1 Tarbiat Modares University 10635 Flow Field and Scouring around Triplex Shielded Spur Dikes in Sharp Bend 1 10 2016 16 3 1 12 17 02 2014 14 09 2014 Spur dike is one of the river training structures that is considered to deviate the river from critical and erodible areas and the flow from the sides and towards the central axis. As a result of flow is developing a circular area with high turbulence around the spur dike. The hydraulic process results development of the scour hole on the upstream of the spur dike and settlement of sediment in the downstream and sides of the river. While scouring in spur dike structures results a serious threat to the river so it is needed to be researches in this field. This paper describes triplex repellent shielded spur dikes (directed to the upstream) with a distance of 3.5 times of the effective length of the spur dike in the outer bank of the channel. The first spur dike is located at 30 degree from the start of bend. The experimental channel is a 90º channel with rectangular section. The radius of curvature to the channel width is 2, which is classified as a sharp bend. Materials used are sands with uniform grains and its mean diameter is 1.28mm and its standard deviation coefficient is 1.3 and the relative density of sediment is 2.35. The results of flow field on flat bed and a scouring experiment are presented. Discharge was 25 l/s and All scour tests were done in 24 hours and in the moving threshold conditions (U/Uc =0.98) and clear water condition. Flow field is recorded using the Vectrino II velocimeter that can profile water in a 3cm column. It was found that in the levels upstream of the first spur dike in an adjacent to bed, stream lines are deviated to the inner bank. While in the middle levels, flow lines upstream of the spur dike is almost parallel to the channel walls and approached the spur dike, resulting deviation in the separation zone. In the scouring experiment it was obvious that at the beginning of the experiment, thus creating the down flow upstream of the spur dikes scouring initiates near the wing of each spur dike and it develops by the horse shoe vortex. But with the time sediment had been washed from upstream of the first spur dike, and moved to the foot of the spur dike until it reaches upstream of the former to the latter. Then scour hole upstream of the second spur dike starts to form. Results showed that the amount of scour upstream of second spur dike is 33 % and upstream of third spur dike is 81 % the maximum amount of scour that occurs upstream of the first spur dike. Mechanism causing scour and flows occurring within this range detailed in this paper.
11343 Experimental study on correlation between the results of different methods of measuring the electrical resistivity of concrete Parsian Hassan e MostofiNejad Davood Tadayon Mohsen e Isfahan University of Technology (IUT) 1 10 2016 16 3 13 25 12 02 2015 17 06 2015 The purpose of this research is to develop relationships to predict the results of measuring the electrical resistivity of the standard test method ASTM C1760 with assistance of other methods’ results. Comparative Methods in this paper are Impedance spectroscopy method , one electrode method and four electrode method. Impedance spectroscopy method is the most common in laboratory studies , ASTM C1760 method (Standard Test Method for Bulk Electrical Conductivity of Hardened Concrete) only has a standard rule and use in laboratory , one electrode method is a new technique in field and it’s application is in the reinforcement structures , and four electrode measurements are more common in field. In laboratory methods, bulk electrical resisitivity measured but in field , usually surface electrical resisitivty evaluated , that is why several source of errors affecting on the results of this test methods. To reach the aim of this research , 49 mix designs with a vast domination of electrical resistivity from about 40 (Ω-m) to 290 (Ω-m) was intended and for each of mix designs , 4 cylindrical and one reinforced slab specimen were made. reinforced slab specimen for one electrode measurement and cylindrical specimens for the other test method measurments were considered. Moreover , the electrical resistance of the aforementioned methods was measured at 28 days age. The results showed that there is a negligible difference between the results of impedance spectroscopy and ASTM C1760 methods; however , the electrical resistivity measured by ASTM C1760 method was slightly higher than the results of impedance spectroscopy method in the concrete. As a result , we can use the results of the impedance spectroscopy method instead of standard test method results in the lack of facilities with accepting about 5% of error. In the four electrode method , a number of factors including the imbalance among the distances between electrodes and structure dimensions can result systematic errors. That is why the measurements’ results with the method is approximately 140% larger than the standard test method results. Due to the lack of a comprehensive relationship for calculating the cell constant in the one electrode method , the value of this constant was obtained by comparing the results of the standard test method. After that , the electrical resistivity values were calculated. Electrical resistivity measurement results which was obtained by this method had also little difference with the standard test method results. Finally 3 relationships separately developed for predicting the result of standard test method from results of the each other test methods. Since the features and conditions of measuring by the standard test method are not available in the entire projects , the current results are capable to predict the standard method’s results with assistance of other methods’ results. 6428 Evaluating Bearing capacity and settlement of shallow footings rested on liquefiable sand using physical modelling Jafarian Yaser Haddad A. 1 10 2016 16 3 27 36 10 11 2014 23 01 2016 Bearing capacity failure and seismically induced settlement of buildings with shallow foundations rested on liquefied soils have resulted in significant damage in recent earthquakes. Engineers still largely estimate seismic building settlement using procedures developed to calculate post-liquefaction reconsolidation settlement in free-field. They commonly disregard residual strength of liquefied soil in their design procedures. Previous studies of this problem have identified important factors involving shaking intensity, the liquefied soil’s relative density and thickness and the building weight and width. Newly studies have also showed that shear deformation combined with localized volumetric strains during partially drained loading are dominant mechanisms. Bearing capacity degradation due to high excess pore pressure development also has been reported in previous studies. Two series of physical modelling experiments involving shallow footing rested on liquefied sand have been performed to identify the mechanisms involved in liquefaction-induced building settlements and bearing capacity degradation. Experiments have performed on Babolsar sand with moderate relative density in a box with two plexiglass sides to observe sand deformations. Earthquake waves can cause pore pressure build up in saturated sands but complete liquefaction always do not occur. Anyhow excess pore pressure generation can cause bearing capacity degradation and excessive settlements. Various pore pressure ratios have been generated by static seepage through box base to assess bearing capacity degradation and excessive settlements before and in complete liquefaction conditions. First series of experiments are consisted of 8 tests related to bearing capacity measurements of square and spread foundation in pore pressure development conditions. Results show bearing capacity reduction due to excess pore pressure development, but there is remarkable strength even in complete liquefaction that is related to post-liquefaction strength of liquefied sand. Square foundations are more affected than spread footings by excess pore pressure ratios. Foundation’s loading behaviour and Shape factors are not affected by excess pore pressure ratios. Pore pressure decreased with loading increscent under the middle of foundation because of particle rearrangement and always was below the induced excess pore pressure. Complete liquefaction has never observed under footing. Safety factor selection is a challenging step in shallow foundation designs for engineers because of its economical view. Recent studies show the important role of shear deformations in shallow foundations as discussed before. In second test series of this experimental study, foundations firstly loaded to some safety factors and then its settlements due to pore pressure build up has measured, loading then increased to complete bearing capacity failure. This series are consisted of 12 tests for two types of foundations and various excess pore pressures, only shear deformations are assessed in this series because there is no volumetric deformation as excess pore pressure is constant during the tests. Results show increase of foundation settlements with safety reduction progressively, settlements for safety factors below 2 are negligible. 