نشریه مهندسی عمران مدرس
سال بیست و سوم شماره 4 (مهر و آبان 1402)

Airports are one of the most vital infrastructures of any country, which play an important role in transporting cargo and passengers to different parts of the world. The preservation and optimal use of airport resources and assets is one of the main goals of airport managers. On the other hand, airlines have a special concern on saving time, fuel consumption, maintaining passenger satisfaction, and so on. One of the most important resources in the world's major airports are the gates of the passenger terminals of airports, which have an undeniable aspect in the better performance of the airport. The assigning of aircraft to these gates has long been a concern for researchers in operations research as well as air transport activists. This research deals with the issue of assigning aircraft to the passenger terminal gate. The problem of optimal gate assignment is a complex issue and requires consideration of many parameters and variables in order to achieve the desired result. In this research, it’s tried to solve the gate allocation problem by presenting a suitable model. Providing an appropriate linear model is one of the main challenges of the problem. A special attention has been paid to the issue of safety. Therefore, by applying safety restrictions, a suitable model is provided. The main purpose of this study is to minimize the scatter of idle (lost) gates while not preventing mismatch between flight size and gate and also justifying safety needs. These cases are assigned and examined in the framework of the optimization model in this research. To solve such problems, which are usually not possible by manual calculations or are very time consuming, the metaheuristic algorithms are used. Since because NP-Hard nature of problem, it is very time consuming and difficult in the usual way. Therefore, this study tries to provide an efficient and fast way to solve the gate assignment problem. In the proposed method, first all the sentences of the objective function were considered as, then all were divided into two categories of hard and soft constraints. On the other hand, in the model of the basic method, the power of two terms in the objective function is used. The proposed model was modified. In the end, it was tried to modify the terms of the objective function and constraints in such a way that in addition to meeting the expectations and constraints of the problem, it allows the use of two flights from the same gate (MARS effect) to increase resource efficiency. The method is based on a genetic algorithm that includes the initial population, selection, combination or mutation, generation of a new offspring, and re-selection. In this study, 5 scenarios with various flights and gates have been used. The improvement of total idle times in the first scenario was 72.75%, in the second scenario 76.92%, in the third scenario 82.38%, in the fourth scenario 82.38% and in the fifth scenario 79.67%. All of results. Show the efficiency of proposed model.

Half warm mix asphalt (H-WMA) is one of the alternatives to conventional asphalt due to its special production conditions.  Half warm mix asphalt (H-WMA) manufactured with high proportions of reclaimed asphalt pavement (RAP). Half warm mix asphalt (H-WMA) are produced and compacted at the temperature range of 60-100 ° C, which requires less temperature for production process of hot mix asphalt (HMA) for example cold mix asphalt (CMA) manufactured at a temperature lower than 60 ° C; (ii) half warm mix asphalt (H-WMA) manufactured at less than 100 ° C, normally at 60-100 ° C; (iii) warm mix asphalt (WMA) manufactured at temperatures of 100-140 ° C. The aim of this study is to investigate the effects of high percentages of reclaimed asphalt pavement (RAP) on the volumetric and mechanical properties of Half warm mix asphalt (H-WMA) mixtures. In this research, bitumen emulsion (CSS-1) and conventional bitumen 60/70 were used. The siliceous aggregates were obtained from a mine near Tehran and reclaimed asphalt pavement (RAP) were obtained from an asphalt plant and its granulation before and after extraction was done according to report number 234.  Generally speaking, in H-WMA, aggregates are heated to temperatures of 100-110 ° C and then mixed with emulsion, which has previously been heated to 60-80 ° C and RAP are heated to 90-100 ° C. To determine the most suitable mixing time in the tests, the coating was visually analyzed after mixing times of 1 and 2 min and the mixing temperature was 95-85 ° C. Thus, a laboratory analysis was carried out in which the behavior of half warm mix asphalt (H-WMA) manufactured with 100%, 70% and 0% reclaimed asphalt pavement (RAP) was compared with that of a control mix, Hot mix asphalt (HMA). Optimum bitumen content for hot asphalt mixture (HMA) and optimum bitumen emulsion content for half warm mix asphalt (H-WMA) were calculated. Then indirect tensile tests (IDT) (at 25° C), moisture damage (TSR) and Semi-Circular Bending (SCB) Tests (at 25° C and -20° C) were performed on half warm mix asphalt (H-WMA) and hot mix asphalt (HWA). indirect tensile tests (IDT) yielded acceptable results, the IDT resistance increased with increasing the reclaimed asphalt pavement (RAP) content. Following this, the moisture damage (TSR) of half warm mix asphalt (H-WMA) improves by increasing the reclaimed asphalt pavement (RAP) content, which can be due to the complete covering of the surface of the aggregates with aged bitumen and the high adhesion force between the aged bitumen and the aggregates and the lack of moisture penetration into the aggregates. emulsified bitumen exhibited proper volumetric (e.g., air voids and density) and mechanical behavior in terms of moisture damage and IDT. On the other hand, the results of SCB tests at medium and low temperatures showed that by increasing the RAP content the samples become brittle, which means that resistance to crack propagation reduced, and it may be the reason for fracture energy reduction. These findings encourage greater confidence in promoting the use of these sustainable asphalt mixes for their use in road pavements or urban streets.

