深埋排水盾构隧道接头铸铁件力学性能试验

Experimental Study on Mechanical Properties of Ductile-Iron Joint Panels for Segmental Joints in Deep-Buried Drainage Shield Tunnels

摘要:

为研究适用于深埋排水盾构隧道的高刚性管片接头铸铁件，对2种型式的高刚性盾构管片接头开展了正弯矩试验，分析了不同型式铸铁件的力学性能及高刚性接头的破坏模式.研究表明，高刚性接头在正弯矩承载时的破坏模式与大偏压受力截面类似，首先螺栓或铸铁件屈服，随后受压区混凝土压碎、接头破坏.若接头铸铁件刚度充足，接头破坏时铸铁件无变形、螺栓屈服，接头承载力较高，且铸铁件锚筋全部受拉，锚筋的锚固作用得以充分发挥；若接头铸铁件刚度不足，接头破坏时铸铁件变形5mm、螺栓未屈服，接头承载力较低，且铸铁件锚筋部分受拉、部分受压，锚筋的锚固作用未能充分发挥.

Abstract:

To study the applicability of DIJPs (ductileiron joint panels) suitable for deepburied drainage shield tunnels, positive bending moment tests for HSSJs with two different types of DIJPs were carried out, and the mechanical properties of DIJPs and the failure modes of HSSJs were analyzed. The experimental results show that: the failure characteristic of HSSJs subjected to positive bending moment, which is similar to the failure characteristic of the compressionbending section with large eccentricity, is that the bolts or the DIJPs yield firstly, and then the segmental joint fails with the concrete in the compressive zone broken. If the flexural rigidity of the DIJPs is sufficient, there is no deformation in the DIJPs, the bearing capacity of the segmental joint is higher, and the anchor bars reach their full potential; if the flexural rigidity of the DIJPs is insufficient, 5 mm bending deflection appears in the DIJPs, the bearing capacity of the segmental joint is lower, and the anchor function of anchor bars is not fully exploited.