Abstract
As a portion of intact rock separating joint surfaces, rock bridge plays a significant role in the stability of rock slopes. This paper aims to investigate the effect of different rock bridges on the mechanical properties and failure mode of rock slope by means of the direct shear test and acoustic emission technique. Field conditions were simulated in direct shear tests which were carried out on specimens with rock bridges at different continuity rates, normal stress, arrangements, and joint angles. Experimental results indicate that the strength of specimens is controlled by the rock bridge and the structural plane. The rock bridge contributes to the strength of the specimen, while the through plane weakens the strength of the specimen. The increase of normal stress can weaken the stress concentration near the tip of the rock bridge and improve the shear resistance of the specimen. The different arrangement of rock bridge has little effect on the normal displacement of the specimen, and has a great influence on the shear strength. The shear capacity of the specimen is related to the angle of the crack, and the angle of the crack is approximately proportional to the peak shear strength. For the specimens with different joint occurrence, the mode of crack propagation at the initial stage is basically the same, and the specimen is finally damaged due to the generation of through cracks in the core area of rock bridge. The instantaneous release of the huge energy generated during the experiment along the shear direction is the root cause of the sudden failure of the rock bridge. The formation, aggregation, and transfixion process of rock bridge is of concern and has been experimentally investigated in this paper for the prevention and control of the locked section rock slope with sudden disasters.
Highlights
A large number of high and steep rock slopes consist of intact rock and joints
A rock bridge is a portion of intact rock separating joint surfaces, which can be called a locked section
Chen et al [25] carried out small-scale direct shear tests of rock bridge with different lengths and a large-scale landslide model with locked section, and analyzed the relationship between acoustic emission (AE) events and record time during the tests
Summary
A large number of high and steep rock slopes consist of intact rock and joints. A rock bridge is a portion of intact rock separating joint surfaces, which can be called a locked section. Xi et al [10,11,12] investigated the crack initiation, coalescence, and propagation processes for concrete materials They quantitatively analyzed the functional relationship between the through strength, the rock bridge dip angle, the friction coefficient of the structural plane, the confining pressure, the connectivity rate and the structural plane dip angle, and proposed the rock bridge through criteria with two non through structural planes. Chen et al [25] carried out small-scale direct shear tests of rock bridge with different lengths and a large-scale landslide model with locked section, and analyzed the relationship between AE events and record time during the tests. The research reveals the influence of the different occurrence of rock bridge on the mechanical properties and failure mode of the locked section rock mass, and explores the mechanism of the high-speed sliding of the locked section slopes
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
