Abstract:

An experimental method to investigate the long-term mechanical characteristics of loaded rockfill under different environmental conditions of drying and wetting, cooling and heating is presented. A series of tests were performed by using a newly developed weathering test apparatus to study the long-term degradation strain mechanism of argillaceous siltstone rockfill under different environmental conditions including drying and wetting cycles, cooling and heating cycles and the coupled wetting-cooling and drying-heating cycles. The test results show that the drying and wetting cycles and the coupled wetting-cooling and drying-heating cycles can induce remarkable additional strains of loaded rockfill, including wetting strain, wet-swelling and dry-shrinking strain and rockfill particle degradation strain. It is shown that the changes of environmental factors can cause degradation of rockfill particle; and the degradation strain of rockfill is a key portion of the long-term strain of high rockfill dam.

Key words: weathering, rockfill, drying and wetting cycle, cooling and heating cycle