盾构输水隧道复合结构力学特性研究

Study on Mechanical Characteristics of Composite Structure of ShieldWater Tunnel

近些年,一种新型的盾构输水隧道复合结构形式(外层为盾构管片、内层为输水钢管、中间层为填充混凝土)被用于城市大型输水隧道的建设。然而,目前对其力学方面的深入研究还较少,力学特性尚不清晰。因此依托杭州市某水源工程,以该种复合结构为研究对象,通过建立精细化有限元模型,研究了该复合结构在不同混凝土填充范围下的力学特性,并以加劲肋间距和内水压为变量进行了设计参数敏感性分析。研究结果表明:填充混凝土能提高复合结构的整体刚度,减小管片变形;内水压可以通过填充混凝土传递至管片,对复合结构整体受力有着显著影响;加劲肋间距可以有效减小输水钢管的局部应力,但超过2.0 m间距后对未布置加劲肋处的影响会减小。

In recent years,a new type of composite structure of shield tunnel for water conveyance,whose outer layer is the shield segment,the inner layer is the water steel pipe,and the middle layer is filled with concrete,has been applied in the construction of large urban water tunnels.However,there are few studies on mechanics,and the mechanical characteristics is still unclear.Based on a project of water source in Hangzhou,the composite structure was taken as the study object.The refined finite element model is established to study the mechanical characteristics of the composite structure with different ranges of concrete filling.Sensitivity analysis of design parameters were carried out based on the variable of the stiffener’s spaces and internal water pressure.The results show that the concrete filling can improve the overall stiffness of the composite structure and reduce the deformation of segments;The internal water pressure can be transferred to the segment through the filled concrete,which has a significant impact on the stress of the composite structure;The stiffener spaces can effectively reduce the local stress of the water steel pipe,but the effect on the position without stiffening spaces will reduce when the spacing exceeds 2.0 m.