جستجوی مقالات مرتبط با کلیدواژه « ژئوگرید » در نشریات گروه « فنی و مهندسی »

Always considering risk, cost and time reduction, the best method for tunnel excavation should be selected and implemented. Choosing the optimal method for tunnel digging requires full knowledge of tunnel digging methods and the parameters affecting them. project conditions and existing infrastructure, project completion time, and environmental issues. Also, the prediction and control of settlement is of significant importance in urban areas, both from the point of view of safety and from the economic point of view. In recent years, the use of working tunnels at a shallow depth has been used to dig underground spaces, including subway stations and similar spaces in different soils, which is popular in urban spaces due to the lack of disruption to traffic. Tunneling at a shallow depth and in weak soil is called STM (Shallow Tunneling Method).Using STM in urban spaces it should be accurately evaluated in terms of settlement on the ground surface and its effects on surface mining structures. In order to check each of the methods, three-dimensional numerical modeling will be used. The purpose of numerical modeling by 3D method is to accurately check the amount of settlement during execution and to determine the best execution method with the least amount of settlement. Different methods with different classifications for drilling have been examined and finally the method that can be used in this study is presented and the best method with the least amount of settlement is introduced as the best option.

Building construction on slopes is inevitable, despite many limitations. Due to the seismicity of Iran, calculating the seismic bearing capacity of foundations is more important. The construction along a slope has been observed to result in a reduction in the bearing capacity. To mitigate this decrease, various improvement techniques, such as soil reinforcements like geogrids, can be employed to partially offset this reduction. The present study investigates the impact of ground slope (10 and 20 degrees) on the bearing capacity of granular soils with varying internal friction angles (25, 30, 35, 40, and 45 degrees) in both seismic and static conditions. This investigation employs the finite element limit analysis method and OptumG2 software to determine the upper and lower bounds of the bearing capacity. The findings indicate that the implementation of kh=0.1 leads to a reduction in the seismic bearing capacity of the foundation, ranging from 2 to 12 percent. The effective length of the geogrid is contingent upon the internal friction angle of the soil and varies within the range of 2B to 3B. Additionally, the study revealed that the optimal distance between the footing and the slope edge (X/B) is influenced by the internal friction angle, with a significantly bigger impact than the slope angle. The optimal distance (X) was estimated to lie within 2B to 4B for internal friction angles of 25, 30, and 35 degrees. Conversely, for internal friction angles of 40 and 45 degrees, the X value was assessed to be no less than 5B.

Carbonate sands are among the potential material sources for marine engineering constructions. However, the brittleness and large deformations created in these sands can affect the stability of marine structures built on these soils. Today, geosynthetics are used to reinforce and increase the strength of these soils. CD triaxial tests were conducted under different confining pressure values to compare the mechanical and deformation properties of reinforced and unreinforced calcareous sand. The influences of configuration of reinforcing layers, confining pressure, relative density, and type of woven geotextile have been evaluated. The results show that compared to the unreinforced carbonate sand, the strength of the reinforced samples increases markedly, and the deviatoric stress-strain curves change from slight softening to hardening and dilatancy. Compared to unreinforced calcareous sand specimens, the strength of reinforced specimens significantly increased such that this growth reached 100% in some specimens with low confining pressure. Also, by increasing the number of geotextile and geogrid layers and applying a confining pressure, the shear deformation shifts toward strain-hardening behavior. dilative behavior of the specimens increases with an increase in the relative density of the specimens. The results showed that the influence of the number of layers and arrangement of geosynthetics on the mechanical behavior and deformation of triaxial specimens decreases with increasing the confining pressure. The amount of strength increase in reinforced specimens at low confining pressure is relatively high and tends to decrease with increasing the confining pressure. Overall, woven geotextile and geogrid significantly improve the apparent cohesion strength of carbonate sand soil. Woven geotextile and geogrid, relative density, and confining pressure all contribute to volumetric changes and dilatancy of reinforced specimens, but particle breakage is more affected by confining pressure. Finally, the results showed that geogrid has a better performance in reinforcement than geotextile.