Two of the important issues in the construction of structures located in seismic coastal areas are the study of the potential of liquefaction phenomenon in saturated sandy soils and seismic structure-foundation-soil interaction (SSFSI). Control of structure damage on the liquefiable soil and large deformations of soil due to seismic loading and, also, the other responses such as: the accelerations at top of the structure/foundation and excess pore water pressure related of this phenomenon are very important. The phenomenon of liquefaction happens due to the occurrence of an earthquake and due to the lack of sufficient opportunity for drainage of excess pore water pressure. One of the effective and useful mitigation methods to control of the liquefaction phenomenon is the usage of dense granular column (DGC) in appropriate dimensions and distances on the ground susceptible to liquefaction. The role of the DGC in controlling the liquefaction phenomenon are follow as: firstly, the DGC is made of materials that are more permeable to sandy soils and cause the excess pore water pressure to be dissipate faster, and secondly, DGC increases the stiffness of the system, which proportionally reduces the excess water pore pressure due to the dilative behavior. To reduce the risks of liquefaction, it is necessary to fully understand its consequences. These consequences depend on permanent soil displacements, structural performance, structural characteristics, foundation and structure dimensions, soil conditions of the structure site, type of loading and earthquake intensity. The presence of the structure and impact of SSFSI affects the intensity of liquefaction and static and dynamic stresses in the soil. Most prior studies (e.g., physical, numerical, or analytical models), ignore the existence of the structure or consider the effect of soil-structure interaction (SSI) on the liquefiable soil layer as an equivalent model. Hitherto, the essence and extend of these interactions are not sufficiently understood. These methods can not properly assess the damage caused by liquefaction; Therefore, these methods cannot be used in the design of structures resistant to liquefaction. Therefore, to accurately study the effect of liquefaction, a method and model is needed that can fully consider the soil, foundation, and structure so that it can be used to correctly estimate the amount of subsidence and displacement of the structure. In this study, to evaluate the seismicity and the mitigation effect of DGCs, using OpenSees finite element software, modeling of DGCs and surrounding soils without structure and models with 5, 10 and 15 storey structures were performed. The three-dimensional soil and DGCs modeled in the software are placed under different earthquakes and the effects of structural layers on the lateral displacement, excess pore water pressure, response of acceleration spectrum, drift and shear force of stories are investigated. The liquefiable soil is modelled through the pressure-dependent multi yield surface soil constitutive law (PDMY02) applied in OpenSees. The results of this study are shown the positive effect of DGC on the reduction of lateral displacement components of soil and structure, foundation subsidence and excess water pore pressure. Also, the presence of the structure on the soil and the increase of its floors have increased the mentioned components except for lateral displacement of soil.

Construction of buildings using non-industrial traditional systems have lots of shortcoming in both quality and quantity. During recent years considerable needs to increase the efficiency in building sector has indicated the fact that using old building construction systems is not responsive to community needs and using superior technology in this field is quite inevitable. Constructing building systems with potential, for industrial and prefabricated production, can meet the quantitative and qualitative needs of the construction industry.
