The phenomenon of liquefaction in loose and saturated Sandy soils is one of the most important hazards for engineering structures during an earthquake. In this phenomenon, the Sand changes its behavior rapidly from solid to viscous fluid, resulting in the instability of the ground. In this research, at first, Sand samples with liquefaction history collected from a site in Dorood, Lorestan, Iran. Samples obtained from depth of 1.8-2.7 and 2.7-3.5 m and in the laboratory, the parameters of maximum density, moisture content, friction angle and cohesion were determined. Then, in order to evaluate the effect of additive on the liquefaction potential, different percentages of clay from Dorood region added to the samples and tested. Finally, three-dimensional finite difference software (FLAC3D) used with inducing Dorood earthquake, to investigate liquefaction potential of stabilized samples by analyzing the u/σ ratio for models. The results showed that adding clay to the soil of this area reduce the friction angle, increase cohesion, and has a favorable effect on the liquefaction potential. Results of this investigation indicated that adding 3% clay to the liquefied Dorood Sand, would lead to decrease the liquefaction potential up to 39%.

The phenomenon of liquefaction in loose and saturated Sandy soils is one of the most important hazards for engineering structures during an earthquake. In this phenomenon, the Sand changes its behavior rapidly from solid to viscous fluid, resulting in the instability of the ground. In this research, at first, Sand samples with liquefaction history collected from a site in Dorood, Lorestan, Iran. Samples obtained from depth of 1. 8-2. 7 and 2. 7-3. 5 m and in the laboratory, the parameters of maximum density, moisture content, friction angle and cohesion were determined. Then, in order to evaluate the effect of additive on the liquefaction potential, different percentages of clay from Dorood region added to the samples and tested. Finally, three-dimensional finite difference software (FLAC3D) used with inducing Dorood earthquake, to investigate liquefaction potential of stabilized samples by analyzing the u/σ ratio for models. The results showed that adding clay to the soil of this area reduce the friction angle, increase cohesion, and has a favorable effect on the liquefaction potential. Results of this investigation indicated that adding 3% clay to the liquefied Dorood Sand, would lead to decrease the liquefaction potential up to 39%

This research describes the goals, design and implementation of a quasi natural gradient, laboratory scale, Sand tank (aquifer) model experiment. The model was used to study the transport of an inorganic tracer (Chloride) in groundwater, within a tropical aquifer (porous medium) material. Three-dimensional Sand tank (1.8 m × 0.3 m × 0.8 m) experiments were conducted to investigate contaminant transport and natural attenuation within the Sand tank. In all, 360 samples were collected during 24 sampling sessions, for the three days of the tracer experiments in the Sand Tank. The Owena Sand is a poorly graded Sand with 88.1 % Sand and 11.9 % gravel. Geotechnical properties including; coefficient of uniformity Cu = 2.53, coefficient of gradation Cz = 0.181, hydraulic conductivity K = 5.76 x 10-4 m/s, bulk density ρ = 1.9 Mg/m3, effective porosity ne = 0.215 and median grain diameter D50 = 0.55 mm, were determined. Other relevant hydraulic and solute transport parameters, such as dispersion coefficients and dispersivities were also established for the tropical soil.

One of the ways to improve the performance of simple solar stills is to use energy storage materials to store energy during the day and use it at night. Several energy storage materials have been studied by researchers, one of which is the use of Sand. In this research, the improvement of a simple solar still performance has been studied using Sand with different grain size distribution inside its basin. For this purpose, four solar still were made in Esfarayen (latitude 36. 20 and longitude 57. 67), Iran, and the effect of Sand grain size distribution on its performance was studied in four treatments. The height of Sand and water was 10 cm and the average grain size of treatments was considered 6. 9, 2. 8, 1. 1 and 0. 7 mm. The experiments were performed for 4 days in mid-August 2020. The results showed that the Sand-containing treatment with an average grain size of 2. 8 mm had better productivity and thermal efficiency than other cases where the average grain size of the used Sand was larger or smaller. Therefore, grain size distribution of the Sand seems to affect the performance of simple solar stills and there is an optimal amount for grain size.