A new type support structure introduction and its contrast study with traditional support structure used in tunnel construction

Referencing the design method of frame-core wall structure used in super high-rise building, a new type supporting system of grid steel frame-core tube was designed, and the structure composition and assembly method for each element were illustrated. A field test was conducted in Jinpingyan tunnel located in the area influenced by 2008 Wenchuan earthquake and the settlement of surrounding rock, internal displacement of surrounding rock, pressure between surrounding rock and primary support, internal force of support arch, axial force of rock bolts, pressure between primary support and secondary lining, and strain of secondary lining were measured to compare under two different support arches of common I-shape steel arch and new type support structure. Moreover, a 3D numerical analyses using FLAC3D software were conducted and the numerical results were compared with results of field test. It was suggested that the new type support structure played a significant role to control the large deformation of surrounding rock.