The Stability Of The Slurry Hole-wall Of Bored Piles In Thick Sand

The stability of the hole-wall is the key of hole(pile) quality. In the thick sand, the hole is easy to collapse and the pile is easy to contain sand. Mud technology is a key factor to ensure the stability of the hole-wall. Pile foundation construction of the Wuhan Er Qi Road Yangtze River Bridge WuChang shore supporting projects work in thick sand, sand thickness reach to50m. This paper study on the stability of slurry wall of bored pile about the project.Research slurry wall of bored pile into the hole (piles) construction process and construction accident of bored piles show that the slurry process is the key process throughout the pile construction process. Through the analysis of mud process with the hole wall stability and pile bearing capacity show that mud quality is the guarantee of the stability of the pore wall and pile bearing capacity. Use the FLAC3D Simulate the hole depth, pore size, sand thickness and mud density with hole wall deformation show that the deeper the hole depth, the larger the aperture, the thicker the sand thickness, the smaller the mud density that the worse the stability of hole.Hole depth (sand thickness) on the hole-wall stability impact than the pore size greater. The statistical analysis of the mud ratio and pile integrity of the pile foundation construction of the Wuhan Er Qi Road Yangtze River Bridge WuChang shore supporting projects show that with the increase of the slurry composition, pile integrity, the better, but the slurry composition increase will increase the costs and reduce the pile bearing capacity, so gain the suitable mud composition ratio, at the same time, the pore size should be appropriate to increase the bentonite proportion with industrial alkali and cellulose ratio is essentially the same.Thick sand technology target is to make the pile foundation construction of the Wuhan Er Qi Road Yangtze River Bridge supporting projects works more efficiency on pore-forming, greatly improved the quality of bore pile provides a strong guarantee for the project complete high quality on schedule. Also accumulated some experience in technology for the future study of bored piles of thick sand.