Evaluation of Curtain Grouting Efficiency by Cloud Model – Based Fuzzy Comprehensive Evaluation Method

Abstract

Because of the concealment and uncertainty of dam foundation grouting, the accurate evaluation of the quality of grouting construction is a major concern. Most of the previous studies pertaining to the assessment of grouting efficiency only take a single factor into account, and only a few efforts have been devoted to the comprehensive evaluation of grouting efficiency, which fail to consider the fuzziness problems caused by the complex relationships among indicators as well as the randomness problems caused by subjective consciousness. Therefore, the curtain grouting efficiency evaluation method considering the uncertainty in evaluation process is proposed which includes three main parts: 1) Based on conventional evaluation indicators of grouting efficiency, where groutability is introduced as a new indicator; 2) a fuzzy comprehensive evaluation method based on cloud model is developed, by which the fuzziness and randomness in assessment are organically combined; and 3) the fuzzy entropy was calculated for indicating the complexity of grouting efficiency level. Then, the proposed method is used to assess efficiency of the curtain grouting for a hydropower station in China, and compared with three other methods. The outcomes display the consistency, representativeness, robustness and superiority of this evaluation method, which make the evaluation results more scientific and objective.