Modares Civil Engineering journal
Year:2016 | Volume:16 | Issue:2|Papers Count:22

In this research an aerobic biological transformation of organic matter in small diameter gravity slope wastewater collection system is evaluated. A sewer network reactor at pilot scale consists of 15 meters length of PVC with 0.1 m diameter, two storage tanks, recirculation pump and an adjustable slope facility was designed and built. Formation of attached growth of microorganism on the inner surface of PVC pipe was made through a plastic net arrangement. Due to the variation of hydraulic mean diameter, contact area with flowing wastewater was ranged from 1.88 to 3.77 m2 (half or full). The synthetic wastewater with similar characteristics of municipal wastewater and settled activated sludge from Yasreb wastewater treatment plant in Qaemshahr City, was used at startup and final stage of this investigation.In order to monitor bio-film attachment rate in the reactor, two P.V.C square plates with dimensions of 10*10 cm2 were positioned vertically in the direction flow of wastewater. The reactor was operated under aerobic conditions and following parameters such as HRT, TEMP, BOD, COD, Do, TN and NH3-N and NO3-N were measured on daily basis. And also biofilm characteristics such as thickness density and surface density were both monitored throughout the investigation, too.Biofilm formation was an irregular shape with thickness of 3-4.7 mm and the density and surface density were 55 mg Ts/cm-3 and between 22.3 and 33.1 m-2 respectively. The concentration of the suspended biomass was varied from 10-15 mg/l at optimum COD removal Oxygen uptake rate was varied as the biofilm attachment in the reactor was varied along length of reactor. The optimum rate of removal in COD and BOD concentration were 59% and 54% respectively. By increasing the COD loading rate by 70 %, removal rate of COD reduced only by 9%. Due to high COD concentration in reactor, the nitrification process was limited. In order to nitrify the wastewater, a longer HRT is required.

Aboozar oil field is located around 75 km south west of Kharg Island, in Bushehr state, southern part of Iran. Aboozar oil and gas complex contains 3 production platforms: Aboozar-A (AA), Aboozar-B (AB) and Aboozar-C (AC). Each of them includes some oil and gas wells which feed the process facilities and in addition each one comprises separate flare system in which separated gas is flared over there. Aboozar field offshore process is limited to oil and gas separation, and the produced gas from the separators is disposed in a common flare system in which more than 36 million standard cubic feet gas mixture are daily being flared. Flaring is the common practice of burning off unwanted, flammable gases via combustion in an open-atmosphere, non-premixed flame. This gas may be deemed uneconomic to process (i.e. if it is far from a gas pipeline or if it is ‘sour’ and contains trace amounts of toxic H2S) or it may occur due to leakages, purges, or an emergency release of gas in a facility. The flaring process can produce different pollutants such as SO2 as an index pollutant which has a substantial role in the environment and human health. SO2 is one the most major pollutants emitted from production platform flares due to gas mixture combustion. This pollutant concentration depends on the composition of gas sent to the flare combustion chamber and also flare combustion efficiency. To specify prevention and mitigation measures, it is needed to know about air pollutants concentration. In highly polluted places, to monitor amount of each pollutant all over the region, we should always measure concentration of pollutant by pollutant emission modeling from the source not to need costly routinely measurement by some special devices. Nowadays, air pollution models are routinely used in environmental impact assessments, risk analysis and emergency planning, and source apportionment studies. A dispersion model is essentially a computational procedure for predicting concentrations downwind of a pollutant source, based on knowledge of the emissions characteristics. These models is based on mathematical calculation and used to estimate pollutants concentration. As the project target, flare modeling as a point source to investigate its concentration around the platforms to understand whether the concentration of pollutant is more than the standard limit value or not was considered. In this project, we have simulated SO2 emission by means of an advanced model based upon the Gaussian model, and we tried to find out SO2 dispersion pathway after flame. In this study, Aboozar production platform flare SO2 dispersion has been simulated by means of AERMOD View software and its concentration was determined. Flare flame length and height was determined, using flare flame net heat release value, to achieve flare effective height. In addition, meteorological data was pre-processed in Rammet View Software to input in main software. Final results showed that SO2 estimated concentration is being exceeded from threshold limit value all over the complex in all living quarters and production and wellhead platforms based upon the American Conference of Governmental Industrial Hygienists standard. The most SO2 Concentration was determined in 800 km far away of AB platform. Relation coefficient between model and Field measurements was calculated equal to 0.97.

Reinforced concrete deep beams have useful applications in many structures, such as tall buildings, foundations, offshore structures, and several others. They as important structural elements having small span-to-depth ratio. The investigation of their behavior is a subject of considerable interest in RC structures researches and some studies on the shear strength of reinforced concrete deep beams have been carried out over the last fifty years. In deep beams, according to shear span-to-depth ratio and web reinforcement the ultimate strength is generally controlled by shear rather than flexure, if the sufficient amount of longitudinal reinforcement is used. Several different failure modes have been identified from experimental studies, due to variability in failure, the determination of their shear strength and identification of failure mechanism are very complicated. In this paper the influence of effective parameters on the behavior of high-strength RC deep beams was investigated. For this purpose, an experimental-analytical investigation was conducted; a total of five reinforced concrete deep beams with compressive strength in range of 60 MPA were tested under uniform contributed top loading. The tested specimens were simply supported and reinforced by vertical steel bars in various spacing. The general behavior of tested beams was investigated. Observations were made on mid-span vertical deflections, cracks form, failure modes and shear strengths. All the beam specimens showed a same response up to failure. The test results indicated that vertical web reinforcement are efficient in shear capacity of deep beams, almost specimens were failed in shear. According to the test results, the shear capacity is affected by amount of web reinforcement and the test specimens are stronger in comparison with those were tested under two-point loading. Elastic solutions of reinforced concrete deep beams provide a good description of the behavior before cracking, but after cracking, a major redistribution of stresses occurs and hence the beam capacity must be predicted by inelastic analysis. Due to their geometric proportions, the capacity of reinforced concrete deep beams is governed mainly by shear strength. Strut-and-tie method is one of the most simple and applicable methods which can be used to simplify analysis and design of deep beams. Strut-and-tie modeling is the most rational and simple method for designing no flexural members currently available. At least, the experimental strength of specimens was compared with predicted results of strut-and-tie method (STM). The results indictes the proposed STM provide acceptable shear capacity of deep beam under uniform loading.

