A Method for calculating jacking force of parallel pipes considering Soil Arching Effect and Pipe-Slurry-Soil Interaction

Abstract

For multiple parallel pipe jacking projects, the calculation of the jacking force is crucial for design and construction. This paper presented a method for the calculation method of the jacking force required by each pipe, which includes the jacking resistance of the excavation face and the side friction around pipe. Firstly, the improved composite arch model in front of the excavation face was established under the limit support state, and jacking resistance of the excavation face was obtained by calculating the limit support pressure according to the model. Then, based on four typical pipe-slurry-soil contact modes, an improved calculation method for side friction was proposed and then corrected for multiple pipes under mutual disturbance. The reliability of the calculation method was subsequently proven by comparison with the model test results and engineering case data available in the literature. The mutual disturbance level among pipes decreases with increasing Poisson’s ratio of surrounding soil. Compared with a single pipe under the same conditions, pipe under the influence of mutual disturbance usually requires a larger force for jacking, so that the required jacking force of the following pipes in multiple parallel pipe jacking projects is usually larger than that of the initial pipe.