隧道拱部钢波纹板-钢架组合初期支护结构及力学特征研究OA

To address the issues of high risk of block falling at the vault and low construction efficiency in traditional initial support technologies for super-large cross-section tunnels under complex geological conditions,this study investigates the mechanical characteristics and engineering applicability of the steel corrugated plate-steel frame composite initial support structure.Numerical simulations and model tests are conducted to validate its safety,deformation control capability,and synergistic bearing mechanism.The results indicate that:(1)The composite support performs similarly to traditional shotcrete-steel frame support in terms of surrounding rock deformation control and structural stress response.(2)It exhibits a higher failure threshold and smaller crack propagation range,with significantly enhanced structural integrity.(3)The corrugated plate demonstrates a differentiated stress mechanism,with compressive stress dominant at the peaks and tensile stress dominant at the valleys.(4)The axial force in the corrugated plate is primarily tensile;at the vault,the axial force increases to a peak tensile value and then decreases,eventually transitioning into compression.This composite structure offers both excellent support performance and high construction efficiency,making it suitable for soft rock,fractured zones,and rockburst-prone strata.