In the last 30 years, many studies have been done concerning the stability analysis of SOIL structures and determination of their deformations. Finite element method, is a powerful tool for investigation in this field. Elasto- perfectly-plastic constitutive law and associated flow rule, along with finite element method are utilized for calculating the safety factor of SOIL SLOPEs. Several failure criteria have been presented. In this paper, nine failure criteria are used for stability analysis of SOIL structures. The results are compared with Bishop Method.

In design science, in order to avoid the complexity of the problem, many involved factors are removed with simple assumptions. Simplifying design relationships causes uncertainty and reduces the validity of calculations. In this research, it is tried to study and investigate the relationships governing the stability of earthen gables from the perspective of uncertainty. The use of stabilizing piles can increase the stability of the gables as a barrier element against sliding and improve its performance against incoming loads, but the safety factor called the reliability factor alone should not be the basis of decisions because it is calculated by conventional deterministic methods. And it is not able to directly express the effect of uncertainties. Therefore, in order to evaluate and apply the role of uncertainties, it is necessary to use probabilistic concepts and methods. In this research, SLOPE stability has been evaluated by deterministic analysis and limit equilibrium method in GeoStudio software in the SLOPE/w module. In the second step, with the help of the probabilistic Monte Carlo method, the uncertainties in the problem are analyzed. Modeling of the reinforced gable has been done by Bishab, Janbo and Morgenstern methods. Bishab and Morgenstern's method showed similar and more reliable behavior than Janbo's method. At the end, the results of deterministic analyzes and the probabilistic Monte Carlo method have been compared in different situations. This comparison with Morgenstern's method has been done to investigate the role of four influential factors in the stability of the gable. The results showed that with increasing the distance of the pile from the bed and heel of the gable as well as the angle of the gable, the reliability coefficient and the reliability index decrease exponentially.

SOILs in arid and semi-arid regions are strongly affected by the accumulation of salts, especially carbonates and gypsum. The SOILs are inherently low in organic matter content and in consequence unstable in the structure which declines the SOIL’ s resistance to water erosion processes. Moreover, the SOILs are weakly covered with natural vegetation cover which exposes surface SOIL to erosive factors, particularly raindrop impact. Therefore, this study was conducted to investigate the splash erosion rate in relation to SLOPE gradient in the SOILs with different properties. Toward this, twelve SOIL texture classes were exposed to simulated rainfalls with 40 mm per hour in intensity for 10-min in four SLOPE gradients (0, 10, 20, and 30%). A total of 144 experimental SOIL boxes with 25 cm ×35 cm in dimensions were investigated using the completely randomized block design. The results of this study showed that significant difference was found among the SOILs in splash erosion (P<0. 001). Among the SOILs, the highest splash erosion rate was observed in Silt (244. 20 gram m-2), while sand showed the lowest value (65. 71 gram m-2). Splash erosion rate was significantly affected by SLOPE gradient. Splash erosion showed a decreasing trend from 0 to 10 SLOPE degrees and increasing trend from 10 to 30 SLOPE degrees. Significant correlations were found between splash erosion and sand, clay, geometric mean particle diameter, bulk density, saturated hydraulic conductivity, organic matter, calcium bicarbonate equivalent and gypsum. Multiple linear regression analysis indicated that the splash erosion was significantly related to the Organic matter, Calcium Carbonate Equivalent and gypsum with a coefficient of determination of 0. 75. The SOIL’ s susceptibility of arid and semi-arid regions to splash erosion can be initially estimated using a regression equation based on these variables.

In this paper, a new scheme for serial communication is proposed. In this method, in addition to the pulse states (high and low), either of negative SLOPE or positive SLOPE of the pulse (saw-tooth waveform) is employed as a representative for another digit. Using pulse SLOPE as a representative for a separate digit will result in sending two-bit-digits using a single pulse, which doubles the transfer rate. The proposed scheme can be used in both synchronized and asynchronized communications and can improve communication speed. Through simulating the proposed scheme, it turned out that this method, because of its proper immunity to noise, can be used as a peripheral interface alongside in-chip communication. The main idea in the raised discussion is to obtain four different geometric pulse shapes acting as four different numbers in the quaternary numeric system, in which it can be serialized/desrialized as easy as pulse states. This proposed method and the suggested system for serialization and deserialization of data can be an adequate alternative in high-speed communication approaches.

This paper provides an overview of the design of thread reinforced SOIL structures with a particular emphasis on the influence of the strength criterion. Due to the heterogeneity of the material a macroscopic strength criterion is determined and discussed for thread reinforced SOIL using the homogenization method for periodic medium in the yield design range. Various types of potential failure mechanisms are analyzed and pointed out by using the failure design theory which allows the stability analysis of a reinforced embankment. An account of the results are presented and compared with recent test results. Current evidence on the feasibility of this type of reinforcing is discussed along the variation of different parameters. Conclusion bears on general design and defines some considerations to be included in such analysis.      

