Analysis and Prediction of Jacking Force

• Main Authors: Haung Hui-Wen, 黃惠文
• Other Authors: 倪至寬
• Format: Others
• Language: zh-TW
• Online Access: http://ndltd.ncl.edu.tw/handle/742ug2

碩士 === 國立臺北科技大學 === 土木與防災研究所 === 103 === Slurry Pressure Balance Machine (SPBM) uses a mix of bentonite and water to remove the excavated soil. The slurry and muck is pumped out of the tunnel to a separation plant at the surface, where the muck is separated from the slurry and the slurry is reused within the slurry system. The pressure of the slurry is used to balance the groundwater and face pressure, ensuring a watertight head at the front of the TBM. During the pipe jacking, the jacking force is an important parameter, Theoretically, jacking force is the total needed forces to overcome on frictional resistance around pipe string and assumed face pressure is a constant, but in this paper, The main component of the jacking force is due to face pressure, When the lubrication used, the frictional resistance can be reduced from 45 to 90%. The jacking Force controlled by the soil type、misalignment of the pipes、lubricant using and work stoppage...etc. This paper discusses four methods of prediction jacking force during a slurry pipe jacking construction and make those conclusions : (1). Annular space is stabilized with sufficient amount of lubricant and pipe weight is less than buoyancy, resulting in no direct contact between pipe and ground soil. Any local variation of jacking force is caused either by face pressure due to driving from coarse soil to fine soil or wood encountered. (2). If deviation is more than thresh hold value of 60 mm, the friction force between pipe and ground soil increase. This effect is cumulative and remains constant in the drive.