Dynamic Response of Buried Pressurized Pipelines When Subjected to Transverse Impact Loading: Experimental Study.

Abstract

This study investigated the dynamic behavior of pressurized pipelines under impact loads in various burial environments. A total of 60 tests were conducted using a drop-weight impact testing apparatus, with high-speed cameras and sensors used to collect data throughout the experiments. This approach enabled a thorough investigation of the effects of the soil type, burial depth, and internal pressure on pipeline behavior. The results show that pipeline deformation decreases as burial depth and soil stiffness increase. Under similar conditions, unpressurized pipelines exhibit significantly greater plastic deformation than pressurized pipelines, indicating superior energy absorption. The application of internal pressure leads to a marked increase in the peak impact force compared to scenarios without internal pressure. Fluctuations in internal volume cause pressure variations, affecting the response of the pipeline. Additionally, higher soil stiffness results in increased peak impact force, particularly in loess environments, suggesting that stiffer soils improve pipeline impact resistance. It is important to note that deeper burial does not always lead to reduced impact forces. In stiff soil conditions, greater burial depth may even amplify the impact force. These effects are closely associated with stress concentration under impact loads, changes in soil support capacity, and the influence of internal pressure. The test data and analysis provided in this paper will contribute to optimizing pipeline design and protective strategies, thereby enhancing their safety and reliability.