Research/Technical Note
Numerical Investigation of Shallow Tunnel Settlement Using the Finite Element Software Plaxis 2D
Issue:
Volume 9, Issue 2, December 2025
Pages:
50-58
Received:
17 January 2025
Accepted:
2 July 2025
Published:
19 July 2025
Abstract: Shallow tunnels are often subject to settlement, which can compromise the performance and safety of underground structures. This is especially relevant for developing cities that need to construct tunnels for transportation infrastructure projects. This study examines the settlement behavior of shallow tunnels through numerical simulations using the finite element program Plaxis 2D. The study investigates the impact of various factors, including stress magnitude, rock type, tunnel depth, soil layer thickness, and tunnel liner thickness, on the settlement behavior of shallow tunnels. The study also guides the choice of the appropriate tunnel structure for geotechnical practice. The results indicate that different soil and rock types exhibit distinct settlement patterns under both vertical and horizontal deformations. For instance, hard rock has less settlement than weak and medium rock, and deep sand has less deformation than sand and clay. The results also indicate that tunnel liner, load distribution area width, and tunnel type are sensitive parameters that influence tunnel settlement. This study contributes to the understanding of factors that affect tunnel settlement, providing valuable insights for future tunnel design and construction. The findings of this study can help improve the stability and safety of shallow tunnels, as well as assist in developing more accurate settlement prediction models.
Abstract: Shallow tunnels are often subject to settlement, which can compromise the performance and safety of underground structures. This is especially relevant for developing cities that need to construct tunnels for transportation infrastructure projects. This study examines the settlement behavior of shallow tunnels through numerical simulations using th...
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Research Article
Assessment of the Impact of Agricultural Activity on Siltation of Meka Dam Reservoir in the Chancho Catchment Using Bathymetric Survey and GIS, Ethiopia Oromia Region Nekemte
Dereje Adeba*
,
Garuma Negasa,
Abeya Lencha,
Abdisa Sandaba,
Habtamu Tilahun
Issue:
Volume 9, Issue 2, December 2025
Pages:
59-65
Received:
16 January 2025
Accepted:
4 July 2025
Published:
25 August 2025
Abstract: Reservoirs are used worldwide supply water for domestic use, irrigation, hydropower generation, and flood management services, Sedimentation affects the sustainability of reservoir operations and overtime, sediments build-up in reservoirs displaces usable storage volume, which in turn negatively affects the beneficial uses of reservoirs and degrades aquatic habitat. An agricultural activity in the chancho watershed is a major issue which increases siltation in the Meka dam reservoir. The bathymetric survey approach is used in the study which is based on a simple comparison of reservoirs morphology at two different time periods, first at the time of the construction of the dam and second at the time of the survey. Bathymetric mapping involves two types of necessary measures: the position and depth measurements. Silt level was directly measured by eco-sound detector. Bathymetric map of the reservoir was done at predetermined 10 m horizontal interval to collect the representative silt level. Echo-sounder was used to measure the depth of silt from reservoir water surface. This device measures the depth of water by sensing and recording the depth of water from surface to top of silt level. Accordingly, 3025 points across the reservoir were surveyed with echo-sounder The deepest measure was found to be 15.01 m, the shallowest depth is 0.47 m and the average depth of Meka reservoir was found to be 6.67 m. The reservoir capacity was determined by ArcGIS tools. The amount of water that can be stored above the original bed level in Meka dam reservoir is found to be 119,960,000 m3 and the amount of water that is stored above the current level of silt in the reservoir is found to be 9,276,000 m3. The half-life of the Meka reservoir is expected to reach within 42 years. Since its construction in, 2007, it’s found that the storage capacity loss of Meka Dam was 17.86%. Therefore, appropriate watershed management strategy should be enforced to alleviate the problem of storage capacity loss of the reservoir due to sedimentation that arises from agricultural activity in the catchment.
Abstract: Reservoirs are used worldwide supply water for domestic use, irrigation, hydropower generation, and flood management services, Sedimentation affects the sustainability of reservoir operations and overtime, sediments build-up in reservoirs displaces usable storage volume, which in turn negatively affects the beneficial uses of reservoirs and degrade...
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Research Article
Optimization of Wheat (Triticum aestevum L.) Water Productivity Under Deficit Furrow Irrigation Using AquaCrop Model
Habtamu Bedane*,
Gudeta Genemu
Issue:
Volume 9, Issue 2, December 2025
Pages:
66-74
Received:
30 July 2025
Accepted:
13 August 2025
Published:
25 September 2025
Abstract: Crop growth models like AquaCrop maximize crop output and water use efficiency by forecasting agricultural indicators including crop yield, dry biomass, and water productivity. This study not only validated and calibrated the AquaCrop model, but also investigated the effects of deficit irrigation on wheat yield and water productivity. The experiment was conducted for calibration in 2022-2023 and for validation in 2023-2024. Five irrigation treatments were utilized in this study: 100% ETc, 80% ETc, 80% ETc at development and mid-stage, 60% ETc, and 60% ETc at development and mid-stage. The test variety was the Kingbird local wheat variety. Applying 100% ETc produced the maximum plant height, biomass, yield, and thousand seed weight (66.97cm, 36.43g, 3.47t ha-1, 9.53t ha-1), while 60% ETc produced the lowest values (63.1cm, 30.4g, 1.94t ha-1, and 7.74t ha-1). The best water productivity of 0.92kg m-3 was seen throughout the development and mid-stages when 80% ETc was applied. The AquaCrop model's root mean square error ranged from 0.002 to 0.25 t ha-1, its model efficiency ranged from 0.81 to 0.95, and its coefficient of determination for grain yield, dry biomass, and water productivity ranged from 0.84 to 0.98. Model efficiency was 0.83, 0.85, and 0.77, yield, biomass, and water productivity had coefficients of determination of 0.96, 0.93, and 0.73, and the AquaCrop model's root mean square error was 0.244, 0.413t ha-1, and 0.03kg m-3, respectively. When 60% ETc was used, the largest prediction error of 17.36 was observed under yield, while when 100% crop water requirement was applied, the lowest prediction error of 0.26 was obtained under biomass. Therefore, it can be concluded that the AquaCrop model can reliably forecast crop metrics that are impacted by different watering schedules.
Abstract: Crop growth models like AquaCrop maximize crop output and water use efficiency by forecasting agricultural indicators including crop yield, dry biomass, and water productivity. This study not only validated and calibrated the AquaCrop model, but also investigated the effects of deficit irrigation on wheat yield and water productivity. The experimen...
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