The growth of railway lines has caused engineers to seek to increase the efficiency of the ballasted railway track, and for this reason, they are looking for an increase in the maintenance intervals and a lower life cycle cost. In high-speed railways and lines with high traffic volume, especially railways with stiff and soft subgrade, the issue of line settlement is one of the challenging factors. According to the methods introduced to strengthen the subgrade so far, the use of geogrid is one of the conventional methods to reduce settlement and maintenance operations, which today requires more investigation in its optimal selection. In this article, an attempt has been made to investigate the effectiveness of geogrid to reduce stresses on the subgrade, sub-ballast layer, and ballast layer, and to explain how to choose it based on the technical parameters. In this study, the types of geogrid and the effect of mesh size, applied stress, and its effect on soil resistance have been investigated and the method of achieving the appropriate selection of geogrid has been suggested. Studies show that by using geogrid, the vertical settlement and horizontal movement of the railway panel can be reduced by 70%.

In this paper, the efficiency of the bedrock grain's characteristics on the performance of its layers was investigated. For this purpose, experimental and numerical studies were performed using ABAQUS software in both static and dynamic conditions. The performances of the geogrid layers in various types of soils by different values of elastic modulus and frictional angles were investigated. It was observed that increasing soil adhesion at a constant concentration, enhanced loading capacity, and reduced the reinforcing efficiency. Study on different soil types by various specifications showed that for soil substrates by values of elastic modulus of 10, 50 and 100 MPa, the effects of the layers of the reinforcement on improving the Settlement were about 75%, 65% and 54%, respectively. In dynamic loading mode, the performance of the reinforcement layers increased compared to static loading, and the improvements of the Settlement were 79%, 72% and 54%, respectively.

Geo-synthetics are made from polymers used to stabilize and improve soil behaviors. Nowadays, geo-grids are widely used in geotechnical engineering applications. In the present study, a surface foundation located on three different soil layers under a uniform load was modeled and analyzed using finite element method under specified acceleration. The intermediate soil profile consisted of loose clay reinforced using two types of geo-grids with different distances. The results showed that by increasing vertical distance between the geo-grid layers, the vertical displacement, axial force, shear force and flexural anchor applied to the foundation also increased. Furthermore, in the case of geo-grid layer positioned at a depth of 5m or more, the shear force and flexural moment increased with a steeper slope in comparison with other cases.

An understanding of of Pressure acting on underground pipes, especially for buried pipes, tunnels and shafts, is often practical and necessary during design . The physical model involves a buried pipe installed in granular soil subjected to strip surface loading. The consequence of introducing a geogrid reinforcement layer above the pipe on the distribution of contact pressure is also survived.The results of laboratory investigations to measure the pressure on pipes have been investigated using tactile sensor technology. This method allows a continuous pressure profile to be measured around the pipes using flexible sheets. Geogrids or flexible sheets are used as reinforcement to improve the strength of soil or other materials. The numerical analysis is first validated using the experimental results and then used to investigate the comprehensive behavior soil -

Granular materials are widely used in construction. The cost and environmental impact of supplying natural aggregates force the construction industry to look for alternative materials for engineering applications. The interface shear strength properties of recycled construction materials including concrete and asphalt with geogrid as alternative backfill materials in reinforced structures were investigated by using Large-scale Direct Shear Test (LDST) apparatus. Also, a comparison is made between the recycled materials and a natural material with the same physical characteristics and grain size. Geosynthetics are mainly used to stabilize and reinforce different types of earth structures such as slopes, retaining walls, bridge abutments, and foundations. In these cases, the interaction between soil and geosynthetic has a vital role. Three types of single-stranded geogrids were tested as reinforcements. The results showed that reinforcement increases the shear strength and internal friction angle. The tensile strength of geogrids does not have effect on the interface shear strength as the geogrids do not reach the failure state during shear test. The shear strength coefficient for these materials was greater than one, which indicates a strong interaction between the geogrid and the materials. Recycled materials including concrete and crushed asphalt have good shear strength and can be used as an alternative to natural materials in reinforced soil retaining walls, although their shear behavior is slightly different. In general, due to the involvement of these aggregates with the geogrid, it leads to an increase in the shear strength of the interface of these materials and the geogrid to the materials themselves. The shear behavior of natural materials and concrete changes from a slightly softening behavior to a hardening behavior on the interface, a process that is more severe in the case of asphalt. Also, the volumetric behavior of the interface of natural materials and recycled concrete with geogrid is more extensive than the materials themselves, the opposite is true for asphalt. Recycled asphalt materials have a lower interaction coefficient than natural materials and recycled concrete. This reason could be attributed to bitumen coating on recycled asphalt aggregates. In general, recycled concrete and asphalt materials provide the minimum shear strength parameters when reinforced with geogrids.

