1. Bishop AW, Green GE, Garga VK et al (1971) A new ring shear apparatus and its application to the measurement of residual strength. Geotechnique 21(4):273–328
2. Borowicka H (1965) The influence of the colloidal content on the shear strength of clay. Proc. 6th Int. Conf. Soil Mech Montreal 1:175–178
3. Chinese National Standard GB 50021-2001 (2001) Code for investigation of geotechnical engineering, Beijing (in Chinese).
4. Chinese National Standard GB/T 50145-2007 (2007) Standard for engineering classification of soil, Beijing (in Chinese).
5. Chinese Sector Standard SL 237-1999 (1999) Specification of soil test, Beijing (in Chinese).