基于粗糙集理论与响应面法的老黏土膨胀敏感性分析方法

评价老黏土膨胀性等级时出现的误差主要源于多因素在参数统计上的不确定性，对此提出老黏土膨胀敏感性分析方法。结合粗糙集理论分析各因素的敏感性并确立主导因素，进而构建老黏土膨胀性等级的多因素定量评价模型，随后通过响应面法，分析主导因素间参数不确定性的交互作用对评价结果的影响。襄阳城区老黏土研究表明，自由膨胀率和体缩率为影响评价结果的主导与次主导因素，二者参数变化产生的交互作用对膨胀性评价等级影响较显著。当体缩率统计值较大时，随着自由膨胀率的上升，膨胀性评价等级变幅较大，偏大的自由膨胀率将高估老黏土的膨胀性，致使评价过于保守，偏小的自由膨胀率则会对其低估，导致结果较不可信；而当体缩率统计值较小时，评价等级随自由膨胀率的上升变化不大，因此评价结果较为准确。所得结论可为老黏土膨胀性评价与分类工作提供参考。 

Sensitivity analysis method of swelling of paleo-clay based on rough set theory and response surface method

The error in evaluating the swelling grade of paleo-clay is mainly due to the statistical uncertainty of many factors.Therefore, a sensitivity analysis method for the swelling of old clay is proposed.Based on rough set theory, this paper analyzes the sensitivity of various factors to the swelling properties of paleo-clay and establishes the dominant factors, and then constructs a multi-factor quantitative evaluation model for the swelling properties of paleo-clay.Subsequently, the influence law of the interaction between dominant factors on the evaluation grade is analyzed.The study of the paleo-clay in Xiangyang urban area shows that the free expansion rate and the volume shrinkage rate are the dominant and secondary dominant factors affecting the expansion evaluation, and the interaction between the change of two has a significant impact on the expansion evaluation grade.When the statistical value of volume shrinkage rate is large, as the free expansion rate rises, the swelling evaluation grade changes greatly.A large free expansion rate may overestimate the swelling of the paleo-clay, causing the evaluation to be too conservative, and the free expansion rate is too small.The expansion rate may be underestimated, resulting in less credible results; when the statistical value of volume shrinkage rate is small, the expansion evaluation grade does not change much with the increase of the free expansion rate, so the evaluation result more accurate.The conclusions obtained can provide references for the evaluation and classification of paleo-clay swelling.