关键词: 顶管施工, 挤土效应, 土体移动, 地面隆起

Abstract: It is shown that the excessive support pressure, deflexion of shield, the friction between shield and soil，and the big grouting pressure will induce the compacting effects during pipe jacking construction. In addition, the heaving process will reduce the total magnitude and widths of the surface settlement troughs after the construction completion. The soil is assumed as a uniform line elasticity material and the initial stress field of the soil is considered. Through the simulation of soil-compacting process by applying an outward elliptic radial displacement to the surrounding soil of shield, the approximate analytical solution of soil displacement fields in half space is obtained in small strains. Considering the spatial effects, the modified calculation formula is also presented. Furthermore, the calculation results from the modified formula are compared with field data. The maximum of surface upheaval is at both sides of axes. The calculated values are a little bigger due to hard surface of ground; while under the hard surface, they are in accordance with the measured values.

Key words: pipe jacking construction, soil-compacting, ground movements, surface upheaval