Abstract: This paper presents a case history of twin parallel rectangular tubes jacking in Xingye Express Line Project. The ground deformation induced by the tube jacking was monitored and the monitored data were compared with the numerical analysis results. The conclusions are as follows: (1) the ground deformation can be effectively controlled by the soil improvement at the end of the launching pit and the micro undercutting of the machine head during the starting and jacking of pipe jacking to ensure the safety of the rectangular tube jacking; (2) During the normal jacking, the shape of the surface cross sectional settlement is consistent with the Peck curve, and the width of settlement trough is 2-3 times of the tube width; (3) The surface horizontal settlement caused by the single line tube jacking is V-shaped, and the surface horizontal settlement caused by the double line tube jacking is W-shaped. The width of the surface settlement groove is 3 times the width of the tube. The surface settlement caused by the construction of the front tube is about 2mm than that of rare pipe tube; (4) The numerical simulation shows that when the twin tubes were jacked to 65m and 60m respectively, the maximum surface settlement caused by the front pipe jacking is 13mm, and the maximum surface settlement caused by the rare tube is 10mm, and the surface within 5m in front of the machine head shows settlement deformation.

Key words: Parallel Rectangular Tubes Jacking, Ground Deformation, Monitoring Data Analysis, Numerical Simulation