  In this paper, the structural behavior of precast concrete sandwich panels (PCSPs) to feasibility of their usage as slab elements in the construction industry is experimental (EXP) and numerical analyses studied. These panels consist of three layers: 1) a regular reinforced concrete layer as the upper face, 2) a thick lightweight concrete (LC) layer as the core, and 3) a normal concrete and tension-resistant reinforced lightweight concrete layer as the bottom face. These layers are joined via a rebar network with truss-shaped shear connectors. The structural behavior of precast concrete sandwich panels under flexure is studied. For this purpose, First, laboratory samples were made and tested for bending. Subsequently, a finite element analysis (FEA) was performed on a sandwich panel model with the specifications and mechanical properties similar to the EXP model in the ABAQUS software. Comparing the results of the experimental and numerical studies revealed a good level of accuracy.  The effect and orientation of the shear connectors in one or two directions were also investigated. The results of experimental and numerical investigation, show a logical behaviour of load-deflection curves According to the results, the PCSPs with two concrete layers had a smaller stiffness and load capacity than those with three concrete layers, When the prefabricated sandwich panels behave as one-way slabs, placing shear connectors parallel to the x-axis (larger dimension) is sufficient to bond two concrete layers for them to act as a single unit, , and the ultimate strength and the composite action of desired were found to depend to a large extent upon the stiffness of the shear connector used. This sandwich panel system can constitute an effective step toward lightening regarding its high bearing capacity and ductility, industrial manufacturing capability, prefabricated nature, multi-layer nature, high quality, lightweight, high construction speed, and reduced costs. Hence, the precast concrete sandwich panels slabs with high-strength faces and LC cores can be a suitable replacement for regular slab systems in buildings Based on the economic and weight comparisons under the code dead and live loads, the proposed prefabricated sandwich composite slab system is approximately 20 percent lighter than the regular slab. Due to possibility of industrial production of precast sandwich panels under standard conditions and simplicity of construction, the introduced novel panels system can be a viable alternative for common floor systems. Besides, the novel system can save amount of material, labor, time, and cost in building construction. This research aims to investigate the composite performance and influential parameters in bearing capacity and improve and develop hybrid concrete sandwich panels for structural purposes to lighten and industrialize construction, a topic of interest in structural engineering.

In urban areas, residential buildings are often located at small distances from each other. The mutual influence of these buildings, depending on the distance between them, under the effect of earthquake vibrations, is of great importance, which has been less studied and investigated. Normally, the soil-structure interaction is considered when only one structure is present on the soil, although the structure-soil-structure interaction takes place when at least two structures are placed on the soil. In case, in addition to the discussed structure and soil layer, another adjacent structure is added to the system, the response of the soil layer will be affected by the presence of both structures and the response of each of the structures will also be affected by the response of the soil layer and its adjacent structure, and therefore the soil and Each of the two adjacent structures will have a mutual effect on the response, which is known as structure-soil-structure interaction. In other words, in this interaction, the vibration energy of a structure affects its neighboring structures through the soil environment and can change its structural response. The presence of the adjacent structure can increase or decrease the dynamic response of the structure and the amount of damage depending on the dynamic characteristics of the soil and the structure and the frequency content of the incoming earthquake. When an earthquake occurs, its waves pass through the soil layers and reach the foundations of both structures. These waves cause deformations in the foundations and structural elements. Therefore, a shear force and an overturning moment are created in the foundation of the structure, which results in the deformation of the foundation and the structure. After that, the vibrations of the structure are transferred to the soil, until this part, the responses and behaviors in these systems (structure, soil and foundation) are similar to the conventional soil-structure interaction; But there is a slight difference in the transmission of these waves from the structure to the soil, which causes the structure-soil-structure interaction. In this research, the structure-soil-adjacent structure interaction has been investigated for building structures based on soil prone to liquefaction. For this purpose, similar buildings of fifteen concrete storey at different distances from each other, along with the continuous environment of the soil bed with different mechanical  properties and the application of the  advanced elasto-plastic constitutive model under the effect of the earthquake acceleration history applied at the bedrock level, have been analyzed. In order to validate the results, the amount of settlement of the structure under static load was investigated and using the results of two laboratory models, the structure-soil-structure interaction analysis process and the soil constitutive model were validated. Based on the obtained results, the structure-soil-structure interaction in the general state increases the lateral displacement of the structure compared to the case with a rigid bed. The interaction effects are different depending on the number and distance of the structures. Also, the results show that the effects of  structure-soil-structure interaction depend on the position and thickness of the soil layer prone to liquefaction, so that with the increase in the thickness of the liquefaction layer, more exess of pore water is produced and finally, the deformations created in the soil and the structure are more intense.

