Abstract: Taking  the highway in Guangxi province as the example，the physical and mechanical performance of carbon shale is tested.The strength of carbon shale  increases with the degree of compaction augment,while the strength  greatly decreases under the condition of water immersion carbon shale.Using the strength reduction finite element method,the influence on compaction and rainfall for carbon shale embankment stability is analyzed by large finite element calculation software.The results show that the safety coefficient of embankment will  increase,when the compaction degree  increases;while it will significantly decline with rainfall.When the compaction degree is up to more than 93%,the carbon shale high-filled embankment slope will be steady-going.

Key words: carbon shale, stability of high-filled embankment, finite element strength reduction method