基于改进山本法的浅埋隧道支护结构受力特性研究

Study on mechanical characteristics of improved shallow tunnel supporting structure based on Yamamoto method

隧道支护结构计算时常假定为正圆形,但与工程实际存在差异。本研究结合谢家烋围岩压力计算理论,改进日本山本法支护结构计算模型,提出一种山岭浅埋隧道三心圆支护结构计算模型。应用于某红黏土隧道支护结构,将改进山本法计算结果与山本法、隧道设计规范电算结果和现场实测值比对。研究结果表明:改进山本法所得围岩压力和支护结构轴力结果与实测数据最接近,最大误差12.9%,且趋于安全;改进山本法所得弯矩结果显示拱脚处弯矩最大,与现场结构破坏形式相符;根据计算结果确定荷载集中部位,制定专项加固方案,保证隧道施工和运营安全。研究成果可为优化类圆形隧道断面理论提供参考,为隧道支护结构计算提供一种新方法。

The calculation of tunnel support structure is often assumed to be positive circular,but it is different from the actual engineering.Based on the theory of surrounding rock pressure calculation,this paper improves the calculation model of support structure of Japanese Yamamoto method,and puts forward a calculation model of three-center circular support structure of shallow buried tunnel in mountain.The results of the improved method are compared with those of the method,the code of tunnel design and the measured values.The results show that the surrounding rock pressure and axial force of supporting structure are the closest to the measured data,the maximum error is 12.9%,tend to be safe.According to the calculation results,the load concentration is determined and the special reinforcement scheme is made to ensure the safety of tunnel construction and operation.The research results can provide a reference for optimizing the theory of circular tunnel section and a new method for calculating tunnel support structure.