1812 Evaluation of deflections in a braced excavation via plastic and consolidation analyses khazaei jahangir 1 10 2016 16 3 37 47 11 03 2015 08 11 2015 Behavior of braced excavation in a cohesive-frictional soil has been evaluated by present paper. Two groups distinct analyses based on plastic calculations and consolidation calculations were implemented by considering time intervals of staged excavation. In order to investigation of time effect and pore water pressure impact on the staged excavation phases, numerical modeling has been conducted by help of consolidation and plastic analyses. In major of former analysis and before present study numerical analyses of staged excavation procedure have selected without considering the effect of time and in form of plastic analyses, while pore water pressures were also ignored. In this, paper thereto the time effect other effects such as length of time interval, kind of analysis depending on drainage conditions, constitutive modeling for soil and location of ground water table were considered. Two dimensional finite element analyses in PLAXIS 2D software are the basis of the numerical calculations of present study. Excavation bracing selected as a kind of concrete facing wall and grouted soil nailing. The results of this research show that the values of excavation wall lateral displacement and soil heave in bottom of the excavation in consolidation analysis by considering time effect in comparison with plastic analysis often reduced approximately 20%. It seems that effect of time and staged excavation just with implementation of numerical deflection analysis depending on the time such as consolidation analysis with creep models can be evaluated and these conditions in plastic numerical analysis with staged excavation without creep (time-depended) models is meaningless. Soft soil creep model (i.e. SSC model) for considering time effect in plastic and consolidation analyses has been used by authors. The results of present paper show that neither consideration of analyses that consider time interval nor analysis such as consolidation analysis that considers time are not adequate, but soil constitutive model that defines the material behavior must be contains time and also in their mathematic equations structure parameters such as time, strain rate and stress rate that vary with time must be taken into account. Present paper analyses show that consolidation analysis by considering time effect obtain less wall deflections by comparison with plastic analyses. However, from present study outcomes can conclude that the plastic analyses also by considering constitutive model that contain time can take into account time effects in stress-strain calculations. On the other hand, responses of plastic analyses by comparison with consolidation analyses always are preservative and show more values. Therefore, in structural designing of bracing of an excavation, reliance on results obtained from plastic analysis is preservative and real values of time-dependent deflections of wall and bottom of excavation via consolidation analyses are obtainable. This paper has recommended that both plastic and consolidation analyses for designing of braced cut were considered by engineers and optimum system between those according to the economically advantages and disadvantages be selected. Because, occasionally reliance on plastic preservative analyses lead to imposition of high values of design and construction costs on a certain project that is revealed by implementation of consolidation analyses that those are not necessary. At the end of the paper, verifications and comparisons are related to the topic of present study have been carried out by authors and the obtained results have been compared with together and then are investigated with the obtained results by present study. 4662 Improved Integration Algorithm for Application to Hybrid Simulation of Numerical and Experimental Models Tasnimi Abbas Ali n ahad n Tarbiat Modares University 1 10 2016 16 3 49 61 01 10 2015 10 03 2016 Hybrid simulation which combines experimental and numerical modeling is a powerful and relatively new test method for evaluating the seismic performance of structural systems. In this method only critical components of structure are tested experimentally while the rest of the structure is numerically modeled in the computer. In this method the response of the structure is achieved by numerically integrating the equation of motion of the whole system. Among numerical integration methods, operator splitting (OS) method is of great interest for hybrid simulation, since not only its results are more accurate and stable in comparison with explicit methods but also its application for hybrid simulation is much more easier than implicit methods; the reason is that in OS method it is not required to conduct iteration on experimental element or estimate its tangent stiffness matrix during the simulation, the tasks which limit the application of implicit methods for hybrid simulation. But OS method suffers from the shortcoming that the use of initial stiffness matrix in its corrector step decreases the accuracy of results in nonlinear range. This paper presents a modified form of OS method which is termed modified operator splitting (MOS) integration method in which by proposing a new procedure in the predictor step, the accuracy of this step is increased. When the accuracy of the predictor step increases, the difference between predictor and corrector displacements decreases and as a result the effect of initial stiffness approximation becomes less important. This would finally result in the improved accuracy of the whole simulation, as is shown in the paper. The performance, accuracy and stability characteristics of the proposed integration method were studied through numerical simulations, where it was assumed that the restoring force of the system is achieved experimentally and no information about the experimental stiffness is available. The results showed that for the wide range of considered systems including various natural periods, various ductility ratios and various degrees of freedom, MOS results are more accurate than OS method. This shows that the employed method of the predictor step of MOS method has successfully decreased the length of the corrector step with initial stiffness assumption. All the employed error indices also verified that not only the results of MOS are in great harmony with the reference solution but also its accuracy is improved over regular OS method, especially in simulations involving severe nonlinearity. Furthermore results of multi degree of freedom systems with high frequency modes show that MOS results are quite stable as long as the accuracy of important modes of the system is maintained, which is usually the case. As in a real hybrid simulation, experimental errors also affect the accuracy and stability of integration methods, in this paper a hybrid simulation algorithm is numerically modeled and the effect of actuator time delay on the performance of MOS method is investigated. It was observed that in the presence of actuator delay, which is known to be one of the most important sources of experimental errors in hybrid simulation, MOS integration method has solved the equation of motion in an accurate and stable manner with very small level of errors in comparison with the reference solution. 