# Dynamic Properties of Calcareous Sands from Urban Areas of Abu Dhabi
## 2 Background and Literature  
[PERSON] and [PERSON] [7] presented results from resonant column testing on the evaluation of stiffness and damping of calcareous and siliceous sands. They tested two reconstituted sand samples that were retrieved from Northwest Australia. Both samples had the same state density and particle size distribution. Six confinements (50, 100, 200, 400, 800 and 1600 kPa) were used. The results indicated higher dynamic properties as well as faster stiffness degradation for calcareous sand compared to silica sand. [PERSON] et al. [9] presented results from CT and RC tests on calcareous and siliceous sand samples from the Bushehr region of the Arabian Gulf. A total of 36 tests were conducted. Bushehr sand is classified as calcium carbonate (CaCO\({}_{3}\)) comprising 53.1% of sample volume. Scanning electron microscopic (SEM) images showed angular and sub-angular soil particles with a rough surface. Bushehr sand is blended with transported soil and biological carbonate materials. It is classified as a poor graded sand (SP). The main objective was to assess the effect of the mean confinement, sample density, and stress anisotropy on the dynamic properties (i.e., shear modulus and damping ratio). The effect of the initial stress anisotropy was insignificant to the dynamic properties; however, the variation of initial mean confinement and relative density showed significant effects. [PERSON] et al. [10] conducted a series of resonant column tests on reconstituted carbonate and siliceous sands samples. All cylindrical samples had dimensions of 50 by 100 mm. The samples were taken from the South China Sea (Jinzhong region). They presented the dynamic properties (shear modulus and damping ratio) for nine samples from each sand type. The main focus of the study was to evaluate the effects of different initial relative densities and different confinements on dynamic properties. The relative density for the 18 samples ranged from 38.6% to 72.7%, while three isotropic effective confinements of 29, 57 and 97 kPa were used. They noticed higher dynamic properties at low strains but faster stiffness degradation for calcareous sand compared to siliceous sand. [PERSON] et al. [12] evaluated the shear modulus of two types of sands with BE, which were collected from different locations of ABD and the Belgian province of Antwerp. Intheir study, they tested several reconstituted cylindrical samples (50 by 90 mm) of calcareous and silica sands. The main focus of the study was to investigate and compare the effects of particle shape on dynamic properties. The results indicated a higher shear modulus in calcareous sands compared to silica sands at low strains. The results only presented variations of Vs with confinements and did not show degradation characteristics. [PERSON] et. al [13] presented the results of a comprehensive laboratory testing program, which included BE, CT, and RC tests. Samples were collected from the hydraulic fill of an artificial island located in the UAE. The fill mainly comprised calcareous sand, which was predominantly aragonite. A total of 37 reconstituted drained and undrained samples were tested. The small-strain Vs and the compression wave velocity (Vp) were measured with BE (30 to 1200 kPa). The results of the RC testing were in good agreement with the results from [PERSON] et al. [8] and [PERSON] et al. [11]. [PERSON] et al. [15] showed the evaluation of dynamic properties for representative calcareous sand from a newly developed coastal area near the Mediterranean Sea. Tests were performed with a resonant column (RC) to study the effect of the void ratio, saturation, particle shape and confinement on the measured dynamic properties. The study showed that the shear modulus was higher for calcareous sand at higher confinements compared to the shear modulus for siliceous sands. Various models have been proposed in the literature to curve-fit the measured dynamic properties as a function of shear strain level.