A simplified method for evaluating the carrying-soil phenomenon in large cross-section rectangular pipe jacking.

• A simplified but effective method is proposed to quantitatively evaluate the carrying-soil phenomenon. • The influence of multiple construction parameters are quantitatively considered. • The effects of some key construction parameters on the carrying-soil phenomenon are detailed investigated. • Targeted recommendations for the design and construction of large cross-section rectangular pipe jacking are provided. During the large cross-section rectangular pipe jacking, the soil within a certain range above the jacking pipe is prone to move along with the pipe jacking machine and jacking pipe under various effects generated by the jacking construction, known as the carrying-soil phenomenon. However, there is currently a lack of evaluation methods to quantitatively analyse this phenomenon. Thus this paper proposes a semi-analytical evaluation method for the carrying-soil phenomenon in large cross-section rectangular pipe jacking. This method considers the soil disturbance caused by the joint effect of the added thrust, the friction force, the grouting pressure, and the over excavation of soil generated during the jacking process through the applications of the Mindlin solution and stochastic medium theory, which allows for a quantitative analysis of the yielding range of the surrounding soil around the pipe jacking and hence a quantitative evaluation of the carrying-soil phenomenon. This method is also well validated by comparing its simulated results with measured ones. Based on the proposed method, the influential factor analysis of carrying-soil phenomenon in large cross-section rectangular pipe jacking is also carried out. It is found that increasing the buried depth, reducing the excavation width, maintaining appropriate grouting pressure, and minimizing ground loss and friction forces can effectively control the carrying-soil phenomenon. [ABSTRACT FROM AUTHOR]