5825 Investigation of Effectiveness of polyvinyl acetate polymer stabilizers on Internal Erosion and strength of kaolinity clay sand Mosadeghi amin 1 10 2016 16 3 63 72 07 05 2014 22 07 2016 The two most common causes of embankment failure are embankment overtopping and internal erosion. Internal erosion of soil resulting from seepage flow is the main cause of serious hydraulic work (dykes, dams) failure, in terms of the risk of flooding areas located downstream. The erosion characteristics are described by the Erosion Rate Index, which measures the increase of erosion rate with respect to an increase in the hydraulic shear stress; and the Initial Shear Stress, which represents the minimum hydraulic shear stress when erosion starts. Values of the Erosion Rate Index span from 0 to 6, indicating that the changes in erosion rates in response to changes in hydraulic shear stress can differ by up to 106 times across different soils. Coarse-grained, noncohesive soils, in general, erode more rapidly and have lower Initial Shear Stresses than fine-grained soils. The challenge in predicting failure due to internal erosion is characterizing the material properties relevant to the rate of failure. Therefore, it is very important to improve the erosion resistance of soils using appropriate and cost effective techniques. In order to control internal erosion and treated erodbile soil, important point is use of modern stabilizers instead of traditional stabilizers which is harmful. In this study, polyvinyl acetate polymer material has been used for treatment erodibility of kaolinity clay sand. To conduct this research, kaolinity clay sand has been treated with different percentages of polyvinyl acetate polymer and it has been tested with hole erosion apparatus in different hydraulic gradients. The hole erosion test (HET) is one of several available procedures for characterizing the erodibility of cohesive soils that might be susceptible to internal erosion investigations of dams and levees. It was first developed in a constant-flow configuration (Lefebvre et al. 1984) and more recently in a constant-head configuration by Wan and Fell (2004). The HET utilizes an internal flow through a hole pre-drilled in the specimen, a flow condition similar to that occurring during piping erosion of embankment dams. In the constant-head configuration, the test head is typically doubled, starting from 50 mm, until progressive erosion of the pre-drilled hole is produced. Measurements of accelerating flow rate through an eroding pre-drilled hole in a test specimen yield estimates of the critical shear stress and erosion rate coefficient. The initial and final eroded hole diameters are used to compute initial and final friction factors, and intermediate hole diameters are then computed from flow rates measured during the course of the test. The result showed that erosion rate of kaolinity clay sand is extremely rapid and polyvinyl acetate polymer stabilizer increased the resistance of kaolinity clay sand to erosion. It was also found that with the addition of polyvinyl acetate polymer and its description has been changed from extremely rapid to moderately slow erosion. While adding polyvinyl acetate polymer kaolinity clay sand caused the increase 60 percent unconfined compression strength. 2112 Comparision between ANN, Fuzzy regression and ANFIS analysis in prediction of coagulation and floculation process 1 10 2016 16 3 73 85 02 11 2014 01 09 2015 Surface water contains various type of suspended impurities that cause turbidity and color. Coagulation is the main process of integrating fine particles and turn them into larger particles. In this study, replacement of the modeling methods by time-consuming and expensive experimental techniques such as JAR test has been discussed. For this purpose, two models of Feedforward and radial basis of artificial neural networks and Adaptive network-based fuzzy inference system and the various kinds of fuzzy regression analysis to predict the ultimate extent of turbidity after coagulation and flocculation process in 3 and 4 Tehran water treatment plants, were studied. The coagulant used in the treatment plant was poly-aluminum chloride (PAC) and the type and concentration of coagulant, pH and turbidity of the raw water, was opted from the basic information. Radial basis model due to the possibility of automatic raising of hidden layer’s neurons to achieve performance function with minimum error, is highly capable in simulating the process of coagulating. Unlike Feedforward networks, radial basis networks required a smaller number of neurons, and also had the ability to change parameters to achieve the desired results. Increasing the number of hidden layer’s neurons and normalizing the input data to the network enhanced the predictability of artificial neural networks. The study also generalize Feedforward networks to predict data validation and correction of the increasing of performance function. Due to the uncertainty which caused by human error in the laboratory, adaptive network-based fuzzy inference system and fuzzy regression, in which the data sets in the form of fuzzy, were used. The results showed that artificial neural networks and fuzzy regression analysis had more ability in simulating the coagulation process and turbidity removal in different experimental conditions rather than adaptive network-based fuzzy inference system and had the ability to replace the JAR test with time-consuming and expensive methods. The best network built to predict the filtered water turbidity in this study was feed forward network with two hidden layers and 6 and 8 neurons and Tansig and Purelin transfer functions respectively in the first and second layers, using normalized data with performance function. This network is able to predict the coagulation process with a Correlation Coefficient of 0.96 and 0.99 Agreement Index and root mean square error 0.0106. Best predicting done by regression analysis using fuzzy quadratic function. This function was able to predict the data validation with a correlation coefficient, and Agreement Index and root mean square error, respectively, 0.94, 0.96 and 0.75. adaptive network-based fuzzy inference system with the use of Gaussmf membership functions for raw water turbidity and pH input ,and type and Trimf had best efficiency to apply coagulant concentration data into network and estimated the filtered water turbidity with correlation coefficient of 0.89, Agreement Index of 0.91, and squares error of 1.02. This system showed that increasing initial turbidity caused removal efficiency increased and the best impaction of coagulation process for the removal of turbidity would be occurred in the range of pH, 7.6 to 8. The best efficiency in operation condition was determined 99.5% in initial turbidity of 160 NTU, pH=8 and 19 mg/L dosage of PAC coagulant type I. 3004 Study of Using steel angle to Upgrade the Seismic Behavior of Centrically Braced Frames 1 10 2016 16 3 87 97 15 05 2014 09 11 2015 Abstract: Seismic Behavior of Concentric brace frames has been one of popular topics in earthquake engineering. Relatively low cost and the ease and speed of implementation has led to the widespread use of these braced frames but past earthquakes experiences show inappropriate behavior, inability to dissipate high energy and the lack of ductility. This paper presents a new mechanism by combining the steel angle and slot in brace member to improve the seismic performance and postponing the buckle. Stresses and displacement of structures using nonlinear static and dynamic analysis by finite element software "ABAQUS" are evaluated. At first In order to verify the results and ensure the implementation details and parameters used in the numerical model, results of laboratory test under cyclic loading were compared. Evaluation hysteresis loop obtained from numerical analysis and experimental results show suitable match. then, for nonlinear static analysis, seven diagonal brace model were created and tested. In the first specimen, the normal braces with no particular change, modeled and evaluated. in the second to fourth models, slot were created near the gusset plate with various dimension to reduce the axial load capacity of brace to less than it's buckling load. In the fifth model to evaluate the performance of steel angles in cyclic loading, brace section was perfectly cut and double angle used to connect two parts of brace for transfering axial load. Finally, in the sixth and seventh models, in the hope that achieving suitable seismic behavior, combination of steel angle and reduced brace section were used. Results indicate improved seismic performance and ductility of CBF systems. Concentration of inelastic response in steel angle results in high energy dissipation and prevents from nonlinear behavior in other elements. In addition, comparing the hysteresis loop of proposed model with that of normal braces shows symmetric and stable rational behavior where strength and stiffness degredation is not seen in the displacement up to about 2 cm while the normal brace buckles in about 1 cm. After that, In order to investigate the behavior of the system under seismic loading, dynamic time history analyses using the horizontal component accelerograms of the Imperial Valley, Loma Perieta and Kobe earthquakes were performed. According to the results of the nonlinear static analysis, proposed sample was chosen as a specimen with acceptable behavior and suitable ductility. Therefore, in this section regarding the long time duration on dynamic analysis, its seismic behavior was compared with the normal brace. Comparison of results obtained from three seismic records, demonstrates less input energy and base shear and appropriate seismic behavior of proposed model due to sensible stiffness reduction of proposed brace. It should be noted that due to the appropriate results obtained in numerical analysis, specimen fabrication and experimental work to verify the results in the next stage of research should be on the agenda. Keywords: Slit brace, steel angles, nonlinear static and dynamic analysis, energy dissipation, ductility. Keywords: Slit brace, steel angles, nonlinear static and dynamic analysis, energy dissipation, ductility. Keywords: Slit brace, steel angles, nonlinear static and dynamic analysis, energy dissipation, ductility. 