The treatment of wastewater generated from acrylonitrile butadiene styrene (ABS) resin manufacturing industry have a great importance due to its high chemical oxygen demand (COD) and some other toxic substances. Activated carbon adsorption, chemical oxidation and biodegradation are the most conventional methods to the treatment of ABS effluents. Among them, the biological treatment as an environmentally friendly technology is highly regarded in the bio treatment and biotransformation of the toxic compounds of ABS wastewater to the intermediate and final compounds such as CO2 and water. This study was conducted to evaluate the performance of an activated sludge system for pretreating ABS manufacturing effluents. The wastewater pretreatment plant is consisted of 3 fine screens, a grit chamber, an equalization basin, dissolved air floatation (DAF) system, an activated sludge reactor and a final clarifier. This system was operated to reduce the TSS and COD values in the effluent in order to obtain to interior discharge permits to the central wastewater treatment utility operated by Tabriz petrochemical complex. Four runs weighed average sampling was conducted during 6 months according to the standard methods of the examination of water and wastewater. The parameters including COD, BOD5, TSS, TDS, sulfate, total kjeldahl nitrogen (TKN), ammonia-N, nitrate-N, alkalinity, cyanide, phosphate and pH were measured in wastewater samples according to the standard methods. The concentrations of acrylonitrile, acrylamide and acrylic acid in wastewater samples were determined using gas chromatography (GC) equipped with flame ionization detector (FID) with capillary column. Microbial structure of activated sludge was also evaluated using R2A, PCA and Nutrient Agar culture media as well the biochemical standard tests. According to the results, at surface loading rate of 2.76 m3/m2.h applied to DAF, the COD and TSS removal efficiencies of 24 and 43% were obtained, respectively. The ratio of BOD5/COD in the influent was 0.57 indicated the moderate biodegradability of ABS wastewater. In addition, the COD and BOD5 removal efficiencies in biological reactor were 59 and 68% respectively, at the organic loading rates (OLR) of 0.79±0.06 kgCOD/m3.d. Totally, the COD, BOD5 and TSS removal efficiencies in the pretreatment system were 80, 90 and 88%, respectively. In addition, at the acrylonitrile loading rates of 0.067±0.008 kg ACN/ m3.d, the removal efficiency of acrylonitrile was 91% which 26% of that has occurred in the biological reactor. Also, the removal efficiency of cyanide was 97% which only 4% of that has occurred in the biological reactor. Twenty bacterial strains were isolated and identified from the activated sludge samples. Among the isolated bacterial strains, four strains include Alcaligenes sp. Pseudomonas sp. Bacillus sp. and Moraxella sp. were identified as heterotrophic nitrifiers. Based on the results, the nitrifier bacteria have played an important role in the degradation of acrylonitrile in the biological activated sludge system. The results of parameters analysis, performance evaluation and microbial assessment revealed the satisfactory performance of COD removal as well nitrification. However, it seems that a significant portion of the volatile organic compounds (VOCs) are removed from the influent wastewater by stripping.

Base isolation systems may be considered as one of the most powerful tools of earthquake engineering pertaining to the passive structural vibration control technologies. It may enable a building or non-building structure to survive a potentially devastating seismic impact. Generally, it is thought that application of seismic isolation is limited to low- and medium-rise structures, and the use of isolation for high-rise buildings considered as impractical or unfeasible. However, existing examples of isolated high-rise buildings in Japan, also in Iran, suggest that these viewpoints clearly disagrees with the real state-of-practice that exists there. Since the 1995 Kobe earthquake, just fewer than 200 isolated high-rise buildings, ranging from 60 to 180 meters height, have been constructed in Japan. However, this strategy is still uncommon in most countries of the world. Implementation of base isolation can greatly decrease inter-story drifts and floor accelerations, which results in protection of building’s contents. As a result, high-rise buildings can be kept fully operational during the earthquake and also immediately occupiable just after the event. In other words, isolation can be adopted for the improved performance of high-rise buildings. To maintain the efficiency, the period of isolation system has to be considered between 4 and 7 seconds. Clearly, structures like this will be vulnerable to long period ground motions. Therefore, it is necessary to study the behavior of these structures under such earthquakes. Long-period ground motions can be divided into far-source and near-fault classes. Most far-source long-period ground motions were generated by large earthquakes and effective propagation paths. Therefore, far-source long-period ground motions are generally associated with offshore earthquakes in subduction zones. Near-fault long-period ground motions are generated mainly by rupture directivity effects in the vicinity of earthquake source faults. They consist primarily of rupture directivity pulses, which can be damaging, especially when combined with site effects and basin edge effects. In this paper, three base isolated models of 8-, 14-, and 20-story shear buildings using isolator type of lead-rubber bearing (LRB) and friction pendulum system (FPS), under long-period ground motions are studied. A set of 14 long-period ground motions – 5 far-source long-period motions and 9 near-fault long-period motions – as well as 14 short-period ground motions were selected. Total earthquake input energy per unit mas was used as a measure to distinguish long-period motions so that those which had a significant input energy over the periods of 2 seconds were considered as long-period motions. For each model two isolators – LRB and FPS – were designed so that the design displacement and the period of systems were exactly the same. The isolators were designed carefully and all dimensions and parameters were checked to insure practicality of the design. Then nonlinear dynamic analysis was implemented to evaluate the response of the structures. Results show that in the cases that input motions are short-period, increasing the height of the structure doesn’t significantly affect the structure response and the isolation displacement are nearly the same. On the other hand, as the height of the structure is increased, its response due to the long-period ground motions becomes more significant, and these motions impose a great displacement demand in the isolation system.

Improvement of bearing capacity of existing foundations is of great significance. There exist many methods for practical purposes. Micropileisone of the most promising methods. Micropile is a replacement pile of small diameter (usually less than 300 millimeter) which is frequently reinforced using steel elements. To construct a micropile, steel reinforcement is placed in the borehole after drilling the borehole and subsequently the grout is injected into it. Micropiles transfer the structural loads to the deeper and stronger layers of the ground and confine settlement (similar to conventional pile foundations). They also improve the mechanical properties of soil layer such as density, bearing capacity, permeability and compressibility. Owing to their advantages, micropiles are widely used as foundations of new structures construction and also for reinforcing the foundation of existing structures.This research aims at experimental investigation of bearing capacity of foundations reinforced with micropiles under the condition of static loading. A small-scale physical model of a foundation reinforced with micropiles was developed and a series of static loading tests were carried out on.The model micropile-foundation was located on loose sand. Density of the underlying soil was kept almost uniform throughout the tests. The foundation model was circular and 100mm and 5o mm in diameter and thickness, respectively. It was made from polyamide and considered to act as a rigid foundation during the loading owing to its material and thickness.This foundation was reinforced with a group of micropiles with 6mm and 200mm in diameter and length, respectively. These model micropiles were made from threaded steel bars. In order to mobilize friction, sand grains were glued to the surface of the micropiles. Various arrangements of micropiles including the number and inclination angle of micropiles were tested. From the comparative examination of the observed behavior of micropile foundations, the influence of micropiles’ arrangement on the mechanism and improvement of bearing capacity of foundation was investigated. Number of micropiles used in the group varied from 2 to 8. Micropiles were inclined at different angles (0o, 15o, 13o, 45o and 60o) to study its influence on the behavior of foundation reinforced with these elements. In order to quantitatively assess the degree of improvement in the bearing capacity of surface foundations reinforced with micropiles, an index R called “Network Index” was introduced in this study. The index R of unity means that the bearing capacity of foundations reinforced with micropiles is simply equal to the summation of the individual value of the surface foundation and that of the micropile group. There is an upward trend in the rate of index R when the number of micropiles is increased. On the other hand, in high numbers of micropiles used to reinforce the foundation, index R declines with increasing of inclination angle. In the case of micropiles with low-inclination-angle being implemented, bearing capacity is improved remarkably; an index R of 1.997 is achieved in this study where 8 micropiles inclined at an angle of 15° were used to reinforce the foundation.

