基于ABAQUS平台的四渡河悬索桥隧道锚围岩稳定性分析

STABILITY ANALYSIS OF ROCK AROUND TUNNEL-TYPE ANCHORAGE OF SIDUHE SUSPENSION BRIDGE BASED ON ABAQUS SOFTWARE

隧道锚在实际工程中应用不多，目前对其稳定性的研究相对较少。基于大型通用非线性有限元分析软件ABAQUS的计算平台，利用该软件提供的用户材料子程序UMAT接口，将基于Rankine准则的Mohr-Coulomb模型添入ABAQUS中，采用Foamn语言开发了接口程序，并在此基础上对四渡河悬索桥隧道锚进行二维弹塑性有限元分析，计算了初始地应力场，模拟了隧道锚与公路隧道的新奥法施工过程，并考虑了开挖过程中隧洞周边接触软弱层的形成。将锚碇围岩的稳定性和锚固系统的整体安全度作为主要研究内容，其计算结果和长江科学院采用FLAC3D的分析结果比较，二者具有一致性。研究结果表明，所研制的接口程序开发思路正确，计算精度满足要求，所完成的工作为隧道锚设计提供了依据，具有相当重要的工程价值。

Tunnel-type anchorage is not widely used in practice, and not enough attentions have been paid to its stability up to now. Based on the user-defined material subroutine interface provided by ABAQUS, a new model by combining Rankine and Mohr-Coulomb criteria is established, and corresponding interface program is developed, in which Fortran language is adopted. Based on this model, a three-dimensional elasto plastic finite element analysis on the tunnel-type anchorage of Siduhe suspension bridge is performed. The initial geostress field is calculated, and the construction process of the tunnel-type anchorage and road tunnel with New Austrian tunneling method is simulated. At the same time, the weak terrane around the tunnel-type anchorage appeared in the excavation is considered. The stability and safety factor of the rock around the tunnel-type anchorage are main contents. The results conform to those from FLAC^3D analysis provided by Yangtze River Scientific Research Institute, which shows the feasibility and validity of the interface subroutine. The results can provide a reference to the current design rule of tunnel-type anchorage.