Surface fault rupture is very dangerous for critical buildings and infrastructures located in or near active faults and can cause irreparable damages. These structures must be designed by considering the undesirable effects of surface faulting. In this case, geotechnical measures, especially the construction of reinforced earth foundations are very effective in reducing the adverse effects of surface faults. The ASTM designation primarily recommends avoiding constructions to the adjacent of active faults probable of causing rupture at ground surface during an earthquake, although it is hard to determine the exact location of surface faulting. The increasing growth of population and the need to develop cities, particularly in metropolitan areas with economic limitations or land restrictions, have attracted the attention of the engineering community more than before to carry out feasibility studies on the construction of buildings in active fault zones. Such a consideration does not negate that the primary recommendation to avoid construction of buildings over active fault zones is the most convenient solution; it rather aims at examining and making engineering arrangements for the construction of buildings in zones with surface faulting potential governable by engineering methods. In addition to buildings, linear projects such as roads, highways, and tunnels must cross regions probable of surface faulting. Therefore, geotechnical measures, particularly designing reinforced soil foundations, contribute significantly to the reduction of undesirable effects of surface faulting. This research is conducted based on a series of tests on foundations reinforced with geogrid, geocell, and a combination of both, subject to normal faulting, to reduce surface faulting ruptures. The tests simulate the behavior of a 1.5 m wide strip foundation, placed over 6 m thick alluvium, subjected to a displacement of 60 cm. Seven tests were performed by different types and numbers of reinforcement, which were scaled to 10. The image analysis was carried out to examine the ground settlement profile, angular distortion, and fault propagation path. The results showed that the geotextiles used in the reinforced soil foundation could effectively reduce the angular distortion, cause uniform settlement, and divert fault propagation path, all protecting the structure against faulting. In a foundation reinforced with one layer of geogrid, a uniform settlement occurred at fault-induced displacement. In particular, the geogrid largely affected fault distribution, angular distortion reduction, and uniform ground settlement. Also, the settlement occurred at a wider zone and reduced the angular distortion by 60%. It means that the geocell affected the reduction of angular distortion and creation of uniform settlement by about 30%; however, it did not affect faulting diversion. The results indicate that the foundation reinforced with a combination of geocell and geogrid reduces angular distortion by 70% acted almost the same as the foundation reinforced with one layer of geogrid. Due to the increased stiffness and compressive strength of geocell, the shear band was more diverted toward the left side, compared to the foundation reinforced with one layer of geogrid. The right boundary of the shear band was also moved to the left corner of the structure. Likewise, the foundation reinforced with a combination of two layers of geogrid and three layers of geogrid reduces angular distortion by 80%. The results also reveal that adding more than two layers of geogrid had no effect on angular distortion reduction and the fault propagation path was more diverted as the number of geogrid layers increased.