Surrounding the central core of a concrete component by means of an internal or external factor such as transverse reinforcements, carbon and polymer fibers and steel sheets causes confinement for the concrete. Confining generally improves the strength and ductility of concrete components. As a result of boosting the local performance of elements, the overall performance of structure is made progress. Recently, tending to build irregular structures has been increasing. The presence of irregularity in the structure has always been one of the challenges faced by engineers.  In this investigation, the influence of confinement phenomenon on the seismic performance (damage level and behavior factor) of the moment resisting reinforced concrete frames with vertical irregularity is assessed. To do so, 31 moment resisting frames with vertical irregularity are categorized in four classes including 3-, 6-, 9- and 12-story and the roof displacement-base shear curves of them are acquired using pushover analysis. The capacity curve of each frame is achieved in two states including neglecting the confinement effect and considering it. The outcomes indicate that not only can confining improve the seismic performance of structures but also it can decrease the imposed damage of structures. In other words, comparing the capacity curves of each frame with/without confining effect shows that taking the confinement effect leads to improving the secant stiffness and strength of the frame. Furthermore, due to confinement effect, lateral load carrying capacities of the frames are boosted and the considered damage levels are achieved in higher base shear and roof displacements in comparison with the state that confinement is not considered. The observed values of damage levels indicate that the influence of confinement for higher frames is more significant and the maximum base shears for the frames with the confining action is around 3-19% higher than those of the frames without confinement effect. For 3-story frames, considering confinement effect leads to improving 3.9, 3.6 and 2.9% in damage levels of DL, SD, and NC. For 6-story frames these values are 6.9, 9.5, and 6.8% respectively. Taking confinement effect results in improving 18.25, 11.8, and 14.6% in damage levels of DL, SD, and NC and 14.3, 14.2, and 13.3% improvement for 12-story frames. Comparing the behavior factors in the two states demonstrates that considering confining effect improves the mean values of behavior factors around 10.4%. In addition, the observed values of behavior factors show that the differences between the amounts of behavior factors (with/without confinement effect) for the frames with more stories are higher. It is manifested that type of irregularity plays significant role on the seismic behavior of the moment-resisting reinforced concrete frames. Comparing the analytical behavior factor obtained in the current study with the prescribed value of behavior factor in Iranian seismic code shows that although the proposed value of Iranian seismic code is conservative for low-rise frames, this value is not met for high-rise frames.

Unreinforced masonry buildings are quite popular in many countries such as Iran, even though they are prone to significant damage against even moderate seismic excitations. In 2003, 26000 people lost their lives and 30000 were injured in southeastern Iran during Bam earthquak. The regional investigations showed an almost total overall collapse of all adobe and masonry buildings. Even to this day, notable number of buildings in Iran is masonry buildings due to low costs, especially in rural areas. Hence, the popularity despite the poor performance has sought researchers to study efficient ways to improve the URM buildings. Generally speaking, masonry buildings are classifed into unreinforced and reinforced; the latter usually beneft from horizontal and vertical steel bars which signifcantly improve strength, ductility and energy dissipation capacity of such walls. Masonry buildings can also be categorized as confned and unconfned. Using horizontal and/or vertical ties usually in the form of lightly reinforced concrete members at the perimeter of walls, their intersection with perpendicular walls and if necessary, around large openings can considerably enhance their ductility and in some cases their strength. Unlike other masonry construction types, the behavior of Confned unreinforced Masonry (referred to CM hereafter) buildings has not yet been fully formulated. This is mainly because of more sophisticated behavioral characteristics of CM walls compared to unconfned Unreinforced Masonry (referred to URM hereafter) buildings. CM is the only masonry system that has been allowed practicing by the Iranian Code of Practice for Seismic Resistant Design of Buildings (Standard 2800) in seismic-prone areas. When it comes to seismic retrofitting of masonry buildings, there are a rather wide variety of available options, e.g. shotcrete, adding steel or FRP sheets on the wall, adding Reinforced Concrete (RC) ties, changing the arrangement and size of the openings, and using Near Surface Mounted (NSM) rods on the walls. Considering the significant number of two-story URM school ‎‎buildings in Iran, there is a need to provide instructions for ‎the ‎type of improvement plan of these buildings. In response ‎to this ‎need, the Organization of Renovation, Development ‎and ‎Equipping of Schools of Iran developed a guideline for ‎the ‎purpose of typifying the improvement plan of these ‎buildings ‎with the shotcrete method in 2021.