Comparative study on calculation model of hydraulic tunnel lining structure between beam element and solid element

According to the standard Specification for Design of Hydraulic Tunnels (DL/T 5195-2004), the free-flow tunnel lining structure should be calculated with beam element of finite element method that based on structural mechanics. However, the practical calculation shows that when the lining structure reaches a certain thickness, the beam element calculation results are no longer accurate. Combining with the engineering example, stress and internal force of lining structure with different thickness were calculated by using beam3 beam element and the solid65 element respectively in frame beam analysis. Differences analysis shows that the solid element is better than beam element in calculation. The influence of solid elements grid size on the result accuracy was conducted, and used to amend the calculation result of the solid element, which provides a certain reference on choosing the right element in the similar projects or structure simulation.