Abstract: Traditional rockfill dams with an asphalt concrete core wall is featured with a linear shape of both the core wall and dam shell. The core wall is deflected by the horizontal pushing of water pressure, and its deflection deformation and the elongation of its axis may induce tensile stress. Generally, a higher dam may have a higher risk of tensile cracks developed in its core wall. In this study, we analyze the generation mechanism of tensile stress in a core wall, and develop two new dam types as improving measures ? a straight dam with a curved core (SDCC) and a curved dam with a curved core (CDCC). Finite element analysis is used to examine the influences of dam height and dam axis length on the deflection deformation and tensile stress in the core wall and to investigate the improving effect of these two types. Results show that a greater dam height, longer dam axis, and larger bank slope ratio of a traditional dam lead to greater tensile stress in its core wall, and consequently a greater reduction in tensile stress if it is modified into either of the two suggested dam types. Analyses on construction technique, construction period, and economic cost show that the new types of rockfill dams are feasible and may have a good application prospect.

Key words: rockfill dam with asphalt concrete core wall, tensile stress, straight dam with curved core wall, curved dam with curved core wall