Yazar "Seyedi, Mohsen" seçeneğine göre listele

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    A numerical assessment of the efficiency of partial saturation as a countermeasure against lique faction-induced uplift of tunnels
    (Taylor and Francis, 2024) Al-Khateeb, Shemim Duraid Abdullah; Issa, Mohammed Jasim Khammas; Seyedi, Mohsen
    Tunnels located in liquefiable soils are prone to flotation following earthquakes. When the shaking-induced pore water pressure buildup continues, saturated soil surrounding the tunnels liquefies, flotation occurs and the soil loses its shear resistance against the uplift force from the buoyancy of the tunnel. Mitigation of liquefaction-induced uplift of tunnels is one of the concerns of geotechnical engineers. This article aims to investigate the efficacy of the available mitigation techniques using a finite element program with an emphasis on the prediction of excess pore water pressures in the surrounding soil and the uplift of the tunnel. In addition to the conventional techniques, a newly developed technique "Partial Saturation" was modeled to examine its effect on the reduction of the tunnel uplift. A parametric study was done to compare the effectiveness of partial saturation with other mitigation techniques. Results showed that the partial saturation technique would effectively dissipate the excess pore water pressure in the soil around the tunnels. It also performs well in the reduction of the uplift of the tunnel. The most appealing advantage of this technique against the other available mitigation techniques is that it can be employed easily without disturbing the soil around the tunnels. A new methodology to numerically simulate the partially saturated sands was described in this paper.
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    An empirical function to predict the liquefaction-induced uplift of circular tunnels
    (2024) Seyedi, Mohsen
    Tunnels buried in liquefiable soils are prone to liquefaction-induced uplift damage during strong earthquakes. Studying the parameters that affect the liquefaction-induced uplift of tunnels is crucial for enhancing the seismic resilience of tunnels, minimizing potential damage, and ensuring the safety of critical infrastructure during strong earthquakes. This study investigates the effects of tunnel diameter (D), burial depth (H), and amplitude of input shaking at the base of the soil layer (amax) on the liquefaction-induced uplift of circular tunnels using numerical simulation. A comprehensive parametric study was conducted to investigate the effect of the H/D ratio and the value of amax on the dynamic responses, such as uplifts and internal forces in the lining of the tunnel. Using the numerical results, an empirical function was proposed to estimate the liquefaction-induced uplift of circular tunnels buried in liquefiable, loose soils. Finally, the results predicted by the proposed function were compared with those of a shaking table test and a centrifuge experiment. It has been demonstrated that the burial depth of a tunnel has the greatest impact on its seismic performance. Under identical input motion, increasing the burial depth of a tunnel with a 5-m diameter from 5 to 10 m resulted in a 270% increase in uplift and increased the internal forces in the tunnel lining, noticeably.
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    Assessment of haditha dam surface area and catchment volume and its capacity to mitigate flood risks for sustainable development
    (International Information and Engineering Technology Association, 2024) Hasan, Raad F.; Seyedi, Mohsen; Alsultani, Riyadh
    The purpose of this study is to assess Haditha Dam’s catchment area and accessible surface area in order to guarantee that these regions can hold water without being at risk of floods. Using topographic data, the study simulated the two-dimensional catchment area and flow area below the dam. The monthly increase in water storage was then computed using the water balance equation and HEC RAS software. These increments were used to determine the required flow that might be utilized to run the dam more efficiently. Significant outflows were found at the start of the operational year. These volumes will probably cause water to accumulate, water levels to increase quickly, and heights to climb. In order to make sure that these regions can store water without running the danger of flooding, the goal of this study is to assess the catchment area of a contemporary dam and its accessible surface area. The study generated a two-dimensional catchment region and flow area below the dam using topography data. The water balance equation and HEC RAS software were then used to determine the monthly increase in water storage. The necessary flow that could be utilized to run the dam as effectively as possible was calculated using these increments. This assessment provides a comprehensive analysis of the dam’s capacity to manage water storage efficiently and mitigate flood risks, contributing to sustainable water management practices.
