吴奎, 邵珠山, 李成龙, 赵南南, 储昭飞. 考虑施工中断影响的隧道力学响应解析模型研究[J]. 工程力学, 2024, 41(10): 169-179. DOI: 10.6052/j.issn.1000-4750.2022.08.0714
引用本文: 吴奎, 邵珠山, 李成龙, 赵南南, 储昭飞. 考虑施工中断影响的隧道力学响应解析模型研究[J]. 工程力学, 2024, 41(10): 169-179. DOI: 10.6052/j.issn.1000-4750.2022.08.0714
WU Kui, SHAO Zhu-shan, LI Cheng-long, ZHAO Nan-nan, CHU Zhao-fei. STUDY ON ANALYTICAL MODEL OF TUNNEL MECHANICAL RESPONSE CONSIDERING CONSTRUCTION INTERRUPTION[J]. Engineering Mechanics, 2024, 41(10): 169-179. DOI: 10.6052/j.issn.1000-4750.2022.08.0714
Citation: WU Kui, SHAO Zhu-shan, LI Cheng-long, ZHAO Nan-nan, CHU Zhao-fei. STUDY ON ANALYTICAL MODEL OF TUNNEL MECHANICAL RESPONSE CONSIDERING CONSTRUCTION INTERRUPTION[J]. Engineering Mechanics, 2024, 41(10): 169-179. DOI: 10.6052/j.issn.1000-4750.2022.08.0714

考虑施工中断影响的隧道力学响应解析模型研究

STUDY ON ANALYTICAL MODEL OF TUNNEL MECHANICAL RESPONSE CONSIDERING CONSTRUCTION INTERRUPTION

  • 摘要: 在具有显著时效变形特征的软岩地层中进行隧道挖掘时,因不可抗力因素导致的施工中断可能会对隧道后方衬砌产生不利影响,从而增加了隧道施工的风险。因此,准确评估隧道纵向施工中断,对硐室围岩和衬砌长期稳定性的影响具有重要意义。为揭示隧道施工中断条件下围岩与衬砌相互作用的力学机制,采用应力释放系数将三维隧道开挖问题等效为二维平面应变问题,并基于经典的负指数型应力释放系数表达式,建立了考虑施工中断工况时改进的表达式。进一步,利用广义Kelvin流变模型表征围岩的时效变形行为,推导了隧道施工过程中考虑施工中断和支护结构滞后安装的时空变形解析解。通过在郑万高铁荣家湾隧道中的应用,上述理论解答的正确性得到了很好的验证。基于理论解答,探讨了施工中断持续时间、中断开始时间以及开挖速度等因素对隧道位移和衬砌压力的影响。参数分析结果表明,由掌子面推进引起的衬砌压力可占总压力的17.3%。施工中断持续时间和开始时间对隧道位移和衬砌压力的演化规律具有重要影响,但对最终的位移和压力的影响可忽略不计。施工中断前的开挖速度越大,最终由掌子面承担的围岩压力减小。当应力释放系数达到0.8时,再次重新挖掘的速度对隧道稳定性几乎没有影响。

     

    Abstract: When tunneling in soft rock stratum with significant time-dependent deformation characteristics, the construction interruption caused by force majeure may generate adverse effects on tunnel linings, resulting in the increase of tunnel construction risk. Therefore, it is a very important task to accurately evaluate the influence of construction interruption on the long-term stability of surrounding rocks and linings. In order to investigate the interaction mechanism between surrounding rocks and linings, the three-dimensional tunnel excavation problem is equivalent to a two-dimensional plane strain one by using the stress release coefficient. The improved expression is established, which is based on the classical stress release coefficient expression in the negative exponential form and takes the construction interruption into account. Furthermore, by using the generalized Kelvin model describing the time-dependent behaviour of surrounding rocks, the analytical solution for temporal and spatial tunnel deformation is derived, where the construction interruption and delay installation of lining structures are considered. Through its application in Rongjiawan tunnel of Zhengwan high speed railway, the theoretical derivation provided is well verified. A parametric investigation is carried out based on the previous analytical solution, including duration and start time of construction interruption and excavation rate. It can be found that the lining pressure caused by the tunnel face advancement contributes about 17.3% of the total lining pressure. The duration and start time of construction interruption exhibit a significant influence on the developments of tunnel displacement and lining pressure, but do not show obvious influence on the final tunnel displacement and lining pressure. A greater excavation rate before the construction interruption leads to a decreasing rock pressure born by the tunnel face. When the stress release coefficient value reaches 0.8, the influence of the excavation rate after the excavation rate can be basically ignored.

     

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