Investigation of Earthquake-Induced Pipe Damage in Liquefiable Soils

Liquefaction occurs in saturated sandy and silty soils due to transient and repetitive seismic loads. The result is a loss of soil strength caused by increased pore pressure. In this study, the response of buried pipes in the Iskenderun region during the earthquakes centered in the subprovinces of Pazarcık and Elbistan in Kahramanmaraş, Turkey, on 6 February 2023, has been investigated utilizing numerical analyses using geological data from two different areas. The effects of shallow and deep rock layers, pipe diameter, burial depths, and boundary conditions have been evaluated. In the analyses, records from two stations located in Iskenderun during the Pazarcık, Kahramanmaraş earthquake have been utilized, taking into account records from shallow rock (station no. 3116) and thick soil layers (station no. 3115), as determined from shear wave velocities. Modeling conducted using station 3116 records has revealed the effect of shallow rock layers on pipe displacement, indicating less damage in areas where the rock layer is close to the surface. The pipe uplift risk is higher when the bedrock is deep, and the overlying soil layer is liquefiable (station no. 3115). It has been determined that depth to bedrock significantly influences upward movement of the pipe. In the areas where the bedrock is deep, expanding the boundary conditions has helped reduce the effects of settlements outside the pipe, preventing the occurrence of pipe uplift. Increasing the pipe diameter has increased the amount of uplift. The analysis results are consistent with field observations.