مهندسی عمران شریف (Feb 2019)
WATER CONTENT EFFECT ON THE BEHAVIOR OF REINFORCED SOIL MIXTURE UNDER SURCHARGE LOAD WITH USING CENTRIFUGE
Abstract
The most important problem in reinforced soil walls and slopes made from the mixture of soil grain and fine-grained is effect of moisture increase and additional pore water pressure onto the body of reinforced embankment. For this reason, in regulations, the maximum amount of fine-grained in materials of embankment is limited to 15\%. In areas where suitable materials for embankment is not available, supply of remote areas is costly. Different regions of Iran soils with high percentage of fine-grained have large ranges in terms of regulation which are not suitable for construction reinforced soil walls and slops. In this study, additional attention has been paid to analysis of the effect of soil moisture content and existence surcharge load parameters in vertical reinforced soil walls and 20\% fine-grained on potential slip surface and behavior of deformation wall using centrifuge. In this study, a set of 6 centrifuge testes on soil walls reinforced with geotextile, which has fine-grained and moisture, was performed using the Geotechnical Research Center of Iran University of Science and Technology centrifuge, and the behavior of physical models in rotation using digital image processing technique was studied.The results showed that by increasing moisture content, the amount settlements on the wall and deformation of wall facing increased, but changes in moisture content have not influence on location of failure surface. It was observed that in high moisture content, friction reduction between the soil and reinforcement leads to reducing reinforcements strain; as the result, reducing reinforcement performance by pull - out test in some cases.It was also observed that reinforced layers placed in upper half of model and near strip footing experienced greater strains. The maximum strain of reinforcing layers always occurred in upper half of model. Also, a combination of image processing techniques all together with centrifuge tests creates a powerful and effective method in physical modeling of geotechnical phenomena, and very valuable results can be obtained from the images recorded during tests.
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