Study on the Propagation Law of Water Hammer Wave in Underwater Blasting and the Reducing Effect of Air Curtain on Water Hammer Wave

Chao Qi,Suihong Wang,Zhixiong Jiang,Zuxiang Hu,Zhiqiang Yin,Haoyuan Wu,Bangbiao Wu

doi:10.1155/2021/9994071

Chao Qi, Suihong Wang + Show 5 more

Open Access

https://doi.org/10.1155/2021/9994071

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Abstract

The harmful effects (water hammer wave, flying stone, and broken quality of concrete) produced in the process of underwater drilling and blasting are the key factors affecting the safety of underwater drilling and blasting. In fact, the harm caused by the water hammer wave is the most significant. As a consequence, it is of great significance to study the propagation law of water hammer waves. Based on the background of the cofferdam demolition project at the inlet section of Shibishan Central Canal in Ningguo City, China, a three-dimensional numerical model was established based on Coupled Eulerian–Lagrangian (CEL) method. Besides, the propagation law of water hammer waves at different water depths with different millisecond times was studied. Meanwhile, the reduction effect of the water hammer wave at different positions of the bubble curtain was analyzed. The results showed that, in the direction of the minimum resistance line of the charge, the attenuation law of the water hammer wave is accorded with the Cole formula and attenuated exponentially. The attenuation speed of the water hammer wave increased at first and then decreased with the increase of the millisecond time. In addition, the attenuation rate of the peak pressure was the fastest when the millisecond interval 30 ms was used. The attenuation of the water hammer wave at different water depths decreased at first and then decreased with the increase of water depth. The attenuation law of the water hammer wave decreased linearly with the increase of the distance between the bubble curtain and the charge. The research results can provide particular guiding significance for similar on-site construction.

Highlights

Academic Editor: Bangbiao Wu e harmful effects produced in the process of underwater drilling and blasting are the key factors affecting the safety of underwater drilling and blasting
The reduction effect of the water hammer wave at different positions of the bubble curtain was analyzed. e results showed that, in the direction of the minimum resistance line of the charge, the attenuation law of the water hammer wave is accorded with the Cole formula and attenuated exponentially. e attenuation speed of the water hammer wave increased at first and decreased with the increase of the millisecond time
It is of obvious practical significance to study the propagation law of water hammer waves according to the interval time of millisecond blasting and the different positions of the air curtain wall

Summary

State of the Art

Many scholars have carried out numerical simulation and field measurement in order to explore the propagation law of underwater blasting water hammer waves and the influence of bubble curtain on the reduction effect of water hammer waves. e types of explosives and blasting parameters are studied by using different numerical simulation software, such as AUTODYN and ANSYS/LS-DYNA. Many scholars have carried out numerical simulation and field measurement in order to explore the propagation law of underwater blasting water hammer waves and the influence of bubble curtain on the reduction effect of water hammer waves. E above researchers focused on single-hole blasting or fixed interval millisecond blasting They did not systematically analyze the influence of millisecond blasting at a different time and using a real bubble curtain wall on the propagation law of water hammer wave. E study of millisecond time on the propagation law of water hammer wave caused by different water depths and bubble curtain was carried out to provide some reference for controlling the harmful effect of underwater blasting Based on Python, a script was written to generate a three-dimensional real bubble curtain wall from large to small in the water depth direction by setting the maximum and minimum radius of bubbles and the difference interval between the minimum particle sizes. e study of millisecond time on the propagation law of water hammer wave caused by different water depths and bubble curtain was carried out to provide some reference for controlling the harmful effect of underwater blasting

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