微型排桩支护结构在隧道明洞段的应用  

Application of Micro-Row-Pile Supporting Structure in Open-Cut Tunnel

作　　者：冉龙洲 袁松 王希宝[1] 廖沛源 张廷彪 RAN Longzhou;YUAN Song;WANG Xibao;LIAO Peiyuan;ZHANG Tingbiao(Sichuan Communication Surveying and Design Institute Co.,Ltd.,Chengdu 610017,Sichuan,China;Southwest Jiaotong University,Chengdu 610031,Sichuan,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 [2]西南交通大学,四川成都610031

出　　处：《隧道建设（中英文）》2024年第S01期334-343,共10页Tunnel Construction

基　　金：交通运输行业重点科技项目(2021-MS1-030);四川省交通运输科技项目(2021-B-01);四川省交通勘察设计研究院有限公司科技项目(232022003)。

摘　　要：为探索微型排桩在高陡边坡明洞段支护结构中的适应性,基于二维杆系荷载-结构模型,提出三排桩支护结构设计计算方法;结合工程案例拟定多种钢管排桩+锚索支护方案,对排桩支护结构的内力及变形特征、不同方案的适应性、钢管桩直径的影响等进行深入研究。结果表明:1)排桩支护中,前排桩、中排桩、后排桩具有几乎相同的内力和变形特征,但前排桩的变形和内力值略大于其他2排桩,前排桩坑底位置是整个支护结构中最不利部位;2)采用增设锚索、预留压脚岩体等方式降低相邻支撑间的竖向间距,可以有效降低支护结构位移和内力,从而使支护结构变形满足相关规范要求;3)随着桩径的增大,钢管桩刚度增大,支护结构水平位移呈指数形式降低;4)增加三排桩直径和仅增加前排桩直径均可以有效降低支护结构变形。支护结构设计中,可以根据开挖高度、施工机械、地形地貌等,选择合适的支撑方式和钢管桩直径,从而实现支护结构快速、机械化施工。In order to explore the application of micro-row-pile in supporting structure of open-cut tunnel with high-steep slope,the design and calculation method for three-row-pile supporting structure is proposed based on two-dimensional load structure model.The internal force and deformation characteristics of the row-pile supporting structure,the adaptability of different schemes,and the influence of steel pipe pile diameter are studied based on various supporting schemes,combining with engineering cases.Results show that:(1)The characteristics of internal force and deformation of the front row pile is almost the same with that of the middle and the rear row piles,but the largest value is slightly larger.(2)It can effectively reduce the displacement and internal force of supporting structure by adding anchor cable or retaining rock at the bottom of the pit,which can reduce the vertical distance between adjacent supports.(3)With the increase of pile diameter,the horizontal displacement of supporting structure decreases exponentially with the stiffness of steel pipe pile.(4)Only increase the diameter of the front row of pile can also effectively reduce the deformation of the supporting structure.When designing support structures,suitable supporting mode,and steel pipe pile diameter can be selected according to the excavation height,construction machinery,terrain characteristics,etc.,so as to achieve rapid and mechanized construction.

关 键 词：隧道洞口 明洞 微型排桩 钢管桩 支护结构 

分 类 号：U45[建筑科学—桥梁与隧道工程]