Experimental study on water conduction of sliding surface in an expansive soil slope

Strength of the expansive soil is sensitive to water content, and the strength declines as the water content increasing. The property change of sliding surface is important to the stability of the expansive soil slope. Therefore, the water conduction characteristic of the sliding surface is important to the stability of the slope. We set three observation pits that are 3 m interval along the toe of an expansive soil slope. The water level in the three pits is pronounced different, and an outflow zone of water appears along the toe of the slide slope a period after a rainfall. The experiment indicates a part of rainwater can flow into the slope soil through cracks on the expansive soil slope during and after the rainfall. This part of rainwater flows along the sliding surface in expansive soil slope under the hydraulic gradient, and the water conduction ability along the sliding surface is serious, which may decreases the stability of the expansive soil slope.