Initiation time and production rate are the major runoff characteristics which can be affected by the changes of SOIL physical properties during rainfall. Temporal variation of these characteristics could be controlled by SOIL texture and SLOPE gradient. This study was carried out to investigate temporal variation of runoff in both different SOIL textures those of clay loam, loam, and sandy loam and various SLOPEs (5 , 10 , 15 , 25(and 30 ) under a 40 mm h-1simulated rainfall in the lab. SOIL texture and SLOPE steepness were the important factors influencing runoff initiation time (P<0. 01) and production rate (P<0. 01). Clay loam appeared the lowest runoff initiation time (16 min) whereas sandy loam showed the longest time (46 min). Runoff initiation time was negatively affected with increasing SLOPE gradient. Significant relationships were observed between runoff initiation time and SLOPE gradient in clay loam (R2=0. 86), loam (R2=0. 86) and sandy loam (R2= 0. 98). The highest effect of SLOPE gradient on decreasing runoff initiation time was in sandy loam (63%) while clay loam showed the lowest value (28%). Significant relationships were found between runoff production and SLOPE in clay loam (R2=0. 89), loam (R2=0. 95) and sandy loam (R2= 0. 94). Runoff temporal variation pattern were strongly varied among the SOILs in the SLOPE gradients. Runoff steadily increased in clay loam during initial rainfall times. This temporal variation of runoff was due to increasing water content and disruption of structure.

The effects of traffic frequency and skid trail SLOPE on dry bulk density, litter mass and rutting are examined. Treatments included a combination of four different traffic frequencies (3, 7, 14, and 20 passes of a rubber skidder) and three levels of SLOPE (<10%, 10%-20% and>20%.) The results showed that dry bulk density, rut depth and SOIL displacement increased with the increase of traffic frequency and SLOPE, but floor coverage decreased. Within each traffic treatment SOIL compaction raised with the increase of skid trail SLOPE, so that significant differences in dry bulk density were observed between SLOPE of<20% and those one >20%. Bulk density has become quite close to the critical value after 14 cycles. With increase of the skidder cycles from 14 to 20, bulk density remained approximately constant. We observed SOIL displacement on the treatments with 7 cycles: rutting on the treatments started with 7 cycles and SLOPE of>20%. SOIL disturbance increased significantly on SLOPEs with>20 % inclination with a dry bulk density of 1100 kg m-3 after 3 cycles compared to 830 kg m-3 on SLOPEs<10 %. In addition the forest floor mass on the treatments with 7 cycles and SLOPEs of>20% (437.6 kg/ha) was significantly (p<0.05) lower than treatments with 14 cycles and SLOPEs of<10% (841.4 kg/ha.) Data suggest that disturbance increased earlier in the steep treatments than in less sloping conditions. The dramatic increase of SOIL disturbance on treatments with SLOPEs of>20% may be associated with increasing load on the rear axle combined with slipping on steep SLOPE trail.

In this study, SLOPEs' stability was examined by SOIL deep mixing method with parametric analyses. To perform the required analyses, the finite element numerical method and PLAXIS software were used, and then the results of this method were compared with the results of limit equilibrium method obtained from SLOPE/w software. These parameters include the effect of the location of the first row of deep mixing columns along SLOPE foundation, area replacement ratio along foundation SLOPE, length, diameter, coefficient of cohesion, distance between deep mixing columns, position of the water level in the foundation, as well as the effect of the surcharge load. According to the obtained results of the analyzed model with both finite element and limit equilibrium methods, the factor of safety of SLOPE stability constantly increases upon the increase of parameters such as amounts of area replacement ratio, diameter, materials viscosity (cohesion of SOIL deep mixing materials), length of deep mixing columns, and depth of groundwater level to the level of SLOPE foundation.

This study was conducted to investigate the effect of SLOPE gradient and SOIL physical properties on water erosion in the furrows of rainfed farms under fallow conditions. The furrows with 6 m length were installed in five rainfed farms with 6. 1, 10. 6, 14. 8, 20. 7 and 27. 1 percent SLOPE steepness at three replications. Results indicated that rill erosion was significantly varied among the five farms. There was no significant correlation between rill erosion and SLOPE gradient, while it was significantly affected by some SOIL properties consisted of sand( P>0. 05), clay( P>0. 05) and aggregate stability( P>0. 05). These results revealed that in coarse textured farms with different SLOPE gradient, SOIL loss through furrows isn't significantly related to SLOPE gradient, but it is significantly affected by SOIL physical properties.