Experimental Study on Mechanical Behavior of Shield Segmental Joints Strengthened by Assembly Reinforced Structures

Abstract:

The internal reinforcement technology is an effective method to control the deformation of shield segmental linings and local joints. The commonly used reinforcement technology is to add steel plates or other structures in a tunnel， but it has the defects of covering the lining surface after reinforcement， which is not conducive to the observation of lining diseases. Assembled reinforced structures were proposed in this paper， and positive and negative bending tests were conducted to study the mechanical properties of the segmental joints with and without the assembled reinforced structures. The experimental results show that the assembled reinforced structures have a certain reinforcement effect on the segmental joints bearing positive and negative bending moments. After the joints open， the assembled reinforced structures bear the load together with the bolts， limit the opening of the joints， and improve the bearing capacity of the joints. However， the reinforcement effect of the assembled reinforced structure on the joint bearing negative bending moment is limited and less obvious than that on the joint bearing positive bending moment. The main reason for this is that the structure is installed on the inner arc surface of the joint， which can effectively control the opening of the inner arc surface of the joint， but the opening restriction effect of the outer arc surface of the joint is small. In addition， the concrete around the connection positions between the assembled reinforced structures and the segments are damaged. The connection is critical for the reinforcement effect of the assembled reinforced structures， which， thus， needs to be further optimized.

Key words:assembly reinforced structure;shield segmental joint;mechanical behavior;bending test