考虑地层渗透性的盾构隧道施工期管片上浮预测

发布时间：2018-04-15 04:01

本文选题：隧道工程 + 盾构隧道　；参考：《岩石力学与工程学报》2017年S1期

【摘要】：地层渗透性影响盾尾同步注浆浆液的凝固,从而影响施工期管片上浮。针对目前施工期管片上浮分析缺乏考虑地层渗透性影响的不足,将同步注浆浆液视为牛顿流体、土层简化为多孔介质,利用渗透力学及流体力学原理,提出渗滤效应下同步注浆浆液固结时间的计算方法;进而将不同地层浆液固结时间、浆液性质及施工掘进速度等因素,表征为管片上浮分析的等效梁模型中的浆液未凝固区长度,对等效梁模型进行改进,建立考虑不同渗透性地层中同步注浆浆液固结特性的管片上浮分析模型,并编制有限元程序对其求解。利用此模型对南宁某含粉砂圆砾、砂层及粉质黏土等地层的盾构区间施工期管片上浮特性进行分析,结果表明:考虑地层渗透性影响的等效梁模型进一步揭示了地层特性影响管片上浮的作用机制,其计算结果与现场实测数据具有更好的一致性,更适合于不同渗透性地层管片上浮分析。同时得到,地层渗透性越小,同步注浆浆液固结时间越长,盾尾浆液压力消散越慢,管片上浮量值越大。
[Abstract]:Formation permeability affects the solidification of shield-tail simultaneous grouting, and thus affects the floating of segment during construction.In view of the lack of considering the influence of stratum permeability in the analysis of pipe floating during construction period, the synchronous grouting slurry is regarded as Newtonian fluid, the soil layer is simplified as porous medium, and the principles of permeability and hydrodynamics are used.A method for calculating the consolidation time of simultaneous grouting under percolation effect is put forward, and the factors such as consolidation time of slurry in different strata, slurry properties and construction tunneling speed are further analyzed.The length of the unsolidified zone of the slurry in the equivalent beam model, which is characterized by the equivalent beam model, is characterized by the improvement of the equivalent beam model, and the analysis model of the segment floating considering the consolidation characteristics of the simultaneous grouting in different permeable strata is established.A finite element program is developed to solve the problem.By using this model, the floating characteristics of ducts in shield section during construction in a silty sand, sand layer and silty clay strata in Nanning are analyzed.The results show that the equivalent beam model, which considers the influence of formation permeability, further reveals the mechanism of formation characteristics affecting the floating of segments, and the calculated results are in better agreement with the field measured data.It is more suitable for the floating analysis of different permeable strata.At the same time, the smaller the formation permeability, the longer the consolidation time of the synchronous grouting fluid, the slower the pressure dissipation of the shield slurry, and the greater the floating value of the segment.
【作者单位】：同济大学道路与交通工程教育部重点实验室;南宁轨道交通集团有限责任公司;
【分类号】：U455.43

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