Abstract
Here, the prediction of friction characteristics for pipe jacking drives during soil traversing has been explored. This work is done in the context of no great understanding of how drivers negotiate highly weathered rock formations. Based on a series of jacking force prediction models, including the Staheli model, Pellet-Beaucour and Kastner models (PK-O models) and proposed modified Pellet-Beaucour and Kastner models (PK-M models), direct shear tests are performed on initial-contacted specimens to obtain the friction coefficient μavg using back-analysis. The evaluation of the reliability of the parameter μavg and the modified vertical pressure σv is carried out through a three-dimensional finite element in ADINA in combination with the “wished-in place” method (WPM). The shear stress of the pipe–rock interface and the compressive stress of the end area are obtained by numerical analysis and in good agreement with the measured jacking force predicted by the proposed PK-M-1 model, indicating the correctness and necessity of considering the degree of the arching effect when modeling strong weathering rock masses. According to these results, the friction coefficient μavg of back-analysis can be used as a reliable input parameter for the finite-element modeling of pipe-jacking force in highly weathered geological formations.