حمیدرضا وثوقی فر

The infiltration of crude oil and its derivatives into the soil leads to changes in the mechanical behavior of the soil in addition to detrimental and environmental problems. This study aims to evaluate the bearing capacity of geocell-reinforced strip footings laid on oil-contaminated sand under eccentric load via numerical modeling using PLAXIS 2D. The behavior of the footing is assessed regarding various oil contents of 0, 3, 6, 9, and 12% under loading with different eccentricities of e/B=0, 1/12, 1/6, and 1/3. Numerical results revealed that soil pollution has a negative effect on the performance of strip footings, so that an increase in oil content led to a reduction in the magnitude of the load capacity. It was observed that reinforcement with geocell increases the bearing capacity of footing located on the oil-contaminated medium under different eccentricities. The effect of reinforcing with geocell was higher for contaminated soil compared to clean one. Further, the load capacity improvement factor (IF) increased by increasing oil content and settlement value. The results revealed that the reinforcing effect increased with an increase in load eccentricity for both clean and contaminated soils. In addition, the use of geocells is most effective when the loading is outside the core of the foundation, i.e., e/B>1/6. The footing tilting around the centerline axis of the footing due to load eccentricity as well as soil reinforcement with geocell led to a reduction in the stress-affected zone and as a result the displacement depth of the soil beneath the foundation.

About 50 thousand tonnes of construction waste is produced in Tehran daily, which is about 7 times the household waste. These movements without having smart and integrated management not only increase the traffic and pollutes the city air but also impose other problems such as illegal waste disposal in passages upon urban management. Hence, by smartification of the construction waste transport system, not only illegal disposal of this debris can be prevented, but also by reducing the truck traffic or their path length, huge positive steps are taken toward reducing overall traffic and air pollution. Via a proper organization of construction waste, in addition to sustaining the natural resources and environment, it can provide monetization and job makings. In this research, the best “buildings’ demolition” management method in Tehran is examined based on the analytical hierarchy process (AHP) with a viewpoint to urban sustainable development. Then, the subsidy and penalty approach is suggested for paying the construction waste charge resulted from various building demolition methods. As a consequence of executing this plan, constructors will have more inclined to demolition methods with less construction waste due to exemptions and fewer waste charges and avoid demolition methods with enormous construction waste due to higher penalties and waste charges. According to the conducted researches and investigations, it has been recommended that for calculation of the charges for construction and demolition resulted from the destruction of the present construction during the announcement of demolition and reconstruction, for immediate demolition with disposal materials and semi-recycled demolition method, equal to and a half of (50%) the construction waste charge approved by Islamic council of the town be received, respectively. Also, it is suggested that the fully-recycled demolition method be free of construction waste charges.

About 50 thousand tonnes of construction waste is produced in Tehran daily, which is about 7 times the household waste. This results in the movement of more than 4500 trucks during the day inside the city. These movements without having smart and integrated management not only increase the traffic and pollutes the city air but also impose other problems such as illegal waste disposal in passages upon urban management. Hence, by smartification of the con- struction waste transport system, not only illegal disposal of this debris can be prevented, but also by reducing the truck traffic or their path length, huge positive steps are taken to- ward reducing overall traffic and air pollution. Via a proper organization of construction waste, in addition to sustaining the natural resources and environment, it can provide mone- tization and job makings. This research was performed based on the analytical hierar- chy process (AHP) with a view to urban sustainable devel- opment to identify the best approach of transporting con- struction and demolition waste in Tehran. It has shown that option “smart and integrated management” with a weight of 0.851 is the best choice for transporting construction and demolition waste compared with the option “using the tradi- tional method” with a weight of 0.149.