The purpose of constructing and using a dam reservoir is storage and conservation of water. Sedimentation declines this object and can arise many problems such as reduction in capacity for flow regulation, reservoir lifetime and flood control volume, blocking intakes in reservoirs and damage of tunnels and turbines, and many other types of sediment-related problems can occur both upstream and downstream of dams. Several techniques have been proposed to prevent entrance of sediment to the reservoirs and removing deposited sediment from reservoirs. However, actual observations of world reservoirs sedimentation rates have revealed that the problem still remains. The “burrowing-type sediment removal suction pipe method” is widely considered among the new methods introduced in the last decade. This study investigated the suction pipe geometrical and mechanical characteristics on the efficiency of the burrowing-type sediment removal suction pipe method. The the suction pipe geometrical and mechanical characteristics of this experimental study includes the bottom holes spacing ratio and suction pipe bends part’s density. The suction pipe with different density at its bend part, used as a new technique conserving distance between bottom holes and sediment. The average concentration of suction flow during the experiment time known as the efficiency of the Hydrosuction sediment removal method. In this research, A series of experiments are carried out to reveal the effect of the bottom holes spacing and density of suction pipe bend part of the Hydrosuction method efficiency. The suction pipe used in this research is a flexible PVC pipe with an internal diameter of 61 mm. The ratio of bottom hole diameter to pipe diameter is 0.25, and the spacing ratio between bottom holes varies from 0.5 to 1. This study, also, used a layout of holes that the bottom holes extended both the upstream and downstream of the pipe bend part. This research also investigates the time series of suction flow concentration and suction cone volume. The results showed that the decrease of the bottom holes spacing ratio from 1 to 0.5 increases the efficiency of the method and the suction flow has its maximum average concentration (efficiency) at spacing ratio 2, with an amount of 1.58 %. Also, the density of pipe bend part has a remarkable effect on Hydrosuction method efficiency. Examination of pipe bend part density showed tha, with the increase of density of bend part from 1.77 to 2.16, the efficiency increases and it decreases just the pipe bend part density’s dimensionless parameter have greater value than 2.16. Suction flow concentration showed that, mostly, the maximum concentration occurs at the beginning of the test and then the concentration curve has an ascending branch, a maximum point and descending branch, respectively. After commencing the test, the suction flow concentration has a rapidly increasing trend untill the pipe reaches to the level of reservoir bottom, then the concentration decreases gradually. Volume ratio of flushing cone to sediment filled under suction pipe location has its maximum value at holes spacing ratio of 2 that its value, in this research, reaches to 5.

Ski jump is one the flow energy dissipators which is applicable downstream of spillway chutes with velocity over 20 m/s. The criteria for hydraulic design of flip buckets are based on the analytical and experimental methods obtained from physical models. Due to the importance of spillways in the safety of dams, these structures should be secure and highly efficient. In the present study, in order to increase the efficiency of the spillway, it has been attempted to optimally design wide- triangular flip bucket angle and chute spillway by applying genetic optimization method. To achieve the aforementioned objectives, firstly, the equations derived for dynamic pressure head on the flip bucket, the exit jet length, and scour depth have been used as the parameters of objective function (Hojjati, 1392). Thereafter, the weights of objective function parameters have been calibrated using data related to the spillway of Karoon 3 dam, and eventually triangular flip bucket angle and chute spillway have been designed with the help of genetic optimization algorithm. Taking into consideration the design parameters of Karoon 3 spillway, the spillway length and angle of triangular flip bucket were obtain as 17.4 meters and 30 degrees, respectively by means of genetic algorithm. However, their difference with, the spillway length and angle of triangular flip bucket of Karoon 3 dam has been obtained as 16% and 0%, respectively wich indicates that the genetic algorithm enjoys high potential for designing the aforementioned parameters. The width of downstream and deflector angle have been obtained 3.6 meters and 30 degrees, respectively with 70% decrease of discharge, 45.4% increase of Froude number, and consistency of the weights of objective function and flip bucket height. Also by assuming the weight constant, increasing Froude number and decreasing the width of spillway, the flow rate increases and results in the increase of the parameters used in the objective function. With the design parameters of Karoon 3 dam remaining constant and the significant increase of weights associated with the parameters of pressure and scour depth independently of each other; spillway width was designed very largely which is not cost-effective. As well, with the design parameters of Karoon 3 dam remaining constant and the decrease of weights associated with the exit jet length in a way that all the three parameters can be viewed equally effective in minimizing the objective function, maximum dynamic pressure and scour depth have been reduced as much as 7% and 16%, respectively; however, the jet length has undergone a reduction of 12% and its width has undergone an increase of 38% which is not fully desirable. As a result, the weight reduction of jet length is not cost effective due to the slight change of scour depth and the maximum increase of pressure on the flip bucket and also the big increase of spillway width. Therefore, it seems preferable that the effect of jet range parameter outweigh the other two parameters because increasing the jet range results in the further depreciation of flow energy which is the main focus of the ski jump dissipator construction.

