润扬大桥北锚碇基础三维数值仿真分析

针对润扬大桥北锚碇基础的安全问题, 利用有限单元法对北锚地基基础的受力进行三维仿真分析,模拟了整个施工过程,特别对其中模拟开挖的方法等问题进行了讨论.将计算出的测斜孔位移及散索鞍支墩处位移等与同期实测结果进行了对比,误差小于30%,证实了所采用的计算方法、本构关系和模型基本正确.最后利用这个计算模型对运营期工况进行了分析,证明锚碇基础的设计是合理的.研究还表明,北锚碇较大的质量使得基础水平位移对摩擦系数的变化并不敏感,而基岩深度对基础位移则有较大影响.

3-D simulation analysis of Runyang suspended bridge's north anchorage

To evaluate the safety of the anchorage foundation of Runyang suspended bridge, finite element method technique was applied to the 3-D simulation analysis of Runyang bridge's north anchorage foundation and ground. The method to simulate the process of construction especially digging is discussed. The calculation results such as the displacements at the places of slope survey holes and the piers of splay saddle are compared with observed dada, and the error is less than 30%. It proves the reliability of the calculation method, constitutive relationship and calculation model, and indicates that the depth of parent rock influences the displacement of anchorage foundation remarkably while the displacement is not sensitive to the change of the friction coefficient between the foundation and the groundsill due to the great weight of the anchorage. The rationality of the anchorage design is also proved by analyzing the working cases of the bridge with this calculation model.