大断面软弱围岩隧道扩挖及局部强化支护力学分析  

Mechanical analysis on large-section weak rock tunnel excavation and local reinforcement support

作　　者：王亮 陈金良 杨光轩 徐祥龙 张策[3] 李嘉诚 吕祥锋 余跃 WANG Liang;CHEN Jinliang;YANG Guangxuan;XU Xianglong;ZHANG Ce;LI Jiacheng;L Xiangfeng;YU Yue(PowerChina Roadbridge Group Co.,Ltd.,Beijing 100160,China;China Electric Power Construction(Guangdong)Zhongshan-Kaiping Expressway Co.,Ltd.,Jiangmen,Guangdong 529142,China;Hebei Provincial Key Laboratory of Ground Subsidence Mechanism and Prevention&Control,Future City Institute,University of Science and Technology Beijing,Beijing 100083,China;China Railway First Group Second Engineering Co.,Ltd.,Tangshan,Hebei 063000,China)

机构地区：[1]中电建路桥集团有限公司,北京100160 [2]中电建(广东)中开高速公路有限公司,广东江门529142 [3]北京科技大学未来城市学院河北省地面塌陷机理与防控重点实验室,北京100083 [4]中铁一局集团第二工程有限公司,河北唐山063000

出　　处：《公路交通科技》2025年第4期151-161,共11页Journal of Highway and Transportation Research and Development

基　　金：国家重点研发计划项目(2021YFC3090303);国家自然科学基金项目(52278326);国家青年拔尖人才支持计划项目(SQ2022QB03353);中电建路桥集团有限公司科技项目(LQKY2021-01)。

摘　　要：【目标】大断面隧道原位扩挖过程中,二次扰动易诱发围岩大变形。把握围岩在隧道原位扩挖过程中的力学响应特征,并制订科学合理的变形控制技术方案至关重要。【方法】采用物理模型试验、理论分析和工程实践相结合的研究方法,研究了隧道原位扩挖围岩及支护过程围岩应力及变形分布特征规律,建立了隧道扩挖围岩力学模型,提出了隧道扩挖局部强化支护方法,并结合工程实测数据对该支护方法进行了有效性验证。【结果】隧道扩挖加剧了地层的损伤卸荷,地层的沉降在垂直方向上具有非线性增长特征,隧道支护结构有效减缓了围岩变形的进一步发展。隧道围岩等级越高,自由面位移越大,隧道围岩平均收敛量与弹性模量呈幂函数递减关系,与扰动因子呈指数函数递增的关系,扰动因子为0.6时的拱脚收敛量与扩挖侧拱脚的收敛量相近,平均误差为4.8%。将局部强化支护方法应用于大常山1#隧道改建工程,现场监测数据表明本研究方法可降低30%的围岩位移量,论证了隧道扩挖局部强化支护方法的有效性。【结论】研究结果为大断面隧道扩挖工程中的围岩稳定性控制和安全评估提供了科学依据,在实际工程中有助于优化支护方案,降低工程风险,提高隧道结构的长期安全性与耐久性。[Objective]During large-section tunnel in-situ excavation process,the secondary disturbances are prone to inducing significant surrounding rock deformation.Understanding the mechanical response characteristics of surrounding rock during in-situ tunnel excavation and formulating scientifically deformation control technology schemes are crucial.[Method]The research approach combined physical model tests,theoretical analysis,and engineering practice.The stress and deformation distribution characteristics of surrounding rock during tunnel in-situ excavation and support processes were investigated.The mechanical model of tunnel excavation surrounding rock was established.The tunnel excavation local reinforcement support method was proposed,which was verified by using field measured data.[Result]The tunnel excavation exacerbates stratum unloading damage.The stratum settlement exhibits a nonlinear growth pattern in vertical direction.The tunnel support structure effectively mitigates further deformation of surrounding rock.The higher the grade of surrounding rock,the greater the displacement of free face.The average convergence of surrounding rock decreases as a power function with Young[DK]’s modulus,and increases exponentially with the disturbance factor.When the disturbance factor is 0.6,the convergence at arch foot is similar to that at excavation side arch foot,with an average error of 4.8%.The local reinforcement support method was applied to the reconstruction project of Dachangshan Tunnel No.1.The field monitoring data show that the surrounding rock displacement is reduced by 30%with the proposed method,demonstrating the effectiveness.[Conclusion]The study result provides a scientific basis for surrounding rock stability control and safety assessment in large-section tunnel excavation projects.In practical engineering applications,the proposed method helps optimize support schemes,reduce engineering risks,and improve the long-term safety and durability of tunnel structures.

关 键 词：隧道工程 支护力学分析 物理模型 局部强化 围岩稳定 

分 类 号：U455.1[建筑科学—桥梁与隧道工程]