Building RCC dams involves pouring and compacting concrete in small layers (30 cm), one on top of another, creating a joint between each layer. This joint could potentially become the “ideal” joint depending on the temperature and lag time between each layer. To check the concrete s temperature using smart sensor is undeniable. Furthermore we use these sensors for RCC dam’s structural health monitoring. The objective of this paper is to introduce a novel model for arranging the smart sensors for RCC dam’s structural health monitoring .The authors suggest a flow chart and prove it with a real case study. This is useful for RCC dams all around the world. The case study is Zirdan RCC dam (located in Iran), and the verification is upon Kinta RCC dam (raised in Malaysia). Step 1, the Zirdan dam is modeled in Abaqus . The program outputs give the actual temperature, the thermal stresses of each node. Step 2,The ANN (Artificial neural network) converts discontinuous results in a continuous estate. Step 2, we use the Monte Carlo to achieve a point in each layer, representative of others. the chosen coordinates are fed into GA (genetic algorithm). Next, we define the parameter of importance coefficient as the temperature arrived from the site divided by the model temperature. finally, assimilating it with cost function will allow for having fewer sensors and sensors being placed further apart. All of the above result in the optimum placement of the thermal sensors in RCC dams.

Zarrinehrud River is one of the most important permanent and water-rich rivers in West Azerbaijan province located in the catchment area of Lake Urmia. In this study, to evaluate the quality of the Zarrinehrud River, with a length of 57.5 kilometers from the outlet of Noroozlou to the drainage dam to the Lake Urmia, QUAL2K computer simulation model was used.

The selected parameters of the model included: flow, dissolved oxygen (DO) and biochemically required oxygen. The selected time for the simulation was May 2016. Model calibration was performed by determining the oxidation coefficients of carbonaceous materials and the re-aeration coefficient of the river, using the mean square root of error (RMSE)

The results show that the water quality of the river downstream of the Noruzlu regulatory dam has caused significant changes in the quality parameters of the river due to receiving wastewater from slaughterhouses, sugar factories, urban, rural and agricultural drains.

Due to the high self-purification capacity of the river, the amount of dissolved oxygen is appropriate and the amount of BOD has reached an acceptable level despite a sudden increase. In terms of matching the observational data with the output diagram of the model, there was a good fit in other parameters except flow rate. In the case of non-compliance of the observed flow data with the simulation diagram, it may be due to unauthorized withdrawals from the river for agricultural purposes.

Summary Several newly constructed tunnels, which have been damaged by earthquake loading, have led to extensive research on the evaluation of earthquake effects on tunnels. Underground structures are increasingly being built and exploited in the context of urban expansion and development. Tunnels are one of the most important underground structures. Failure of several tunnels under earthquake loading, and especially damage to these tunnels, have been the reasons to investigate the effects of earthquake on the tunnels.   Introduction Various activities, especially during earthquake, on the adjacent structures are of particular importance. This importance will be more in the vicinity of the historical building, due to their vast material and spiritual values. In this research, using the Henkel type I and three scale accelerometers related to the earthquakes in Northridge, Tabas and Kobe, and employing the expanded FESCAM program in MATLAB environment, the historical structures of thirty-three buildings have been studied.   Methodology and Approaches In this research, nonlinear time histories analysis has been used to generalize Henkel's relationship and to calculate the exact difference. The input waves have been investigated by the researchers for use in the Henkel harmonic waves function. The Henkel function of the first type using the mentioned accelerations is used considering the amount of dissociation, the degree of strain and stress around the twin tunnels as an additive parameter to the limited element analysis of the present study.   Results and Conclusions In this paper, the operation of differentiation is expanded with the use of mathematical relations. A case study of twin tunnels is Si-o-se-pol twin tunnels. The results of this study show that the mean displacement of horizontal thirty three bridges there in comparison with the failure to consider the effect of fractionation is increased by 28.8% and the displacement rate of the thirty three bridges compared to the failure includes the difference of 11 / 30%. Moreover, the displacement of underground structures during an earthquake is less than that of the ground structures. The results of the Mann-Whitney test with the SPSS software program have shown that there is no significant difference between the seismic performance of the thirty three bridges with the effect of tunneling dispersion and without the effect of tunneling dissociation (P-value≥0.05).

