超大跨度明挖隧道结构形式比较研究  

Comparative study on structural forms of super-large span open-cut tunnels

作　　者：苟瀹谂 魏名泽 冉龙洲 Gou Yueshen;Wei Mingze;Ran Longzhou(Sichuan Communication Surveying and Design Institute Co.,Chengdu Sichuan 610017,China)

机构地区：[1]四川省交通勘察设计研究院有限公司,四川成都610017

出　　处：《山西建筑》2025年第8期155-158,共4页Shanxi Architecture

摘　　要：常规矩形明挖隧道在跨度较大时受力极为不利,在埋深较大时往往需要较厚的结构尺寸,造成工程浪费。以双向八车道下穿隧道为例,对常规矩形结构、微起拱拱形结构及折线拱结构的内力进行了对比研究,并对折线拱结构起拱高度、折线拱尺寸对结构内力影响进行了研究。研究表明,微起拱拱形结构和折线拱结构相较于常规矩形结构,最不利位置的弯矩降低约17%和15%,结构厚度可减小,节约工程量约12.5%;折线拱起拱越高,结构高度越高,结构最不利位置弯矩越小,结构最不利位置弯矩随结构起拱高度呈线性降低;在结构整体高度不变的情况下,折线拱尺寸越大,结构最不利位置弯矩越小。文章指出折线拱结构相较于微起拱拱形结构更有利于施工,在埋深较大时超大跨度明挖结构可采用折线拱形式。Rectangular open-cut tunnels exhibit unfavorable stress conditions under large spans and often require thicker structural dimensions at greater burial depths,which leads to engineering waste.Taking a bidirectional eight-lane underpass tunnel as an example,this study conducts a comparative analysis of the internal forces in conventional rectangular structures,slightly arched structures,and polygonal arch structures,and the influence of arch height and polygonal arch dimensions on internal forces is investigated.The results indicate that,compared to conventional rectangular structures,the slightly arched and polygonal arch structures reduce bending moment at the critical positions by approximately 17%and 15%.This allows for reduced structural thickness,saving approximately 12.5%in construction costs.A higher polygonal arch rise increases the structural height and further decreases bending moments at critical positions,with the bending moment decreasing linearly as the arch rise increases.Under a constant overall structural height,larger polygonal arch dimension leads to smaller bending moments at critical positions.Compared to slightly arched structures,polygonal arch structures are more advantageous for construction.Thus,polygonal arch form is recommended for super-large span open-cut structures under significant burial depths.

关 键 词：超大跨度 明挖隧道 结构形式 折线拱结构 微起拱结构 

分 类 号：TU997[建筑科学—市政工程] U455[建筑科学—桥梁与隧道工程]