This paper develops a new comprehensive evaluation method of grouting quality with multi-indices synergy

to solve the problem that the traditional evaluation methods rely on a single index and suffer poor capability of reflecting the behaviors of grouted rock mass. First

we construct an index system with four indicators: post-grouting Lugeon value

rock wall integrity index

acoustic wave speed

and unit grout consumption

in order to evaluate the dual criteria of permeability and compactness. Then

we use an analytic hierarchy procedure and the entropy weight method to calculate subjective and objective weights separately

and combine the weights to balance expert experience and data characteristics through applying the game theory. Finally

we achieve the quantitative grading of grouting quality by constructing a membership degree matrix based on the fuzzy comprehensive evaluation method. Application to a hydropower station project in Southwest China shows a comprehensive evaluation weight vector of [0.396

0.2655

0.1658

0.2091]T and the grouting quality indices of 4.307

3.769

4.356

and 4.365 for the four evaluation units respectively. Compared with the traditional single-index method

this new method gives the same overall trend of grouting quality

but can identify local weak grouting areas with higher accuracy. This study demonstrates the advantages of multi-indices synergy

rational weighting

and robust evaluation of our new method

and lays a basis for better grouting quality assessment and supplementary grouting decision-making.