核电工程软岩地基沉降计算及沉降预测

为了解软岩地基的沉降变形规律,基于国内某实际软岩地基核电工程,建立核岛软岩地基三维有限元模型,提出了适应于软岩地基时效力学特性的流变模型,通过二次开发将所提出的黏弹塑性本构模型嵌入到FLAC3D软件中。同时采用的敏感度熵权属性识别综合评价模型对地基软岩力学模型参数进行敏感性分析,并基于均匀设计-改进遗传算法-神经网络集成理论的岩体力学参数反演分析方法,结合现场监测资料,反演获得了地基软岩的弹塑性和黏弹塑性模型的力学参数。利用反演获取的力学参数对已发生的核岛地基沉降变形进行数值重演,分析了当前荷载条件下地基沉降变形量及不均匀变形,并对后续地基沉降变形量及不均匀变形进行了预测。该套分析方法可以用于类似软岩核电工程的地基沉降变形计算以及沉降预测。

Settlement Calculation and Prediction for Nuclear Projects Located on Soft Rock

In order to discuss the deformation properties of the soft rock, based on the specific nuclear project located on the soft rock, a three dimension finite element model of Nuclear Island foundation was generated and the rheological constructive model which is suit for the soft rock was developed in this paper. This constructive model was embedded in software FLAC3D. The comprehensive assessment model of the attribute recognition based on the entropy weight of sensitivity was adopted in the sensitivity analysis for the geotechnical parameters of soft rock. And the inversion calculation applying the uniform design –advanced genetic analysis-neural network method was also carried out. Based on the monitoring data, the new geotechnical parameters used in elastic-plastic model and viscoelastic-plastic model were obtained through inversion calculation. Then the settlement analysis was carried out using the numerical method based on the optimized parameters. The settlement prediction also can be produced. The method used in this paper can be adopted in the settlement calculation of soft rock in the similar projects.