‎ In this research, based on the results obtained from five two-‎‎story URM schools, the accuracy of this guideline is ‎evaluated. ‎For this purpose, the investigated buildings in the ‎two cases of ‎flexible roof without ties and rigid roof with ties ‎in ETABS ‎software using shell elements and spectral dynamic ‎analysis ‎method, once based on the requirements of the ‎guideline and ‎once based on the Code 360 was evaluated and ‎retrofitted using ‎Shotcrete.‎ The results of this research show that the guideline ‎in the case ‎‎of flexible roofs leads to ‎minimum vulnerability of the walls of ‎‎the studied buildings. In the case of a rigid roof, the ‎results ‎‎show that according to this guideline, some of improved and ‎‎unimproved walls are ‎vulnerable in both direction; In such a ‎‎way that the ‎average percentage of vulnerable walls in terms ‎of ‎‎relative length for the first floor is 63% in the ‎longitudinal ‎‎direction and 38% in the transverse ‎direction, and for the ‎‎ground floor in the ‎longitudinal direction is 56% and in the ‎‎transverse ‎direction is 17%.‎

An efficient approach to road safety coupled with preventive maintenance of asphalt pavements is the application of colored slurry seal, as it improves the road visibility while enhancing the aesthetic aspects of the urban space. Around the globe, application of colored surface treatments on roads has witnessed a growth in recent years, especially in urban areas. This study aims at investigating the feasibility and effectiveness of using electric-arc furnace steel slag as an alternative to natural aggregates in the colored slurry seal mixture design followed by a performance assessment of the resultant mixture. For this purpose, first, characteristics of the aggregate and steel slag were investigated. Next, performance of the designed slurry seal mixture was assessed by testing five different mixtures containing the slag at 0, 10, 20, 30 and 40 wt.%. Evaluation and comparison of the asphalt specimens were performed by conducting 30- and 60-min wet cohesion tests, 60-min wet track abrasion test, loaded wheel-sand adhesion test, and loaded wheel-displacement test according to ASTM D3910. Based on the XRF results, the considered steel slag powder contained a significant amount of calcium oxide (~ 57% of natural aggregate). The high CaO/SiO2 ratio for the steel slag indicates its alkalinity, which suggests its improved adhesion to bitumen thanks to its rather acidic nature. According to FESEM results, the steel slag material was found to be composed of particles of angular geometry with a rougher surface and higher porosity than natural aggregates, further indicating better slag-bitumen adhesion. Performance assessments indicated superior performance of the steel slag-containing specimens of colored slurry seal. Among the studied mixtures, the one with 40 wt.% steel slag exhibited the best performance, as shown by 27.8 and 37.3% increase in the mixture cohesion upon 30- and 60-min wet cohesion tests, respectively, as compared to the control specimen. Furthermore, 47.7% lower moisture sensitivity and 50.8% and 40% smaller vertical and lateral displacements, respectively, were observed for the slag-containing mixture. The bleeding potential of the mixtures decreased with increasing the steel slag dosage from 0 to 40 wt.%, so that the mixture containing steel slag at 40 wt.% exhibited 23.7% lower bleeding potential. Trying to optimize the asphalt emulsion dosage, it was figured out that the optimal content of asphalt emulsion increases with the added content of steel slag to the mixture. Accordingly, the mixture containing steel slag at 40 wt.% required 1.9% more asphalt emulsion to achieve a given cohesion level within a certain time. Based on the results of this research, in order to improve performance characteristics of colored slurry seal mixtures while observing environmental obligations, it is recommended to use steel slag as an alternative to natural aggregates in this type of surface treatment. Therefore, according to the environmental issues and the limitations of natural resources, it is recommended that steel slag be replaced by natural aggregates up to 40% in the colored slurry mixture. By replacing steel slag, proper adhesion and cohesion between asphalt mixture materials is achieved and its resistance to moisture sensitivity, traffic loading and bleeding is improved.