9728 effect of organic matter, chelatant and surfactants on desorption of phenanthrene and heavy metals from clayey soil: mixture of kaoline, montmorillonite and sand ayatynia milad iran university of science and technology 1 10 2016 16 3 99 108 15 02 2015 04 11 2015 Understanding the combined effect of soil organic matter (SOM), surfactants and chelatant on the partitioning of polycyclic aromatic compounds and in soil/water systems and on their desorption is important to predict the effectiveness of surfactant-chelatant-enhanced remediation systems. In this paper the effect of soil organic matter’s content and presence of surfactants and a chelatant on desorption of six different polycyclic aromatic hydrocarbons namely acenaphthene , fluorine , phenanthrene , anthracene , fluoranthene , and pyrene was investigated and the results of phenanthrene was reported. It also investigates the effect of coexistence of three differenet heavy metals namely: lead, zinc and nickel on polycyclic aromatic hydrocarbons and their effects on desorption of these compounds. The basic soil was made from a mixture of kaolinite, montmorillonite and sand. Then this basic soil was spiked by two diffrenet level of organic matter through batch experiments to achieve three different soils named S0, S1 and S2 which has 0.33, 1.29 and 2.11 percent organic carbon, respectively. After that, this three different soils was spiked by heavy metals with the same way mentioned before (bathch experiments). As a result, six differenet soils was created under the name of: S0, S0M, S1, S1M, S2, S2M. and finally these six soils were spiked by mentioned polycyclic aromatic hydrocarbons. And finally the whole desorption experiments was done on these mentioned soils. Two surfactants chosen in this paper was triton x 100 and tween 80 and the chelatant was ethylene diamine tetraacitic acid (EDTA). Results showed that, surfactants improved the deorption of both heavy metals and polycyclic aromatic hydrocarbons and it also could be understood that triton x 100 had higher effectiveness than tween 80 in deorption of both heavy metals and polycyclic aromatic hydrocarbons. Furthermore it was found that soil organic matter had preventative effect on desorption of both heavy metals and polycyclic aromatic hydrocarbons. Both soil organic matter and surfactants are amphiphilic substances and because of that it is possible that this result is due to the sorption of surfactants into soil organic matter and consequently caused a reduction in desorption effectiveness of polycyclic aromatic hydrocarbons. and further increase in soil organic matter content caused more reverse effect on surfactants productivity. It was also found that, presence of lead, zinc and nickel could have preventative effect on desorption of polycyclic aromatic hydrocarbons too, and this could be due to some specific interactions like cation л binding between heavy metals and phenanthrene while they coexist in the interface of soil and water. Another reason of heavy metals preventative effect on desorption of polycyclic aromatic hydrocarbons could be due to their indirect effect through which, heavy metals act as an cation bridge between clay particles and organic matter mollecules and by this mean prevent soil organic matter mollecules to be dissolved in water. On the other hand scientists have proved that polycyclic aromatic hydrocarbons have great affinity to partition in to soil organic matter. Therefor by retaining more organic matter in soil through cation bridge mechanism, desorption of phenanthrene was reduced. 4926 Numerical analysis of effective parameters on liquefaction occurance result from earthquake on site of buried pipelines Sharafi Hassan Parsafar Payam 1 10 2016 16 3 111 120 29 06 2014 22 07 2016 Abstract: Saturated granular soils are possible liquefied when subjected to earthquake loading. This phenomenon is result from generation of excess water pore pressure because of non enough time to water drainage and govern non- Consolidated Condition. When liquefaction is occurred, many forces are generated and undergrounds structures are affected. In this research numerical analysis on buried pipelines in FLAC 2D software are performed and verified duration a comparative process with experimental result from ASCE organization. In present research surveyed effects of various parameters on liquefaction occurrence and probable damages to buried pipelines as dilatancy and friction angle of soil, relative density of back fill around the pipe, diameter and buried depth of pipe and underground water level. Results indicated that uplift of pipe decrease when dilatancy and friction angle of soil increased in constant relative density condition. This result is different for varied relative density. In low and medium relative density by increasing of dilatancy angle, uplift of pipe increase, reach to pick and decrease. But floating decrease with increasing dilatancy angle for high relative density always. Buried pipe in depth trench and increase of dead load result from back fill on pipeline and usage of pipes with small diameter, decrease uplift the pipe in liquefaction occurrence too. Of course don’t expect perform this subjects in all conditions. for example conflict ion to other underground installation, necessary hydraulic gradient for fluids flow or excavation in region with up underground level, don’t make to excavation of deep conduits. The analysis demonstrate that vertical displacement and damages to pipe is decrease if around installed pipe in conduit back fill with non- liquefied soils. In this new analysis all physical properties of soil and pipe in model are without any change except the cohesion and friction angle of soil around the pipe. Cohesion soils are low potential to liquefaction. For this reason we increase this coefficient from zero to 30 kpa and reach the friction angle to 30 degree. Results are demonstrated in a graph that show uplift versus thickness of non- liquefied soil normalized with diameter of pipe. Final parameter that surveyed in this research is effect of underground water level on floating buried pipeline. Results show decrease of underground water level cause to decrease of floating and damages to pipeline. For this purpose add a new water level to base model and run the analysis. In next steppes the underground water level is lesser and results are show in a graph that explain variation of vertical displacement versus water level normalized by thickness of soil model. This work possible by excavation of drainage shaft and drop down water level nearby the pipeline. Of course, look this work isn’t economical proposal for long transmission pipelines as petroleum or water conveyance. But in limit industrial sites as refineries this proposal is an improvement work to prevent any damage and and continual service of lifelines duration of unpredictable phenomenon. Keywords: Liquefaction, buried pipelines, FLAC, finite difference method, Finn’s model. Liquefaction, buried pipelines, FLAC, finite 12019 Developing cyclic Dual Loading Protocols for the Columns of Moment Frames Based on Their Seismic Demands, and Evaluation of Their Cyclic Behavior FARAHI MOJTABA Erfani Saeed Amirkabir University of Technology Professor Assistant, Amirkabir University of Technology 1 10 2016 16 3 121 136 23 05 2015 04 11 2015 The column members of moment frames are subjected to high axial forces as well as inelastic rotations during a seismic event. Estimating the boundaries of these simultaneous structural demands on the columns of special moment frames are one the aims of this research. These demands were evaluated in this research by performing a vast number of non-linear time history analyses on some archetype frames. Totally, eight archetype buildings were designed under two levels of spectral accelerations represent the Maximum Credible Earthquake (MCE) and the Design Earthquake (DE). Both geometric and material nonlinearities were taken into account. Far-field earthquake record set proposed by FEMA P696 was utilized in this study to conduct the required time history analyses. This set includes 44 individual seismic records with different magnitudes and other specifications. Each sample SMF was excited by each of the individual records with two different intensity levels referring to DE and MCE respectively. After performing numerous time history analyses, the boundaries and the characteristics of the axial force and the story drift ratio demands on columns were fairly stablished for the seismic events with MCE and DE intensity levels. It was proved that they might experience the axial force around 0.3 of their yielding capacity as well as the drift ratios up to 0.06. Moreover, based on the results of these analyses, a representative loading protocol was also developed for the column members of special moment frames because the effect of