基于直觉模糊集的膨胀土胀缩性评价

膨胀土胀缩等级的分类是治理膨胀土工作中的首要问题，为了准确评价膨胀土的胀缩性等级，以便于现场及时采取相应工程措施，减少灾害的发生，本文提出了综合考虑主、客观权重的直觉模糊集评价模型。选取液限、胀缩总率、塑性指数、天然含水率和自由膨胀率5个评价指标构成评价属性集。针对某高速公路的钻孔土样建立直觉模糊评价模型，并分析了指标权重变化对于胀缩性评价结果影响的灵敏度。研究结果表明：基于直觉模糊法的评价结果与模糊数学法、物元可拓法、变权靶心贴近度法和未知测度法的评价结果较为吻合，本文通过与4种有效模型评价结果相互印证的方式验证了直觉模糊集理论建立的评价模型应用于膨胀土胀缩性评价的合理性和可行性；针对某高速公路的局部钻孔土样的指标模糊性分析表明，自由膨胀率、塑性指数、天然含水率、胀缩总率、液限的指标权重的选取对胀缩性评价结果的敏感性依次减弱，其中自由膨胀率模糊性值最小、敏感性最强，而液限的模糊性值最大，因而随着液限权重的变化对胀缩性评价结果的影响较小。

Evaluation on the swelling-shrinkage of expansive soil based on intuitionistic fuzzy set

The classification of the grade of swelling-shrinkage for the expansive soils is the critical problem in the management of expansive soils. To accurately evaluate the swelling-shrinkage grade of expansive soil and to reduce engineering disasters, a model based on intuitionistic fuzzy sets was proposed comprehensively considering subjective and objective weights. Five factors, including liquid limit, swell-shrink total ratio, plastic index, natural water content and free swelling ratio, were selected into the set of evaluation attributes. An intuitionistic fuzzy evaluation model was established based on the soil samples taken from a highway, and the sensitivity of index weights to the evaluation results of swelling-shrinkage was analyzed. Research results show that: the results from the presented model conforms to the actual results and are in good agreement with the evaluation results from fuzzy mathematics, extension theory, target approaching in variable weight, and unascertained measure method. By comparing with the evaluation results of 4 effective models, the rationality and feasibility of the proposed evaluation model was validated. Index fuzzy analysis on the local borehole samples taken from a highway shows that: the sensitivities of the index weight of free swelling ratio, plastic index, natural water content, swell-shrink total ratio and liquid limit to the evaluation result of swelling- shrinkage decrease in turn, the free swelling ratio is the most sensitive one in all indexes, but the index weight of liquid limit has the least effect on the evaluation result.