# Investigation of Earthquake-Induced Pipe Damage in Liquefiable Soils
Similar seismic damage to pipelines, characterized by pipe uplifting behavior, has been observed in major seismic events such as the Loma Prietra earthquake and Nausea-Oki (Okushiri) earthquakes [28; 29; 30; 31]. In a study conducted by [PERSON] [32], pipeline damage in industrial areas and oil pipelines was evaluated following critical past earthquakes. [PERSON]'s study [33] implemented a seismic scenario analysis using a spatial grid to evaluate earthquake damage to underground pipelines in an urban area. Types of damage to underground pipelines were classified, pipeline disaster management procedures were discussed, and improvement measures such as establishing a geographic information platform and conducting disaster impact assessments for hazardous material pipelines were proposed. [PERSON] [34] conducted a first-level spatial assessment of earthquake-induced damage in the region hosting Europe's largest onshore oilfield and oil/gas extraction and pretreatment plant, with a pipeline that transports the plant's products to the refinery in Taranto on the Ionian seacoast. In a study by [PERSON] et al. [35], the effects of geological hazards such as landslides, high peak ground acceleration (PGA), liquefaction, and surface rupture on natural gas pipelines during the Kahramanmaras earthquake were evaluated. In the study conducted by [PERSON] [36], the damage to water supply pipelines during the 1995 Hyogoken-Nambu earthquake was investigated. An overview of the damage to water supply pipelines in the Hanshin region was presented, and the relationship between the damage to water supply pipelines in Kobe city, geological characteristics, and building damage was discussed. It was determined that liquefaction caused extensive damage to the pipelines, and earthquake damage in various pipe types and diameters was examined. In the study by [PERSON] [37], the effects of the Christchurch earthquake on the water distribution system were investigated through geospatial analyses using the LiDAR method. Areas prone to liquefaction and the repaired pipelines in these areas were shown. The study conducted by [PERSON] et al. [38] presents firsthand observations and experiences specific to different pipeline systems in earthquakes in New Zealand, which occurred in a period of 27 years, from 1987 to 2014. In the realistic and economical design of engineering structures, laboratory model experiments and advanced constitutive models can be utilized alongside numerical analyses. They accurately predict potential large soil deformations after liquefaction, which remains challenging with traditional methods. Soil conditions and seismic characteristics influence the displacements after liquefaction. In this study, the uplift behavior of pipes in liquefiable soils has been investigated. In this context, a centrifuge test has been numerically modeled to examine the behavior of buried pipes in liquefiable soil during earthquakes. In the analysis, the user-defined PM4 Sand model in PLAXIS 2D ([[https://www.bentley.com/software/plaxis-2d/](https://www.bentley.com/software/plaxis-2d/)]([https://www.bentley.com/software/plaxis-2d/](https://www.bentley.com/software/plaxis-2d/)) (accessed on 21 May 2024)) has been used, and the uplift movement of a concrete pipe has been examined. Experimental measurements at a depth of 1.1D and a seismic acceleration of 0.22 g have been compared to numerical analysis results to validate the model. In some areas of Iskenderun, damage occurred in stormwater and drinking water pipelines and facilities during the earthquakes in Kahramanmaras on 6 February 2023, negatively affecting the continuity of urban life. Numerical analyses have been conducted using field soil conditions and actual earthquake records to evaluate the damage observed in steel pipelines in two areas in the Iskenderun district. In Study Area 1, the damage at the Iskenderun port has been examined using earthquake station data from the Kahramanmaras Pazarcik earthquake (records of stations 3115 and 3116).