Experimental and Numerical Investigation on the Damage Effects of Concrete Pier under Contact Explosion
The damage effects of concrete pier under the action of contact explosion are studied.Firstly,the K&C,HJC,RHT and Kong-Fang models are respectively used to numerically calculate the failure effects of concrete pier.The failure modes,the number of cracks,the number of broken blocks and the change in residual heights of core and side are discussed and compared with the test results.The results show that the four models can effectively predict the failure modes of concrete pier:the upper half and lower half of concrete pier show different failure modes under the explosion of the top group charge.The upper half is broken and damaged to form a large number of fragments ranging from 1 cm to 10 cm in diameter,and the lower half is ruptured to be cracked into a limited number of blocks.Kong-Fang model can more reliably predict the number and residual heights of broken blocks.On this basis,the variation of damage characteristic parameters of residual blocks with the charge volume was studied.It is found that,with the increase in the charge from 1.0 kg to 4.5 kg,the number of broken blocks increases to 25 pieces,and the size of the bottom surface of a block decreases from40cm to 15cm,which is about1/5-1/25 of the size of concrete pier in the broken part.The core residual height and side residual height decrease rapidly when the charge volume increases from 1.0 kg to 3.5 kg,and are stabilized at 40 cm and 28 cm,respectively,after the charge of 4 kg,and no longer changed significantly.Based on the above research results,the formulas for the changes in the number of blocks,the residual height of the core and the residual height of the side are fitted.The research in this paper provides a basis for the effective implementation of concrete pier blasting operations.