Experimental Study On Rock-breaking Efficiency Of Reef-clearing Equipment With Breakers In Mountain Waterways

Among the existing reef cleaning methods,the reef blasting method has the highest construction efficiency but is not environmentally friendly.The existing environmentally friendly reef cleaning methods can not give consideration to high-efficiency reef cleaning.In promoting the construction of the Yangtze River economic belt with ecological priority and green development as the premise,it can be predicted that the research and development of a new type of environmental protection reef clearing equipment is extremely necessary for the future development of inland waterway regulation projects.In this thesis,an improved reef cleaning equipment scheme is proposed on the basis of the underwater robot carrying the broken hammer array.Through the combination of theoretical analysis,test and mathematical model,this paper explores the rock breaking efficiency under the ideal condition of this reef cleaning equipment scheme,and puts forward suggestions on the optimization of the construction method.This achievement,as a preliminary research result on the optimization of rock breaking efficiency and construction method of this reef cleaning equipment scheme,can provide a basis for further research and improvement of this reef cleaning equipment scheme.The overall research results are as follows:(1)In this thesis,the penetration depth of the rock mass by the breaking hammer is taken as the standard to measure the rock breaking efficiency.Based on the ideal situation,that is,the ship body shaking range is very small during the operation of the reef cleaning equipment,the water test is simplified to the land test,and the model scheme is designed.Through the test,the process data of the penetration depth of the model reef cleaning equipment to the test blocks with different strengths under the ideal situation are obtained,Through the scale,the process data of the penetration depth of the prototype reef cleaning equipment into the rock mass with different strength under different gears are calculated.Taking time and strength as independent variables and the penetration depth as dependent variables,the empirical formula of the relationship between the penetration depth of the prototype reef cleaning equipment and time and rock mass strength under each gear is regressed.Then it was found in the model test data that,from the perspective of the 150 s total penetration depth of the model breaking hammer,the total penetration depth increased significantly when the breaking hammer raised the working gear from gear 1 to gear 3,while the total penetration depth did not increase significantly when the breaking hammer raised the working gear from gear 3 to gear 5.(2)In view of the phenomenon in the process of drilling depth test,the process of the effective force of the drill rod when the model breaking hammer strikes at different gears is experimentally studied.Through the analysis of the change process of the effective force with time,the maximum striking force that the drill rod can provide under each gear is obtained.It is found that the maximum striking force that the drill rod can provide increases significantly when the working gear of the breaking hammer increases from gear 1 to gear 3,The increase of the maximum striking force provided by the drill rod in the process of increasing from gear 3 to gear 5 is much smaller than that in the process of gear 1 to gear 3.Through the research on the relationship between the maximum striking force provided by the drill rod and the total penetration depth of 150 s,the rationality of this phenomenon in the penetration depth test is explained.(3)Through the experimental research results of rock breaking efficiency,combined with the actual situation of the project and the existing technical level,the best working gear of the crushing hammer in the process of underwater operation is determined from the perspective of overall operation efficiency.(4)An operation mode that can improve the overall operation efficiency is proposed,and the safety and feasibility of this operation mode are verified by finite element analysis.