One of the most critical issues in weak Grounds is soil Improvement, which is considered reused in a new geotechnical structure or improves the current structure condition. In the present research, implementing a limited, finite element numerical method to predict the rate of Ground settlement level before and after the implementation of Ground Improvement in the eastern access tunnel drilling process of Khorasan Square Station located in Tehran Metro Line 6. Since the tunnel route passes under residential buildings and shops, with the excavation of this part of the Khorasan Square Station project, large amounts of settlement exist on the Ground surface, which cracked buildings and shop structures. Based on this, piling, fore poling, and anchoring Improvement methods can be used for loose and fallen Grounds that were modeled numerically by MIDAS GTS NZ software. In this research, in addition to investigating the performance of the mentioned methods, the effect of geometric parameters, including the covering of fore poling pipes, pile length, and the diameter of anchors, was investigated. The criteria for investigating, the Displacement occurred at Ground level, and tunnel crown is considered. Results showed that all methods have been useful in reducing Ground settlement and tunnel crown. Also, Among the above-mentioned Improvement methods, the method of using the fore poling method with anchorage has reduced the plastic points surrounding the tunnel and also has a greater effect in reducing the settlement of the Ground, so that it has reduced the maximum settlement of the Ground surface by 50%.

Among all methods for Ground Improvement, stone columns have become more popular recently, owing to their simple construction and plentiful availability of raw materials. However, in relatively softer soils, ordinary stone columns (OSCs) experience significant bulging owing to the minimal confinement offered by the surrounding soil. This necessitates the introduction of reinforcements in the stone column, to enhance their strength in such circumstances. The subject of this investigation was the assessment of the behavior of horizontally reinforced stone columns (HRSCs), introduced in layered soil, under the raft foundation. The soil material included was idealised using an isotropic linearly elastic fully plastic model with a Mohr-Coulomb failure criterion. There are a total of six separate factors required by the Mohr-Coulomb criterion. These include cohesion (c), the soil's dry unit weight (γd), the Poisson ratio (μ), the angle of internal friction (φ), the angle of dilatancy (ψ), and the Young's modulus of elasticity (E). At the very beginning, the load-settlement response of unreinforced soil was evaluated followed by a comparative study between square and triangular arrangements of stone columns, at different spacings, under the raft, to arrive at the configuration that encounters minimal settlements and lateral deformations. Furthermore, circular discs of suitable geogrid material were introduced along the length of the stone column. The elastic behaviour of geogrids is governed by two properties: tensile modulus and yield strength. The load-settlement behavior and lateral deformations of the resulting reinforced stone columns, with OSCs were compared. Furthermore, the spacing between the circular discs of geogrids was kept at D/2, D, 2D, and 3D, where D is the diameter of the stone column. According to the findings of an investigation conducted using FEM software, the performance of a granular pile group that is laid out in the shape of a triangle encounters much less lateral deformation and settlement than the square arrangement. The results also show that the performance of HRSCs was way better than those of OSCs, under the same in-situ soil conditions.

Introduction: The design engineers usually follow a specific decision-making process for optimal selection of the type of required foundation and its design. In this state, in case the surface foundation is not appropriate for the project conditions, before making any decisions about the use of deep foundations, the proper methods for optimization of the liquefied soil should be evaluated in order to compare the advantages and disadvantages of each of them with those of deep foundation, in terms of efficiency, implementation problems, costs, and finally to select the best choice. One of the best methods of soil Improvement is the use of stone columns. The rationale behind the use of stone columns is the high shear strength of materials and the provision of lateral grip by surrounding soil...

Increasing construction industry and the need to build structures on lands that do not have sufficient load-bearing capacity resulted in the development of soil Improvement techniques to enhance site capability. The use of stone columns for the Ground Improvement for reasons such as environmental compatibility, cost effective, minimizing the liquefaction potential of the Ground, settlement reduction, increase of the load-bearing capacity and significant reduction in the period of consolidation is considered as one of the most effective soft soil reinforcement methods. Stone columns can be designed to bear on the hard stratum or as a floating system where the toe is embedded in the soft layer. What in recent years were as the basis for designing of groups of stone columns were based on the theories developed for single stone columns ignoring the group interaction. Most of the existing design methods for stone columns adopt unit cell idealization which is not applicable to spread footing. To assess the influence of various parameters on the performance of a group of stone columns, in this paper which is based on the finite element method, the effect of hardness and resistance parameters affecting the load bearing capacity was discussed. More than 140 analyses of different parameters of soil and stone columns were carried out and were discussed in the form of graphs to compare the effects of these parameters. Results showed that using stone columns had a significant impact on increasing the bearing capacity of the soft Grounds. The rate of growing enhances with increase of replacement ratio of stone columns into the soft soil due to group interaction. Increase of elasticity and internal friction angle of column materials as well as soil Poisson's ratio have a significant impact on increasing load-bearing capacity on the other hand when Poisson's ratio of stone columns increases any substantial change isn’ t see. In addition of bearing capacity increase, growth of replacement ratio enhances the impact of strength and stiffness parameters of soil and columns on bearing capacity increase which shows the influence of the group interaction. End bearing columns were observed as a factor influencing the increase of bearing capacity and intensifying the effect of stiffness and strength parameters on column bearing capacity.

