考虑微拱效应的隧道洞口段管棚合理间距确定方法及参数分析  

Determination method and parameter analysis of reasonable spacing of pipe-shed support in tunnel portal section considering micro-arch effect

作　　者：张小波[1,2] 张雕 姚池 杨建华[1] 蒋水华 荣耀 ZHANG Xiao-bo;ZHANG Diao;YAO Chi;YANG Jian-hua;JIANG Shui-hua;RONG Yao(School of Infrastructure Engineering,Nanchang University,Nanchang,Jiangxi 330031 China;Jiangxi Transportation Research Institute Co.,Ltd.,Nanchang,Jiangxi 330200,China)

机构地区：[1]南昌大学工程建设学院,江西南昌330031 [2]江西省交通科学研究院有限公司,江西南昌330200

出　　处：《岩土力学》2023年第6期1625-1635,共11页Rock and Soil Mechanics

基　　金：国家自然科学基金(No.52068033,No.52004127);中国博士后科学基金(No.2021M691358);江西省交通运输厅科技项目(No.2021Z0002);江西省研究生创新专项资金项目(No.YC2022-s075);南昌大学学位与研究生教育改革研究项目(No.NCUYJSJG-2022-071)。

摘　　要：管棚支护是隧道工程在复杂地质环境中常用的辅助施工手段,其主要依靠管间微拱效应发挥支护作用,而微拱的形成和破坏与管棚间距密切相关。综合考虑侧向土压力及微拱截面应力的非均匀分布特征,确定了考虑侧向土压力作用的微拱合理拱轴线形状,并推导了其标准方程,结合微拱的破坏条件提出了管棚合理间距的计算方法。对所提出的方法进行工程算例分析,并与已有关于管棚间距的计算方法进行了对比,验证了该方法的合理性。在此基础上,对影响管棚间距的主要参数进行分析,研究结果表明:管棚间距与拱顶荷载呈负相关关系,与管棚直径、土体黏聚力呈线性正相关关系,与土体内摩擦角呈非线性正相关关系,且土体内摩擦角的增大对管棚间距增大的影响也随之增大。随荷载的增大,上述参数对管棚间距的影响均减弱。Pipe-shed support is a commonly used auxiliary construction method for tunnel engineering in complex geological environments,and it mainly relies on the micro-arch effect between pipes to play a supporting role.The formation and failure of micro arches are closely related to the spacing between pipe-sheds.After considering the lateral earth pressure and the non-uniform distribution of micro-arch section stress,the shape of the rational arch axis is determined and its standard equation of micro-arch is derived.By combining the failure conditions of micro-arch,a calculation method of rational pipe-shed spacing is obtained.Several engineering cases are adopted to verify the proposed method and the rationality of the method is validated by comparing with existing calculation methods of pipe-shed spacing.On this basis,the main parameters affecting the pipe-shed spacing are analyzed.The results show that the pipe-shed spacing is negatively correlated with the vault load.The pipe-shed spacing increases linearly with the increase of pipe-shed diameter and soil cohesion,and increases in nonlinear with the internal friction angle of soil.Significantly,the increase of internal friction angle of soil has an increasing impact on the pipe-shed spacing.However,the influence of the above parameters on the pipe-shed spacing is weakened with the increase of load.

关 键 词：隧道洞口 微拱效应 侧向土压力 拱轴线 管棚间距 

分 类 号：TU94[建筑科学—建筑技术科学]