盾构管片UHPC加固技术及力学性能分析

针对盾构隧道运行期管片破损问题，提出了利用具有优异的力学性能和耐久性能的超高性能混凝土（UHPC）材料加固管片的方法。建立了UHPC加固通缝拼装管片的三维非线性有限元模型，讨论了加固前后管片力学特性和变形行为，揭示了UHPC加固的承载机理和破坏模式。在此基础上，探讨了不同厚度、配筋率的UHPC加固层对加固效果的影响。研究表明，UHPC加固盾构隧道不仅能有效控制管片变形，提高结构承载力，并且在满足抗裂性能的条件下，顶底相对位移继续发展的容许值可以达到厘米级。该文研究将为隧道管片加固提供新思路。

REINFORCED TECHNOLOGY AND MECHANICAL PROPERTIES OF SHIELD TUNNEL LINING WITH UHPC

The damage problem of shield tunnel-segments during the operation of a shield tunnel is becoming increasingly serious in the world. Thusly, a new method is proposed to reinforce the tunnel lining based on the ultra-high-performance concrete (UHPC) which has high performance in the mechanical properties and durability. A three-dimensional nonlinear finite element model for reinforcing the shield tunnel with UHPC is established. This method discusses the mechanical properties and deformation behavior of structures and reveals the bearing mechanism and failure mode of the reinforcement with UHPC. Subsequently, the influence of different thickness and reinforcement ratio of UHPC reinforcement layer on the structural reinforcement is investigated. The simulation results indicate that this new method for reinforcing the shield tunnel with UHPC can effectively control the deformation of the segment and enhance the bearing capacity of the structure. Furthermore, the allowable value of the further development of the relative displacement between top and bottom can reach centimeter level under the condition of satisfying the crack resistance. This research results provide a basis for further research and development of this new method.