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

Abstract

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.

Keywords

• paleo-clay
• swelling
• uncertainty
• rough set theory
• response surface method
• sensitivity analysis