矿山法铁路隧道拱部预制衬砌接头选型设计研究

Research on Joint Selection and Design of Prefabricated Lining at Crown of Railway Tunnel Constructed by Mining Method

铁路隧道整体现浇衬砌质量问题频发,难以满足高速度、高密度运营铁路的安全要求。结合矿山法施工与预制装配式衬砌的优势,探索一种拱部预制衬砌新技术,而接头是拱部预制衬砌的薄弱点与关键点。通过采用理论分析及数值计算对拱部预制衬砌接头选型与设计进行研究,结果表明:(1)环向L形榫接头更能适应现浇边墙与预制拱部衬砌之间施工精度差异较大的问题;(2)考虑不同受力状况、不同衬砌结构厚度、不同安全储备,提出L形榫接头最小抗压宽度与抗剪结构高度;(3)纵向斜螺栓接头能够提供一定纵向紧固力,所需纵向顶推行程小,符合拼装工艺要求;(4)综合构件环向尺寸,以预紧力需求确定需配置4套纵向斜螺栓。

The quality problems of cast-in-place lining of railway tunnel occur frequently and the safety requirements of high-speed and high-density railway operation can hardly be satisfied.Combined with the advantages of mining method construction and prefabricated lining,a new technology of prefabricated arch lining is explored.As the weak point and key point of prefabricated arch lining,theoretical analysis and numerical calculation are used to study the type selection and design of the joints.The research shows:(1)Circumferential L-shaped tenon joints can better adapt to the large difference in construction accuracy between the cast-in-place side wall and the prefabricated lining.(2)Considering different stress conditions,different lining structure thicknesses,and different safety reserves,the minimum compressive width and shear structure height of the L-shaped tenon joint are presented.(3)The longitudinal inclined bolt joint can provide a certain longitudinal fastening force,and the required longitudinal pushing distance is small,which meets the requirements of assembly process.(4)Four sets of longitudinal inclined bolts are required according to circumferential dimensions of integrated components and the requirements of preload.