformation of slope. It also should adopt promptly the effective measures to prevent the occurrence of landslide failures. |
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