The Space Curve Differential Equation of Elastic Foundation-Beam and its Application

The loads, such as active and/or passive earth pressures as well as aboveground changing loads, will add to the buried long-distance pipeline during operating. These problems to be solved involving with the pipe strength should be calculated in designing stage. As a important basis of calculating the distortion and strength of the buried pipeline, the paper gives out the space curve differential equations of elastic foundation-beam (displacement equation). The equations are used to calculate the one-end restraint and two-end restraint. Taking the assumed two sections of steel pipe as an example, the calculations for its one-end restraint and two-end restraint have been made with the equations given in the paper. The results show that the set calculating error is less than 0. 001, which is more accurate. Meanwhile, the equations can be used to calculate the moment of flexure, shear force and stress of buried pipeline. However, the availability of these equations should also be verified by the actual test results.