Abstract:

As the contact surface of large segmental joints to be more complex, the stress and deformation of joints under load will also have more complex results. By using mechanical model of segmental joints which can simulate complex joint characteristics, mechanical analysis of segmental joints with two different contacts on a same joint surface is carried out, and valuable conclusions are drawn. The study results show that: (1) When the gap on side of the joint surface of segmental joints increases appropriately, the collapse of joint concrete can be delayed, the joint failure bending moment level can be increased, and the change of failure form from brittle failure of concrete crushing to plastic failure of bolt yielding can be promoted, which is beneficial to structural design. (2) When the local pressurebearing liner with appropriate thickness is filled in the middle of the joint surface, the relationship curve between bending moment and rotation angle tends to be linear, the bending rigidity level does not decrease significantly, the opening of the joint does not increase, and the pressure in the middle of the joint surface is always sufficient, which is beneficial to waterproofing. (3) Improper selection of contact size and material on a same joint surface will lead to a significant decline in joint performance, so it should be designed carefully.

Key words: shield tunnel, segmental joint, mechanical analysis, coexistence of different contacts, complex joint surface