This study presents the experimental results and numerical analyzes on the conical and pyramidal shell foundations located on loose unreinforced and reinforced with geogrid sand. The results have been compared with the values studied for flat circular and square foundations. Laboratory studies were performed on different types of shell foundations with different apex angles using small-scale physical modeling. In order to extend of study for determination of the effect of various conditions of foundation’s depth to width ratio and the number of geogrid layers on bearing capacity ratio, numerical analyses have been done by limit analysis method. The results have shown that, in general, increasing the depth of the foundations and the use of reinforcing structures ameliorate the geotechnical performance of foundations in both flat and shell models, although this enhancement is more evident in plane foundations. The load bearing capacity for the foundations with 180°, 120°, 90°, and 60° apex angles is put up to 40%, 36%, 32%, and 28%, respectively by rising in the foundation depth to Df/B=0.5, and is raised to 76%, 67%, 61%, and 55%, respectively by the growth of the foundation depth to Df/B=1.0. The use of geogrids increases the bearing capacity of plane foundations more than the shell foundations. The use of a single geogrid layer increased the bearing capacity of the foundations on the soil surface by an average of 79%, while the use of two layers of geogrid increased the bearing capacity by 86%, reflecting the fact that the use of two layers of geogrid will not significantly improve the bearing capacity in comparison to the condition when the soil is reinforced with a single geogrid layer. Bearing capacity of buried foundations with Df/B=0.5 is increased to 50% and 53% by using a single geogrid layer and double geogrid layer, respectively, and with Df/B=1.0 is increased to 28% and 30% by using a single geogrid layer and double geogrid layer, respectively, in comparison to foundations which are built on surface unreinforced soil. For foundations on the soil surface with 180°, 120°, 90°, and 60° apex angles, using a single geogrid layer increases the average bearing capacity to 99%, 81%, 75%, and 60%, respectively, and the use of two layers of geogrid increases to 110%, 90%, 78%, and 62%, respectively. These conditions are less pronounced for buried foundations and the increase in load bearing capacity for footings with all apex angles is about 50% for Df/B=0.5 and 29% for Df/B=1.0. The use of two layers of geogrid will have less impact on the foundations with smaller apex angles.

Construction on problematic soils, such as soft soils, is usually associated with numerous difficulties. Soil improvement is one of the available solution to encounter the problem in which the geotechnical conditions and the soilchr material properties are essentially improved. Reinforcement of soil is usually carried with aim increasing soilchrshear strength and reducing the erosion and/or settlement, permeability control and etc... . Geosynthetics are made of the polymer materials which are used as reinforcement in geotechnical projects. Geosynthetics, depending on their application, have different types, which can be referred to as geotextile, geogrid, geonet, geomesh, geomembrane, geocell, geocomposite. Considering the mechanical and hydraulic properties of the geosynthetics, they are used in various fields. The suitable design and use of these materials leads usually to significant increase in the factor of safety, performance improvement, and cost reduction in projects when compared with other classical solution. In recent decades, extensive studies have been conducted on the types of Geosynthetics and their function. On the 3D geosynthetics, however, deep studies are of few. In this study, the soil interaction with gridanchor as 3D geosynthetic (G-A) and the effect of various parameters (transverse distance of anchors from each other, joint angle of anchor to the geogrid relative to the horizon, aperture size and normal steress) for gridanchor has been investigated. Also, their performance has been compared with geogrids as 2D geosynthetics (G). In geogrids, the aperture size of geogrid, tensile strength of the samples and normal steress are considered as variables. The Pull out test is considered as the basic experiment to approach the goals of the current studies. According to the variables considered for each type of reinforcement systems, 50 pullout tests have been performed on the samples. Of these, 13 tests were performed as observational tests to ensure the accuracy of the test results. The soil used in this study is poorly graded sand (SP). Gridanchor is a type of geosynthetics that was first used by Mosallanezhad et al. In 2008. The results outcome of tests indicate that the use of Gridanchor and compared with geogrid has a significant effect on increasing the reinforced substratechr pullout load. The effect of normal stress parameters, anchor installation angle and anchor distance from each other on the performance of the gridanchor has been investigated and optimal values have been proposed. If using geogrid in high normal stress, it is better to use geogrid with higher tensile strength. So that if a grid anchor is used in high stresses, it is better that the distance of the anchors from each other is greater than their distance in low stresses. Generally, the use of three-dimensional geosynthetics performs better at normal stresses and low displacement.

