The study of dynamic properties of carbonate sand through a laboratory database
- PDF / 1,209,548 Bytes
- 13 Pages / 595.276 x 790.866 pts Page_size
- 75 Downloads / 206 Views
ORIGINAL PAPER
The study of dynamic properties of carbonate sand through a laboratory database Xin Liu 1,2 & Sa Li 1,2 & Liqiang Sun 1,2 Received: 7 December 2019 / Accepted: 20 March 2020 # Springer-Verlag GmbH Germany, part of Springer Nature 2020
Abstract Carbonate soils are located in temperate and tropical regions of the earth. This kind of soil has special mechanical properties compared with siliceous sand due to special sedimentary environment. In this paper, resonant column device is used to investigate the shear modulus and damping ratio of carbonate sand in the South China Sea at small and moderate shear strain amplitudes. At the same time, the dynamic properties of siliceous sands with the same gradation are also studied for the comparison. The influence of isotropic effective confining pressure and relative density on the dynamic characteristics of the sands is studied. The shear modulus of tested carbonate and siliceous sands increases with the increase of effective confining pressure and relative density. The influence of relative density on the shear modulus and maximum shear modulus of carbonate sand is more obvious than that of siliceous sand under identical test conditions. The damping ratio of both two sands decreases significantly with the increase of effective confining pressure, but the influence of relative density on the damping ratio is not obvious. A comparison between the dynamic characteristics of the carbonate and siliceous sand shows that carbonate sand has higher shear modulus, higher damping ratio, and faster shear stiffness degradation. Based on this study and other existing dynamic and cyclic tests data of different carbonate soils, a database of normalized shear modulus and damping ratio for carbonate soils was created, and a modified hyperbolic model was proposed for calculating the normalized shear modulus and damping ratio of carbonate soils with different calcium carbonate contents. Keywords Carbonate sand . Siliceous sand . Shear modulus . Damping ratio . Database . Modified hyperbolic model
Introduction Carbonate soils are a special geotechnical material rich in calcium carbonate or other insoluble carbonates. This type of soil is mainly distributed in the continental shelf and coastline of tropical or subtropical regions (Holmes 1978). For example, there are a large number of carbonate soils on many islands and reefs in the South China Sea. Carbonate sands are formed in the marine sedimentary environment, and its material composition mainly originate from shells, corals, and biological debris (Zhou et al.
* Sa Li [email protected] 1
School of Civil Engineering, Tianjin University, Tianjin, China
2
State Key Laboratory of Hydraulic Engineering Simulation and Safety, Tianjin University, Tianjin, China
2018). Therefore, this kind of sand presents different characteristics in comparison to terrigenous sand, such as remarkable intraparticle voids, irregular particle shape, and particle crushing (Semple 1988; Brandes 2011; Salem et al. 2013; Xiao et al. 2017; Zhou et al. 20
Data Loading...
