For the purpose of getting the strength value of Baihetan interlayer shear belt with the characters of dislocation history

large scale spread

assembled multiplex structure

multiplex mineral

etc.

six kinds of tests are introduced

including ring shear test

high stress direct shear test and triaxial compression test for soft argillization layer

and straight shear test

triaxial compression test and in-situ shear test for multiplex shear belt. Based on the testing data of above six tests

the relationships between strength of shear belt and loading mode

value of normal stress

character of specimen and moisture content are summed up. The strength properties of shear belt

include assembled structure effect

thin cementation effect

confining pressure effect and water soften effect are found. What’ more

the conceptions of “original strength” and “disturbed strength” of interlayer shear belt are put forward

which have different cohesive strengths and friction angles. These cognitions can provide useful cures for supporting design of Baihetan underground caverns and study of similar argillization layer in deep underground engineering.