It is very important to focus on treatments aimed at strengthening and improving the asphalt layer to increase the life of the pavement. Among the methods to increase the life of asphalt concrete pavement against structural failures that have been discussed in this study include the asphalt mixture modification approach (using Nano-silica) as well as asphalt reinforcement approach (using geogrid). In this study, based on the results of previous studies, the increase in fatigue life of these two approaches and their comparison with the fatigue life of control samples has been investigated. To determine the fatigue life of asphalt mixtures, the fatigue test of 4 points bending (4PB) beams under constant strain conditions (at 3 levels of 500, 700 and 900 micro-strains) has been used. The results show that by addition (in wet method) of Nano-silica to pure bitumen, the fatigue life of asphalt mixture is increased for both samples of Nano-silica modified and geogrid reinforced asphalt mixtures. For example, at a strain level of 500 micro-strain, the addition of 5% Nano-silica increases the fatigue life by about 193.9% (equivalent to 2.94 times) and the installation of a geogrid layer increases the fatigue life by about 212.4% (equivalent to 3.12 times). Also, asphalt mixtures reinforced with geogrid at the strain levels of 500, 700 and 900, respectively, increased the fatigue life of the mixture by about 6.5% (equivalent to 1.06 times), 61% (equivalent to 1.61 times) and 1.8% (equivalent to 1.02 times) compared to the samples modified with Nano-silica.

Geosynthetics are mainly used to stabilize and reinforce different types of earth structures such as slopes, retaining walls, bridge abutments, and foundations. In these cases, the interaction between soil and geosynthetic plays a significant role. In order to investigate the factors affecting the static, cyclic, and post-cyclic pullout behavior of a type of geogrid produced in Iran under the brand name of GPGRID80/30 embedded in uniform sand, an experimental study was carried out using a large-scale pullout apparatus. In order to study the monotonic and post-cyclic pullout behavior of geogrid in different conditions, a series of monotonic pullout tests and multistage pullout tests were performed. Given the effect of vertical effective stress on the pullout resistance, the maximum apparent friction coefficient of the surface of the geogrid and soil and deformation along the geogrid was investigated using monotonic tests. In the multistage pullout test, the influence of vertical effective stress, cyclic load amplitude, frequency, and number of tensile load cycle on the post-cyclic pullout resistance was studied. The results indicated that with an increase in the vertical effective stress, the pullout resistance of the geogrid and the maximum apparent coefficient of friction would increase and decrease, respectively. A comparison of the results of the multistage pullout tests and constant rate pullout tests with the vertical stress of 60 kPa showed that the cyclic loading had no significant effect on the post-cyclic pullout strength compared to the static pullout strength of the embedded geogrid in the sandy soil; however, with vertical effective stresses of 20 and 40kPa, a reduction in the maximum post-cyclic pullout strength was more evident than the pullout strength. Increasing the effective vertical stress and cyclic load amplitude in the second stage of the multi-stage test would enhance the cumulative displacements along the geogrid sample. A comparison between the loading-unloading tensile stiffness at the end of the second stage and tensile stiffness at the beginning of the second stage suggested that the cyclic loading would increase the tensile stiffness and finally, at the third stage of the experimental multistage test, the tensile stiffness would decrease as the displacement increased until it reached the corresponding value in the constant-rate displacement test.