simultaneous change of the axial force demand on columns along with the change of plastic rotation in these members was neglected in all of introduced loading framework for these members. On the other hand, the utilized loading frameworks in different research studies were introduced quite arbitrarily and with no root in the real seismic demands of these structural members. Hence, a statistical approach implemented to extract the loading cycles based on the results of the mentioned non-linear time histories. This loading protocol includes cycles of varied axial force ratios as well as simultaneous cycles of lateral loading. Providing such a loading regime can pave the way to investigate the behavior of the columns of moment frames using more sophisticated numerical models that cannot be ordinarily employed to perform time history analyses under seismic records due to excessive computational costs. The overall response of steel columns may be dominantly affected by the local effects like as local bucking at large deflections. Hence, the response of some archetype individual columns was fairly investigated under the proposed loading protocol by utilizing continuum finite element simulations which are expected to be able to capture deliberately these kinds of local effects. The investigation not only revealed more on the details of the behavior of these members, but also proved the versatility of the proposed loading protocol in comparison to the previous loading procedures implemented on columns. In order to do so, the numerical models of the archetype columns were also loaded under the proposed lateral loading protocol besides constant levels of axial loading and the results of both cases were compared. It was shown that implementing a constant axial load besides the cyclic lateral cyclic loading may not be an appropriate loading framework and the results would not represent the seismic demands in these members accurately. 10996 The role of Sulphur Polymer and Crumb Rubber additives in resistance against stripping of asphalt mixes KAVOSY AMIR UNIVERCITY 1 10 2016 16 3 137 146 16 11 2014 17 01 2016 Premature failures are experienced in road pavements. Among the various failure modes, moisture damage is probably the most occurring distress in asphalt pavements. In fact, the continuous presence of water in asphalt layers weakens the bond between aggregate particles and bitumen, ending to stripping of mixes. With this regard, several parameters affect water damages to asphalt layers. Among these, aggregates type and source, bitumen type and grade, mixture design, construction practice, traffic volume, environment and the additive properties could be named as the most affecting parameters. In order to prevent stripping, one of the most effective methods is to use anti-stripping additives. Among the various additives, sulphur which is a byproduct of petroleum gas production industries, has been known to increase stiffness of bituminous mixes appreciably, provided that it is added properly and at right amounts. However, due to environmental drawbacks of this additive (i.e. emission of disturbing gases) and the too much stiffening effects that imparts to mixes, sulphur alone was banned to be used in road pavements for several decades. In the recent years, combined additives, consisting of sulphur and polymers have been produced and applied into asphalt mixes. These additives have shown to have less adverse environmental effects (i.e. reduced emission of gases such as ). The effects of these additive types is so that their sulphur component provides stiffness to mixes and their polymer portion imparts some flexibility to mixes and increase the adhesion properties of the mix binders. “ASTM D8” Standard Testing Method. In this research a locally produced sulphur polymer additive, named ‘Googas’, was used and applied in a continuously graded asphalt mix. This new product had lower emissions of gas, compared with the conventional sulphur mixes. In addition, it provided enhanced properties to mixes, compared with previously made sulphur alone containing mixes. In order to reduce the stiffness of mixes and provide these with more flexibility, CRM (Crumb Rubber Modifier) modified binders were used as the replacement of conventional penetration grade binder of mixes. CRM binders were prepared containing different amounts of crumb rubber. The preparation was carried out in the laboratory using a high shear rate mixer upon following The results showed that increased amounts of Googas sulphur polymer although resulted in increased compression strength, reduced the moisture resistance of mixes substantially. In fact, it was seen that when asphalt mixes were cooled to ambient temperatures, the sulphur tended to change from liquid into solid state, contributing little to bitumen adhesiveness. In contrast, mixes containing CRM binders alone, showed increased tensile properties, as indicated by increased ITS testing results. With analyzing the laboratory results, optimum amounts of the above two additives were determined. In fact, increased amounts of CRM resulted in increased tensile resistance of mixes (i.e. showing a gradual increasing trend). This was up to CRM’s of 18% to 20%. Further increases resulted in lower tensile strengths. Hence, optimized mixes were designed containing both CRM and sulphur polymer additives. 8870 Active Vibration Control of Frame Smart Structures by New Approach karimpor b دانشگاه صنعتی شاهرود 1 10 2016 16 3 147 154 29 11 2013 01 05 2014 In this paper, new approach is presented for controlling the structural vibrations. In spite of previous methods, which are used mathematical concepts, the proposed active control technique is based on structural dynamics theories in which multi actuators and sensors are utilized. Each actuator force is modeled as an equivalent viscous damper so that several lower vibration modes are damped critically. This subject is achieved by simple mathematical formulation. First, the proposed multi actuators control method is formulated based on structural dynamics theories. Then the sensors and actuators' locations are determined by simple algorithm. For numerical verification of the proposed technique, the displacement's variations of a five-story shear building, excited by seismic load (Elcentro Earthquake), are evaluated. This study shows that the proposed method has suitable efficiency for reducing structural vibrations. According to the results, the maximum shift in the structure of the upper floors 5 degrees of freedom are reduced by 70%.Smart structures are systems that can teach and protect themselves against the external excitation such as wind and earthquake. Analyzing and designing of smart structures is based on set of sciences including materials science, applied mechanics, electronics, bio-mechanics and structural dynamics. In this procedure, maintaining the structural performance against the external hazards is very important issue called control system. Many studies have been performed in the field of structural control. These methods can be categorized into three groups i.e. passive, semi-active and active procedures (Akutagawa et al. 2004). Due to the simplicity, low cost of assembly and no need to the external power, the passive control systems are numerous. However, the constant control feature makes these systems fail during the earthquakes. In other words, these systems are designed to work only for a certain excitation and limited frequency bound. The passive control system tries to remove the kinetic energy from the structure. Because of the mentioned constraints in passive algorithms, active control is highly regarded systems to cope with the earthquake. These techniques have suitable efficiency in different excitation so that they could exactly sense and adopt the structural vibrations. To achieve this goal, each active control method is constructed based on algorithm, which verifying its efficiency and accuracy. The application of such systems began in 1989.In these systems an external power source is required so that this applied force is affected the structural equilibrium equation. This applied force may lead to instable vibrations if the active control algorithm is not suitable. Hence, the complexity, the calculations volume, the instability risk and the uncertainty factor are some difficulties arise from active control systems. It should be noted that, good performance of active methods depends on some parameters such as the reliable algorithm and the suitable positions for both sensors and actuators (Guclu et al. 2008; Chen et al. 2001;Rudinger et al.2007; Hoang et al.2008). The common active control algorithms have been listed in Table 1, followd by the main idea used in each method (Datta et al.2003). 