On The Rectification And Remedy Of Pre-stressed Pipe Piles In Soft Soils And The Construction Quality Control

As the pre-stressed pipe piles have many advantages such as short construction period, low noise and pollution, it has been widely used in coastal area of thick soft soils in China. In actual projects with pre-stressed pipe piles, however, there are many thorn problems we have to frequently meet, such as the engineering piles displaced, tilting and even broken, and these piles must be reinforced and rectified. In this thesis, a study on the rectification and remedy of pre-stressed pipe piles in soft soils as well as the construction quality control is made with the case history of pre-stressed pipe piles project. The main research work is as follows:1. The development and characteristics of the pre-stressed pipe piles in China is summarized, and the advantages and disadvantages of the pre-stressed pipe piles construction are discussed and analyzed.2. By comparing and analyzing some case histories of pre-stressed pipe piles in soft soil at southeast coast of China, the principles and methods of rectification and reinforcement are summarized.3. The problems commonly encountered in the construction of pre-stressed pipe piles in soft soils are concluded, and the method of construction quality control for pre-stressed pipe piles are proposed, including: (1) Control strictly the quality of high-strength pre-stressed concrete pipe piles; (2) Select good pile machine and pile tip, and enhance the performance monitoring of pile machine; (3) Make reasonable arrangements for the order and the speed of piling; (4) Strictly control the pile driving process; (5) Keep continuously pile driving, and avoid stopover; (6) Control reasonable end pressure.4. The impact of the pile driving process on the surrounding environment and its prevention are studied, and the measures to reduce and prevent the harmful effects of pile driving are summarized.The work made in the thesis can be used for reference in design and construction of the pre-stressed pipe piles engineering.