Soil-Structure Interaction of Buried Pipes Under Cyclic Loading Conditions


1 Civil Engineering, Amirkabir University of Technology

2 Civil Engineering, Khaje Nasir Toosi University of Technology


The safety of lifelines, as the most important urban facilities, under different conditions highly depends on the safe design and performance of these buried structures. This cannot be achieved unless their actual behaviors are well understood and considered at the designing stage. A new physical model was developed in Amirkabir University of Technology to study the behavior of buried pipes under different loading conditions. The model is capable of simulating and monitoring flexible pipes under different conditions. The depth and the position of the buried pipes as well as the type and density of the surrounding soil can be changed and controlled. The cyclic loads with different amplitudes as well as monotonic loads can be generated and applied to the soil surface. The generated load can be applied on the pipe centrally or eccentrically. The radial deflections of the tested pipes were measured by a special probe and data acquisition system developed for this model. A series of different tests were carried out to study the soil-pipe interaction. The main factors affecting the behavior of these buried structures were studied in the paper. Among them, the soil density and the pipe depth proved to be the most important factors affecting the soil-pipe interaction. The influence of the impact at the first cycle was also found to be one of the main factors affecting the pipe behavior.