2 The underwater blast-induced ground vibration is mainly consisted of three parts: (a) the impulse wave acting directly on the rock mass, which is the main cause of the ground vibration with a high-frequency and intense vibration (b) the opposite sloshing force in the water with a lower vibration and slower attenuation and (c) the viscosity force acting on the interface between the liquid and structure. 1 In underwater drilling blasting, approximately 30% additional energy is lost compared to open blasting due to energy reflection on the interface and the liquid sloshing dissipation. Underwater blasting technique is widely employed in cofferdam removal, foundation excavation and waterway dredging engineering. High-frequency components are found to be highly filtered due to the water sloshing underwater. Additionally, the frequency spectrum characteristics observed from blasting either on land or underwater are discussed. The novel predictor, formed by adding the depth ratio of the water to the scaled distance law suggested by Duvall and Fogelson, is verified by the agreement of the measurement data in this case with a correlation coefficient of 92%. The experimental results show that PPVs underestimated by the conventional equation (with a correlation coefficient of 64%) increase the risk of potential damage for protected objects. The impact of the high rock quality designation (RQD) puts limitations on the PPV attenuation, particularly for ground vibration induced by underwater blasting. The geological investigation and the laboratory rock testing show that the weathering degree of the rock mass results in exponential increase in geological parameter α and linear increase in attenuation coefficient β.

A series of blasting experiments distributed over five sites were performed in the dredging engineering of the waterway at the Taishan Nuclear Power Plant. The aim of this study is to propose a novel model for predicting peak particle velocity (PPV) considering the effects of the geological factor (i.e., weathering state), rock properties (i.e., rock quality designation) and engineering category (i.e., blasting on land or underwater) on the attenuation of the ground vibrations and frequency. CONTRACTOR is bound to deduct from monthly invoicing the total cost of explosives, inputs, accessories and drill service used during that month, justifying the aforesaid items by invoices, with a maximum for 0.19 USD per ton.Underwater drilling blasting has significant vibrational attenuation effects compared to deep-hole blasting. In this case, explosives, supplies, accessories and drill service shall be supplied at Site during the lifetime of this Agreement, and explosives factor in escalating formula shall remain steady. With the intention of maintaining the price of $0.19 per tonne, effective on the date of the Agreement herein, CLIENT shall supply CONTRACTOR at its expense any explosives, supplies, accessories, loading of the explosives into the drill holesand blasting as required to meet production programs. Cy.) CONTRACTOR shall provide blasting services including loading blast holes with explosives in accordance with the directions of the CLIENT.

Depth charge explosive: High explosive Column charge explosive: Anfo Blasting cost ( including items such as: explosives, supplies and accessories, drill service for blasting, and etc.) used by CONTRACTOR to set base price per tonne of ore is US$0.19 ( Nineteen cents U.S. Blasting. Blasting parameters used in CONTRACTOR’s offer are as follows: Specific explosive consumption: Up to 200 grams per tonne.

Deathspank rock sample blasting cap