Dynamic Responses of Precast Columns with Socket Connections Subjected to Impact Load

Abstract A precast column with a socket connection is one of the attractive choices in prefabricated structures, particularly due to their ease of assembly, efficiency in construction, and structural integrity. It has been proven to exhibit similar failure pattern and mechanical performances to that of a monolithic column when subjected to earthquake loading. However, studies on their behaviors under impact loading are very limited. This paper aims to investigate the dynamic responses of columns with socket connections under impact load. Numerical models were developed and validated against the test results. Analyses were conducted to compare the impact performance differences between monolithic and socket columns. Additionally, to investigate the effects of the design factors on the impact performances of the socket column, parametric studies were conducted and four design factors were considered. The results revealed that the socket depth, axial force ratio, and impact height were the primary factors affecting its impact performance, while the connection diameter ratio and bottom plate thickness had minimal effect. Specifically, a shallow socket depth (0.4 D ) resulted in higher pressure in the socket wall and also increased the damage of the column. The impact height determined the overall failure pattern of the column and also affected the damage state of the filling materials. The increase of the axial force ratio could effectively minimize the displacement and damage of the column but also led to an increase in the impact force.