Currently, there are a lot of powerful FEM packages which are used for different types of analysis of structures. However, using these softwares for assessment of seismic safety and strengthening of historical masonry buildings are envolved with some problems. Complex building geometry, low information about physical and mechanical properties of materials, lack of precise information about composing material of internal parts of thick elements, prohibition of execution of destructive tests on these buildings, consumpsion of considerable cost and time for analysis process are some of the problems for engineers and researchers working professionally on numerical modelling of historical buildings. The structural analysis of the Citadel was approached by a 3D finite element model based on the concepts of homogenized material and smeared crack modeling using the ANSYS code v.10.0. The nonlinear behavior of the masonry was represented by combining plasticity with a smeared crack approach. The perfectly-elastic plastic behavior with the Drucker-Prager (DP) yield surface was used to reproduce the plasticity properties, whereas the Willam-Warnke (WW) failure surface was considered for model crush and cracking. Through different analyses carried out with ANSYS software, the following results were obtained:While the gravity capacity of the structure is high, its lateral resistance to equivalent static loading is not enough.Dynamic bearing capacity of the structure in y direction, along wing walls, is less than x direction, along web walls. One reason for this may be the existence of numerous cracks scattered in the web wall. Therefore, web wall has the most vulnerable wall in comparison with two other walls.The seismic sensitivity of two wing walls is different. Vulnerability of East wing wall under x direction excitation and vulnerability of west wall under y direction earthquake are higher.Arge Tabriz walls remains stable up to 0.25g for both Chi-Chi and Erizincan accelerograms. However, the structure loses its stability in 0.3g while according to historical documents and a recent investigation, the Maximum considered earthquake for Tabriz could be as high as 0.64g.Simplified Kinematic Limit Analysis (SKLA) is a powerful method for the analysis of historical buildings. This method is recommended for strengthening of historical masonry buildings in Italian O.P.C.M.3431 ordinance. Applied rules in this method are based on virtual work principle.In this paper, this method (SKLA) capability for assessing the seismic safety of Tabriz Alisha Citadel is investigated. For this, the results of analysese of this building by two methods of SKLA and FEM are compared. The comparison of the results of two methods has shown acceptable accordance. High analysis speed and being free of precise mechanical properties of the buildings material are main features of SKLA method. However, tracing the magnitude of stresses and deflections in different points, revealing collapse time and sequence of fracture of walls are main features of FEM. It seems that the SKLA can be utilized as a high speed and low cost tool for primary assessment of seismic safety of masonry buildings.

Rivers have been always the main source of water for human kind and the basic element of population development. The interaction between river flow structure and the bed-forms is common problem in river engineering that should be considered to better recognition of behavior of the river flows. Moreover, vegetation in natural rivers increases roughness of the main channel and flood plains which affects the geometry of channels, flow structure, bed resistance and consequently the pattern of sediment transport. In general, bed-forms and vegetation significantly influence flow characteristics, thereby result in non-uniformity in flow; variation of the turbulence intensity, increasing the near-wall shear stresses, and modified velocity distributions. To date, limited works on the impacts of the bed-forms and the vegetated banks on flow characteristics has been reported. Considering the role of bed-forms on sediment transport, turbulence production and flow resistance, investigations on details of flow-bed-forms interaction, vegetated banks and flow structure seem to be essential.In this study, the influence of straight crested gravel bed-forms and vegetation of the banks of channels on flow turbulent characteristics are investigated based on model experimentation. For this purpose, seven fixed artificial 2-D straight crested bed-forms were built inside a rectangular flume 8 m long, 0.4 m wide and 0.6 m deep. The graded gravel particles used to create the bed-forms had an average diameter of d50 = 10 mm. Johnson grasses with a diameter of 2.8 mm were used to simulate vegetation cover attached to the channel side-walls. Since, the fully developed flow was just observed after the fifth dune, experimental measurements were performed over the fifth and sixth dunes. Overall, three runs were performed over the dunes with a wave length, height, angle of repose and flow depth of 0.96 m, 0.04 m, 28 degrees and 0.28 m, respectively. In the first case 17 velocity profiles and in the second and the third cases 21 velocity profiles were measured. All the tests were performed with a constant discharge of 0.024 m3/s. The instantaneous three-dimensional velocity components were measured using a down-looking Acoustic Doppler Velocimeter ADV. Velocities were recorded point by point with a sampling rate of 200 Hz and the sampling volume of 5 mm. The sampling duration was at least 120 seconds. Overall, about 45400000 velocity data were collected, filtered by WinADV software. Results indicated no negative velocities for both bare and vegetated banks. For no vegetation case (bare bank), the least value of velocity was zero at a small region on the lee side of the dune. Whereas, for the case of vegetating the side-walls, the zero value of velocity was located at the dune's stoss. Negative vertical velocity value in both cases of with and without vegetation along a dune confirmed that separation is not dominant for the case of straight crested dunes compared to the corresponding sharp-crested bed-forms. The Reynolds stresses increase for the case of vegetating the side-walls compared to the case of without vegetation cover. This is in part due to the increase of flow resistance, while the side-walls are vegetated.

It is well known that general concrete alone lacks excellent mechanical properties especially in tension, hence there is need for modification by polymers. Research on polymer concrete began in the 1950s and it has been actively used since the 1970s. The use of Polymer cement concrete is in rapid increase as it possesses improved qualities over conventional concrete. Adequate design of polymer concrete members requires appropriate understanding of its mechanical behavior. There are three kind of polymer concrete: A) polymer concrete (PC): this kind of polymer concrete is formed by polymerization a mixture of a monomer of a thermoset polymer and aggregate, B) latex-modified concrete (LMC): this kind of polymer concrete is named polymer Portland cement concrete. In this way Conventional concrete is replaced with part of mixing water with latex and C) polymer-impregnated concrete (PIC): it is produced by impregnating or infiltrating a hardened concrete with a monomer then polymerization is done.There are many polymers that used in polymer concrete same as polyester, epoxy, styrene monomer and methyl methacrylate (MMA). Polyester concretes are viscoelastic and will fail under a sustained compressive loading at stress levels greater than 50 percent of the ultimate strength. Sustained loadings at a stress level of 25 percent did not reduce ultimate strength capacity for a loading period of 1000 hr.The main purpose of this paper is to investigate the effect of post curing effects on the mechanical properties of polymer cement concrete. Polyester was introduced to the mix as cement replacement by weight. A suitable concrete mix was designed and produced, using three different ratios of Polyester as cement replacement varying between conventional concrete for 0% Polyester to 30% Polyester. Two types of samples were cast, compacted and then cured for 28 days. The polymer concrete samples include two types, one has post cured and the other was without post curing. The cylinder specimens were tested in compression and split tension to determine the compressive and the tensile strength. The variation of compressive strength, tensile strength were determined and assessed for samples especially for samples with and without post curing. Based on the experimental program post curing has Significant effects compressive and tensile strength of concrete samples. The effect of weight percentage of polyester resin and post curing condition were investigated in relation to the mechanical properties of polymer concrete. The results indicate that an increase of polyester content in polymer concrete enhances the mechanical properties same as the tensile and compressive strength of the composite. Also, post curing increases mechanical properties, especially in the lower weight percent polyester. It seems that post curing causes increased degree of cross-linking in resin and increased the effect of polyester in the composite in lower percentage. It can be seen that post curing increased the mechanical strength for lower weight percentage of polyester more than the higher ones. In other words, lower weight percentage of polyester is more effective than the higher. This result comes from the effect of cross-linked density of polyester in polymer concrete composite because cross-linked density is very low when the weight percentage of polyester is low. Post curing can increase the cross-link density of polyester therefore increasing the mechanical properties of polymer concrete.

