Hysteresis Effect of Water Retention and Permeability of Unsaturated Soils on Instability of Slope Due to Rainfall

非饱和土保水性和渗透性对降雨导致边坡失稳的滞后效应

• 批准号: 10660227
• 负责人: SHIMADA Kiyoshi
• 金额: $ 1.79万
• 依托单位: Tokyo University of Agriculture & Technology (1999)Okayama University (1998)
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 1998
• 资助国家: 日本
• 起止时间: 1998 至 1999
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-10660227/
• 关键词: Slope Stability; Rainfall; Water Retention Curve; Hysteresis; Earthquake; Numerical analysis; 不飽和透水係数

The test for hysteresis of water retention curve and that for unsaturated permeability were carried out on Masa soils produced in Okayama. The effect of the unsaturated properties of slope soils on the reduction behavior of the safety factor is examined with the numerical program of the slope stability analysis considering the reduction of the shear strength of unsaturated soils due to the rain infiltration. The numerical program is also improved for considering both the effect of the rain infiltration and that of an earthquake on the slope stability. The numerical results give the following conclusions.(1) The hysteresis of the relationship between the volumetric water contents and the relative permeability can be neglected.(2) The safety factor of a slope, whose soil has the water retention curve showing a small magnitude near saturation, can show the sudden drop due to rain infiltration.(3) The test obtaining the water retention curve should be carried out under absorbing condition, when the results are supposed to be applied to the instability problem due to rain infiltration.(4) The slope suffering from the rain infiltration becomes more unstable when the earthquake strikes the slope.

保留水曲线的滞后测试，并在冈山（Okeama）生产的MASA土壤上进行了不饱和渗透率的测试。考虑到由于降雨渗透而导致的不饱和土壤的剪切强度的降低，斜坡稳定性分析的数值计划检查了斜率土壤不饱和性能对安全系数还原行为的影响。考虑降雨渗透的影响和地震对坡度稳定性的影响，数值程序也得到了改进。数值结果给出以下结论。（1）可以忽略体积水含量和相对渗透率之间关系的滞后。（2）斜坡的安全系数，其土壤的土壤保留量很小，显示出较小的饱和度接近饱和的幅度，可以显示出由于降雨而表现出的降雨时，可能会在降雨中降低降低。 （4）当地震撞击斜坡时，由于雨水渗透而引起的不稳定性问题。

项目成果

Shimada, K, H. Fujii, S. Nishimura, T. Nishiyama and T. Mrii: "Slope instability due to rainfall and earthquake"Proc. of International Synposium on Slope Stability Engineering. 1. 653-656 (1999)

Shimada、K、H. Fujii、S. Nishimura、T. Nishiyama 和 T. Mrii：“降雨和地震导致的斜坡不稳定”Proc。

Shimada,K, H.Fujii, S.Nishimura, T.Nishiyama and T.Morii: "Hysteresis effect of decomposed granite soil on slope instability due to rainfall"Proc. of 8th Congress of International Association of Engineering Geology. 3. 1981-1986 (1998)

Shimada，K，H.Fujii，S.Nishimura，T.Nishiyama 和 T.Morii：“风化花岗岩土对降雨引起的边坡失稳的滞后效应”Proc。

Shimada,K, H.Fujii, S.Nishimura, T.Nishiyama and T.Morii: "Slope instability due to rainfall earthquake"Proc. of International Symposium on Slope Stability Engineering. 1. 653-656 (1999)

Shimada，K，H.Fujii，S.Nishimura，T.Nishiyama 和 T.Morii：“降雨地震导致的斜坡不稳定”Proc。

K.Shimada, H.Fujii, S.Nishimura, T.Nishiyama, T.Morii: "Hysteresis effect of decomposed granite soil on slope instability due to rainfall" Proc. of 8th International Congress for International Association of Engineering Geology and the Environment. 3. 198

K.Shimada、H.Fujii、S.Nishimura、T.Nishiyama、T.Morii：“风化花岗岩土壤对降雨引起的边坡失稳的滞后效应”Proc。

Shimada, K, H. Fujii, S. Nishimura, T. Nishiyama and T. Morii: "Hysteresis effect of decomposed granite soil on slope instability due to rainfall"Proc. of 8th Congress of International Association of Engineering Geology. 3. 1981-1986 (1998)

Shimada、K、H. Fujii、S. Nishimura、T. Nishiyama 和 T. Morii：“风化花岗岩土对降雨引起的边坡失稳的滞后效应”Proc。