Research On Pile Foundation Construction Technology Of Guangzhou Wanda Cultural Tourism Town-Wandamall Project

In this paper, the research status of cast-in-place pile and pre-stress concrete pipe pile and difficulties of the pile foundation construction in karst region are illustrated.On the background of Wandamall-Guangzhou Wanda cultural tourism city, we carry out the research of the pile foundation construction technology. The main contents are as follows:(1)According to the construction organization plan and the actual situation of the construction. Experimental pile foundation construction scheme is designed. 13 piles(including 1 whole-pipe cast-in-situ pile and 8 revolving digging cast-in-place bored piles and 4 jacked-in PHC pipe piles) are tested. Experimental construction is carried out.(2)During the process of experimental construction. Grouting treatment technique is adopted to solve the problem of karst cave existing in the position where2 rotary drilling bored piles works in. Because of the complex geological condition,it is hard to prevent pile deflection and collapse of hole wall. The measures like maintaining the water level in the drilling more than 2m above the water table and using of a bentonite slurry Wall are taken.(3)The optimized analysis of rotary drilling bored pile, whole-pipe cast-in-situ pile, jacked-in pipe piles can be made in terms of cost, bearing capacity and pile forming situation. The forming situations of these piles are fine, but pipe pile cannot construct in the position where karst cave exists. Experimental results show that,ultimate capacity of rotary drilling bored piles(1000mm) is 17050 k N, ultimate capacity of pipe pile(PHC 500/AB 125)is 5500 k N. The cost of whole-pipe cast-in-situ pile is expensive, the revolving digging cast-in-place bored piles and jacked-in PHC pipe piles are economy.(4)Static pressure tube pile, rotary drilling bored pile and punch holes pile are selected. Pipe pile is used in the position where geological condition is good and the bearing capacity of the design requirements is low. Rotary drilling bored pile is used in the position where karst cave exists and the bearing capacity of the designrequirements is high. Punch holes pile is used when the pile dips into the bedrock under 1m or the height difference over 3m in the same pile position. This paper put forward the pile foundation construction scheme of Wandamall Ski-resort area.The construction measures and quality management of rotary drilling bored pile,punch holes pile and jacked-in PHC pipe piles are taken.