1673-159X

CN 51-1686/N

含水率对下蜀土抗剪强度的影响

Study on the Influence of Moisture Content to Shear Strength Tests for Xiashu Soil

  • 摘要: 为研究不同剪切方式中,含水率对下蜀土抗剪强度的影响,选取下蜀土为研究对象,进行多组原状土样的快剪、慢剪和反复直剪试验。试验结果表明:下蜀土试样含水率在19%~28.2%之间变化时,随着含水率的增加,土的抗剪强度总体呈下降趋势,但不同剪切方式中影响规律不同。快剪试验中,含水率对土体抗剪强度的影响较大,当含水率增加到23.5%附近时,黏聚力和内摩擦角均急剧下降;慢剪和反复直剪试验中含水率对土体的抗剪强度影响较小。快剪和反复直剪试验中,土的抗剪强度主要受黏聚力控制;慢剪试验中,土的抗剪强度主要受内摩擦角控制。快剪、慢剪和反复直剪分别模拟下蜀土滑坡中的快速滑动、缓慢滑动和古滑坡的再次滑动,试验结论可为不同类型下蜀土滑坡的防治工程提供参考。

     

    Abstract: In order to study the effect of moisture content on the shear strength of Xiashu soil, the quick shear, slow shear and repeated direct shear tests of undisturbed soil samples were carried out. The results show that when the moisture content is between 19% and 28.2%, the shear strength decreases with the increase of moisture content, but the influence of moisture content on the shear strengths in the three kinds of shear test is different. The influence of moisture content on the shear strengths in the quick shear test is larger than that in the slow shear and repeated direct shear tests. In the quick shear test, when the soil moisture content increased to 23.5%, both cohesion and internal friction angle have fallen sharply. In the quick shear test and repeated direct shear test, shear strength is mainly controlled by the cohesion. In the slow shear test, shear strength is mainly controlled by the angle of internal friction. Quick shear, slow shear and repeated direct shear tests simulated the quick-moving Xiashu soil slide, slow-moving Xiashu soil slide and the resurrection of old landslide, respectively. The test results can provide a reference and basis in the landslide control engineering.

     

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