Seismic responses of slopes with different angles in coral sand

• Published in: Journal of mountain science 2021-09, Vol.18 (9), p.2475-2485
• Main Authors: Zhang, Yan-ling, Ding, Xuan-ming, Chen, Zhi-xiong, Wu, Qi, Wang, Cheng-long
• Format: Article
• Language: English
• Subjects: Acceleration; Corals; Displacement; Earth and Environmental Science; Earth Sciences; Ecology; Environment; Excitation; Geography; Liquefaction; Original Article; Pore pressure; Pore water pressure; Pressure; Pressure ratio; Sand; Seismic response; Shake table tests; Shear stress; Soil; Soils; Water levels
• ISSN: 1672-6316; 1993-0321; 1008-2786
• DOI: 10.1007/s11629-020-6546-9

This paper investigates the seismic responses of slopes in coral sand taken from a reef island in the South China Sea. A series of shaking table model tests were conducted to explore the responses of soil acceleration, excess pore pressure, and slope displacement for three slope angles (5°, 10°, and 15°). The results show that the excess pore pressure ratio of the slope decreases due to an increase in the initial shear stress when the slope angle increases. The acceleration response of the soil increases with the increase of the slope angle. The slope displacement presents substantial increments as the excess pore pressure ratio increases. In addition, the lateral movement, and slope settlement present substantial increments as the slope angle increases. No liquefaction is observed under a dynamic excitation of 0.2 g in the coral sand site. Under a dynamic excitation of 0.4 g, the site liquefies quickly, the acceleration amplification factor decreases, and the lateral movement and the settlement of the slope surface both increase compared with that under 0.2 g excitation. For the slope with an angle of 15° at 0.4 g, the flow distance of the sand strip increase by 289.47% compared with that in the 5° case. The lateral movement of the slope surface near the water level line is substantially larger than that away from the water line. The largest settlement is observed near the middle section of the slope (below the water level) under a dynamic excitation of 0.2 g. In contrast, the largest settlement under a dynamic excitation of 0.4 g occurs at the top of the slope.