EXPERIMENTAL STUDY ON DETERIORATION OF PHYLLITE FROM SLOPE SURFACE UNDER CONDITIONS OF DIFFREENT DRY-WET CYCLES

The places in Gansu Bailong, Sichuan Jialing and Yunan Xiaojiang river basin have complex dry-wet climate characteristics. Phyllite slope in debris flow gully is easily affected by dry-wet climate, which can cause the collapse of the slopes. The slope collapses provide rich source materials for debris flow in such areas. After investigated the climate conditions in the study area, we select 3 kinds of conditions:common condition, dry-wet condition and extreme dry-wet condition. These three conditions are very beneficial to rock breaking. The phyllite in the surface of debris flow is the research object. And these three kinds of condition are taken as the experimental conditions. After dry-wet cycles maintenance, we carry out macroscopic observation of samples. We also test their quality-rate of change, elastic wave velocity, uniaxial compressive strength, analyzed new components of phyllite. After the observation and tests, we get some results. They explain that under different dry-wet circulations the degradation behavior and mechanism of phyllite are different. These results also reveal that the best influent factor is the extreme dry-wet. It provides a useful reference for regional evaluation and prevention of debris flow disaster in the study area.