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    Enhancing geotechnical properties of clayey soil with recycled plastic and glass waste
    (International Information and Engineering Technology Association, 2023) Al-Mohammedi, Amenah Adnan Shakir; Seyedi, Mohsen
    Expansive clay soils, characterized by their propensity to undergo significant volume changes in response to moisture variations, present considerable challenges in construction engineering. These challenges manifest as structural damage, including fractures, asymmetrical settlements, and erosion. This study investigates the application of sustainable waste materials, specifically a mixture of plastic and glass waste, as an innovative approach to soil stabilization. In the context of Anbar, Iraq, laboratory experiments were conducted to evaluate the efficacy of incorporating plastic and glass waste in various proportions (0%, 4%, 5%, 6%) into clayey soil. The primary focus was to assess changes in geotechnical properties, notably the reduction in swelling potential and alterations in the maximum dry unit weight of the soil. Results indicated that the inclusion of waste materials in the specified proportions significantly mitigated the soil's swelling behavior, with reductions of 2%, 3%, and 5% observed for the respective waste content. Concurrently, enhancements in soil density were recorded, with increases in the maximum dry unit weight by 4%, 5%, and 9% corresponding to the same proportions of waste additives. These findings underscore the potential of using recycled waste materials in soil stabilization, aligning with environmental sustainability goals through the repurposing of waste. Additionally, this approach offers an economically viable alternative to traditional stabilization methods. The utilization of waste materials not only addresses the environmental impact of construction activities but also contributes to the broader goal of waste management and resource conservation.
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    Impact of train-induced vibrations on residents’ comfort and structural damages in buildings
    (Springer, 2024) Seyedi, Mohsen
    The rapid growth of urbanization and the progress of industrialization have resulted in the construction of over or near-track buildings. Train-induced ground-borne vibrations have attracted attention because they can damage buildings and cause residents discomfort. This study conducted a series of finite element analyses on three 5-story concrete framed buildings, which were subjected to the passage of trains at various speeds. One of the buildings was modeled as an over-track building, whereas the other two buildings were located in close proximity to the track but at different distances. The present study investigated the impact of train speed and track-to-building distance on the acceleration and velocity responses of buildings. The comparison of residents’ comfort levels and the structural safety of buildings against potential damages was conducted using international standards as the controlling criteria. Furthermore, an efficient mitigation technique was implemented, involving the utilization of open trenches with different depths between buildings and the railway track. This approach was employed with the aim of minimizing the detrimental impacts caused by trains-induced vibrations. The findings indicated that the over-track building was impacted by the train-induced vibrations more than near-track buildings. Furthermore, it was shown that although the passage of high-speed trains can disturb the comfort of building residents and potentially cause some structural damage to buildings, it did not lead to any significant story drifts in the structures. Finally, the minimum required depth of open trenches to mitigate train-induced vibrations was computed for every type of buildings and train speeds.
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    Numerical analysis of geogrids and recycled concrete aggregate for stabilizing road embankments
    (2023) Al-Dulaimi, Marwa Abdulkareem Mohammed; Seyedi, Mohsen
    The amplification of urban development and the extension of road networks necessitate a comprehensive understanding of various soil improvement techniques for civil engineering applications. Soil enhancement methods, typically trusted and practical, are pivotal in addressing geotechnical engineering challenges. This study focuses on the numerical evaluation of the efficacy of geogrids and recycled concrete aggregate (RCA) in the stabilization of road embankments. Critical soil properties such as water absorption, soil erosion, and settlement susceptibility are significantly improved through these methods, promoting sustainable land use, environmental conservation, and infrastructure durability. Literature reveals that the use of geogrids or waste materials like RCA contributes effectively to soil layer enhancement. In this investigation, road embankment models, with and without the aforementioned improvements, were developed and assessed under vehicular load conditions. The findings demonstrated that the incorporation of geogrids or RCA significantly bolsters the stability of road embankments. A noteworthy reduction in vertical settlement, up to 45%, was achieved when geogrids and RCA were concurrently utilized in the embankment. This suggests that these methods, individually or in combination, could provide a viable solution for enhancing the performance and stability of road infrastructures. Further research is proposed to explore the long-term performance of these enhancement methods under various environmental and load conditions.