Evaluation of hydraulic conductivity through particle shape and packing density characteristics of sand–silt mixtures     

Abdellah Cherif Taiba  Youcef Mahmoudi  Leila Hazout  Mostefa Belkhatir  Wiebke Baille 《Marine Georesources & Geotechnology》2013,31(10):1175-1187

Abstract

This study aims to evaluate the relationship between saturated hydraulic conductivity with particle shape and packing density characteristics of silty sand soils. The article presents a series of hydraulics tests performed on three kinds of sand with different particles shapes (Chlef rounded sand, Fontainebleau sub-rounded sand and Hostun sub-angular sand) mixed with low plastic rounded Chlef silt in the range of 0–30% fines content. The sand–silt mixture samples were tested in the constant-head permeability device at a loose relative density (D_r = 18%) and a constant room temperature (T?=?20?°C). The obtained results indicate that the measured saturated hydraulic conductivity (K_s) correlates very well with the fines content (F_c), packing density in terms of [maximum void ratio “e_max,” minimum void ratio “e_min,” predicted maximum void ratio “e_max”_pr and predicted minimum void ratio “e_min”_pr] and particle shape characteristics ratios in terms of roundness ratio (R_r = R_hs/R_mixture) and sphericity ratio (S_r = S_hs/S_mixture) of the silty sand materials under consideration. Moreover, the analysis of the available data show a noticeable success in exploring the prediction of the saturated hydraulic conductivity (K_s) based on the particle shape and packing density characteristics (R_r, S_r, e_max, and e_min) of the studied sand–silt mixture samples.  相似文献   

Design,manufacture and calibration of the SARI portable rainfall simulator for field and laboratory experiments     

Ataollah Kavian  Maziar Mohammadi  Artemi Cerdà  Moghadaseh Fallah  Leila Gholami 《水文科学杂志》2019,64(3):350-360

The Simulator of Artificial RaInfall (SARI) rainfall simulator (RS) is a newly designed, constructed and calibrated, portable, two-nozzle RS with low water consumption, accurate measurement, easy management and low cost. The raindrop size distribution and velocity and mean rainfall intensity were measured. The best rainfall spatial distribution was achieved with nozzles separated by 50, 60 and 70 cm, and with oscillation angles of 30, 45 and 60°, at a pressure of 60 kPa. The uniformity coefficient varied from 57 to 61% and rainfall intensity from 48 to 101 mm h^?1. The raindrop diameter varied from 0.2 to 9.9 mm. The raindrop velocity at the optimum pressure of 60 kPa, which was measured with high-speed photography, ranged from 1.1 to 7.1 m s^?1. Comparison with other RSs shows that the SARI simulator is a suitable apparatus to research soil erosion and runoff generation under laboratory and field conditions.  相似文献