Water Inrush Mechanism and Safety Control in Drilling and Blasting Construction of Subsea Tunnel

Abstract

Dai, C.-Q.; Long, Y.-X.; Lv, Y.-L.; Hou, W.-Z., and Sui, H.-T., 2019. Water inrush mechanism and safety control in drilling and blasting construction of subsea tunnel. In: Gong, D.; Zhu, H., and Liu, R. (eds.), Selected Topics in Coastal Research: Engineering, Industry, Economy, and Sustainable Development. Journal of Coastal Research, Special Issue No. 94, pp. 218–222. Coconut Creek (Florida), ISSN 0749-0208.Based on the water inrush (WI) patterns of shallow buried tunnels, this paper elaborates on the WI mode and mechanism during the drilling and blasting of subsea tunnels in consideration of the characteristics of high-water pressure and complex geology of submarine tunnels. Then, through the main analysis for the deformation law of surrounding rock caused by drilling and blasting, it establishes the relationship between subsea/tunnel vault crown settlement and WI in construction under the construction conditions of unfavourable geological body, to obtain the two main failure modes of submarine tunnel: stratum cracking and partial separation failure. Besides, according to the characteristics of stratum deformation, the deformation displacement analysis of the roof and side walls of the tunnel was conducted to establish the safety control risk early warming mechanism on the basis of the risk control relationship between the measured values, early warning values, alarm values and limit control values of the stratum deformation. Finally, based on the core safety risk factors of the planning, design and construction stages of the subsea tunnel, the corresponding safety risk control measures were formulated.