Study On The Technology Of Reef Blasted With Deep Hole Method In The Deep Water Environment Of Sea Bed

Dalian Port harbor,Dalian Xingang renovation project of underwater reef project and Dalian Xingang trench excavation engineering,are deep Zhajiao,depth of over 30 m;in deep water,jet,waves,tidal range,turbulence characteristics such as poor environment,the indicators for efficient,safe and rapid completion of the project the reduction of shallow reef;combined with the engineering practice,combined with the existing technology,the use of GPS positioning system,adopt fine drilling technology,optimizing blasting design methods to study the key points of engineering.The main research results are as follows:1.for deep water(more than 30m),jet(1.4m/s)sea conditions,the ship is equipped with 800t type construction platform of drilling and blasting,using GPS positioning system(HD8900 and HD600)and RTK(base station precision index:+2cm+2ppm)implementation of measurement positioning,establish plane control network,to inspect each ship,and will automatically read the height of the water level control software of data input to the location,hole position,implementation of scientific management and information management,realize the deep-water reef fine blasting.2.in drilling practice,summarized and put forward the underwater drilling position:Three Character Classic "quasi platform","steady","fine",to ensure the hole drilling precision,good blasting effect."Quasi" refers to the reef ship’s position must be accurate,each position based on blasting,blasting a position at a time,each position and actual position coordinate design coordinates must be consistent,position,overall quasi."Stability" refers to the ship or affected by the tide,wind and water,in the jet,waves,hull to ensure stability,to ensure the accuracy of drilling."Precision" is the bit value of the drill bit reaching the bedrock surface through the water and mud layer.Its error is less than 20cm.The accuracy of hole location is the key to ensure the accuracy of the hole net parameters,and is the key to ensure the underwater blasting effect.3.in the trench under water blasting,according to the foundation of different shapes and dimensions,different depth layout position,design of hole net parameter.The overall shape of the trench repeatedly blasting reef blasting technology,all did not appear after the shallow trench.4.,according to the topography and geological conditions of reef,we should optimize the parameters of hole net,improve the charge structure,reasonably increase the depth of over drilling,make the charge in place,reduce and reduce the number of shallow points.