Scour around pier in the flow is an Inevitable issue. Estimation of scour depth and understanding the flow field around pier would help us to design with safer factor. The most important factor of scour around pier is changing of streamelines that leads to a system so called local scour. It consist of two vortices: horseshoe vortices and wake vortex. The obstacle creates down flow jet in front of pier that collide with bed sediments and carry them to the downstream, making the horseshoe vortice. The wake vortex is caused by splitting the streamelines and formation of low pressure flow field region and absorption of flow in rear of pier and pick up the bsd sdiments in this district.In this study we used the numerical model SSIIM as a CFD model to simulate flow and scour pattern Simultaneously around a group piers. This model can be used in hydraulic and environment engineering and has the ability of sediment transport calculation in bed transient movement with temporal dependent as the most important advantage in compare with the other CFD models. The verification of this model was implemented by data and results reported for side by side piers examinations as one of the group categorize. In this model we considered the k-e and k-e seperately as a turbulence model to solve the eddy viscousity of 3D Navier-Stokes flow equations and use their outputs as inputs of sediment transition equations, we used Power-Law scheme as one of the descritization method of First-Order upstreame scheme to solve the flow and sediment equations on the grids. The pressure term of Navier-Stokes equations in cells was calculated by SIMPLE algorithm which is the First-Order upstreame scheme too. Also by changing the G/D distant ratio on the other simulation runs, we generated the diagrams with comparative situation with experimental diagrams.Results in the last time of simulation showed there is much more value of horizontal and vertical velocity between the piers than the other sides. It was 57% of final maximum scour depth in first hour of calculation. Similarly to velocity, The final scour patterns showed there is more scour depth counters between the piers. In details it was deriven that the scour depth pattern was symmetric in early time of calculation, but with time passing it appeared more in the region of between the piers. Although Numerical results show the SSIIM model have calculated the erosion depth in front of piers with high accuracy resulted from good calculation of down flow, comparisons between model results and data show the scour depth pattern that the model calculated the wake vortices behind the piers and Interference the horseshoe vortex between the piers with overestimate value and there are deeper countors of scour depth than experiment diagram. Also the RMS index of scour depth has been calculated in the grid and it represented the values of 0.0353 for k-e model and 0.0899 for k-e model. Therefore, the k-e turbulence model resulted better scour depth pattern calculated in compare with k-e turbulece model.

In last decades, most of the famous seismic design codes, had concentrated mainly on far field earthquakes. Generally no special requirements were introduced to minimize near fault earthquake effects. Near field ground motions have caused several structural damages in recent decades, causing seismic codes to be updated with related requirements. As a result, it seems necessary to evaluate domestic seismic design codes and their requirements to see their effectiveness in designing safe structures against near fault earthquakes. In this paper seismic behavior of concentrically braced frames (CBFs) designed based on different seismic design codes is comparatively studied. Various Frames of different heights, (5, 8 and 12 stories), and bracing types (X-bracing and inverted V bracing) are designed based on the Iranian seismic code (standard no.2800) and also taking into account the near fault requirements of AISC-ASD 89 and UBC-97. These frames are analyzed using a nonlinear time history analysis method, namely “Incremental Dynamic Analysis” (IDA) under near field ground motions. IDA is an emerging method in analysis of structures which allows estimating seismic capacity, limit states and demand via series of nonlinear dynamic analyses using multiple scaled ground motion records. A total of 15 near filed time histories are selected according to special characteristics namely: fault distance to site (less than 10 km), fault direction, earthquake moment magnitude, time history frequency content, time history velocity content, shear wave velocity in the site soil and near fault wave’s pulse nature.The 15 selected earthquake time histories were scaled in several steps. To achieve a more accurate point for yielding point of the frames, 0.1g steps were used in the initial elastic region. From the end of the initial elastic point up to the end, 0.2g steps were used for scaling the records.On other important step was to select proper intensity measure and damage measure. According to FEMA-350 requirements, the maximum inter story drift was selected as damage measure. For selecting a proper intensity measure, four intensity measures were selected and compared together, namely: first mode spectral acceleration Sa (T1), first mode spectral velocity Sv (T1), peak ground acceleration PGA and the equivalent first n modes spectral acceleration Sn (T1). Among them, first mode spectral acceleration Sa (T1) showed the least dispersion in the analysis results.Finally, all the 20 frames designed were analyzed using the 15 time histories selected in multiple steps and IDA curves were extracted. Using FEMA requirements the points corresponding to 2 performance levels namely IO and CP were defined on summarized IDA curves using which it was possible to compare the performance of the frames.The results of this paper imply that frames designed based on the near field seismic design criteria of UBC-97 have better performance under near-field earthquakes comparing to others. It can be concluded that the requirements of the Iranian seismic code (standard no.2800) should be updated according to the effects of near fault earthquakes. Besides, frames with X-bracing system showed better performance in comparison with chevron ones. Also the deficiencies in the seismic requirements of the domestic codes are more obvious while designing taller frames and moving from 5 story frames to 8 and 12 story ones, their seismic performance obviously deteriorate.

Investigation of the correlation between engineering demand parameter (EDP) and intensity measures (IMs) has received substantial attention in performance-based earthquake engineering for prediction of seismic demand of structures. In this study the seismic demands of buried steel pipelines are investigated in a performance-based context. Several nonlinear dynamic analyses of two buried steel pipe models with different D/t, H/D ratios and different soil properties and different pressures, performed under a suite of far-field earthquake ground motion records were scaled to several intensity levels to investigate the behavior of buried pipeline from elastic response to failure. Several scalar ground motion intensity measures (IMs) are used to investigate their correlation with engineering demand parameter (EDP) which is measured in terms of peak axial compressive strain in critical section. Using the regression analysis the efficiency and sufficiency of candidates IMs is investigated.To investigate the effects of different material and geometrical properties, two buried pipeline of API 5L Grade X65 models with different pipe and soil properties are considered. To simulate soil effects on pipe in axial, transverse and vertical directions bilinear force displacement curves (elastic-perfectly plastic) representation of soil are employed based on suggestions of the American Lifeline Alliance. The FEM was used in the analyses. The buried pipeline and the surrounding soil are modeled using shell, spring and damper elements. Each node of the model was connected to three spring-dashpots.Before deciding which ground motion IMs correlate well with seismic demand on buried pipes the first question to be answered is: how is the seismic demand measured? Usual failure modes of continuous buried pipelines are tensile ruptures or buckling because of compressive strains. Compressive straines that result in bukcling are smaller than strains induce tensile failure. Therefore, the peak axial compression strain at the critical section would seem the obvious candidate to use for EDP of buried pipe. It is necessary to examine a wide range of potential IMs for determining the best IM for evaluating the buried pipe response. Therefore a total of 16 different IMs are considered.Using an efficient IM results in smaller variability in the structural response for any given IM. Chosing an efficient IM causes the number of analyses and earthquake records needed to evaluate the probability of exceedance of each value of EDP given the value of IM to be reduced. In this paper, a one-parameter log-log linear regression of peak axial compressive strain on IM is utilized in evaluating the efficiency of each alternative IM. A sufficient IM results in EDP conditionally independent, for a given IM, of earthquake magnitude M and the source to site distance R. Using a sufficient IM, yields ignoring the effects of magnitude and distance in accurately predicting of EDP. Quantifying the sufficiency of IM is done by using the one-parameter regression of peak axial compressive strain on M or R for a given IM. Among the models investigated in this study it was seen that RMSd is the optimal IM for buried steel pipelines based on efficincy and sufficiency conceptions.

