WAJIMA Tomoya

Simulation for slaking process of mudstone by particle calculation model

OHTSUKA Satoru

Swelling and slaking phenomena mainly occurring in mudstone cause ground disasters such as swelling, landslide and slope failure. Among them, mudstones including swelling clay minerals such as montmorillonite and bentonite are remarkably increased in volume due to water absorption. In addition, as they dry, cracks are formed on the surface and inside so that weathering is promoted and fine grain is generated, which greatly affects the strength of cut slope including embankment and embankment. Therefore, it is one of the important tasks from the viewpoint of ground disaster prevention to grasp the weathering process due to absorption and drying shrinkage of mudstone in detail.
Therefore, in this study, we extended the DEM model for detailed understanding of the process of slaking phenomenon due to repeated wet / dry cycles of mudstones containing swelling clay minerals, and simulated the slaking phenomenon of mudstone subjected to dry and wet cycles in two dimensions The applicability of the proposed model was verified from the obtained results.
As a result of the simulation, it was possible to change the fracture behavior of the DEM model by changing the fixing stress between the particles, but with the parameters of the intergranular fixing stress similar to that of the soft rock, the slaking rate is not sufficient and the appearance Was also different from the actual mudstones. In the simulation of this time, by introducing the non-expansion region, the slaking rate and the deformation behavior were changed and the weathering behavior of the actual mudstone sample approached. As future prospects, actual stagnation of the mudstones is thought to weaken the sticking between the particles due to infiltration, so it is possible to realistically model by newly introducing a parameter whose expansion amount varies depending on the water content and water content is there.