Effects of unconfined compressive strength and breakage on the bearing capacity of rubble mounds: Insights from laboratory and DEM investigations
Effects of unconfined compressive strength and breakage on the bearing capacity of rubble mounds: Insights from laboratory and DEM investigations
Due to the rising cost of high-quality rock in Japan, the use of materials with lower unconfined compressive strength (UCS) than those specified in the standard for rubble mound structures is gaining increased attention. To ensure their safe application, it is essential to understand how stone characteristics, particularly strength and crushability, influence the overall bearing capacity. This study presents centrifuge model experiments on standing mounds constructed from two rock types with different UCS values, together with discrete element method simulations of a benchmark rubble mound composed of bonded particles representing eight different UCS levels, to evaluate bearing capacity and investigate particle breakage behaviour. The results indicate that, up to maximum stress levels of 300 kPa, both materials exhibited quite similar bearing capacity despite about threefold difference in UCS. It is due to the bearing capacity being insensitive to UCS under limited particle breakage at low stress levels, whereas a pronounced nonlinear dependence on UCS emerges once UCS drops below a critical threshold associated with extensive breakage at high stresses. These findings highlight the importance of considering breakage effects across different stress levels when evaluating the physical and mechanical performance of structures composed of crushable materials.
Rawiwan Sukhumkitcharoen; Itsuki Sato; Masahide Otsubo; O. Kurihara; Hidenori Takahashi
11th International Conference on Physical Modelling in Geotechnics (ICPMG2026)
Session 6: Onshore and offshore foundation systems
https://doi.org/10.53243/ICPMG2026-142