Research On The Resistance Of RC Piers With Rectangular Hollow Section Subjected To Blast Loading

The response of RC piers with the rectangular hollow section under the blast loads is studied with numerical simulation methods and the residual bearing capacity of the section with an opening is researched with theoretical ways for the fact that the piers,whose resistance to blast loads is rarely studied,are under the risk of terrorist attack.The main work and the innovativeness of the paper are introduced as follows:(1)Based on the ALE algorithm,an experiment of RC slabs under the blast loads is simulated with Ansys/Ls-dyna software.The simulation result matches the experiment phenomenon quite well,which proves the feasibility and the rationality of the simulation methods conducted in the dissertation.At the same time,the propagation of the blast wave and the formation process of the opening are studied.The study shows that the damage mechanism of RC slabs: The concrete at the top is damaged because of compression pressure;The concrete at the bottom is damaged because of tension pressure;The longitudinal reinforcement is mainly stretched;The hooping reinforcement is mainly compressed.(2)The pier's response and damage pattern is studied through numerous numerical simulation.The size of the opening is obtained.The research results show that the size of the opening is in a linear realationship with the equivalent TNT weight or the proportion distance and the damage pattern can be divided into three levels.When equivalent weight is small,the side slab and the back slab is little influenced while when the equivalent weight is big,the side slab and the back slab is influenced more evidently.(3)The residual bearing capacity of the section with the opening resulted from blast loads is studied with theoretical ways and the security of piers is discussed The results show that the size of the opening has bigger influence on the small eccentric compression bearing capacity compared with the big eccentric compression bearing capacity.When the broken side is compressed the bending and compression capacity is smaller than the state that the broken side is pulled.When the equivalent TNT weight is less than 90 kg,the piers will not collapse under the nomal axial compression force.The cross-section will damage mildly when the equivalent TNT weight is less than 30 kg and will damage severly when the TNT equivalent weight is between 30 kg and 90 kg.