Vertical soil pressure calculation model of rectangular box jacking considering grouting effect

Abstract

In view of the current situation that there are few studies on the calculation model of the vertical soil pressure on the rectangular box jacking, the calculation model of the soil pressure on the rectangular box jacking considering the grouting effect is established based on the Terzaghi soil pressure calculation theory and combined with the characteristics of the rectangular box jacking engineering, and an improved calculation formula of the soil pressure on the rectangular box jacking is proposed.Based on the real-time monitoring data of vertical soil pressure in a rectangular box jacking project in Suzhou, the variation rules were explored and the accuracy of the calculation formula was verified.The results show that the shear zone in the soil is generated from both sides of the pipe wall and develops in the vertical direction, and can penetrate to the surface; under the critical state, the frictional angle of the shear zone is fully developed, and the friction coefficient of the shear zone is calculated by the critical internal friction angle and its sinusoidal value; under different grouting pressures, "active soil arch" and "passive soil arch" may appear above the pipeline.The comparative analysis between the calculated value and the measured value shows that the improved calculation method can better envelop the vertical earth pressure range of the rectangular box pipe.

Keywords

• rectangular box jacking
• vertical soil pressure
• terzaghi theory
• grouting effect
• calculation model