9BAO Cheng-gang, GONG Bi-wei, ZHAN Liang-tong.Properities of unsaturated soils and slope stability of expansive soils[A]. The second International Conference on Unsaturated Soils [ C]. Beijing: Internationl Academic Publishers, 1998.
10BISHOP A W, BLIGNT G E. Some aspects of effective stress in saturated and unsaturated soils [ J ]. Geotechnique, 1963, (3) : 177 - 197.