Analytical computation of settlement displacement of buried pipeline caused by excavation

Excavation can induce the settlement deformation of adjacent buried pipeline. Obtaining the deformation is of great significance for evaluating the normal use and safety of pipeline. In this study, based on the elastic foundation beam theory, the calculation formula of the settlement displacement of buried pipeline is derived, and the influence of the two parameters of the surface center settlement and the calculation length on the settlement displacement of pipelines is emphatically analyzed. According to the geometric relationship between the buried pipeline and the edge of the foundation pit, the calculation length can be used to divide into five working conditions. The rationality of the analytical method is verified by comparing with two cases. In the case of excavation in Beijing, the spatio-temporal variation rules of settlement displacement of buried pipeline were analyzed. The results show that the variated trend of the calculated settlement displacement in different periods is consistent with that from measurement, but the calculated value is slightly higher than the measured value. The surface center settlement has a significant influence on the pipeline settlement displacement. larger input causes more concave settlement curve, and smaller input leads to smoother settlement curve. The decreasing rate of settlement displacement increases from the central point to end, and decreases near the boundary point, with the range of about one tenth of the calculated length. The proposed method in this study is conservative in the evaluation of pipeline settlement, which is a supplement to the existing settlement calculation theory of buried pipelines, and can provide a important information for predicting the distribution of pipeline settlement in the early stage of construction.