Eccentrically braced frame (EBF) is known as a lateral force resisting system in steel structures which dissipate the earthquake energy through the links. The importance of this issue increases when the structure is exposed to successive earthquakes because in the seismic active zones, a large earthquake may consist of numerous successive shocks (foreshock or aftershock) which can lead to permanent displacements and resistance loss in these frames. In a seismic scenario, the most damage will often occur in the link beam – as the structural fuses – and the other members will remain in the elastic region, while the link beams may fail under successive earthquakes in most of the structures and other members such as adjacent beams, columns and braces, will behave non-linearly. This paper evaluates the energy dissiption of links in high strength frames with 304L series steel link beams in an area with a high seismicity risk under different critical scenarios with/without seismic sequence phenomenon. In these links, there will be no risk of corrosion. The highest energy dissipates in the Links of EBF frames, so by examining the energy dissiption in this member, it is possible to judge the energy dissiption of the entire frame. In this regard, 2D eccentrically braced frames with a variety of materials were designed based on the Iranian earthquake design code (Standard No. 2800, 4th version – 2014), modeled in Opensees software. For this purpose, "Force Beam-Column Element" has been selected for the implemension of beam and column elements. Brace elements are modeled using "Trust Element". Moreover, a behavior curve is defined with the Parallel material command to introduce the end elements of the link length. Also, the "Elastic-Perfectly Plastic Material" model has been assigned to the material model of the Parallel material. Link elements are implemented using an element with concentrated plasticity. To define the shear behavior of links, two zero length elements have been used, and the behavior curve of parallel materials has been defined for them based on the study of Eskandari and Vafai in 2015. Based on Hoveidai's proposal in 2019, the Ramberg-Osgood model has been used for the cyclic response of stainless steel materials in Opensees software and the Steel02 model has been used for the st37 and st52 materials. In the following, seismic scenarios with and without seismic sequence are selected based on effective peak acceleration (EPA) which has been suggesteb by Rajabi and Ghodrati Amiri in 2020. In order to nonlinear dynamic analysis of the studied eccentrically braced frames, single and successive earthquakes should be scaled based on the design spectrum. For this purpose, the suggested spectrums in Standard No. 2800 and proposed methodology by Abdollahzade in 2019 have been used, respectively. The results indicate that the amount of energy dissiption through links increases between 2 and 3 times after the consecutive earthquakes compared to the main shocks while after the seismic sequence, a lower average energy dissiption ratio has been reported for this frame. Also among the studied frames, the high-strength frame with stainless steel links has a higher energy loss of 10.4% compared to normal frames and 31.6% higher than frames with stainless links under seismic sequence. Therefore, the using of this type of material can be suggested for all or some members of normal eccentrically braced frames, especially in active zones with high seismic risk.

The decrease in access to groundwater resources and the constant drop in the water level of aquifers in different regions of the world due to the over extraction and unsustainable management of these resources have caused many environmental, economic and social problems. In the regard, lots of researches have been carried out about the groundwater market as a suitable solution for aquifers restoration. However in some cases the water market has increased the tension on water resources due to the lack of proper water market mechanism and monitoring of water withdrawals. The main purpose of this paper is to propose and evaluate a mechanism for the groundwater market in order to redistribute the water rights of groundwater resources and determine the exchange price in the market, taking into account the existing uncertainties. Therefore, proposing efficient and effective groundwater market mechanism, taking into account the institutional, economic, social and environmental components, is of great importance.  In this article, proposing and evaluating the mechanism of the smart water market, a model has been presented for the management of groundwater resources by considering the existing uncertainties. Also, remote sensing of evapotranspiration is proposed as a new approach to measure and monitor water consumption in the groundwater market. In this regard, the uncertainty resulting from the error of remotely-sensed evapotranspiration in the results of the groundwater market mechanism has been evaluated using the robust decision-making (RDM) method. Based on the uncertainty resulting from the error of the remote sensing of the evapotranspiration, the amount of allowed water rights in each season has been considered as an interval. Since the probabilistic distribution of these variables is not known, it is necessary to use non-probabilistic methods to analyze the uncertainty and reach a robust decision. In this regard, considering all possible combinations of seasonal water rights (as different market scenarios) and calculating the decision criteria for each of them, the degree of desirability of these scenarios can be determined. The methodology can be generalized for different study areas, however to evaluate its efficiency, the proposed models and algorithms are assessed using the data of Nough region in Rafsanjan plain, as one of the forbidden plains with high economic value of water in terms of pistachio production. By designing and evaluating groundwater market mechanism, taking into account the economic and social components, sustainable management of groundwater resources is expected to be promoted and farmers' livelihoods to be less affected by water restrictive policies. The results show that the proposed mechanism of the seasonal groundwater market has increased the economic efficiency of water consumption in the study area by 25%. Also, with the implementation of the water market, the redistribution of water rights has a better fit with the users’ cultivated area. Finally, using RDM method, the best scenario is determined as a decision including the allowed water rights values for four auction seasons in the year of market implementation. By choosing the allowed seasonal water rights within the range of strategies related to the best scenario, it is possible to achieve a sustainable policy of seasonal redistribution of groundwater rights in the presence of uncertainty in the market monitoring algorithm.