Local site conditions have a great eect on ground motion and, consequently, underground structures, as important lifelines, have a vital in uence on disaster management after earthquake occurrence. Among the local site topographies of interest are tunnels, which are located underground. A tunnel is an underground passageway, completely enclosed except for openings for the entrance and exit, commonly at each end. A tunnel may be for pedestrian or vehicular road trac, for rail traf- c, or for canals. Some tunnels are aqueducts to supply water, for consumption or for hydroelectric stations, or are sewers. Upon impact with a tunnel, induced earthquake motion would generate diraction waves, which increase the damage in adjacent structures. In order to investigate the eect of wave diraction on near fault ground motions, the twin tunnels of the Shiraz subway and their adjacent structures have been studied in the present article. Articial neural networks (ANNs) are a eld of science aimed at mimicking natural learning using mathematically based approximation. A single biological neuron is composed of three major parts: the cell body, the axon, and the dendrite. With known combinations of input and output data, a neural network can be trained to extract the underlying characteristics and relationships from the data. Then, when a separate set of input data is fed to the trained network, it will produce an approximate but reasonable output. Neural networks are highly nonlinear and can capture complex interactions among input/output variables in a system without any prior knowledge about the nature of these interactions. In this study, an appropriate articial neural network has been generated in order to estimate the amount of diraction of near fault earthquake waves. The results show that an idealized neural network has a high level of precision in comparison with results derived from nite element analysis. Finally, a sensitivity analysis was performed on input parameters and their percent of importance was evaluated.

In this study, contribution of exhaust emission and CO distribution was estimated in enclosed residential complex parking.
This was a descriptive - analytical study consisted of two stages. In the first stage, the emission contribution of vehicles was determined. In order to determine the contribution of exhaust gas emissions, through gas species, only four species CO, O2, CO2, and N2 were measured. Concentration of CO, O2, and CO2 was estimated using data obtained from the vehicle emissions monitoring system. The amount of N2 was estimated from sum ratio of all species, which equals to 1. Then, using computational methods, the amount of the emission contribution from vehicles. In the second phase, to measure the distribution of CO pollutant, gas sampling and collecting was performed using sampling bags made of inert materials with a volume of 10 l at six points. Sampling was conducted in accordance with the requirements of OSHA ID 210. The Obtained data were analyzed using SPSS Ver.16 software and Pearson statistical test (P > 0.05 means there was no significant difference).
Maximum contribution was estimated for Pride with amount of 44.4 g/s and minimum contribution was estimated for Tiba with amount of 0.3 g/s. The minimum and maximum distribution value of CO concentration was achieved 3.6 and 69.48 ppm respectively. It was found that no significant relationship was observed between the values of exhaust emissions and CO distribution. However, the distribution of concentration was associated with locations and the number of openings, the number and type of vehicle, time of operation of the vehicle, the vehicle performance, and environmental factors.
Measuring vehicles CO emission indicated that the concentration was beyond the permissible level recommended by the World Health Organization at some. Moreover, it was indicated that natural air conditioning is an effective alternative for improving the air quality in built environments and suitable quality in built environments is achievable through reasonable architectural design, without need to spend too much expense.

A high resolution finite volume method for solving the shallow water equations with voronoi mesh is developed applying MATLAB software in this paper. The scheme is formally uniformly second order accurate and satisfies maximum principles. The model is verified by comparing the model output with condition of anti-symmetric and circular dam break with documented results. For more investigation we utilized SPSS statistical software. Very good agreement has been achieved in the verification phase. It can be considered as an efficient implement for the computation of shallow water problems, especially concerning those having discontinuities. A simple example of the collapse of water supply reservoir in a valley is used to demonstrate the capability of the model. The presented model is able to resolving shocks, handling, complex geometry, including the influence of steep bed slopes.

