A series of load-bearing model tests were conducted to study the bearing behavior and failure mechanism of a shallow foundation on/behind a poorly cemented sandstone slope. The model rock slope was made of artificial rock that simulates natural poorly cemented sandstone. The similarity of their mechanical characteristics was examined by similitude comparison. The comparisons confirmed that the properties of the artificial material are close to those of natural poorly cemented sandstone. The load-bearing behavior can be divided into four stages: the stress-adjusting stage, the linear stage, the non-linear stage, and the ultimate stage on load-settlement curve. The failure zone and mechanism were also identified. The failure mechanism was composed of an active zone, a transitional zone, and a passive zone; the failure zones eventually propagate into the sloping side. Slope angle and setback distance affect the area and shape of failure zones, as a consequence, significantly affecting the ultimate bearing capacity. The results of model tests indicate that the ultimate bearing capacity decreases with increasing slope angle and increases with increasing setback distance. When the setback distance is more than 2.5 times of the width of the footing, the ultimate bearing capacity is close to that of level ground. The bearing behavior and failure mechanism on poorly cemented sandstone are distinct from the cases of hard rock or soil; it possesses both plasticity and brittle characteristics. Based on the observed behavior from the model tests, the failure mechanism may be modeled as a multi-block translation mechanism.
|Number of pages||11|
|Journal||International Journal of Rock Mechanics and Mining Sciences|
|State||Published - 1 Dec 2008|