关键词: 沉管隧道, 陆域最终接头, 卵石基床, 摩擦止退, 预应力粗钢筋

Abstract: There are many technical difficulties in antireaction construction of castinplace onland final joints of immersed tunnels, i.e., multiple underwater operations, complex procedures, and quality control. Therefore, a case study is conducted on the Hanjiang rivercrossing immersed tunnel in Yuliangzhou, Xingyang, China. No independent antireaction structure is arranged, and the friction of the pipe joint is used as antireaction function. The results demonstrate the following: (1) The friction coefficient between pebble foundation bed and immersed tunnel and the friction coefficient between pebble foundation bed and immersed tunnel considering the influence of backsilting are obtained by laboratory and field tests. (2) The principle of friction antireaction of the final joint is studied, the land final joint of the immersed tunnel with friction antireaction is developed for the first time, the end antireaction structure is eliminated, prestressed coarse reinforcement is adopted as a temporary connection measure, and selflubricating thrust bearing is set up to eliminate the shear force. The engineering practice validates that the force and the tensioning amount of the pipe joint meet the requirements, and the land final joint of immersed pipe tunnel with frictionantireaction is safe and reliable.

Key words: immersed tunnel, onland final joint, pebble bed, friction antireaction, prestressed coarse steel bar