Blast responses and damage evaluation of shield tunnelling segments: Experimental investigations

The blast resistance of two groups of full-size standard shield tunnelling segments (STSs) with different reinforcement ratios was investigated by field explosion experiments. As the scaled distance decreases, the STSs will suffer cratering, cracking, spalling and breaching damages in sequence, and they have five grades of damages, including slight damage, primary damage, medium damage, severe damage and breaching. Through residual load-bearing capacity experiments on the exploded STSs, the structural damage factor of the STS under specific scaled distance can be quantitively evaluated. It is found that the cracking damage has little effect on the load bearing capacity of the STS, while extensive spalling of the concrete has a serious impact on the load-bearing capacity. The breaching can let the STS lose 60% of its load-carrying capacity. Moderately increasing the reinforcement ratio of the STS can effectively improve its anti-blast performance.

Automated summary

Through field explosion experiments, it was found that shield tunnelling segments with different reinforcement ratios exhibit varying levels of damage during explosions, which have different impacts on the structural load-bearing capacity. Modestly increasing the reinforcement ratio can effectively enhance its blast resistance.