Abstract: The uniaxial compression mechanics test was carried out by simulating the osmotic pressure generated by the centrifugal test. The influence of the penetrating force on the mechanical properties of the filling body was studied, and the deformation characteristics of the filling body sample were discussed with the change of the osmotic pressure. The results show that as the penetration force increases, the interval of the stress-strain curve of the sample decreases first and then increases, the interval of the elastic phase shrinks, and the yield stage is not obvious. From low osmotic pressure to high osmotic pressure in the test process, the failure mode of the sample is successively characterized by tensile failure and shear failure, the number of cracks generated increases, and the morphology tends to be more complicated. On the basis of the mechanical test, a damage-softening constitutive model of the filling specimens with different osmotic pressures is established, considering the stress-strain relationship of the specimen in the compaction stage. The verification results show that the theoretical curve and the experimental curve are highly consistent. The model is suitable for analyzing the uniaxial compression mechanics of filling bodies with different osmotic pressures. The study provides a reference for the development of supergravity centrifugal simulation and underground seepage experiments.

Key words: filling body, centrifugal simulation, osmotic pressure, mechanical properties, constitutive model