A micromechanical interpretation of the capillary effect of unsaturated granular material in a pendular state

Capillary force and rupture of funicular liquid bridges between three spherical bodies

“…After the pioneer works of Haines [11] and Fisher [12], the pendular water bridge has been well understood by using two spherical particles with either controlled water volume [13][14][15][16][17][18][19][20] or constant suction [21,22]. Wet granular materials has also been investigated using the Discrete Element Method (DEM) [23] with the pendular water bridge effects [17,21,[24][25][26][27][28][29]. It is aware from the literature that within the pendular state, the capillary force, which represents the magnitude of inter-particle adhesive effect, and the rupture distance, which determines the total number of interactive pairs, are the main factors for the material strengthening.…”

A micro–macro investigation of the capillary strengthening effect in wet granular materials

“…In the simulated materials by some authors [42,52,43,9], the water bridges between particles are based on the Young-Laplace solution and the sample moisture content is constant, while the toroidal shape water bridge model is also adopted by some other researchers [7] and they obtained similar material behaviours. Furthermore, suction controlled simulations are carried out [47,48,58], in which matric suction is constantly maintained through the sample. Recently, Gladkyy and Schwarze [11] compared the DEM simulation results by using different water bridge model, and it is observed that the macroscopic results are closed to each other.…”