Analytical solution for longitudinal response of pipeline structure under fault dislocation based on Pasternak foundation model

The fault dislocation causes the rupture of the overlying soil on the site, resulting in enormous damage to the underground pipeline structures across the overlying soil. Through the researches on the longitudinal response of the pipeline structures of the overlying soil layer under the fault dislocation, the Pasternak double-parameter model is introduced so as to take the nonlinear interaction between the pipeline and the foundation into consideration, and an analytical solution for the longitudinal response of the pipeline structures is derived using the complementary error function. The calculated results of analytical solution are consistent with those of the model tests and numerical simulations, which proves the correctness of the analytical solution. Through the parameter sensitivity analysis, the influences of the shear stiffness of the elastic layer, the coefficient of subgrade reaction and the fault dip on the longitudinal response of the underground pipeline structures are discussed. The research results show that the longitudinal response of the pipeline structures under fault dislocation based on the two-parameter Pasternak foundation model is more accurate than that of the Winkler foundation model. The shear stiffness and reaction coefficient of the subgrade will change the maximum bending moment and shear force of the underground pipeline structures. In contrast, the coefficient of subgrade reaction and fault dip will change the influence area and the maximum value of the bending moment and shear force. In the influence area, the bending moment and shear force of the pipeline structures are several times higher than those in other locations, and the structures are prone to shear failure, which is the main disaster occurrence area.