Extrusion damage in the concrete face was widely observed in high concrete-faced rockfill dams in the last two decades. However, the accurate estimation of the concrete stress remains a great challenge. In this paper, a thermo-mechanical coupling method is presented to numerically evaluate the solar radiation effect on the concrete stress within the dual mortar finite element framework. The heat conduction is modelled as a transient time-dependent equation and hence the heat flow can be determined by meteorological data. The thermo-mechanical coupling is conducted in a weak way such that the linear system can be split into two subsystems friendly to the linear solver. The present method based on using nonconforming meshes is validated by the comparisons with node-to-segment method, conforming mesh and analytical solution. The application to a concrete-faced rockfill dam indicates that the phase lag and amplitude damping effects are apparent in the thermal analysis, confirming the importance of using transient heat conduction theory. The observed slab-slab separations emphasis the importance of using dual mortar contact method. The thermal stress is found to be larger than 10 MPa and therefore needs to be considered in the design and safety assessment.

在过去的二十年中，在高混凝土面板堆石坝中广泛观察到混凝土面板的挤压破坏。但是，准确估计混凝土应力仍然是一个巨大的挑战。本文提出了一种热力耦合方法，以数值计算太阳辐射对双砂浆有限元框架内混凝土应力的影响。热传导被建模为瞬态时间相关方程，因此可以通过气象数据确定热流。热机械耦合的执行方式较弱，因此可以将线性系统分为对线性求解器友好的两个子系统。通过与节点到分段方法，适形网格和解析解的比较，验证了基于非适形网格的本方法。在混凝土面板堆石坝中的应用表明，在热分析中，相位滞后和振幅阻尼效应是明显的，这证实了使用瞬态热传导理论的重要性。观察到的板-板分离强调了使用双重砂浆接触法的重要性。发现热应力大于10 MPa，因此在设计和安全评估中需要考虑。