Research On Key Technology Of Blasting Demolition Of Concrete Filled Steel Tube And Reinforced Concrete Mixed Structure Arch Bridge

With the change of the modern idea of transportation construction,road Bridges in the construction of the proportion of the increase,many Bridges because of all sorts of reason want to demolish or dismantle the reconstruction,the characteristics of the blasting demolition of high efficiency,convenient widely used in bridge demolition.Anxi inscription based on the enterprise appointed did choose the bridge for the research object,the blasting demolition demolition of concrete filled steel tube with half through bridge main arch and the bearing type side arch hybrid structure composed of reinforced concrete arch bridge,to dismantle the difficulties encountered as a research point,the results are as follows:(1)reference for other similar domestic component cutting blasting and the blasting demolition of similar Bridges,on the basis of solving the project is the hardest steel pipe concrete cutting blasting technology problems;In front of the arch bridge for blasting demolition,in view of the project concrete-filled steel tube arch rib do experimental study on the cutting blasting technology and parameters,the two comparative parameter validation test.The experiment proved that steel pipe connection of detonating cord and the low detonation velocity explosive method for concrete-filled steel tube cutting no effect;With longitudinal prestressing steel pipe cutting + longitudinal cloth hole charge method is feasible;The results after optimization and reasonable blasting parameters were obtained.(2)according to the contrast test parameters,combined with the location and environment of the main arch bridge,the parameter adjustment after the design of the main arch controll and cloth hole parameters of blasting cut blasting by blasting effect of video and observation,the accuracy of the values of parameter design is verified.(3)the original bridge demolition of detonating tube initiation system with detonating tube cross coupling,because of its inherent shortcomings.In this paper,we study a kind of alternative cross connection of products,five hair in detonating network connection detonating tube detonators,in order to reduce the number of nodes in the network and misfire probability;Detonating tube is studied through experiment and analysis of the possibility of multipass connection parts production and manufacturing.Make test samples before bridge blasting and applied to the detonating network,to detonate the whole network after initiation,development of detonating tube seven connection succeeded.In July 2012 patented,doing during this thesis to seven connection after further on the details,after product to market.(4)will be developed by detonating tube seven connection pioneered in detonating tube detonating network,the node of a large number of reduced the detonating tube,help to optimize the detonating tube compound double insurance delay detonating network,improve the network of explosive detonation,the blasting bridge,is successful and effective.Remove the two technologies used in the bridge design scheme,design of series-parallel delay detonating network,reasonable arrangement of initiation time order,to reduce the harmful effect caused by blasting.In this paper,the main arch of the pretreatment method,the parameters of the incision design,construction technology and the corresponding safety measures,can provide reference for future similar projects.