桩板式挡土墙是山区道路工程建设中经常采用的一种支挡结构，由于抵抗水平荷载的需要，传统桩板式挡土墙结构桩和板的尺寸通常做得较大，桩体的布置较密，不经济。基于此，提出一种新的适用于山区道路的桩拱组合式挡土墙，利用拱结构受压性能较好的特点，采用拱板代替传统的平板，拱板与桩基础的上部连接，整体结构可以通过装配式或者现浇制作而成。基于土压力和桩基水平承载力理论，分别建立拱板主动土压力计算模型和抗滑桩计算模型，利用拱板荷载传递给桩基的基本原理，建立桩拱挡土墙整体结构的力学平衡方程，通过求解平衡方程获得桩拱挡土墙整体结构的极限承载力。通过参数分析，分别讨论了不同的桩体几何尺寸、拱板几何尺寸以及土体参数对桩拱组合式挡土墙极限承载力的影响，结果表明，增加矩形截面的长宽比、桩体嵌入深度、土体摩擦角等可以有效提高桩拱组合式挡土墙的极限荷载。

Sheet-pile retaining wall is a very common retaining structure is widely used in construction of mountain road. However, in order to resist the lateral load, conventional sheet-pile retaining wall is of relatively large size, which is less economical. Under this condition, a new pile-arching retaining wall, which is suitable for mountain road construction, is proposed in this study. Considering that the arch structure is of good compression performance, the arching plate is used to replace the conventional plate structure, and the arch plate is connected with the pile foundation. The whole structure could be prefabricated or constructed in the way of cast-in-place. Based on the theories of earth pressure and lateral loaded pile, computational models were proposed for the active earth pressure of arch plate and the anti-slide pile. Then, the theoretical model was validated by comparing the predictions with the numerical results. Subsequently, parametric studies were conducted to investigate the influence of the geometric parameters of pile, geometric parameters of arch plate and the soil parameters on the limit load of the new pile-arching retaining wall structure. The results show that increase of ratio of length to width of the rectangular pile cross section, the embedded depth of pile as well as the friction angle of soil could effectively improve the limit load of pile-arching retaining wall structure.

TU476

国家自然科学基金（51420105013、51708063）