11747 Numerical study of the effect of soil-bag system to improve geotechnical bearing capacity of the bed soil Lakirouhani Ali Bahrehdar Mohammad 1 10 2016 16 3 155 164 07 12 2014 22 07 2016 Using of reinforcement elements in improving geotechnical properties of soil has been considered by a human for many years. In recent years, many improvements have been made in the field of improving poor soils and reinforcing them. Soil reinforcement is used as an effective method to improve the soil layers in order to increase the bearing capacity and reduce the settlement. Soil-bag system is one of the new polymer products. That can be used as a soil reinforcing element in various projects. Soil-bag system was developed in order to increase the bearing capacity of the soil and reduce its settlement. The kind of filling materials mostly depends on the application of soil-bag system and availability of materials. The most important characteristic implemented into the structure of soil-bag system is tension strength of the polymer implemented in the bag. Bags implemented into soil-bag system are generally built of polyethylene or polypropylene polymers. When soil-bag system undergoes vertical loading, tension force produced into the bag cover causes to increase vertical force (N), consequently, this causes to increase the force between soil particles (= soil friction coefficient and F=.N). Earth reinforcement using of soil-bag system causes to increase bearing capacity and it causes to minimize transformation of foundation bed influenced by the imposed load. The results of simple pressure test on the foundation reinforcement with soil-bag system by Yongfu Xu show that when soil-bag system is exposed on external load, it exhibits high strength which a fundamental portion of this strength is resulted from tension force generated in the cover of polymeric bag. Of other characteristics of soil bags, the absorption of vibrations resulted from traffic load can be addressed. In this study, the bed soil models in reinforced and non-reinforced conditions have been investigated using numerical method. Numerical studies have been done in three dimensional cases using finite element method (Abaqus). In this method sand and polypropylene polymer bag behavior were defined by using Mohr-coulomb and Elastic- Perfect Plastic models. Also, the effects of soil-bag system in increasing the bearing capacity and reducing settlement were evaluated. Another resistance-based parameters of soil-bag system which was examined in this research, is the effect of internal friction angle of soil on the bearing capacity of soil-bag system. Regarding the results of numerical method, it is observed that the maximum tension concentration in the above-mentioned model is placed in the corners of polymeric bag. The results show that the more is the friction angle between soils particles, the resistance of soil-bag system will also be increased against the external loading. There are proper matching between the results obtained from numerical studies and field studies done by other researchers. The results show that the bearing capacity of reinforced bed is almost 2 times bigger than the non-reinforcement bed. 642 Effect of Separating Wall Geometry on Flow Pattern of a Large-Scaled 90° Open-Channel Junction salehi neyshaburi seyed ali akbar tehran-modares un 1 10 2016 16 3 165 175 24 09 2013 01 05 2014 Abstract: Open-channel junctions are common structures in hydraulic and environmental engineering. The interaction between the main and branch flows, causes the main flow to be diverted toward the opposite bank and create a separation streamline at the downstream corner of the junction. Formation of a 3D separation zone with lower pressure immediately near the branch-side bank is one of the most distinctive characteristics of a flow in open-channel junctions. The recirculating flow in this low-pressure zone not only prepares a suitable space for sedimentation, but also increases the velocity near the opposite bank of the main channel and its bed and thereby leads to local erosion. Reducing the sedimentation in recirculation zone and eliminating the erosion near the opposite wall of the channel are two major concerns of designers of these structures. Open-channel junctions have a broad application in civil and environmental engineering. Formation of a low-pressure zone with recirculating flow (high sedimentation) accompanied by a high-velocity zone (high erosion) are the most characteristic features of flow in junctions. Numerous experimental, numerical and analytical researches have been conducted to explore the flow structure in the junctions and investigate on methods for reducing the effects of sedimentation and erosion on channels. A large number of researches have been performed to grasp the complicated concept of hydraulic phenomena and correct the related deficiencies in junction of open-channel flows. Implementing a separating wall in the middle of the branch channel is thoroughly investigated in this research to understand its effect on the flow pattern and its contribution in reducing the sedimentation and erosion potential in an open-channel junction. Initially, the numerical two-phase model of a previous experimental study, is prepared and its results are validated. Following that, a one-phase model is prepared based on the fact that the difference between maximum and mean elevation of water free surface is less than 10%. According to the negligible (less than 3%) discrepancy between numerical one-phase and two-phase results in predicting the maximum U* after the junction in channel, acceptable similarity between U* contours and U* variation along the flow depth in numerical (one-phase) and experimental studies and considerable increase in computation time of two-phase analysis, one-phase analysis is implemented instead of two-phase one in the rest of this research. Finally, effects of separating wall are evaluated in a large-scaled industrial 90° open-channel junction and some new geometrical efficiency measurements are devised and assessed to improve the wall performance. Among proposed geometrical modifications on the wall head, circular profile had the best performance in reducing the maximum velocity after the junction. The results show a considerable improvement in flow pattern which causes a significant reduction in sedimentation and erosion potential in open-channel junctions. Keywords: Open-channel junction, Separating wall, Numerical model, Erosion, Sedimentation. 6592 Analytical application of maximum sediment transport capacity to determine hydraulic geometry relationships in gravel bed rivers mahmoodi mahsa majdzade tabatabai Mohammad Reza Mousavi nadushani Saeed Shahid Beheshti University Shahid Beheshti University 1 10 2016 16 3 177 191 14 12 2014 17 06 2015 Development of erosion and sedimentation processes due to human activities or natural changes will threaten the stability of the rivers and cause hydraulic and morphological changes. Continuous changes will result in a lot of damages including damage to structures constructed in the rivers. Therefore, preserving the rivers in the equilibrium (regime) state is of great importance. In other words, determination of the stable hydraulic geometry of the rivers is one of the most important cases on which the design, planning, management and training of the river are founded. Two basic approaches have been used to predict the hydraulic geometry of gravel-bed rivers: (1) Those based on empirical regime equations; and (2) those based on the simultaneous solution of the equations governing channel flow. Currently there are considerable restrictions with the use of both methods for channel design purposes. Existing experimental hydraulic geometry relationships have been obtained for particular field conditions and based on limited data, and can be used only under the same conditions. Equally theoretical methods are applicable only to straight or fixed width and with static stability channels, due to our lack of knowledge regarding the mechanisms controlling width adjustment and meander development, a large number of theories have been developed in this regard that the basic assumptions of all include a steady and uniform flow as well as stream changes toward the equilibrium state and the main difference between these theories is the hydraulic mechanisms employed by the models to describe how the stream reaches the equilibrium state. In this Paper, an analytical model for assessing the stable condition (static and dynamic stability) and predicting river response to the applied changes (such as hydraulic changes) was proposed and univariate and bivariate hydraulic geometry relationships to be applicable in the rivers with dominant bed load, were derived. For this purpose, after reviewing the previous researches in this field, the principles and concepts of the regime and hydraulic geometry were presented. In the next step, by using the analytical model, a system of equations was solved without including bank stability constraint (unconstrained model). Due to lack of required equations to solve the system, extremal hypotheses were used. According to these theories, the