Long-term stability of arch support and bedrock of Daning River Bridge

The arch support at Wushan end of Daning River Bridge is constructed on weathered solution-collapse breccias, which is soft and prone to creep. Evaluation of long-term stability of arch support and breccias is of great importance for the security of service of Daning River Bridge. Based on the laboratory creep test results of weathered solution-collapse breccias, a creep constitutive model is established and the parameters are proposed. Using the creep model, the long-term evolution of stress and deformation of the arch support and breccias is analyzed by means of the 3D finite element method (FEM). The openings and shear stress between the contact surface of arch support and breccias are studied. Numerical results show that: (1) the creep of breccias can cause local tensile stress concentration on thrust resistance piles; (2) the arch support and bedrock show compatible deformation during long-term creep, and the opening of the contact surface is very small. In addition, the shear stress in most part of the contact surface is less than 0.1 MPa. This study may be helpful for the design of arch support and long-term maintenance of the slope.