Weir is a structure that is made in the body or in supports of a dam to safely discharge the excess volume of water from a reservoir. It is the main factor of safety for dams during floods. A Piano Key Weir (PKWs) is a modified type of labyrinth weir that is designed and built for increasing weir capacity at a specified water head on the weir crest compared to linear weirs. It can provide a specified discharge with a significantly lower upstream water depth. Considering that there is little information about energy loss in PKWs, this article dealt with the experimental study of energy loss in a type-A trapezoidal PKW. The experiments were conducted in a flume made from metal with a length, width, and height of respectively 10, 0.75, and 0.80 m in the hydraulic laboratory of the department of Water and Hydraulic Structures in the Faculty of Civil and Environmental Engineering, Tarbiat Modares University, Tehran. They were performed with weirs with and without steps in their outlet keys at the different flow rates of 30, 40, 50, and 60 L/s. The flow from the upstream tank of 2.05 m length was conducted by a guiding wall to enter the weirs after passing a distance of 1 m. A type-A trapezoidal PKW with 3 keys was utilized. The examined weir had an inlet key width of 0.175 m, outlet key width of 0.051 m, upstream and downstream overhang length of 0.125 m, lateral wall length of 0.5 m, weir height of 0.2 m, weir wall thickness of 0.012 m, and inlet and outlet key slope of 0.53. 3 weir models with different dimensions and number of steps were employed at the outlet keys. The first, second, and third weirs were investigated with 5, 10, and 15 steps, respectively. The PK weir geometry creates a 3D flow field that can be characterized by inclined jet and free fall jet exiting the inlet and outlet keys, respectively. to the downstream and into the outlet keys. The results showed that the energy loss was higher at lower flow rates. The average energy losses were 15.73, 24.93, and 18.52% in the 5-, 10-, and 15-step weirs compared to those without steps, respectively. The discharge coefficients were calculated and compared via two methods. The discharge coefficient calculated with an integral relation was 2.64% higher than that calculated with the general relation for weirs. In addition, this coefficient increased with an increase in the ratio of the weir crest length to its total width. The difference in energy loss measured before the hydraulic jump at a distance of 10 times the weir height was about 3%. The energy loss decreased with an increase in the flow rate and depth of the flow upstream of the weir. The presence of steps at the weir outlet keys had an increasing effect on the energy loss. The highest energy loss (24.93%) was observed in the 10-step weir. Some relations were presented for calculating the amount of energy loss in the type-A trapezoidal stepped PKW, as well as its amount on each step.