For positioning in navigation systems, at first the signal arrival time or arrival time differences is calculated and then the time differences is converted to geographical Lat/Long information using a specific algorithm. The aim of this study is to analyze the integrated algorithms for estimation of arrival time in order to improve positioning accuracy in Ground-based loran systems. For this goal, the common algorithms of arrival time and arrival time difference were investigated firstly and were compared based on CRLB approach. Afterwards, by calculating RMSE index the performance of the suggested algorithm was evaluated using information of three transmitter stations. The results have shown that the proposed approach had promising performance in compare to TOA (the lower noise variances and the minimum error) algorithm.

Wheat Ground beetle Zabrus tenebrioides (Goeze) (Coleoptera: Carabidae) is an important wheat pest in Iran and some regions of the world. This pest causes damage to wheat by feeding on the root, stalk, and leaves. Farmers try to control this pest by the foliar application of different insecticides, but this method causes damage to the environment. To find an effective method to control this pest, the thiamethoxam insecticide (Cruiser®) efficiency was evaluated using seed treatment in this study. An experiment based on a randomized complete block design with four treatments and four replications was conducted in a field in Ramhormoz city, Khuzestan province (Iran). The treatments were 150 and 200 ml of thiamethoxam plus 2350 ml of water for seed treatment, 2,000 ppm of diazinon by field spraying at the wheat tillering stage, and a control. The results indicated that the average plant density in 150 and 200 ml of thiamethoxam (333.58 and 333.28 plant/m2, respectively) was more than those of diazinon (258.28 plant/m2) and the control (182.12 plant/m2). The average ear density in 150 and 200 ml of thiamethoxam (513.78 and 506.12 plant/m2, respectively) was more than those of diazinon (321.22 plant/m2) and the control (260.86 plant/m2). According to the present results, farmers can use 150 ml of thiamethoxam plus 2350 ml of water for 100 kg of seeds to control this pest by seed treatment.

This paper presents a rigid circular footing model with specified properties and dimensions on a sandy-clay soil with Mohr-Coulomb material. This model is analyzed dynamically with finite difference 2D FLAC software under vertical component of Ground excitations. Then the soil is improved with cement grouting and analyzed again. Consequently, the load-settlement curves under a circular footing, due to vertical component of Ground accelerations through the underlying soil, are plotted. Also the dynamic bearing capacity of natural and soil cemented foundation is presented and discussed. The analysis results show that adding 2, 4 and 6 percent of cement, with certain conditions, cause 2.7, 4.2 and 7.0 times increase in dynamic bearing capacity, respectively, in comparison to normal soil.

This research examined the utilization of bottom ash mixed with silica fume in the Ground Improvement technique by constructing columns beneath the soft clay. Utilizing the bottom ash was an effective method and easily available in the market and the application of silica fume in the study improved the result through its pozzolanic characteristics. The vibro-replacement method was implemented during the bottom ash column installation process. The properties of the materials involved in the research were examined by suitable geotechnical tests complying with relevant standards. The important parameter, shear strength was accessed by conducting the Unconfined Compression Test (UCT). In this study, a total of seven (7) batches of soil samples were involved comprising the control sample. From each batch, it had five (5) soil samples which included the 14 mm and 20 mm diameter of column with the height of 60 mm, 80 mm, and 100 mm. From the results of shear strength Improvement, the 14 mm diameter column with height penetrating ratios of 0.6, 0.8, and 1.0 were showing 58.97%, 88.56%, and 69.81% respectively. The next column design which had the 20 mm diameter with the height penetrating ratio of 0.8, recorded the highest Improvement of 38.73%, followed by 1.0 and 0.6 which resulted in 32.81% and 19.19% respectively. The use of correlation technique had streamlined the complexity of the independent variables and verified the reliability of the results through the R2 value. In summary, the Improvement in shear strength was significantly influenced by the column design.

Monitoring the changes in land surface temperature (LST) caused by seasonal and non-seasonal fluctuations is essential due to its profound impact on the human and natural environment. The use of remote sensing satellite imagery has been extensively considered for the continuous monitoring of LST with its low cost and high speed. In this research, first, three conventional temperature extraction approaches based on Plank’ s law were used to extract LST of surrounded areas of Lake Urmia. Then, using a linear regression and observations of the temperatutre in meteorological stations, LST maps extracted from conventional methods were modified. The results showed that conventional temperature extraction approaches for TM and TIRS sensors of Landsat Satellite had an accuracy of about 4 ° C and 8 ° C, respectively. After modifying LST maps using the linear regression, this accuracy reduced to 1 ° C and 0. 5 ° C for TM and TIRS sensors, respectively. This indicated the proper performance of the regression approach presented in this study for temperature modification.