TA572 : Evaluate the effect of different lengths and diameters on the behavior and bearing capacity of stone cloumn mixed with crumb rubber using extensive physical modeling
Thesis > Central Library of Shahrood University > Civil & Architectural Engineering > MSc > 2021
Authors:
Mohammad Elyasi Nezhad [Author], Mohsen Keramati[Supervisor]
Abstarct: With the growth of population and car production, large volume of waste rubber would be collected in order to accumulation or burial in predicted places. High cost of burial, high volume of rubber due to low specific gravity, fire hazard and pollution due to prolonged burning of rubber and other problems would cause many environmental problems. Our country as the same as other involved countries is faced with these challenges due to the importance of the environmental problems and high rate of wasted rubbers annually. One way to deal with this problem is re-use of these wasted rubbers in civil engineering which has high user potential in various fields. One of these applications in civil engineering is stone column which is as an option in order to correcting bearing capacity of loose soils, the increment of drainage capability and the reduction of subsidence in structures constructed on these soils. The aim of these performed experiments is investigation the effect of using crumbs of rubber on the bearing capacity of stone columns. In this research, crumb rubber waste is used as an alternative material instead of sand materials and its impact on the behavior of stone-column has been studied. One experimental study on a type of Polica pipe by three diameters of 84,115,160 mm and four lengths 35,50,75 and 125 cm by use of a type of crumbs of rubber with dimensions (the most optimal) by volumetric percentage of 40% (the most optimal percentage) has been done in one large-scale physical modelling device. Then 12 series of experiments of direct cutting in large scale has been done within three volumetric ratio of mixture sand and crumbs of rubber. Findings of this test in direct cutting box in large scale and physical modeling device show the increment of the bearing capacity of mixed stone columns by 40% of volumetric rate of crumbs of rubber rather the pure sand. The results of direct-cut of large scale experiments show that by adding 40% of volumetric rate of crumbs of rubber to the sand then the bearing capacity of stone column would be increased rather than the pure sand but by adding more than 40% of crumbs of rubberto the sand, the result would be opposite and the bearing capacity of stone column would be reduced as compare by the pure sand. The experimental results of large-scale of physical modelling show that in one stone column by fixed length, the bearing capacity of stone column would be increased by the reduction of l/D rate. Also on the case of fixed diameter of 84, 125, 160 mm, by the increment of I/D rate up to 3.125, 4, 5.95 respectively, then the bearing capacity of the sand column would be increased and then by increment of I/D rate up to 7.81, 10, 14.88 respectively, then the bearing capacity would be decreased. The best performance of the sand column is shown in the length of 50 cm and the diameter of 160 mm by l/D rate of 3.125 which causes 21% of the increment in the bearing capacity of the sand column. As conclusion, this study shows that using of crumbs of rubber as an alternative material instead of the sand could be as an economical way in order to the increment of the bearing capacity of stone columns and it could be as the best solution for the environmental problems
Keywords:
#Geo-technique of the environment #crumb rubber waste #stone column #soil improvement #bearing capacity Keeping place: Central Library of Shahrood University
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