Abstract:In order to observe and measure the deformation and damage characteristics and the real-time change of pore structure of coal sample under different stress,temperature and the effect of osmotic pressure condition,a multifunctional loading system which could work with industrial CT test bench was developed.The system could simulate the environment of high temperature and high pressure in deep formation,and realize real-time data monitoring and control of axial compression,pressure,osmotic pressure and temperature.The loading system was controlled by the fuzzy PID controller.The simulation and experimental tests show the high resolution and stability in controller.The multifunctional loading system was pseudo triaxial loading with the CT scans and permeability measurement of sample at the same time.Through the experiments of the system,a series of stress strain curve and CT images of raw coal under different loading were gotten and the experiment results verified the validity and reliability of the multifunctional loading system.