Environmental pollution, in general, and water pollution, in particular, are of concern to the scientific community worldwide. Color removal from wastewater has been a matter of concern, both in the aesthetic sense and health point of view. Color removal from textile effluents on a continuous industrial scale has been given much attention in the last few years, not only because of its potential toxicity, but also mainly due to its visibility problem. Methylene Blue (MB) is cationic dye, used in several industries such as paper, leather, cotton, pulp, wool etc., for coloring their final products. The effluents of these industries containing huge amount of dyes, discharged into waters bodies, cause severe damage to the environment. Acute exposure to MB will cause increased heart rate, vomiting, shock, cyanosis, jaundice and tissue necrosis in humans. Several methods have been used for the removal of dyes from the aquatic environment, including physical, chemical, and biological processes. These methods inevitably add to the cost of the overall process and some present the complication associated with the possible toxicity of degradation products. Among the methods, removal of dyes by adsorption is regarded as one of the competitive methods because of high efficiency, economic feasibility and simplicity of design/operation. Biosorption based on binding capacities of different low-cost adsorbents includes natural, agricultural, and industrial by-product wastes. They are attractive because of their abundant availability at low or no cost, their good performance in removing dyes from aqueous solutions as well as minimum volume of sludge to be disposed. Sawdust, among the low cost adsorbents, is one of the most promising adsorbent for removing dyes, and some other unwanted materials from waste water. Not only is sawdust abundant, but also it is actually an efficient adsorbent that is effective to many types of pollutants, such as, dyes, oil, salts, heavy metals, etc. If it was possible to use sawdust as adsorbent of contaminants from industrial waste water, it would solve simultaneously two problems, both waste disposal and purifying waste water of contaminants to desired limits. In the present study have been investigated the efficacy of Populus nigra sawdust as a wood waste (without chemical changes) in the removal of methylene blue from wastewater. Isotherms (using langmuir and freundlich isotherm models) and absorption kinetics (using pseudo first-order, pseudo-second order, elovich and intraparticle diffusion models) has been studied and was observed that the process treatment followed from langmuir isotherm model (R2=0.996) and its kinetic is consistent with pseudo-second order reaction (R2=0.999) and the mechanism was controlled by surface adsorption and intraparticle diffusion. The thermodynamic parameters such as change in enthalpy (DHo), entropy (DSo) and Gibb’s free energy (DGo) of adsorption systems were also determined and evaluated. This adsorbent had high absorption capacity equal 26.85 mg/g to the absorption of cationic dye methylene blue. The results showed that Populus nigra sawdust, natural sorbent is good to absorb methylene blue color of the water water which has removal percentage equal 84.68% in the optimal conditions.

This paper presents the pull-out characteristics of inclined hooked steel fiber from cementitious matrix. The effect of fiber embedded length and angle of inclination are evaluated together with the interaction of these parameters. The experimental program involved single fiber pull-out test of five inclination angle and four embedded length. The studied inclination angles were 0, 15, 30, 45 and 60 degrees. The embedded lengths were 10, 15, 20 and 25 mm. Compressive strength of matrix was 40 Mpa. The length and diameter of hooked steel fibers were 50 mm and 1mm, respectively and their tensile strength was 800 Mpa.At least five specimens were prepared and tested for each combination of inclination angle and embedded length. A special mold supplemented by a cross shaped device was designed to hold the fiber in desired angle and embedded length. X-ray radiography was used to verify the inclination angle and embedded length of fiber. All the specimens were tested at 28-day age. Pull-out test performed under displacement control condition in order to record descending branch of pull-out curves. A load cell and a displacement transducer were used to acquire pull-out load and slip during pull-out test. Pull-out load versus slip were recorded and parameters such as maximum pull-out force and its associated slip, pull-out energy, fiber efficiency and matrix spalling were drawn for comparison purpose.Based on the experimental results, the pull-out response of hooked steel fibers is predominately influenced by fiber embedded length and inclination angle. The results indicate that the peak pull-out load is maximized at approximately 30 degrees, although at greater inclination angle, the peak pull-out load decreases. The fracture load also decreases as fiber inclination angle increases. The additional shear stress imposed on inclined fibers; provide mechanisms favoring slip between the crystals in the steel. This causes a reduction in both yield and ultimate strength of the finer, resulting in a reduced fracture load. The results indicate that providing the hook is fully mobilized, the peak pull-out load is almost independent of embedded length of fiber. The results indicate that fracture of fiber is more presumable at greater inclination angle.Slip associated with peak pull-out load increases as the inclination angle increases. This can be attributed to matrix spalling. Matrix spalling also causes the drop of pull-out load in pull-out curves. The load drop is directly related to the size of crushed matrix. Matrix starts to spall at 30 degrees inclination angle. The results indicate that increase in embedded length and inclination angle result in increase of pull-out energy. An inclined fiber with respect to the loading direction absorbs a greater amount of energy at a given slip than an aligned one, with maximum pull-out energy occurring around 30 degrees. Fiber efficiency increases as the embedded length of fiber increases. Maximum fiber efficiency occurs at 30 to 45 degrees and decreases at greater inclination angle. The effect of elastic deformation of fiber during pull-out test was taken into account by calculation of elastic deformation and subtracting from slip, although, its effect was negligible.

Digital Elevation Models (DEMs) are one of the most important inputs in most rainfall -Runoff models and also in deriving watersheds geomorphological characteristics. One of the most important issues that should be taken into account when using DEMs in rainfall runoff modeling is the effects of DEM source on the results of the models. At present time, radar based DEMs are attracting a considerable attention in many earth related fields. Currently, there are several sources such as: Shuttle Radar Topography Mission (SRTM) data and the advanced space thermal emission radiometer (ASTER) that due to ease of access and free of charge, have an important role in hydrological modeling and the extraction of geomorphological parameters of catchments. This paper addressed the effects of different DEM sources: ASTER, SRTM, and 1:50000 topographic based DEM on the topographic index and performance of a semi- distributed model, called TOPMODEL. The obtained results indicated that by increasing DEM cell size, disregarding its source, the topographic index inceased. Also, it was illustrated that for all cell sizes other that 30 m there was no difference between the results of ASTER and SRTM DEM. Such a coincidence was observed for TOPO DEM for cell sizes larger than 100 m, as well. Results showed that the effect of data resolution on the average daily discharge, average saturation deficit of basin and the average distance to water table level is not meaningful. In daily discharge simulation, the performance of TOPMODEL when using the TOPO DEM, based on the NASH- SUTCLIFFE efficiency index, was the highest and for the SRTM DEM was the lowest. In flood simulation, upto 200 m resolution, TOPMODEL efficiency was constant disregarding the DEM source, while its efficiency reduced for cell sizes greater than 200 m in all conditions. It was illustrated that by increasing the cell size, surface runoff contribution to total runoff, in contrast to subsurface flow, increased. According to achieved results, the percentage of simulated surface runoff from SRTM DEM was higher than the other two sources. It was observed that the number of cells of low slope in SRTM DEM is greater than the other sources, which was concluded as the main reason for this issue. Reducing the slope of a cell could reduce its potential to carry subsurface flow, which in turn could increase the cell potential to be saturated. It was concluded that DEM different sources effects on average saturation deficit and water table is negligible, and these ouputs of TOPMODEL is mainly affected by DEMs cell size. Finally, this important conclusion was drawn from the present research that the information content of ASTER DEM is nearly similar to TOPO DEM and higher than SRTM DEM; therefore, between satellite based DEMs, it is more convenient to use ASTER DEM for rainfall runoff modeling.

