Influence of Highway Tunnel Invert Defects on Overall Structure and Structural Analysis
The inverted arch of a highway tunnel is an important lower load-bearing and functional structure,and its service durability and stability are the foundation for tunnel operation.The study takes the structural defects of inverted arches as the starting point,summarizes and proposes the main causes of inverted arch defects and the most common types of quality defects.In view of the representative defects such as virtual slag at the bottom of the inverted arch,insufficient depth,insufficient structural thickness,weakened material properties,and insufficient stiffness of the upper and lower connections,a regular analysis of the impact of different degrees of defects on the bearing safety of the affected parts and the degree of impact was conducted,in combination with the load-structure method.The results show that:1)Local defects in the inverted arch mainly affect the bearing safety of the affected parts.Overall defects in the inverted arch not only affect the inverted arch structure itself,but also cause overall damage to the upper structure;2)The impact of different defect types on load-bearing safety varies.Defects such as insufficient structural thickness and material performance degradation＞loose and uncompacted bottom slag＞insufficient depth of inverted arch＞insufficient connection stiffness between upper and lower structures＞increased load on surrounding rock;3)During the construction of inverted arch,3/5 times of the design strength,stiffness,size and other size and other conditions can be used as auxiliary criteria for quality baseline to facilitate rapid determination of defect status under special conditions.The research results can be used for the analysis of the causes of inverted arch defects and the control of construction quality.
万方数据
维普
