Existing design models of soil pressure at the top of buried steel pipes are limited to small-diameter pipes. This study aims to investigate the behavior and design model on the soil pressure for large-diameter pipes considering the pipe diameter, diameter-to-thickness ratio, and cover depth. The distribution and size of soil pressure are obtained from finite element models and compared with traditional design models. Sensitivity studies of soil parameters, trench parameters, and friction coefficients are discussed. Furthermore, an innovative design model of soil pressure for large-diameter pipes is proposed. The results indicate that the basic distribution pattern of soil pressure is the “inverted basin”/parabola for large/small-diameter pipes, respectively. Peak soil pressure typically appears in the pleura of pipes with great flexibility and deep cover depth. The modulus and Poisson's ratio of backfill and soil-soil friction coefficient have an influence range of within 10% for soil pressure, while trench parameters have a more significant influence. Prism load is too large at high cover depth, and Marston load is small at low cover depth. The proposed basin model for soil pressure adopts the form of “straight line + parabola” for distribution and “Marston + pleura” load for size, with high accuracy and strong adaptability.

现有的埋地钢管顶部土压力设计模型仅限于小直径管道。本研究旨在研究考虑管径、径厚比和覆层深度的大直径管道土压力的行为和设计模型。从有限元模型中得到土压力的分布和大小，并与传统的设计模型进行比较。讨论了土壤参数、沟槽参数和摩擦系数的敏感性研究。此外，提出了一种创新的大口径管道土压力设计模型。结果表明，土压力的基本分布格局分别为大管径和小管径的“倒盆”/抛物线。土壤压力峰值通常出现在管道的胸膜中，具有很大的柔韧性和较深的覆盖深度。回填模量、泊松比和土土摩擦系数对土压力的影响范围在10%以内，而沟渠参数的影响更为显着。棱镜载荷在高覆盖深度时太大，而在低覆盖深度时马斯顿载荷很小。所提出的土压力盆地模型采用“直线+抛物线”分布、“马斯顿+胸膜”载荷大小的形式，精度高，适应性强。和 Marston 载荷在低覆盖深度时很小。所提出的土压力盆地模型采用“直线+抛物线”分布、“马斯顿+胸膜”载荷大小的形式，精度高，适应性强。和 Marston 载荷在低覆盖深度时很小。所提出的土压力盆地模型采用“直线+抛物线”分布、“马斯顿+胸膜”载荷大小的形式，精度高，适应性强。