Xi'an LETRY Company applies its self-developed rock joint seepage-shear coupling servo testing system for conducting large-scale plane stress-strain rock joint seepage-shear coupling servo tests, three-dimensional tests for underground and surface engineering, and research on the mechanical properties of soft rock specimens.

Using real-time digital photography and three-dimensional video technology, the macroscopic and mesoscopic deformation fields and stress fields of rock masses during roadway excavation and support processes are tested and analyzed. This research investigates the excavation, failure, and support balance evolution processes and patterns of deep roadways under high in-situ stress conditions to determine the stability theory of deep roadway rock engineering and develop reasonable and effective support strategies.

Main performance indicators:

1. Servo-controlled shear testing subsystem

(1) Maximum vertical force: 1000kN;

(2) Vertical force measurement accuracy: ±1% of indicated value (within 5% to 100% of full scale);

(3) Maximum horizontal force: 500kN;

(4) Horizontal force measurement accuracy: ±1% of indicated value (within 5% to 100% of full scale);

(5) Vertical deformation measurement range: 0-20mm;

(6) Vertical deformation measurement accuracy: ±1% F·S;

(7) Displacement speed range: 0.5mm/min to 100mm/min;

(8) Displacement speed accuracy: ±1% of indicated value (within 5% to 100% of full scale);

(9) Force and displacement control accuracy: ±1% of indicated value (within 5% to 100% of full scale);

(10) Horizontal deformation measurement range: 0-20mm;

(11) Horizontal deformation measurement accuracy: ±0.5% F·S;

(12) Vertical deformation measurement uses four displacement sensors, with deformation control based on their average value;

(13) Horizontal deformation measurement uses two displacement sensors, with deformation control based on their average value.

2. Seepage subsystem;

(1) Seepage pressure: 0.2MPa

(2) Seepage pressure accuracy: ±1% of indicated value (within 5% to 100% of full scale);

3. Joint surface morphology testing subsystem

(1) Maximum specimen size: 0.4m in X and Y directions (horizontal);

(2) Joint surface Cartesian coordinate system travel: 0.2m in Z direction (vertical);

(3) Morphology testing accuracy: ±0.001mm.