Abstract:

The super-large shallow-buried box culvert with jacking method and pipe-roof crossing Beijing-Zhuhai Expressway in Zhengzhou is the largest in soft soil in Asia. How to control the soil displacement and protect the expressway are the main problems considered in design and construction. With in-situ data, FLAC is employed to study the soil displacement during the construction process. By analyzing the measured results and numerical stimulation results, the soil displacement regulations are given as follows: ① The biggest settlement point of the pavement is not on the axis, and the distance between the point and the axis is about half span of box culvert. ② The biggest horizontal movement is in the soil in front of excavating face with the same elevation of the box culvert axis. The horizontal movements of pipe roof composites are roughly equal to that of the pavement. ③ The pore water pressure is more sensitive to the disturbing of soils in the process of box culvert jacking.

Key words: pipe-roof, box culvert, numerical simulation, soil, displacement