In today's, the preservation and maintenance of masonry structures in historical areas have become very important. A significant part of this issue is rooted in the use of non-reinforced construction materials in the building of such structures. In Iran, most of the historical buildings were built using masonry materials. The buildings were designed according to the special architecture of this region. The existing structures mostly consist of masonry walls as well as some openings with arched configurations. In these types of walls, the wall consists of two piers and an arch on top of them. Since Iran is located in a highly seismic zone, investigating the performance of these types of structures is essential under the action of earthquakes and lateral loadings. Therefore, in this paper, a numerical investigation is accomplished on the in-plane behavior of traditional brick arches under the action of lateral loads. To this end, the numerical model of a sample of an existing arch (in Kerman’s Mesgari bazaar) was considered. The model was developed on STKO software. In this regard, the nonlinear response of bricks and mortar joints was simulated by using the DamageTC3D material. As well, the geometry of the wall was constructed with four-node plane-stress elements. The lateral capacity of the wall was assessed under the action of gravity loads. To this end, the wall was analyzed under gravity loads with intensities of 0.0 to 0.2 MPa. Next, it was pushed laterally through the pushover analysis and the shear force-displacement capacity curve of the wall was obtained. Through a specific procedure, the obtained capacity curves were estimated with a bilinear graph. By using this graph, the performance points corresponding to the wall’s capacity were extracted and a complete discussion was made regarding the shear capacity and the corresponding displacement to each performance point. Based on the obtained results from the analysis, it was observed that with an increase in the intensity of the applied gravity load, the maximum shear capacity of the walls increases. However, a higher increase in gravity load intensity (over a specific limit) would cause more damage to the arch which leads to a smaller shear capacity. Also, it is observed that the distribution of cracks and their pattern along the walls follow a similar outline. However, crack widths are affected strongly by the intensity of the applied gravity load on the wall.

Self-compacting concrete (SCC) is known for its outstanding characteristics such as superior mechanical and durability properties. Corrosion of rebar due to penetration of chloride ions in the reinforced concrete elements is of particular importance. Therefore, this issue in the SCC must be investigated. Pozzolanic materials could be used in the SCC to increase the resistance of concrete against chlorine ion penetration. In this research, effects of pozzolanic materials including micro silica, nano silica, fly ash, rice husk ash, as well as limestone powder on the mechanical and durability characteristics of self-compacting concrete placed in chloride environment have been studied. The results show that nano-silica increases the mechanical and durability characteristics of self-compacting concrete. Moreover, the SCC containing combination of nano-silica and pozzolanic materials has better properties than the one containing nano-silica.

In mechanics of rock fracture and comminution, researchers have always been looking for a relationship between the consumed energy and the particle size distribution of the disintegrated rock specimen. This relationship has important industrial applications considering the fact that comminution of rock is a very energy demanding process and its efficiency is very low. Furthermore, investigating the damage evolution of rock under different loading rates, helps to better understand and more accurately design rock structures such as tunnels, rock slopes and foundations subjected to dynamic loading. In this work, a hybrid finite-discrete element numerical model was used to simulate rock disintegration under different loading rates in the Split Hopkinson Pressure Bar (SHPB) system. The rock and the steel bars in the SHPB apparatus were simulated by the Bonded Particle Model (BPM) and finite element model, respectively. BPM is a simplified version of the discrete element method in which the discrete particles are spherical in shape. Spherical particles or balls in the BPM are very useful in reducing the computational time; the contact detection of the spherical particles is computationally very fast. The computer program CA3, which is a 3D code for static, dynamic and nonlinear simulation of geomaterials was used for the numerical analysis. To capture the rate dependent behavior of rock, a micromechanical model was utilized in which the bond strength at a contact point increases as a function of relative velocity of involved particles. The numerical model was calibrated to mimic the mechanical behavior of Masjed Soleyman sandstone. To facilitate and expedite the calibration process of the BPM system, the curves and dimensionless parameters introduced in the literature were used. Input pulses with different intensities were applied to the specimen in the numerical modeling of the SHPB system. The input energy and the energy consumed to disintegrate the numerical rock specimen were evaluated by the numerical integration. Different particle sizes in the BPM system were used to investigate the impact of combined particle size and input energy on the rock disintegration. The results suggest that the energy consumption density for rock crushing changes linearly with the stress rate. Furthermore, it is shown that the dynamic strength of the rock increases with the increase in the consumed energy density. The disintegrated numerical specimen was carefully inspected and its particle size distribution was obtained. This was achieved by using a searching algorithm to identify the clusters in the damaged specimen; each cluster was made of one or several spherical particles. The volume of each cluster was calculated by finding the volume of its constituent particles and the porosity of the specimen. This volume was used to obtain the equivalent radius of the cluster; the cluster shape was imagined as a sphere to identify the equivalent particle or cluster size. The mean particle size (D50) of the damaged numerical specimen shows a linear relationship with the stress rate in a logarithmic coordinate system, which is consistent with the physical test results reported in the literature.