river behavior is justified in order to optimize a specific morphologic parameter. a good agreement was observed between the developed exponents of hydraulic geometry relationships in this paper and the results of the empirical and analytical hydraulic geometry relationships. This represents the self-adjusting mechanism of alluvial channels by introducing the channel shape factor (bed width/depth ratio) and the inclusion of extremal hypotheses in the flow governing equations (continuity, flow resistance and sediment transport equations). Finally, developed model were calibrated using the field data of the United Kingdom and the mean relative error of the bankfull width and depth calculation is obtained 47% and 35%, respectively. obtained results confirmed the efficiency of the proposed model. Development of erosion and sedimentation processes due to human activities or natural changes will threaten the stability of the rivers and cause changes 7063 Evaluation of factors affecting the shear strength of the biologically treated sandy soil using Taguchi method mirmohammad sadeghi masoud 1 10 2016 16 3 191 202 22 02 2014 04 11 2015 Population and civil infrastructure continue to expand at unprecedented rates. On the one hand, the growing needs for the development and, on the other hand, the environmental crisis, stress the importance of finding methods not harming the environment while they are able to meet the requirements for development. Infrastructure demands are even more severe in other countries, particularly in developing ones. Infrastructure is insufficient in countries such as China, where 10 million people immigrate to major cities each year. Population growth is particularly acute for historic cities and regions where expansion is limited by geographical boundaries and inadequate soil conditions. The confluence of these factors necessitates the exploration and development of new alternative soil improvement methods and associated reliable monitoring techniques. Bio-mediated soil improvement is an innovative, and interdisciplinary technique with the approach of being environmentally friendly, which utilizes some bacteria utilizing some bacteria to precipitate calcite on soil particles. In addition, this system broadly refers to a chemical reaction network that is managed and controlled within soil through biological activity and whose byproducts alter the engineering properties of soil. Therefore, Microbial carbonate precipitation (MCP) has experienced an increased level of interest in recent years for applications such as restoration of calcareous stone materials , bioremediation, wastewater treatment, strengthening of concrete and selective plugging for enhanced oil recovery. In this research, to attain the highest number of experiments without repeating the unnecessary ones, Taguchi design method was utilized. The Taguchi method was developed to improve the implementation of total quality control. The effect of factors on characteristic properties (response) and the optimal conditions of factors can be determined using the Taguchi design. It is feasible to find out the optimal experimental conditions with the least variability. Taguchi analysis is based on choosing the best run by analyzing signal-to-noise ratio (S/N), whose form depends on the experiment objective. A standard L9 orthogonal array with four parameters consisting of bacterial cell concentration, molar concentration ratio of nutrient solution, curing time, and inoculum ratio, each was assigned three levels, was selected. In this regard, soil samples were stabilized in sandy soil columns. Two-phase stabilization were conducted by adding the bacterium Sporosarcina pasteurii PTCC 1642 in the first phase and nutrient in the second phase. Specimens were subjected to direct shear stress test with the normal stress of 12.5, 40, 68 kPa. ANOVA suggested that the effect of each parameter on the direct shear stress. The most effective parameter was curing time with 45.97% of the overall variance of the experimental data followed by bacterial cell concentration (22%), molar concentration ratio of nutrient solution (20%), and inoculum ratio (12%). The direct shear strength increased from 6, 18, 31 kPa for the normal stress of 12.5, 40, 68 kPa to 470, 491, 512 kPa in optimally treated specimens. 3397 Reliability of Marine Steel Structures Against Corrosion Moarefzadeh Mohammad Reza Assistant Professor/The University of Imam Hossein 1 10 2016 16 3 203 215 14 04 2014 17 06 2015 Abstract Reliability analysis of steel structures subject to seawater corrosion is of considerable interest for coastal and offshore marine steel structures. These are often very expensive and have high consequential costs and implications should failure occur. Since corrosion of steel structures causes deterioration of structural strength, usually gradually with time, safety assessment is of considerable importance for new structures (those in the design stage) and also for those which are already in operation. Marine corrosion is a complex phenomenon and subject to various influencing factors each of which has its own inherent uncertainty. In any safety assessment, in principle, the uncertainty of each factor should be studied and taken into account. Since such an action is too difficult, in practice some test programs are normally conducted and all uncertainties caused by different factors are assumed to be included in the relevant corrosion measurements. In addition, in any corrosion reliability analysis for steel structures exposed to seawater, two different models must be taken into consideration: (1) A physical model indicating general corrosion behaviour as a function of exposure time and (2) A stochastic model describing probabilistic treatment of uncertainties observed in real corrosion data. The first has been traditionally treated by invoking a simple power law and in particular a linear relationship. However, using realistic long-term data, validity of such a model has recently been challenged. The second model (i.e. probabilistic modelling of corrosion process) has been dealt with in literature in different approaches, including either taking the corrosion annual rate as a random variable or proposing a stochastic process such as Gamma process. This is usually proposed as a general structural deterioration process. The second approach provides, doubtlessly, better treatment of corrosion uncertainties; however it can be shown unfortunately that the Gamma process is unable to reflect the corrosion uncertainties in some circumstances. In this paper, two sets of corrosion data collected in different seawaters around the world with different temperatures are used. This requires processing of data in such a way that the data sets remain consistent with each other and that outcome is data that can be considered as belonging to one statistical population. Herein, first, a simple algorithm is proposed to transform the whole data to one common temperature. Second, a novel Markov-chain based model is developed which meets long term second-order corrosion statistics (i.e. means and standard deviations of corrosion losses). It is based on a corrosion model that previously has been calibrated extensively to field observations of corrosion and to literature-reported realistic data. Although actual long-term field observations of marine corrosion of steel are scarce, it is shown that particularly for the standard deviation the new model is well capable to be consistent with the long-term data. It is noted that herein, only the corrosion data collected in marine immersion zones are considered (i.e. those taken in splash zones and atmospheric zones are not considered). Further, only general corrosion (i.e. not pitting corrosion) is accounted for herein. These issues, obviously, have to be addressed separately. 