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

非饱和渗流、应力耦合行响粘类工程岩体强度和稳定性重要素。

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50万年风吹雨打后，恶地国家公园岩丘陵与孤山矗立在一片草原之海中。