In this study, the effect of geogrid on the ultimate bearing capacity of strip footing, which was imbedded on sandy soil and under eccentric loads (VM) was investigated by using PLAXIS 2D finite element software. After numerical verification, the effect of parameters, such as the amount of eccentricity, applied vertical force, the number of reinforced layers and layout of the layout of geogrid layers on the ultimate bearin capacity of strip footing were studied. The results of analyzes were presented in the form of dimensionless graphs. Based on the analyses result, the optimum depth of first geogrid layer from foundation (u), the vertical intervals of the layers (h), the number (N) and layout of the geogrid layers have been determined. The results of the analysis show that by adding the geogrid layers, the bearing capacity of footing under the eccentric load increases significantly. The amount of the effectivity is related to the layout of layers and and the amount of the eccentricity. In the optimum layout of the layers, the position of geogrid layers depends on the number of layers. Also, the optimum number of layers for obtaining the maximum bearing capacity at eccenric load condition was obtained to be 4 layres in the present study. The optimum depth for the first, second, third and fourth layers, at the optimal layout, was 0.5, 0.7, 0.3 and 0.9 meters from the base of the footing, respectively.

In the present study, the effect of geogrid layers and soil density were investigated in the sand slope model reinforced with geogrid layers. The soil slope did not have stability in normal condition and was unusable for embankment operations. But it reached to the appropriate bearing capacity for embankment operation with improvement made by reinforcing and compacting the desired soil. The main purpose was to compare the footing bearing capacity and soil swelling of the reinforced with the non-reinforced states and also to evaluate the impact of the two soil compacted states with various thicknesses. 19 different states were investigated. The main parameters studied were soil density, the number of geogrid layers, and the distance from the slope edge. The results indicated that the soil slope, which had no stability in the non-compacted -unreinforced state, achieved high bearing capacity using geogrid layers and soil compaction. So that the maximum bearing capacity in compacted reinforced state and when footing was located 30 cm from the slope edge was 433 percent higher than the only reinforced state and 325 percent higher than only compacted state. Also, swelling of first layer of slope was significantly lower relative to the tolerance amount of bearing capacity and more uniformity was observed in all slope locations.The results also indicated that, in the compacted-unreinforced state, an increase in the number of compaction layers did not affect the bearing capacity of footing in the vicinity of the slope. But by moving the footing from the slope edge to 30 cm, the increasing the number of compaction layers from 5 to 7 layers caused increasing the bearing capacity by 34%.s.

Ring footings have been used in various industries like oil and gas. So this kind of footings is very important and doing some works to improve their behavior, can be very important. In the present study, by using experimental tests, the behavior of ring footings with a constant outer diameter of 300 mm based on reinforced bed with granular rubber particles alone and also in combination with a geogrid layer, subjected to static loads, has been investigated. The results showed in both unreinforced and rubber-reinforced bed, the ring footing with inner to outer diameter ratio of 0.4 had the maximum bearing capacity. Also the optimum thickness of rubber-reinforced layer is equal to 0.5 times the outer diameter of ring footing; in this case the bearing capacity can be increased by 41.5% compared with the unreinforced bed; more increases than optimum value, have reverse results and lead to decrease in bearing capacity and increase in settlement. Using geogrid layer can activate reinforcing effects of rubber-reinforced layer with high thicknesses, but its value is not big enough to overcome the negative effects of using rubber-reinforced layers with higher thicknesses than optimum value. At last, using geogrid reinforcement in combination with rubber particles can be more effective than using each of them alone. In geogrid-rubber reinforced bed, the bearing capacity can be increased by 62.7% compared with the unreinforced bed.

This paper presents post-cyclic-monotonic behavior of BOF and EAF steel slags as ballast and subballast layers with and without geogrid or tire chips, and comparing their behavior with limestone material. Tests were carried out by the large scale triaxial equipment. The confining pressures are chosen with respect to the stress levels in typical rail road track. The tested specimens were prepared by maximum dry density. The used square shape geogrid has aperture sizes of 25*30.5 mm and the depth of placement about 5cm above and middle of subballast. Size of tire chips was 12.7-25 mm and mixed 7% by weight, only in ballast layer. Maximum deviatoric stress, secant modulus, unloading-reloading modulus, friction angle and particle breakage are investigated. Results indicated that performing cyclic loading on ballast layer before the post cyclic-monotonic tests decreases the axial strain corresponding to maximum deviatoric stress. Post-cyclic-monotonic friction angle of ballast and subballast with and without geogrid ranges from 57-65°. The friction angles of the steel slag of ballast, subballast and ballast/subballast specimens are similar to traditional ballast materials. The values of and decrease as moisture of specimen increases. Average poison ratio for mention layers is about 0.3. Marsal breakage index (Bg) of the single layered steel slag ballast is almost two times of the limestone ballast. Presence of steel slag subballast increases Bg of the steel slag ballast to about 2 times. According to fouling and breakage indexes of steel slag ballast under post cyclic-monotonic loading is relative clean. Saturation of ballast specimen causes increase of particle breakage, therefore the drainage of ballast materials is necessary. Usage of tire chips is not recommended in ballast due to high rate of decreasing of modulus and friction angle. Results indicated that the steel slag particle may be used as natural aggregate in ballast and subballast layers.

