A new type of steel-concrete composite aqueduct, made of steel trough and concrete cover connected by shear studs, is proposed. The composite aqueduct has better fluid tightness, lighter weight, higher capacity and faster construction speed compared with traditional prestressed concrete aqueducts; therefore, it has a broad potential to be applied in water transfer projects. To study the structural performance of the composite aqueduct, a fine finite element model is established by using ABAQUS, whose results are representative of the typical spatial deformations experienced by the aqueduct. Parametric analyses are carried out in the longitudinal and transverse directions. The results indicate that the longitudinal stress is higher than the transverse stress, and a significant shear lag is found on the steel bottom plate. Thus, design parameters are dictated by the longitudinal stress of the steel bottom plate. In order to facilitate the estimation of the longitudinal stress, a fiber model that considers the shear lag effect is developed. The formula of the effective width is fitted based on the results of a series of finite element-based parametric analyses. The fitted formula is more accurate and simpler compared to several national codes, and the error of the stress is usually less than 10%.

提出了一种新型钢-混凝土组合渡槽，由钢槽和混凝土盖板通过剪力钉连接而成。复合渡槽与传统的预应力混凝土渡槽相比，具有更好的流体密封性、更轻的重量、更高的承载能力和更快的施工速度；因此，它在调水工程中具有广泛的应用潜力。为了研究复合渡槽的结构性能，利用ABAQUS建立了精细的有限元模型，其结果代表了渡槽所经历的典型空间变形。在纵向和横向上进行参数分析。结果表明，纵向应力大于横向应力，钢底板存在明显的剪力滞。因此，设计参数由钢底板的纵向应力决定。为了便于估计纵向应力，开发了考虑剪力滞效应的纤维模型。有效宽度的公式是根据一系列基于有限元的参数分析的结果拟合的。拟合公式比几个国家规范更准确、更简单，应力误差通常小于10%。