Experimental Study on Dynamic Interaction Characteristics of Pier-Pile Composite System under Horizontal Impact

Based on the principle of dynamic similarity test and similar test materials such as particulate concrete, a scale test model under horizontal impact of heavy vehicles is established. And based on four different horizontal impact test conditions, the dynamic response of pile-soil composite system under different impact momentum and the dynamic interaction characteristics of pile-soil interface are analyzed systematically. Based on the ultrasonic damage identification theory, the dynamic damage evolution law of pile under different horizontal impact energy is analyzed. The results show that when the impact velocity is low, the peak value of impact force increases nonlinearly with the increase of impact velocity, and when the impact velocity exceeds a certain level, the growth rate of peak value of impact force tends to be stable. The greater the horizontal impact momentum and impact energy, the more serious the impact damage degree of pile. The dynamic damage index D of pile is quadratic function with horizontal impact momentum p and impact kinetic energy E_k. Under the horizontal impact load, the main failure mode of the pile is tensile failure on the impacted side, and a large amount of transient earth pressure increment will be generated on the pile-soil interface on both sides of the pile. Improving the compressive strength of the soil on the pile side can effectively improve the horizontal impact resistance of the pile-soil composite system.