Research About Drilling Techniques Of 130m Depth Drill Hole Grouting Pile Of The Yellow Rriver Bridge At Qingdao To Yinchuan Highway

Along with our country national economy fast development,the highway construction rank is more and more high,the bridge construction scale is more and more big. Cast-in-place concrete pile is one kind of foundation design pattern that developed most rapidly and applied most widely to bridge building, is a current technical hot spot. Under this situation and background,research about drilling deep pile-bore techniques of large diameter, has extremely vital practical significance and instruction function.This article has summarized drilling bore techniques of Qingdao-Yinchuan highway Jinan Yellow River bridge 125m cast-in-place concrete pile.This is the most deep pile-bore in our country. This article has given success example and model experience for Yellow River tail water large bridge cast-in-place concrete pile which depth is ultra hundred meters. The following is this article primary coverage.First chapter "Introduction", has outlined our country bridge cast-in-place concrete pile techniques production and development situation, has introduced our country at present the most deep bridge pile, has showed this article's content and goal.Second chapter " Research about theory of drill bore craft ", according to project condition and specification, referring to our country cast-in-place concrete pile drilling bore craft techniques, has analysed three kinds of drill bore craft——normal direction circulation drilling, suction pump reverse circulation drilling and air lift reverse circulation drilling. Finally we have determined drill bore craft of the most deep pile. This craft is that normal direction circulation drilling is used to drill shallow bore and air lift reverse circulation drilling is used to drill deep bore. At the same time, according to drill bore requests of craft and quality, has selected the most appropriate drill and drill bit. The drill type is Zhongshengjianji ( Nanjing )ZSD250/150 , the drill bit is cage type and is made up of double waistband and shaving knife.Third chapter " Technological parameter and Technical measure", according to pile-bore engineering design target (130m depth, 2m diameter , < 1/300 gradient ), has calculated technological parameters of air lift reverse circulation drilling (air mixer submersion depth, air pressure, unit time blast quantity, mud weight, drilling velocity, drilling pressure and so on), has researched questions discovered during drilling pile-bore process, has adjusted and optimized techniques parameter. At the same time, has analysed the causes of quality accident that drilling pile-bore possibly occurs, has proposed precautionary measure to prevent drilling pile-bore deflection or expansion, to prevent mud paste or bury drill bit.Fourth chapter " Techniques of drilling cast-in-place concrete pile-bore ", according to achievements about theory and practice research, in terms of drilling bore construction processing, has summarized drilling 130m pile-bore techniques (drilling 0~40m pile-bore need reverse direction circulation with pump sucking with pump sucking slewing, drilling 40~130m pile-bore need reverse direction circulation with air lifting slewing), has pointed out key points of each processing.Fifth chapter "Examination of drilling pile-bore and Analysis of research achievements", has introduced a sort of currently advanced pile-bore quality examination method (JJC-1D type cast-in-place concrete pile examination system), has showed examination result of drilling pile-bore, has summarized success experiences of drilling ultra hundred meters pile-bore at Yellow River tail water, has pointed out questions not yet solved completely and gave suggestions.This article is about reality construction example's research and summary. Under the similar condition, its foundation data, technical parameter and key points of each working procedure, has importent reference effect to drilling deep bore.