Abstract: For the study of the strength of reinforced soil, the direct effect of reinforcement was only considered by most researchers, but the indirect effect of reinforcement should also be considered. If the indirect reinforcement was considered, the strength of reinforced soil would be greatly improved. Thus, from the perspective of indirect reinforcement, the failure of reinforced soil was still divided into tensile failure and adhesive failure. For the triaxial specimen of diagonally reinforced soil under axisymmetric load, the specimen was considered to be in the state of limit equilibrium. By changing the cohesion of the soil in the indirect effect, the sample was considered to be in a static equilibrium state through internal force analysis. Thereby, the expression of the major principal stress of reinforced soil under limit equilibrium condition was obtained. Then the detailed discussion and analysis were made under the situation that the increased cohesive force was covered with reinforced action range, the filler was sand, the angle between the reinforced layer and the sample cross section was zero degree and the indirect action was not considered. The results show that when the cohesive force of the soil increases in the indirect reinforcement action range, the strength of the reinforced soil will be greatly improved; when the effect of indirect reinforcement is the all over the scope of the reinforcement layer, the indirect reinforcement effect will be maximized; when the angle between the reinforcement material and the sample cross-section is zero degree, the reinforcement effect is best; when the indirect reinforcement is considered, the reinforced sand also exhibits a high cohesive force; when the indirect reinforcement effect is not considered, the strength expression becomes the expression of reinforced soil strength under normal conditions.

Key words: geotechnical engineering; indirect reinforcement; cohesion; tensile fracture; adhesive failure; reinforcement angle; parameters for soil-reinforcement interface

摘要： 对于加筋土强度的研究，多数研究者大都仅考虑加筋的直接作用，但还需考虑加筋的间接作用，若考虑间接加筋作用后，加筋土强度还会有很大提高。为此从间接加筋作用出发，仍将加筋土的破坏分为拉断破坏和黏着破坏，针对轴对称荷载下斜向布筋的加筋土三轴试样，认为试样处于极限平衡状态，通过改变间接作用范围内土的黏聚力大小，并通过内力分析，认为试样处于静力平衡状态，从而得到极限平衡条件下加筋土的大主应力表达式，再针对增大的黏聚力满布加筋作用范围、填料为砂土、加筋层与试样横截面夹角为零度及不考虑间接作用等情况做了详细讨论分析。结果表明：当间接加筋作用范围内土的黏聚力增大时，加筋土强度会有很大提高，当间接加筋作用满布加筋层的作用范围，则间接加筋作用会发挥到最大；当筋材与试样横截面夹角为零度时，加筋效果最佳；当考虑间接加筋作用时，加筋砂土也会表现出很高的似黏聚力；当不考虑间接加筋作用时，则强度表达式就变成通常情况下的加筋土强度表达式。

关键词: 岩土工程；间接加筋作用；黏聚力；拉断型破坏；黏着型破坏；加筋角度；土-筋界面参数