Coupled unsaturated flow in claystone has high effect on strength and stability of underground engineering.

非饱和渗流、应力为是影响粘土类工程体的强度和稳定性的重要素。

Whittled by a half million years of wind and rain, the haunting claystone hills and buttes of Badlands National Park rise above the surrounding sea of grasslands.

历经了50万年的风吹雨打后，恶地国家公园的黏土与孤山矗立在一片草原之海中。