OPTIMIZATION ANALYSIS OF CONSTRUCTION METHOD FOR SHALLOW-BURIED TUNNEL WITH LARGE SECTION

In order to find the most reasonable construction method for the Qingdao Jiaozhou Bay subsea tunnel withlarge section in land area, numerical simulation for the four kinds of common construction methods had been made bythree-dimension finite differential software FLAC3 D．The analytical results indicate that the double side headingmethod is better in the surface settlement, tunnel deformation and stability of surrounding rock than the other threemethods．The DC construction method is more beneficial to the lining safety than the others．In the actual process ofconstruction, it should be comprehensively considered lots of the factors including the construction period, schedule, tunnel depth, tunnel diameter and so on in the selection of construction method．It' s difficult to install the steelsupport because of the big span, high clearance and bench in Qingdao subsea tunnel with large section in land area．The CD method should not be used in the construction and the double side heading method is the best selection takinginto account all the factors．The double side heading method has achieved significant social and economic benefits inthe Qingdao Jiaozhou Bay subsea tunnel with large section in land area and will play a very good reference andguidance for similar projects in the future．