Liquid storage tanks are considered as a vital artery with high importance. Therefore, the dynamic behavior of liquid storage tanks should be investigated. In this study, At first, the verification of finite element method based on the result of scaled experimental tank with different dimensions of elements was done.Then, modal and time history analyses were conducted and the free surface sloshing was investigated. The results of different element types were compared with the experimental results used statistical program SPSS17. In the next step a concrete rectangular tank with 1000m3 capacity was studied with different dimension of elements. Finally, the time history of North ridge earthquake record was applied to 1000m3 tanks with two and three horizontal and vertical components and the result of this analysis was evaluated. The results of modal and time history analyses showed that the effect of dimension of elements on the response is considerable and modal analysis alone cannot validate the modeling of tanks with the finite element method and the dimensions of elements with ratio height to length larger than 1 did not show good agreement as well as the results of dynamic analyses showed that The presence of vertical earthquake ground motion in combination with horizontal ground motion do not have any significant effect on the sloshing behavior water in the tank. However, the vertical earthquake acceleration can have remarkable effects on the maximum hydrodynamic pressure, and its distribution on the tank walls.

Building industry is one of the most energy consuming parts of the developed and developing countries. Cooling, heating and ventilating systems devote a great amount of this consumption so studying natural ventilation systems have become more important in order to improve their performance. In this paper, air flow has modeled by a computational fluid dynamic model with finite volume method in solar chimney as a new kind of natural ventilation system and in a combined system with Baadgir. For this reason, different turbulent models have been compared by a valid statistical test in order to find a suitable turbulent model in these systems and at the end a ke-RNG model has been selected. Also the effect of increasing height, span width and thermal gradient of the walls on improvement of solar chimney’s performance have been studied by computing parameters like mass flow rate and mean velocity.

In this article, based on the modified model of interaction of soil and container, Analysis Lrz·hyy Mylmharhay nuclear stockpile is presented. For Systems must be designed Mylmhar predicted size, direction and type of stresses Induced stresses and their effects on intact rock mass around The estimated drilling. Other factors affecting system design Mslhsaz The rock mass, it is predicted lifetime. To assess Mylmhargzary connection, it is necessary rock mass interaction - consider Mylmhar Be taken. Before considering a system of land holding, profile Load - deformation of rock mass must be determined. Complex structures Including nuclear ones, which are under high tension, stiffness and installation time Vyzhhyy Mslhknndh system is important. In this case, kind and hard cover Should react when Barbrdary rock mass) interaction curves Land (to be consistent. Mylmhar or cables if inhibitory paste before deformation Rock mass to be installed, not elected Mylmharhay with Tghyyrshklhay Bhvjvdamdh be consistent. However, if after the occurrence Mylmharha Tghyyrshklhay paste Mylmharha be installed and also not hard enough, probably Tghyyrshklhay paste Find more rocks, and if these tensions are very high in Mylmharha affect. Asharhshdh problems with the correct interaction model Rock mass and are high maintenance. In this study, Aslahzkrshdh Run time is Amalshdh holder.

A high effort for the seismic evaluation of existing buildings has been undertaken during the recent decades. Nevertheless, due to the diversity of the buildings and the complexity of the various effective parameters on the seismic vulnerability of the buildings, preparation and compilation of the required standards are very difficult. For this purpose, in this paper, after reviewing the guidelines for rapid visual screening evaluation of the existing buildings as well as a systematic sampling of 116 buildings in Tehran based on a professional experience of professors and engineers in the related field, a rapid method for the seismic evaluation of existing buildings is presented. The questionnaire prepared for this purpose includes information related to the foundation and the soil, structural and architectural issues, connections, infill walls hue mechanical and electrical facility of the building. Using Delphi method, the experts’ opinions were employed to establish the weight factors for the list of the subjects considered in the questionnaire.