Abstract:In view of developmental features of the weak structural planes of excavation high slopes in the coal strata,the shearing rheological test device for the weak structural planes is designed and built in the saturated situation. The time-dependent deformation characteristics of the weak structural planes in the coal strata are studied systematically. On the basis of rheological mechanical tests,which lasts for nearly 1 year,the comprehensive time-dependent constitutive equations of each type of the weak structural planes are established,and the long-time strength parameters are acquired by adopting Burgers rheological constitutive equation. The results of rheological tests show that the long-term cohesive force of the weak structural planes c ranges from 57 to 160 kPa under the saturated conditions,and j is between 12° and 18°,which decreases about 60% in contrast with that of saturated quick portable shearing test. The results obtained are important for feedback analysis,deformation mechanism and optimum design of slope related to safety of stabilization during the reservoir operation in engineering region. And referenced constitutive model is provided for the similar weak structural planes of high slopes.