One of the efficient ways in order to reinforce the earth slopes is Geogrid Encased Stone Column (GESC). This technique can increase bearing capacity and decrease settlement rate of slopes. The aim of this study is to perform a three dimensional finite difference method (FLAC3D) for GESC in the stabilization of sand slopes. According to the results of 3D numerical analysis, the existence of geogrid-encased stone column, increases stability to an ideal level compared with ordinary stone column-reinforced slopes. Different parameters including stone column diameter, the coupling spring stiffness, coupling spring cohesion, coupling spring friction, S/D ratio, and the layout of encasements evaluated and discussed in this paper. The influential parameter in geogrid in order to reinforce stone column, is coupling spring cohesion. By increasing the parameter, slope bearing capacity of reinforced slope increases linearly. This indicate that use of geogrid reinforced stone column, based on type of geogrid characteristics, can enhance earth slope bearing capacity up to 1.8 times of slope reinforced by ordinary stone column. The maximum bearing capacity with a row of stone columns was obtained for S/D=2. However, the reduction of S/D does not necessarily imply the increase of bearing capacity of slopes.

Concrete is one of the main materials used in the construction industry and there are disadvantages to the conventional method of using steel, which reduces the breakage and concrete failure. Today, the spread of the science of applying polymeric materials to overcome these disadvantages has quickly taken its place in concrete ingredients. These materials can produce stronger concrete with greater flexibility and a smoother surface and can increase concrete resistance to erosion, impact and corrosion. In this research, using Geogrid, which is a family of geosynthetics, the tensile strength of concrete increased by 15%. Because it is used as a solid with very low risk, the geogrid is placed at different distances from the neutral warp. Based on the results of the experiments and according to the diagrams obtained from the geogrid experiments, if utilized as a semi-solid in the tensile region, the geogrids will result in the equal distribution of stresses and will have a better effect on increasing tensile strength. Of course, using a combination of steel and geogrid in the tensile region and according to the geogrid characteristics, it is easier to achieve a soft failure (tensile failure), which is the best type of failure for concrete structures.

Natural soft clay soils due to the lack of sufficient bearing capacity and the high deformation potential require to be improved using either chemical stabilization methods or physical methods such as soil reinforcement or pre- compression. The method used is greatly influenced by technical and the economic considerations as well as the physical characteristics required (Abdi and Zandieh, 2014). Chemical stabilization generally results in increasing the strength and the bearing capacity and reduces the swelling- shrinkage potential of the clayey soil. On the other hand from ancient times humans have used natural fibers to alleviate the weakness of soil in resisting tensile stresses (Abu-Farsakh et al., 2008). Now-a-days due to the technical progress made synthetic materials such as geo-synthetics are used for soil improvement. Use of geo-synthetics such as geogrids and geotextiles have grown rapidly in the construction of soil structures such as embankment dams for reducing the volume of materials needed as well as drainage purposes, increasing bearing capacity in foundation engineering, etc (Alawaji, 2001). These materials are easy to use and environmentally friendly. Coarse grained materials are also employed in construction of reinforced soil structures due to high drainage and shear strength characteristics as well as volume stability due to moisture variations and time (Alawaji, 2001).