5508 Numerical investigations on effect of intake location and diversion angle on flow pattern in a channel bend by SSIIM2 Software Asiaei hossein 1 10 2016 16 3 215 226 07 01 2013 22 07 2016 The use of lateral intake is one method of providing water from river. The most important issue in branch channel gets the maximum of water and lowest sediment. The rivers rarely run on straight paths in nature, and most rivers have meandering forms. In a river bend the presence of centrifugal force leads to the formation of secondary flow. As a result water particles near the surface are driven outward. The secondary flow advects the main flow, leading to high velocity at the outer bank of the bend. On the other hand the flow at the bed of a channel is directed toward the inner bank. The interaction of the main flow with the secondary flow forms the so-called helical flow in the bend. This flow system has important consequences in the longitudinal, transverse, vertical velocity distributions, transport of momentum and streamlines at different levels of water. Therefore layout the intake outer bank of bend is one of the ways to reduce sediment input to the lateral intake. Combining the helical flow and complex flow pattern in front of the lateral intake is added complexity of this three- dimensional flow pattern. The flow approaches the intake; it is accelerated laterally by the suction pressure at the end of the branch channel. This causes the flow to divide so that a portion enters the branch channel with the remainder continuing downstream in the main channel. The portion withdrawn by the branch is delineated by a curved shear-layer surface, denoted as the dividing stream surface Because of the streamwise curvature of the dividing stream surface, the diverted flow experiences an imbalance between the transverse pressure gradient and shear and centrifugal forces that initiates a clockwise secondary motion cell. This secondary motion interacts with the separation zone along the inner wall of the branch channel. In design of lateral intakes, determination of appropriate intake location and diversion angle is very important. In this paper, we simulated lateral intake at different location and different angel by using the SSIIM numerical model to investigate dividing stream surface and separation zone at main and branch channel. For this purpose the flow is simulated using standard k-ε model and RNG model. For calibration of model we used the result of the Montaseri et.al (2008) investigation. The results show that in the curved channel the dividing stream surface has a completely different structure than the lateral diversion in a straight one. In other words, wide of dividing stream surface near bed is smaller than near surface. Furthermore, in any locations dividing stream surface width near the bed and separation zone has largest dimension at 90 degree diversion angle and has smallest dimension at 30 degree diversion angle. Also, in 135 degree location, dividing stream surface width near the bed has smallest dimension and dividing stream surface width near the surface has largest dimension at any diversion angle. 7033 Performance Evaluation of Monte Carlo Simulation and FORM Method to Calculate Probability of Failure for Concrete Gravity Dams in Sliding Failure Mode under Static Loading MiarNaeimi Farid Azizyan Golamreza Akbari Gholamhossein PhD Student/University of Sistan and Baluchestan University of Sistan and Baluschestan University of Sistan and Baluchestan 1 10 2016 16 3 227 240 05 03 2015 04 11 2015 Failure of a concrete gravity dam will cause unavoidable human loss and financial damages. In this study SARIYAR concrete gravity dam, located in turkey was chosen as a case study and its probability of sliding failure in various condition was studied. The most important reason in sliding failure of a concrete dam was lateral and uplift loads, caused by increase in the level of reservoir water. Different scenarios were considered in which might happen for a dam, all the possible height of reservoir water simulated. Afterward, Probability of failure and reliability index was calculated with Monte Carlo simulation and FORM method in all conditions and comparison with each other. The influence of the Number of Simulations (NOS) in the Monte Carlo method was also discussed. Results showed that, in some cases, the resistance of the system was much more than the loads and limit state function had a significant distance from samples. In such states, Monte Carlo was unable to calculate the probability of failure with each NOS but FORM method obtained the Reliability Index (β) in these situations. It became clear that these values were far from reality. With increase in the forces, responses from Monte Carlo had a high degree of precision. The probability of failure generated by FORM method was less than a reality. Failure of a concrete gravity dam will cause unavoidable human loss and financial damages. In this study SARIYAR concrete gravity dam, located in turkey was chosen as a case study and its probability of sliding failure in various condition was studied. The most important reason in sliding failure of a concrete dam was lateral and uplift loads, caused by increase in the level of reservoir water. Different scenarios were considered in which might happen for a dam, all the possible height of reservoir water simulated. Afterward, Probability of failure and reliability index was calculated with Monte Carlo simulation and FORM method in all conditions and comparison with each other. The influence of the Number of Simulations (NOS) in the Monte Carlo method was also discussed. Results showed that, in some cases, the resistance of the system was much more than the loads and limit state function had a significant distance from samples. In such states, Monte Carlo was unable to calculate the probability of failure with each NOS but FORM method obtained the Reliability Index (β) in these situations. It became clear that these values were far from reality. With increase in the forces, responses from Monte Carlo had a high degree of precision. The probability of failure generated by FORM method was less than a reality. Failure of a concrete gravity dam will cause unavoidable human loss and financial damages. In this study SARIYAR concrete gravity dam, located in turkey was chosen as a case study and its probability of sliding failure in various condition was studied. The most important reason in sliding failure of a concrete dam was lateral and uplift loads, caused by increase in the level of reservoir water. 9685 Assessment of eccentric brace effect in steel structures performance and comparison of it with moment frame system in progressive collapse phenomenon sajoudi tousarvandani behnam daneshjou 1 10 2016 16 3 241 252 13 05 2014 21 10 2015 Structure safety in the design of civil engineering projects has always been very important for engineers. One of the mechanisms that structure will fail and in recent years is much attentioned to it is progressive collapse. Progressive collapse in structures during earthquakes even in an explosion near the construction has become a major challenge and can create problems for structures and may even lead to the destruction of the entire structure. Currently the most available structures is only designing against the gravity loads and lateral loads (wind and earthquake).In fact a resistant structure against the earthquake is not resistant against the progressive collapse necessarily. Therefore designing the new and special structures against the progressive collapse is necessary. Progressive collapse is defined as extension of primary local failure from element to other element that finally collapsed all part of the structure or big part of it. Potential hazards that cause progressive collapse are fires, gas explosions, make a mistake in design of structure, accidents, bomb and even an unprincipled excavation that cause sudden removal one or more elements of structure and etc. The purpose of this paper is to investigate progressive collapse in steel structures with eccentric braced frames that also the influence of parameters such as height, bracing arrangement and type of structural system is examined In this study it is analyzed the progressive collapse due to column removal in steel eccentric braced frames that are designed seismically according to Iranians guidelines(seismic regulations of Iranian 2800 code) with using of alternate path method and nonlinear dynamic analysis. Also in the continuation of research it is analyzed the progressive collapse due to column and brace removal simultaneously in steel eccentric braced frames and analysis the progressive collapse in moment frames and comparison of it with eccentric braced frames. Also it is evaluated the influence of parameters like number of floors, location of braces and type of connections. For this intent two structures with five and ten stories with braces in middle spans, and also two structures with five and ten stories with braces in lateral spans, one structure with five story with system of moment frames and one structure with combinatorial system of moment frames with eccentric brace which is five story in ETABS program were analyzed. Then one of outside frames for analysis of progressive collapse modeled in SAP2000 program. Results showed that remove a single column only when there is not any brace beside the removed column and simultaneous removal of columns and braces only in the last floor causing progressive collapse to the structure. Results showed that the probability of progressive collapse with simultaneous removal of columns and braces will increase when the height of the frames that middle spans is braced increases and will decrease when the height of the frames that lateral spans is braced increases. Also with comparison of eccentric braced frames and moment frames is resulted that eccentric braced frames is stronger than the moment frames against the progressive collapse. But combinatorial system of moment frames and eccentric brace in comparison with the other analyzed systems is completely resistant system.