浅埋偏压黄土隧道地表旋喷桩加固工艺参数研究  

Jet Grouting Pile Reinforcement Parameter in Shallow-buried Bias Loess Tunnel

作　　者：王志超[1] 李伟[1] 黎盼 赵博涛 王毅斌 WANG Zhi-chao;LI Wei;LI Pan;ZHAO Bo-tao;WANG Yi-bin(School of Highway,Chang’an University,Xi’an,Shaanxi 710064,China;The Engineering Design Academy of Chang’an University Co.,Ltd.,Xi’an,Chang’an University,Xi’an,Shaanxi 710064,China;Shaanxi Construction Machinery Construction Group Co.,Ltd.,Xi’an,Shaanxi 710032,China)

机构地区：[1]长安大学公路学院,陕西西安710064 [2]长安大学西安长安大学工程设计研究院有限公司,陕西西安710064 [3]陕西建工机械施工集团有限公司,陕西西安710032

出　　处：《公路交通科技》2024年第7期126-133,共8页Journal of Highway and Transportation Research and Development

基　　金：长安大学中央高校基本科研业务费专项项目(300102212204)。

摘　　要：在黄土隧道修建过程中,其洞口段因浅埋偏压、围岩软弱破碎等通常需要进行加固处理。地表旋喷桩法具有适用范围广、加固效果好等优点,被广泛应用于隧道浅埋偏压段软弱围岩地表加固工程。以浅埋偏压黄土隧道进口段初期支护侵限为研究背景,介绍了现场地表旋喷桩加固的施工过程;建立了侵限段三维加固模型并分析了地表旋喷桩加固前后的变形控制效果,说明了处治措施的合理性;对比分析了现场监控量测结果,验证了数值模拟的准确性;开展了地表旋喷桩的工艺设计参数优化分析。结果表明:由于偏压作用,地表最大沉降值偏离隧道中心线,且拱顶中心线处沉降>右拱肩处沉降>左拱肩处沉降;施加地表旋喷桩对于减小地表沉降十分有效,地表最大沉降值减小了45.5%;采用地表旋喷桩加固处理后,拱顶处加固效果最为显著,较加固前沉降减小了57.9%,同时加固后左、右拱肩沉降差值减小了17.4%;建议隧道浅埋偏压段地表旋喷桩加固工艺设计参数:桩直径为0.4~0.6 m、桩间距为1.2 m、横向加固范围为1.5~2倍洞径、竖向加固范围为洞身两侧旋喷桩与隧道拱底平齐。During the loess tunnel construction,the tunnel portal usually needs to be reinforced due to shallow-buried bias pressure and weak and broken surrounding rock.The surface jet grouting pile method has the advantages of wide range of application and good reinforcement effect,and is widely used in the surface reinforcement of weak surrounding rocks in shallow-buried bias section of tunnels.In this study,the initial support encroachment of shallow-buried bias loess tunnel inlet section was taken as the background.The construction process of surface jet grouting pile reinforcement on site was introduced.The three-dimensional reinforcement model of encroaching section was established.The deformation control effect before and after surface jet grouting pile reinforcement was analyzed to illustrate the reasonableness of treatment measures.The field monitoring and measurement results were compared and analyzed to verify the numerical simulation accuracy.Optimization analysis of process design parameters for surface jet grouting pile was carried out.The result indicates that due to the bias pressure,and the maximum surface settlement deviates from the tunnel centerline,the settlement at vault centerline > settlement at right arch shoulder > settlement at left arch shoulder.The application of surface jet grouting pile is very effective in reducing surface settlement with the maximum surface settlement value reduced by 45.5%.After the reinforcement treatment with surface jet grouting piles,the most significant reinforcement effect achieves at the vault,reducing the settlement by 57.9% compared with the pre-strengthening settlement.While the difference in settlement between the left and right arch shoulders is reduced by 17.4% after reinforcement.It is suggested that the design parameters of surface jet grouting pile reinforcement process for the shallow-buried bias section of tunnel are as follows:the diameter of piles is 0.4-0.6 m,the spacing of piles is 1.2 m,the range of horizontal reinforcement is 1.5-2 times of hole dia

关 键 词：隧道工程 地表加固 数值模拟 高压旋喷桩 浅埋偏压 

分 类 号：U452[建筑科学—桥梁与隧道工程]