A series of triaxial compression tests were performed in an attempt to evaluate the bene ts of plastic wastes and investigate the engineering properties of SAND REINFORCED with such materials. In this research, the e ects of the contents (0, 0. 25, 0. 5, 0. 75, and 1% of the dry weight of SAND) and types of plastic wastes (Poly-Ethylene Terephthalate (PET) and Poly-Propylene (PP)  bers) as well as the con ning pressures (50, 100, and 200 kPa) on the SAND behavior in Babolsar, Iran were investigated. The values for deformation modulus (up to 84%), peak (up to 7 times of the unREINFORCED SAND), and steady state shear strength increased upon reinforcement. Moreover, axial strain at failure for  ber-REINFORCED SAND increased up to 1. 5 times its unREINFORCED counterpart (from 3. 36% to 8. 53% for 1% PP usage at con ning pressure of 50 kPa). Generally, it can be concluded that using plastic wastes in the SAND would result in low-cost soil reinforcement and a reduction in the disposal problem of these kinds of wastes.

This study presents the numerical analysis of triaxial drained test results on fine SAND specimens REINFORCED with carpet strips, using the Plaxis software, Two sets of test results of plain coarse and fine SAND specimens were also analyzed. This comparative study revealed the following conclusions:1) The stress-strain and volume change characteristics of plain SAND specimens obtained from the laboratory tests and the numerical analyses were agreeable. The accuracy however seems to be controlled by the magnitude of confining pressure and also the size of SAND particles. The numerical results of the coarse SAND were much more reasonable and comparable.2) The results for the fine REINFORCED SAND were not quite well and agreeable with the experimental values. The discrepancy was more pronounced for the volume change results, and also with the increase of fiber content or aspect ratio. It seems that the hardening soil model may not be appropriate in capturing the real behavior of fiber REINFORCED SAND particularly with respect to the volume change characteristics.

In recent years, scraped tires have become an environmental burden and economic problem. Reusing waste tires for reinforcing slopes can be a suitable solution for the disposal and reduction of the number of waste tires. In this paper, a series of experimental model tests have been carried out to investigate the behavior of Horizontal Elements of Waste Tire (HEWT) in stabilizing SANDy slopes. Digital images taken of the side of the model during incremental loading and Particle Image Velocimetry (PIV) were used to investigate the slope under surcharge loading. Some important parameters such as the length, number, and location of the reinforcing tire layers were studied in this paper. There is an obvious plastic zone on the unREINFORCED and REINFORCED SANDy slope shown using PIV. It shows that scrap-type reinforcement highly improved the strength of the SANDy slopes and the model resulted in bearing capacity about 3. 5 times larger and settlement about three times less in comparison with an unREINFORCED SANDy slope.

An experimental study is carried out to improve the bearing capacity of soils by using geotextile. In the present study geotextile (tire reinforcement) is used as geotextile, whereas SAND is used as a soil medium. This research work presents the results of laboratory load tests on model square footings supported on REINFORCED SAND beds. A total of twenty-seven load tests are conducted to evaluate the effects of single layer reinforcement placed below square model footings. The parameters of the testing program of the research work are the depth of reinforcement, the plan area of reinforcement, and the number of reinforcements. From the experimental data, it is indicated that there is an optimum reinforcement depth at which the bearing capacity is the highest. Also, the optimum size of reinforcement is found to be 1.5 B×1.5 B irrespective of the type of reinforcing materials used. The bearing capacity of REINFORCED SAND is also found to increase with the number of reinforcement layer and reinforcement size when the reinforcement is placed within a certain effective zone with high relative density. The optimum placement position of geotextile is found to be 0.5B to 0.75B from the base of the footing .The tests are done at two different relative densities, i.e., 40% and 60%. The bulk unit weight of SANDy soil is 14.81 KN/m³. Maximum gain in load carrying capacity is obtained when depth of reinforcement/width of footing (Dr/B) is 0.5 at relative density of 40% and 0.75 at a relative density of 60%.In addition, the data indicate that increasing reinforcement beyond a certain value would not bring about further increase in the bearing capacity of the soil.

Conventional investigations on the behavior of REINFORCED and unREINFORCED soils are often investigated at the failure point. In this paper, a new concept of comparison of the behavior of REINFORCED and unREINFORCED soil by estimating the strength and strength ratio (deviatoric stress of REINFORCED sample to unREINFORCED sample) at various strain levels is proposed. A comprehensive set of laboratory triaxial compression tests was carried out on wet (natural water content) non-plastic beach silty SAND with and without geotextile. The layer configurations used are one, two, three and four horizontal reiriforcing layers in a triaxial test sample. The influences of the number of geotextile layers and confining pressure at 3%, 6%, 9%, 12% and 15% of the imposed strain levels on sample were studied and described. The results show that the trend and magnitude of strength ratio is different for various strain level. It implies that using failure strength from peak point or strength corresponding to the axial-strain approximately 15% to evaluate the enhancement of strength or strength ratio due to reinforcement may cause hazard and uncertainty in practical design. Hence, it is necessary to consider the strength of reiriforced sample compared with unREINFORCED sample at the imposed strain level. Only one type of soil and one type of geotextile were used in all tests.

The most important parameters in evaluation of dynamic behavior of soil structures such as highways, retaining walls, and embankments are shear modulus and damping ratio. A fiber REINFORCED soil behaves as a composite material in which fibers of relatively high tensile strength are embedded in a matrix of soil. Shear stresses in the soil mobilize tensile resistance in the fibers, which in turn imparts greater strength to the soil. This study deals with assessment of fine SAND REINFORCED with carpet and geotextile strips when subjected to dynamic loading by performing two sets of cyclic triaxial test- large scale and small scale. In these tests the influences of various parameters such as confining pressure, mixture ratio, and the ratio of strip length to its thickness which will herein be referred to as aspect ratio on the dynamic behavior of REINFORCED fine SAND were studied. The results demonstrate that the effects of this kind of reinforcement on shear modulus in low confining pressures (less than 100kPa) are negligible and in high confining pressures are considerable.

fiber REINFORCED soil behaves as a composite material in which fibers of relatively high tensile strength are embedded in a matrix of soil. Shear stresses in the soil mobilize tensile resistance in the fibers, which in turn imparts greater strength to the soil. In this paper a study on the influence of synthetic fibrous materials in improving the dynamic strength characteristics of a fine SANDy soil is reported. The study is aimed at converting fibrous carpet waste into a value-added product for soil reinforcement. A series of stress controlled cyclic triaxial tests were carried out on fine SAND specimens REINFORCED with randomly distributed carpet strips. The dynamic deformation properties of the REINFORCED SAND are defined in terms of shear modulus and damping ratio. The effects of parameters such as fiber content and aspect ratio, number of cyclic loading and the level of confining pressure on the aforesaid parameters were investigated. The results clearly indicate the increase of damping ratio of REINFORCED samples in different confining pressure. The increase is more pronounced in higher fiber contents and aspect ratios.

Triaxial consolidated drained, unconfined compression, and CBR tests have been conducted in order to study the stress-strain, strength, and volume change characteristics affine SAND specimens REINFORCED by polymeric fibers made from carpet wastes. The variables are aspect ratio (length/width) and weight percentage of the fibers. The results indicate that the peak strength and total volume change of REINFORCED specimens increase whereas the maximum elastic modulus decreases as the fiber content increases. The rate of increase in the peak strength and total volume change, however, diminishes with increasing the fiber content. The effect of increase in the aspect ratio on results is similar to that of the fiber content.