Research And Application On The Technology Of Pouring Concrete Of Bored Piles Under Water

With the development of national economic constructions, tall and heavy buildings increase a lot, such as industry and civil buildings, bridges, ports and docks etc. Bored piles are suitable for different kinds of geology conditions as deep foundations. They have strong bearing capacity, little noise, few public damages and strong earthquake resistance, so bored piles are applied to deep foundations more and more widely. As to pile foot or pile shaft lies below water level or to the place that water flow can't be enclosed, it has to use the subaqueous concreting method to pouring the piles. There are many methods of subaqueous concreting. Due to tremie methods can pour large quantities of concrete under water rapidly without draining water, can make use of the advantageous underground condition to maintain the poured concrete, operation equipments and facilities are simple, and can be applied to all kinds of construction conditions. Therefore,tremie methods are applied much more widely than others.Because of its concealment of construction, complexion and succession of technics, construction accidents such as reinforcing cage floating, pipe blockage or break, borehole collapse, happen frequently. Piles often suffer from honeycomb, spongy surface, cavity, slurry mixed, segregation or abruption and so on. Then great economics will be lost. The quality of the subaqueous concreting construction is the key technology to a guarantee of pile building quality. Therefore, the problem of the subaqueous concreting construction desiderates discussion, research and solution.According to the subaqueous concreting construction circumstances of bored piles of Chongyang Reservoir Bridge in Xixia town, Nanyang city, Henan province, this paper mainly discusses preparations for the tremie method of pouring the concrete under water, critical technologies and control points in the construction course, the cause and trouble removal of the common problem that happened in the subaqueous concreting construction. Researching on the technologies of the subaqueous concreting, can help choose more reasonable parameters, can instruct the construction better, accelerates the construction process, decreases the quality problem, ensures the quality safety, improves the social and economic efficient, has important significance of theory instruction and practical application values to the practical projects.