新建建筑上跨施工对浅埋大断面隧道结构的安全影响研究  

Research on safety effort of shallow tunnel with large cross-section over crossed by a new built building

作　　者：沈佳佳 万利 张长安 吴涛 SHEN Jiajia;WAN Li;ZHANG Chang’an;WU Tao(Shandong Provincial Communications Planning and Design Institute Group Co.,Ltd.,Ji’nan 250031,China)

机构地区：[1]山东省交通规划设计院集团有限公司,山东济南250031

出　　处：《铁道科学与工程学报》2022年第9期2672-2681,共10页Journal of Railway Science and Engineering

基　　金：山东省交通运输厅科技计划项目(2019B55)。

摘　　要：浅埋大断面隧道上方新建建筑附加荷载通过围岩传递至隧道结构,会增大隧道衬砌内力,影响隧道运营安全。囿于边界条件、围岩性质、荷载分布等众多影响因素,附加荷载在浅埋大断面隧道围岩中的传递规律复杂,最终作用于衬砌结构的附加荷载难以确定,在此前提下,如何合理评估附加荷载对隧道结构的作用仍是工程实践中的重要课题。以某建筑扩建工程为背景,提出一种基于应力扩散原理并结合数值模拟用于分析新建建筑对下方浅埋大断面隧道结构影响的新方法。建立“地层—结构”模型从应力扩散角度研究地表建筑荷载作用下附加应力随深度的变化规律,得出应力扩散角范围;运用“荷载—结构”模型结合零阶优化算法研究附加应力扩散角与隧道二次衬砌安全系数、最大裂缝宽度之间的关系;综合分析评估得到在新建建筑荷载作用下浅埋大断面隧道结构的安全性能。工程实践结果表明:新建建筑施工期间下方隧道结构安全稳定,与评估结论一致,监控量测沉降值与计算结果吻合,隧道运营期间衬砌工作状态良好,无新增结构裂缝,符合设计预期。所提出的分析方法概念清晰,流程简洁,结果合理、可靠,对类似工程的设计、施工具有参考价值。The additional load caused by constructing a new building upon a shallow tunnel with large cross-section would be transmitted to the tunnel structure through the surrounding rock.It would be increased internal force of lining as well as affected operational safety of tunnel.Due to many influencing factors such as boundary conditions,surrounding rock properties,load distribution and so on,the transfer law of additional load in surrounding rock of shallow tunnel with large cross-section was complex.And it was difficult to determine the additional load acting on lining structure.On this premise,it was still an important subject to assess the effect of tunnel structure caused by additional load reasonably in engineering practice.Taking ecological culture park of Chaoyangshan as project background,a new method that based on stress diffusion principle and numerical simulation had been put forward for research the effort of shallow tunnel with large cross-section which under a new built building.Variation of additional stress caused by surface building load with depth had been analyzed by stratum structure method model from the perspective of stress diffusion and then rang of stress diffusion angle had been calculated.Relationship between stress diffusion angle,safety factor and maximum crack width of secondary lining had been analyzed by load structure method model combined with zero-order optimization algorithm as well.At last,safety effort of shallow tunnel with large cross-section that over crossed by a new built building had been gotten by comprehensive analyzing the results upon.Engineering practice shows that the tunnel structure is safe and stable during construction of the new building which is consistent with the evaluation conclusion as well as the value of monitoring measurement is consistent with the calculation results.The lining works well during the operation and has no new structure cracks occurring which meets the design expectations.The analysis method is clear in concept,simple in process,reasonable

关 键 词：浅埋隧道 地表建筑 数值计算 应力扩散 

分 类 号：TU94[建筑科学—建筑技术科学]