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.

This paper introduces some experimental data measured from 63 impact tests of pre−stressed strand cables. The test specimens consist of seven steel wires that have a length equivalent to 100 times the outside diameter. To ensure consistency with the engineering service status, the strand cables are fully installed in a specially designed device and are axially pre−stretched to 0% to 40% of the ultimate bearing capacity before being subjected to lateral impact. The mass of the indenter is 50.34 kg, and the maximum impact velocity reaches 13 m/s. Two dimensionless variables, axial force and input kinetic energy, are used to control the experimental parameters. The recorded test data show that input energy and pre−stress level are the key factors governing the impact behavior, which is mainly characterized by plastic deformation controlled by the combination of tension and flexure, and the dynamic fracture concentrated in the impact zone is controlled by the joint effects of compression, tension and shear. As the impact energy increases, the dynamic mode of the test specimen changes from elastic rebound to plastic deformation, and finally evolves into fracture of some or all steel wires, which correspond to slight, partial and total loss of pre−tension, respectively. An increase in the level of pre−stress will significantly reduce the critical displacement of the structural failure but has little effect on the critical failure energy. The present paper provides a basic experimental data and mechanical analysis framework for the analysis, design and evaluation of the mechanical behavior of strands under accidental lateral impact.