关键词: 土质边坡, 砌石挡土墙, 极限分析, 下限法, 极限承载力

Abstract: Stone retaining wall is constructed to resist the lateral earth pressure. Its characteristic is regarded as a discontinuous medium, whereas the characteristic of the soil behind the wall is a typical continuous medium. In this paper, the ultimate bearing capacity of masonry retaining wall was studied by combining the lower bound theory, the mixed numerical discretisation and linear programming. Firstly, soil mass was discretised by triangular finite elements to simulate its continuum mechanics characteristics, while the masonry wall was discretised by rigid block elements to simulate its non-continuum mechanics characteristics. Thus, constraint conditions of the statically admissible stress field were both proposed for soil and the masonry retaining wall. Meanwhile, constraint conditions were also proposed for interfaces between finite elements and block elements. By considering the overload coefficient as the objective function, the linear programming model was established for calculating the ultimate bearing capacity of masonry retaining wall. In addition, the interior point algorithm was employed to solve the problems of linear mathematical programming. At last, the ultimate load (or safety factor) of slope and its corresponding stress field were obtained directly. Moreover, three typical examples were conducted to validate the proposed method. Therefore, this study successfully introduced the mixed numerical discretisation into the limit analysis.

Key words: soil slope, stone masonry retaining wall, limit analysis, lower bound method, ultimate bearing capacity