Abstract: This paper describes five indexes for evaluating the deformation compatibility of clay core wall dams, i.e., major principal stress, stress level of core wall, maximum settlement of dam body, settlement rate of core wall, and vibration time for compaction. We use these indexes and 3D finite element analysis to examine the deformation compatibility of a core rockfill dam, and come to the conclusions as follows: (1) Functional relationship between each index and the relative density Dr of dam shell material can be summarized by a fitted equation; For each index, an effect function can be obtained using a normalization method. An objective function is obtained by assigning a weight factor to each effect function, and the weighted average value can be used to determine Dr of the optimal dam shell material. (2) Without construction cost taken into account, the Dr obtained by each single index may vary greatly in a wide range of 0.49 to 1.0, while it is reduced to 0.78-0.81 if determined using multi-objective optimization, a reasonable range that meets the design specification. (3) With construction cost considered for a construction elevation of 384 m, Dr of 0.783 is determined for an equal-weight scheme requiring a vibration duration of 90 s. The multi-objective optimization method is beneficial for dam construction .

Key words: clay core dam, deformation compatibility, multi-objective optimization, dam shell material, relative density