Improved analytical solution of lateral soil restraint for pipes buried in dry sand considering arching effects

Abrupt transverse ground movements induced by landslide, strike-slip offset, and excavation can exert excessive soil restraints on buried pipes and threaten the pipe safety. The determination of lateral soil restraint is therefore a key factor for the evaluation of buried pipes in such areas. However, effective analysis solutions to assess the area of failure zone of surrounding soils and to estimate the soil resistance on pipes are still limited. In this work, an improved implicit limit equilibrium model is proposed to calculate the ultimate lateral soil restraint of buried pipes in dry sand, in which the effect of active soil wedge is considered, and the heights of equal settlement plane in both passive and active wedges can be estimated. Comparisons are made between collected physical modeling results and calculations from different methods. Results show that the proposed method yields a better approximation to the measured data. Parametric studies are subsequently conducted, which illustrate that the ultimate soil lateral restraint is influenced by the pipe diameter, internal friction angle, and constrained modulus of soil. The influence of effective soil unit weight is minimal. The proposed method is beneficial for safety evaluation of buried pipes subject to lateral dragging.