Tunnels with super-large cross-sections mainly face problems such as large tunnel spans, complex geological conditions, poor self-stability of the surrounding rocks, and poor stability of tunnel structures. If inappropriate support or construction is selected, large deformation, instability, and/or construction damage may occur. Therefore, by considering the Nanlong composite interchange project as the research engineering background, numerical analysis is carried out via FLAC3D finite difference software. Combined with the site survey data, comparative analyses of the displacement field, stress field, and plastic zone are carried out for different construction methods and support schemes. Based on the results of Flac3D numerical simulation analysis and compared with the reserved core soil method for excavation, the double-side heading method for super-span tunnels with weak surrounding rock has advantages and feasibility. In addition, by comparing the schemes and the results of numerical simulation, it is preliminarily concluded that the high-pretension negative Poisson's ratio long and short anchor cable compensation support is characterized by control effects compared with the traditional passive and strong support. The aforementioned can provide technical support for tunnel excavation under complex geological conditions.

来源平台：ENGINEERING GEOLOGY FOR A HABITABLE EARTH, VOL 4, IAEG XIV CONGRESS 2023