Prestressed double-layer lining (segmental lining and prestressed lining) of shield tunnels has good seepage resistance and strong stability, and is a new type of support structure with great potential in high internal water pressure water transmission projects. For prestressed water conveyance tunnel projects, the reasonable value of lining tensioning prestress is the key to the economy and safety of the project. Accordingly, relying on the Pearl River Delta Water Resources Allocation Project, designed similar model tests for prestressed double-layer lining of water conveyance shield tunnels under the completed cable tension condition (CCTC) and design water pressure condition (DWPC) and established the corresponding ABAQUS three-dimensional finite element model to investigate the variations in the mechanical characteristics of the double-layer lining structure under different prestress conditions. The study determined the reasonable prestress range for the inner lining under a design internal water pressure of 1.5 MPa. The results indicated that under the CCTC, the prestressed lining is pressurized in the whole ring, the overall displacement level of the segmental lining is lower than that of the prestressed lining, the double-layer lining contact surface has a tendency to be detached, and with the increase of the structural prestress, the pressurized damage of the prestressed lining concrete develops gradually. Under the DWPC, the double-layer lining contact surface is completely closed under the action of internal water pressure, and the cracking risk of prestressed lining concrete increases with the decrease of prestress. Through numerical simulation, the reasonable range of prestressing force for shield tunnel lining is 68 %σcon ∼ 137 %σcon, and the results can provide a reference for the design and construction of prestressed double-layer lining structures of similar shield water tunnels.

中文翻译：

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高内水压力下盾构水隧道双层衬砌预应力调控研究


盾构隧道预应力双层衬砌（管片衬砌和预应力衬砌）抗渗性好，稳定性强，是一种在高内压输水工程中具有巨大潜力的新型支护结构。对于预应力输水隧洞工程，衬砌张紧预应力的合理值是工程经济和安全的关键。因此，依托珠江三角洲水资源配置工程，设计了在完工电缆张力条件 （CCTC） 和设计水压条件下输水盾构隧道预应力双层衬砌的类似模型试验，并建立了相应的 ABAQUS 三维有限元模型，研究了不同预应力条件下双层衬砌结构的力学特性变化。该研究确定了在 1.5 MPa 的设计内水压力下内衬的合理预应力范围。结果表明：CCTC作用下，预应力衬砌全环加压，节段衬砌整体位移水平低于预应力衬砌，双层衬砌接触面有脱落的趋势，且随着结构预应力的增加，预应力衬砌混凝土的加压损伤逐渐发展。在DWPC作用下，双层衬砌接触面在内部水压作用下完全闭合，预应力衬砌混凝土开裂风险随预应力的减小而增加。 通过数值模拟，盾构隧道衬砌的合理预应力范围为68 %σcon∼ 137 %σcon，研究结果可为同类盾构水隧洞预应力双层衬砌结构的设计与施工提供参考。