The stress state of the built-in corridor in core rock-fill dam on thick overburden is extremely complex, which may produce cracking and damage. The purpose of this paper was to investigate the effect of thick overburden on the stress and deformation of the built-in corridor in a rock-fill dam, and ascertain the damage causes of the corridor. The rationality of the analysis method for corridor with similar structure is another focus. The approach is based on finite-element method and the calculation result accuracy is verified by the field monitoring data. The improved analysis method for corridors with similar structure is proposed by comparing various corridor load calculation methods and concrete constitutive models. Results demonstrate that the damage causes of the corridor are the deformability difference between the overburden and concrete and the special structural form. And the calculation model considering dam construction process, contact between concrete and surrounding soil, and concrete damage plasticity can reasonably reflect the mechanical behavior of the corridor. The research conclusions may have a reference significance for the analysis of tunnels similar to built-in corridors.

厚上覆岩心堆石坝内置廊道受力状态极为复杂，容易产生开裂和破坏。本文旨在研究厚覆盖层对堆石坝内置廊道应力和变形的影响，并确定廊道的破坏原因。结构相似的廊道分析方法的合理性是另一个重点。该方法基于有限元法，计算结果的准确性由现场监测数据验证。通过比较各种廊道荷载计算方法和混凝土本构模型，提出了结构相似廊道的改进分析方法。结果表明，廊道的破坏原因是覆盖层与混凝土之间的变形能力差异以及特殊的结构形式。考虑大坝施工过程、混凝土与周围土体接触、混凝土破坏塑性的计算模型能够合理反映廊道的受力行为。研究结论可能对类似内置廊道的隧道分析具有参考意义。