Bearing capacity and deformation behavior of rigid strip footings on coral sand slopes

• Published in: Ocean engineering 2023-01, Vol.267, p.113317, Article 113317
• Main Authors: Luo, Zhao-gang, Ding, Xuan-ming, Ou, Qiang, Fang, Hua-qiang
• Format: Article
• Language: English
• Subjects: Bearing capacity; Coral sand slope; Failure pattern; Geogrid reinforcement; PIV technology; Strip footing
• ISSN: 0029-8018; 1873-5258
• DOI: 10.1016/j.oceaneng.2022.113317

Porous coral sands formed by the remains of marine organisms are important foundation-filling materials for artificial island construction and other marine geotechnical projects. A typical situation is that the significantly reduced bearing capacity of a rigid footing adjacent to coral sand slopes threatens the safety and stability of the upper structures. In this study, a series of model-scale tests were conducted to investigate the bearing capacity and deformation behavior of a rigid strip footing resting on the top of coral sand slopes with consideration of the effects of edge distance, slope height, slope angle, number of geogrid layers, burial depth and spacing of the geogrid layer. The measured deformation field based on particle image velocimetry (PIV) technology indicates that the unreinforced coral sand slope is dominated by unilateral sliding patterns, and its bearing area is significantly smaller than that of the geogrid reinforced coral sand slope (GRCSS). The bearing capacity in unreinforced coral sand slopes increases with the increasing edge distance, and the decreasing slope height and angle. Although the geogrid reinforcement significantly improves the bearing capacity, it is also affected by the number of layers, burial depth and spacing between reinforcement layers. Besides, the reduction coefficient of bearing capacity (RCBC), the bearing capacity factor (Nγq) and the normalized bearing capacity (Nγq/NγqR) were further calculated and discussed based on the test results and classical bearing capacity theory. •Geogrid reinforcement significantly improve the bearing capacity of coral sand slopes.•Multiple effects on geogrid reinforced coral sand slopes (GRCSS) are considered.•The measured deformation field using PIV reveals the failure mechanism of slopes.•Calculation and modification of bearing capacity for reinforced and unreinforced slopes.