نشریه مهندسی عمران فردوسی
سال سی و ششم شماره 1 (بهار 1402)

Groundwater resources are one of the main sources of freshwater supply, especially in arid and semi-arid areas. Estimating the amount of recharge is one of the most important problems in the sustainable management of groundwater resources and assessing the abstraction potential of the aquifer. In this research, first, the recharge potential in the Garmsar plain aquifer was obtained using six factors including slope, land use, geomorphology, lithology, drainage density, and line density, and then, to validate the resulting map, recharge was evaluated using the water table fluctuations and Piscopo methods. The results from the recharge potential map showed that its amount decreases from the alluvial fan in the north of the area to the margins. The amount of annual recharge of the aquifer varies from 1.95 mm in the south to 478 mm in the north of the area by the water level fluctuations method. The maps obtained from both methods showed the same trend in the area; the north of the aquifer area, which is located at the top of the Garmsar alluvial fan, has the highest amount of recharge, and the values decrease towards the south and the edge of the aquifer. The results obtained from the evaluation of the groundwater recharge value confirmed the potential map well.

In this paper, the effect of reverse dip-slip fault movement on a tunnel, being perpendicular to the fault plane in plan view, is modeled numerically with finite-element software, Plaxis 3D and the effect of factors such as fault dip angle, soil type and tunnel’s depth on “fault rupture path”, “ground surface displacements” and “deformation and forces in the tunnel lining” is presented. The results indicate that the presence of tunnel gives rise to zones of stain localization in the soil underneath the tunnel and somewhat prevents the rupture zone to reach the ground surface on its top (centerline of the tunnel) whereas it causes relative uplift on the ground surface on both sides. Moreover, in deeper tunnels, the impact of faulting on lining forces is more pronounced. Furthermore, to reduce the influence of the outer boundaries, performing sensitive analysis, appropriate dimensions are recommended for modeling the interaction of fault and tunnel. It is shown that axial force, especially in mild fault dip angles, is very sensitive to model length while bending moment can be correctly estimated by typical modeling dimensions (i.e., model length 4-5 times the soil layer height).

The quality of traffic flow is one of the main characteristics of the transportation network, which is widely used in issues related to urban planning, route prioritization, reducing traffic congestion and travel time; Therefore, estimating the volume of traffic and predicting it in the future is one of the important issues for transportation planners. The problem of prediction requires modeling and determining the variables affecting changes in a particular phenomenon. In this research, travel demand is predicted using time series methods. The data required for this research have been prepared from the Roads and Transportation Organization. In this study, in order to build a model, two autoregressive processes and moving average have been used. Using the above methods, the amount of demand in the coming years up to the horizon of 1404 on the Qom-Tehran freeway is predicted. The results of the study showed that among the self-correlated and moving average models and the combination of two models, namely the self-correlated moving average, the third model has a more acceptable accuracy. The parameters of this model (4,5) ARMA were obtained. Also, the validity of the constructed model, based on the average value of absolute error percentage, was 0.047, R and R2 values were calculated 0.94 and 0.89, respectively, which shows that the model has acceptable accuracy.

Due to technological improvement and the development of photovoltaic (PV) systems, the application of PV installation for net-zero energy buildings (NZEBs) is promising. However, to achieve more reliable results, precise energy analysis is necessary to take into consideration both the urban plans restrictions and the climatic conditions of renewable energy resources and building energy consumption. This study aims to define the most favorable configuration of building components and PV installation to meet NZEB requirements, considering urban development plans limits. First, a sensitivity analysis was performed to indicate the most influential variables that affect building energy demand and cost. Next, an optimization process was conducted to concurrently minimize the building energy consumption and capital cost. Besides, a different configuration for PV panel installation was used for quantifying the possibility of achieving NZEB. The results show that in a residential 3-story building the optimized configuration of the building envelope and systems can reduce electricity consumption by 20%. The rooftop PV account for 87.2% and PV installation on the southern façade contributed to 12.8% of total electricity generation. PV installation on the south façade and roof covers 88.2% of the building's electricity demand.

In this research work, the remediation of a clay soil contaminated with dimethyl phthalate ‎was ‎studied by using electrokinetic method. Contaminated soil was made with the ratio ‎of 0.04 mg/g. ‎Non-ionic (Tween 80) surfactant and solution of 0.1 M NaOH were ‎used as anolyte. A reference ‎test was also considered with distilled water as ‎anolyte and catholyte. pH and EC and volume of ‎flow out fluid were measured ‎during the tests in both electrode reservoirs. At the end of each test ‎the shear ‎strength, pH, EC and degree of remediation of soil was measured at different ‎distance ‎from anode. The removal of contaminated was measure by a GC (Gas ‎Chromatography) apparatus. ‎The results showed that the amount of flow out fluid ‎for NaOH was nearly 20% more than the ‎solution of Tween 80 and distilled water. The ‎results also indicated that the strength of soil for ‎different solution is increased ‎by increasing the distance from anode. The value of it around the ‎cathode for ‎solution of NaOH was 14 kPa that was about 50 and 57% more than the distilled ‎water ‎and Tween 80. It was found that the degree of remediation at cathode is less than ‎anode. The ‎percentage of remediation for Tween 80 solution around the anode and ‎cathode were 53.88 and ‎‎16.5% respectively but for NaOH they changed to 50.82 and ‎‎23.26 near anode and cathode ‎reservoir. It was resulted that the effectiveness of NaOH ‎solution in remediation of soil was more ‎than the other used solutions.

Stabilizing materials can be used as a soil improvement technique when dealing with inappropriate soils. This study investigates the effects of wetting and drying cycles on the clayey soil stabilized with Calcium Lignosulfonate and also polyethylene fibers. For this purpose, unconfined compression strength and durability of the prepared samples under wetting and drying cycles are investigated. Atterberg limit tests, standard compaction tests and unconfined compression tests have been performed on the prepared samples. Also, the optimum curing duration for soil stabilized with lignosulfonate is investigated. The results show that lignosulfonate-stabilized clay was not sufficiently durable against wet and dry cycles. Based on this result, the stabilization of clay with lignosulfonate stabilizer has a great weakness that is the main drawback to the use of this stabilizer. Addition of 4% polyethylene fibers increases the durability of stabilized samples up to 600% against wet and dry cycles. Also, adding polyethylene fibers to stabilized clay soil with lignosulfonate reduces the weight loss of the materials (70%).