In this paper iron oxide nanoparticles were employed for removing of toluene from aqueous solutions with initial concentration of 100 ppm by Fenton-Like process. Iron oxide nanoparticles synthesised from spent catalysts of Tabriz Petrochemical Styrene Unit using a ball mill. these nanoparticles were characterized by BET, XRD, XRF and FE-SEM analysis. The milling of spent catalysts was performed in dry ball mill. Dry ball milling of spent catalysts was carried out in presence of argon as an inert gas. Iron oxide nanoparticles with diameter about 18 nm were obtained after 4 hours by dry ball milling of spent catalysts using 15 balls with a diameter of 20 mm. The milling was performed at a rotation speed of 400 rpm. The results of BET analysis showed that specific surface of catalysts has increased more than 9 times with the milling of spent catalysts. XRD patterns showed that during dry milling, some of Fe3O4 has converted to Fe2O3. Due to the higher rate of reaction of Fe2O3 compared to the Fe3O4 in Fenton process, this conversion causes higher rate of toluene elimination from aqueous solutions. The crystal size of spent catalysts and synthesized iron oxide nanoparticles was calculated by Scherrer equation. The crystal size of spent catalysts and synthesized iron oxide nanoparticles were obtained 56.6 nm and 33.9 nm respectively which confirmed the results of BET analysis. The concentration of toluene in aqueous solutions was measured by Gas Chromatography (GC-Agilent 7890A) equipped with FID detector and HP-Plot Q column (30m ´ 0.530 mm´ 40.0 mm) using liquid-liquid extraction by hexane. Hexane and samples were mixed with volume ratio of 1/10. Samples were injected to GC in volume of 1 micro liter by a syringe (Agilent). Experiments were performed at pH=3 and room temperature (25oC) in a batch reactor in volume of 500 ml with a mechanical stirrer. Due to study of interaction between the parameters and determining the optimal conditions, experimental design was performed by RSM method. [H2O2]/[Catalyst], [H2O2]/[concentration of pollution] and time (min) were considered as efficient parameters on removing of toluene. Quadratic equation with high correlation coefficient fitted using RSM method. R2 and R2 (adj) values of predicted model for removing of toluene in Fenton-Like process were obtained 99.14% and 98.37% respectively. The results showed that [H2O2]/[Catalyst] and [H2O2]/[concentration of pollution] have optimum ranges. The optimum ranges for [H2O2]/[Catalyst] and [H2O2]/[concentration of pollution] were obtained 0.36-0.5 and 4-5.5 respectively. Optimal values for [H2O2]/[Catalyst], [H2O2]/[concentration of pollution] and time (min) for removing of toluene in Fenton-Like process were obtained 0.460, 4.928 and 105.7 respectively. In optimum conditions for efficient parameters, complete removal of toluene by Minitab software was predicted. Experiments in the optimum conditions also confirmed the results of Minitab software. The results showed that spent catalysts of Tabriz Petrochemical which are considered as waste, have a good ability for activation of H2O2 and removing of toluene from aqueous solutions.

Side weirs are flow diversion structures which have wide application in hydraulic and environmental Engineering. Diversion structures in side wall of open channel are to be used in order to divert flow from main channel. Side weirs, side orifices and side sluice gates are diversion structures which have wide application in dams, irrigation, drainage systems and combined sewer systems. Side weirs are one of the most important and applicable hydraulic structures for water controlling and directing systems that requires careful review and accurate designing due to their critical importance. In this paper, the flow over a sharp crested rectangular side weir in open channel was simulated by FLOW-3D software. RNG k-e turbulence model was used to apply the Navier-Stokes equations and the VOF method was used to model the free surface profile changes. In the present study, at first, results related to the distribution of the different components of velocity and angle of the outlet jet adjacent to the crest of the rectangular sharp crest side weir at various heights of the weir crest are validated with experimental data from Bagheri and Heidarpour (2012) research. Then the effects of upstream Froude number on flow pattern and free surface around the side weir were investigated. The results of this study indicated that with decreasing upstream Froude number the maximum and minimum longitudinal velocity along the side weir increases and decreases, respectively. By decreasing upstream Froude numbers, the longitudinal velocity in the vicinity of the side weir is negative because of the reverse flow formed in this area. The maximum lateral velocity along the side weir increased with decreasing upstream Froude number. That is why the discharge through the side weir increased with decreasing Froude number. The maximum vertical velocity along the side weir increased with decreasing the upstream Froude numbers because more flow is diverted to the side weir with decreasing the upstream Froude numbers. Distribution of the different components of velocity in the direction of flow height in the middle of the weir crest indicated that by reducing the upstream Froude number, longitudinal velocity distribution in the depth direction became more non uniform, especially near the weir crest. For different upstream Froude numbers, lateral velocity would increased up to a certain elevation from the weir crest and then decreased toward the free surface. By increasing Froude number, the maximum lateral velocity occurs at greater heights above the side weir crest. The maximum vertical velocity for different Froude numbers occurred near the weir crest. Vertical velocity gradually decreased toward the free surface. By reducing the upstream Froude number, the vertical velocity near the free surface of flow is negative due to flow motion to downward. Free surface of the flow experienced extreme changes at the end of the side weir when upstream Froude number was increasing. By increasing the Froude number, the angle of inclination of the outlet jet along the side weir increases. Also by increasing the Froude number, the separation zone around the side weir in near the main channel bed, especially in the channel cross-section decreases.

