Fundamental Study on Preventive Measures of Slope Failure and Reinforcement Method for the Bearing Capacity of Granular Assemblies

1)边坡破坏机理及预防措施为了研究颗粒土边坡的破坏机理及有效加固，进行了大量的颗粒土边坡模型试验。研究发现，颗粒土边坡表现为表面破坏而非圆滑破坏，粘聚土边坡表现为圆滑破坏。颗粒土边坡破坏时的角度几乎等于内摩擦角。有黏聚土失稳时的坡角与圆滑移法计算的坡角基本相等。模型试验结果也表明，如果对破坏的“触发点”进行改进，加固方法是非常有效的。2)承载力加固方法(a)通过对“土袋”加固地基承载力试验进行模拟，研究“土袋”加固地基的加固机理。找出了采用“土袋”提高承载力的原因，以及承载力与“土袋”张力的关系。b)采用对部分地基进行包裹加固的方法，提高地基承载力。通过“土袋”加固铝棒和实土的承载力模型试验，以及动、静荷载作用下铁路轨枕道砟地基承载力的全尺寸模型试验，研究了“土袋”加固地基的效果。试验结果表明，对部分基础进行包覆后，地基承载力大大提高，铁路轨枕和道砟基础的变形减小。

1) Mechanism and Preventive Measures of Slope FailureMany model tests of granular soil slope have been conducted to study the failure mechanism and effective reinforcement of granular soil slope. It was found that the granular soil slope behaves as the surface failure not circular slip failure while the slope of soil with cohesion behaves as circular slip failure. The angle of granular soil slope at failure is almost equal to the internal friction angle. The angle of the slope of soil with cohesion at failure is almost equal to that obtained by as circular slip method. The results of model tests also show that if the "trigger" of the failure is improved, the reinforcement method is very effective.2) Reinforcement Method for the Bearing Capacitya) The simulation on the bearing capacity test of the footing improved by "soilbag" was conducted to study the mechanism of this improvement method. The reason why the bearing capacity increases by using "soilbag" and the relation between the bearing capacity and tension of the "soilbag" have been found out.b) The reinforcing method by means of wrapping up a part of the soil foundation has been introduced to increase the bearing capacity of the foundation. The model tests of the bearing capacity on aluminum rods and real soils improved by "soilbag" and the full scale model tests of the bearing capacity on ballast foundation through the railway sleeper under dynamic and static load have conducted to study the effects of "soilbag" in improvement of soil foundation. The test results show the bearing capacity of the foundation increases greatly and the deformation of the railway sleeper and ballast foundation decreases after wrapping up a part of foundation.