Analysis of Jacking force for EPB

• Main Authors: Yi-Zhi Cai, 蔡佾志
• Other Authors: P.E., Shong-loong Chen Ph.D.
• Format: Others
• Language: zh-TW
• Online Access: http://ndltd.ncl.edu.tw/handle/xrxkej

碩士 === 國立臺北科技大學 === 土木工程系土木與防災碩士班 === 105 === Earth Pressure Balance system is a method which uses the combination of exca-vated soil material and impermeable bentonite stabilizing solution in order to provide stability at the cutting face of the EPB machine. The excavated material is then pumped to the ground surface using mud tubes for muck removal and separation. In addition, this method uses a close circuit system which allows the bentonite solution to be circulated through a water treatment equipment and reused by the EPB machine. Operation of the EPB machine requires many years of experience to determine any sudden deviation or changes in soil material during pipe jacking, such as driftwood, boulders, composite sites and even trash during the advancing process. It is very important during the operation of pipe jacking that sufficient knowledge of the geology and type of soil on site is known, the appropriate aperture and cutting tools needed and mostly importantly to determine what the cutting head face will encounter due to the soil type. Moreover, during the jacking process the operators knowledge and experience will allow at any time for quick response to make necessary adjustment such as regulation of advancement speed and change of slurry discharge speed due to geological changes on site. In this study, three gravel layer were selected and the data of each pipe were recorded for the process of pipe jacking. The data collected were the soil type, the deviation and stability of tunnel and other local factors which may affect the total thrust force.