The electrokinetic (EK) approach is one of the popular choices for the extraction of inorganic contaminants (e.g. heavy metals) from a soil matrix. On the other hand, many factors can affect the performance of EK contaminant remediation. Therefore, in the present study a series of macro and micro level tests including electrokinetic experiments, pH and electrical conductivity (EC), adsorption and desorption, X-ray diffraction (XRD) and scanning electron microscope (SEM) analyses were performed to investigate the effects of time and pore fluid characteristics on the efficiency of EK remediation. For this purpose, the kaolinite clay was separately infected with different solutions containing zinc nitrate and lead nitrate in concentrations of 20 and 40 cmo1/kg and then electrokinetic experiments on a laboratory scale were conducted at 2 V/cm voltage gradient in time periods of 3, 6, 12, 24 and 48 days. Nitric acid was also used as a catholyte solution to enhance the soil remediation process. The results obtained show that the soil response to the EK remediation is a function of the contaminant characteristics, the pH of soil-electrolyte system and the time of testing. In EK contaminant remediation from a soil matrix, it is significant to pay particular attention to the effect of the concentration and type of contaminant on the applicability and efficiency of this method. The results reveal that under the same conditions, especially in the low times, extraction efficiency from samples containing lead was measured approximately 70 percent of the samples containing zinc. This is because the lead tends to more adsorbe on the clay surface and has a greater tendency to form precipitate. In addition to the type of contaminants, it was found that the increase in concentration of contaminants in the soil through a series of physical-chemical reactions accelerates clean up capabilities, particularly in the initial time period of the EK experiments. Catholyte conditioning with acidic solution enhanced the removal of heavy metals, which is mainly due to microstructural changes and an increase in the mobility of pollutants. In fact, based on the X-ray diffraction and scanning electron microscope analyses, the microstructural characteristics and the arrangement of the clay particles have an important role in the process of electrokinetic soil remediation. The formation of flocculated structure decreases the retention capacity of the clay particles and also increases the flow path, which enhance the efficiency of pollutant extraction. It was found that the soil remediation, especially in the parts close to the anode, greatly enhanced with increase the time of EK test; however, the further increase in time had a limited impact on results, especially in the samples containing high concentrations of zinc. This indicates that there is an optimum time in the process of cleaning up heavy metals from the soil by EK method, which depends on the type and concentration of contaminant. Moreover, it was seen that the extent of contaminant removal from anode side towards the cathode side is considerable when catholyte conditioning with acidic solution is used. In other words, reducing the pH of soil-electrolyte system has a significant impact in increasing the efficiency of pollutant extraction.

In this research, the statistical parameter of the flow around T shaped spur dike located in a 90 bend was investigated. Experiments were conducted in a 90 bend at Tarbiat Modares University. The velocity was measured using ADV apparatuses. the frequency of the ADV set to 50 HZ this frequency was used by many previous researchers. Two different submerged spur dike with submergence ratio equal to 5% and 50% were used. The submergence ratio is the ratio of the flow depth on crest of the spur dike to spur dike height. The spur dikes were located in 45 degree respect to the beginning of the bend and the experiments were done in freeze bed condition. As the flow structure has the main role on sediment transport phenomena, the flow around the spur dike were investigated using parameters such as: Probability of the events (the ratio of the number of the events to the total of the events during the velocity measurement), variation of the events during the velocity measurements, shear Reynolds stresses in stream wise and lateral direction and angle of the events (the ratio of the vertical velocity fluctuation to the stream wise velocity fluctuation). The results showed that two secondary flow formed in lateral direction of the channel and the secondary flow effect on the upstream of the bend. These flow effect on sediment transport mechanism in lateral and longitudinal directions. In the upstream toe of the spur dike the Reynolds stresses in 5% submergence spur dike is greater compared to the 50% submergence spur dike since stronger horseshoe vortex due to the stronger down flow formed in this region. The scour hole propagation along the shear layer in longitudinal direction may be due to the increasing the probability of the sweep and ejection events and variation of the interaction events, decreasing the angle of the events and increasing the Reynolds stresses. The Reynolds stresses along the shear layers located in 5% spur dike is greater than the 50% spur dike and larger scour process may be expected in this region. The stability of the events is more pronounced compared to the instability of the events. Hence, stability of the events has the main role on flow structure around the submerged spur dikes. The angle of the sweep and ejection were minimum near the bed surface and maximum in the middle of the flow depth. Two different zones with maximum angle of sweep and ejection were observed that showed the fluid parcels deviate to the downstream recirculating zone. The angle of the events has different value near the over topping flow that passed from the crest of the spur dike. The flow measurements and analysis of the statistical parameters confirmes the previous researchers conclusions about larger scour hole around the spur dikes with lesser submergence. This may related to the difference of the flow structures around the submerged spur dikes especially near the upstram toe of the spur dike. The maximum turbulent events occurred in the shear layer and hence different flow structure was detected in this region.

Damage probability of structures caused by excavation wall movement is an important design aspect of support system in urban areas. This will be more important, if the adjacent structure be old or have low strength parameters. Frame distortion and crack generation are signs of building damage to excavation-induced ground movements which is a challenge in projects involving deep excavations. These highlight the importance of evaluation of building response in excavation projects. The aim of estimation and evaluation of building response is to establish limiting criterion for excavation support system design to certify the structure safety against undesirable damage. Thus, limiting criterion prepares a framework to determine the damage level of building based on excavation induced ground movements. Mentioned limiting criterion also is named Damage criterion or Damage model. Damage models are too practical before design progress of nailing wall. Based on uncertainty in data from excavation project and variability of the many factors that contribute to the response of nearby structures, existing Damage models are rare and generally need special instrumentation of excavation wall and nearby structures, so they cannot prepare a simple framework to use in practical situation.This paper describes a study of building response to excavation-related ground movements and provides procedure for damage assessment of building near excavation projects. This study uses field data based on 10 case studies and 90 calibrated 3D FEM models in addition to probabilistic analysis to establish new simple damage criterion for design consideration of excavation supported by soil nail wall technique. Presented Damage model simply relates the damage level of structure to maximum displacement of excavation wall. To create this paper following stages are used:1.Case studies:31 deep excavation (16.7-31 meters) from expert companies are studied in first stage.2.First filtering of the collected data: part of collected data (14 projects of 27 projects) is eliminated from data base because of inaccuracy in the results of monitoring, unfavorable results in displacement caused by nearby galleries or underground facilities, inappropriate execution and etc. 3.Evaluation of the structures in the excavation-affected zone (EAZ). 4. Second filtering of database: part of first-filtered data is eliminated from data base because of non-deductible conditions of structure in EAZ, mismatch between damage level and results of monitoring and etc. At the end of this stage only ten masonry structures (TMS) were selected to continue case studies. 5. Creating and calibrating FE models: at this stage, FE models are included excavation wall and adjacent structure were extended for each of TMS and were calibrated based on field results. 6. Idealization of calibrated TMS’s FE model (ICTM): each of calibrated TMS’s FE models were modified and idealized by removing water table, modification of excavation condition, simplification of structure frames and etc.7.Development of damage levels: in the last stage, DPI calculated from ICTM for each frame of structure and then compared with the value of excavation wall deflections. Finally, damage levels developed based on resulted database.