Effect of Fine Content on the Bearing Capacity of Replaced Sand Gravely Subgrad-Field Test

The compacted soil replacement procedure has been widely used worldwide for overcoming the unfavorable actions of some problematic soils,such as expansive,collapsing soils and ground fill.Compaction of the replacement soil is necessary for stabilizing such layer for improving its performance.In this study,gravelly-sand soil,which consists of gravel,sand and fines,is widely used as replacement soil in the field.The effect of fines content on possibly achieved density of such soil is experimentally investigated.A series of laboratory compaction and plate loading tests were carried out on the replaced soil at different fine contents of 0,5,8,10,12 and 15%.The results showed that,the supporting capacity of a replacement soil increases with the increase of its dry density.Therefore,the density of the replacement layer is the major factor controlling its behavior under the effect if external stresses.Compacted sand and gravelly sand are preferred materials when used for soil replacement.They tend to have better engineering properties,if they are placed according to the standard specifications.Another experimental stage of the effect of fines on the bearing capacity of circular footings on gravelly-sand with different percentages of fines was performed.It was found that a fine content of 10%gives the highest dry density,if the soil is compacted according to modified proctor specifications and with the addition of fines,the footing settlement increases and the ultimate bearing carrying capacity decreases.

Geotechnical Characterization of Silty Clay Reinforcedwith Jute Cloth as Waster Product

Soil reinforcement is a recent and special field of soil improvement.It covers a range of techniques,which consists of placing inclusions in soil.The most conferences devoted partly or totally the behavior of foundation on reinforced subgrade without regarding the basic characteristics of the reinforced soil.So,the paper presents an experimental investigation into the mechanical and compressibility properties of the reinforced silty clay samples by jute cloth at intermediate depth.The effects of the reinforcement on shear stress and shear failure were studied;also,the presence of the reinforcement on behavior of consolidation process was distinctly described.The laboratory tests were supported by the finite element analysis to identify only the consolidation process and explained the effect of the reinforcement on the effective vertical stress and pore water pressure.The results indicated that the presence of such reinforcement has a considerable effect in increasing the shear strength of the reinforced samples and decreasing the compressibility especially decreasing the soil movement also,relieving both the effective and pore water pressure.