An analytical model for the rotational behavior of concrete segmental joints with gaskets

Abstract

To investigate the rotational behavior of concrete segmental joints with gaskets, bending tests are performed by detailed three-dimensional continuum numerical models for joints with and without gaskets. Based on the numerical results, an analytical model is proposed to analyze the rotational stiffness of the segmental joint and extend the simulation with related parametric studies. The bending tests reveal that the rotational behavior of the segmental joint with gaskets can be divided into four stages for both the sagging and hogging moment cases. The analytical results reveal that the sealing gasket has little influence on the joint rotational behavior, while the elastic gasket has a significant effect of reducing the joint rotational stiffness. Besides, the rotational behavior of the joint with gaskets is affected by the axial force and the bolt pre-tightening force to a certain degree. The proposed analytical model allows the effect of the properties of bolts and various gaskets, the concrete contact force, the geometry of the joint section, and the subjected loads to be taken into consideration. The analytical results are well consistent with the numerical results, and the analytical model can be adopted for simulation of the segmental joint with various gaskets.

An Improved Analytical Approach for Segmental Joint Rotational Behavior Considering the Elastic Gasket

“…The joint rotation angle (θ) is illustrated in Figure 6, and it can be calculated by using Equation (21). According to Equation (23), the rotational stiffness (Kθ) of the joint can be obtained by using the curve of the slope of the joint rotation angle (θ) versus the bending moment (M).…”

“…To take account of the EG, as presented in Figure 2b, the existing analytical approaches for the joint with EG are mainly based on the assumption that the concrete is much more rigid than EG, and the deformations of EG are much greater than those of the concrete. Therefore, only the compressive strains of EG are taken into consideration, while the compressive strains of the concrete attached to the EG are neglected [19][20][21][22][23][24]. In sum, this assumption only considers the stress generated by the compression of the EG instead of the concrete-EG-concrete composite structure.…”

“…However, according to the constitutive model of EG, the rigidity of EG tends to be increased rapidly with increasing the compressive stress, and the EG can no longer be considered as a flexible material in this condition [16,25,26]. This leads to the result that, when the joints are subjected to large loads, the joint rotational stiffnesses calculated by the analytical approaches cannot coincide well with the numerical results [22][23][24]. Therefore, the deformations of the EG and the attached concrete should be both taken into consideration in the analytical approach to calculate the joint rotational stiffness.…”

Characteristic parameters’ optimization based on contact pressure of sealing gasket for segmental joints

“…As for the influence of the gasket holes opening rate on the sealing gasket waterproofing, based on the previous research conclusions, 4,5,6,8,10,12,14,21,22 the gasket model in this section will adopt the ''Sheffield'' section with double-row circular staggered holes. The influence of the area change of closed holes portion (orange), open holes circular portion (blue), and open holes trapeziform portion (green) on the waterproof performance of the sealing gasket was studied with the opening rate as the control variable.…”

Study on Internal Force of Tunnel Segment by Considering the Influence of Joints

“…Among the above three models, the beam-spring model is the most widely used one in the calculation of the segment ring. In the beam-spring model, since the joint stiffness has a significant influence on the internal force of the segment [12][13][14], many scholars have carried out model experiments on the stiffness of segment joints [15][16][17][18][19][20][21].…”