Print ISSN: 1681-6900

Online ISSN: 2412-0758

Main Subjects : Civil


SWOT-Based Assessment of the Maintenance Management of the Wastewater Treatment Plants in Iraq

Reem Tareq Al-Attar; Faris H. Al-Ani; Mahmoud Saleh Al-Khafaji

Engineering and Technology Journal, 2022, Volume 40, Issue 5, Pages 677-694
DOI: 10.30684/etj.v40i5.2146

In Iraq, due to WWTPs being old and outdated, an evaluation of the maintenance management is needed to highlight the points of weaknesses and strengths of the plants. In this paper, the strength, weakness, Opportunities, and Threats (SWOT) analysis model is designed with the Delphi Technique and Liker-scale and applied to the old Rustumiya project in Iraq (ORP). The design and application of this model are based on the design, operation and maintenance drawings and reports, and field visits to the ORP. In addition, three rounds of the questionnaire were sent to more than 80 experts varied in qualification and experience, considering the SWOT elements of the methods, materials, and human resources issues. The weight, relative importance, and implementation of each item in each SWOT element and the SWOT elements and issues were computed. The results showed that in the internal elements, the degree of importance of the weakness has a higher value of importance than the strength. In the external elements, the opportunities are considered more important. For the four issues, methods have the lowest weight while the materials have the highest. This alerts the major development required in this sector for a new plan for selecting and preparing maintenance materials. However, human resources come after the materials in terms of importance. The developed SWOT analysis model is beneficial for evaluating WWTPs with simplified and realistic results. Further, it can evaluate other projects like irrigation projects and water treatment plants.

Finite Element Simulation of Repeated Loading Test of Asphalt Concrete

Noor S. Hatem; Miami M. Hilal; Mohammed Y. Fattah

Engineering and Technology Journal, 2022, Volume 40, Issue 5, Pages 661-667
DOI: 10.30684/etj.v40i5.2128

In this paper, the Abaqus 6.14 version program was used to carry out a three-dimensional finite element analysis to predict the rut in the asphalt laboratory model. In a previous study, a cylinder model of asphalt was tested under the influence of traffic loads and temperature. The test was simulated using the finite element method considering the boundary conditions, load steps, and temperature. The cohesive zone model (CZM) approach was used in the Abaqus program to analyze the spread of the rutting in the model to simulate the fracture and improve the sample structure and the materials used. The Abacus program analysis showed satisfactory results when compared with the experimental results. The numerical and experimental displacement results indicate that the program can simulate the rut that occurs in the model. Using a temperature of 55 ° C showed that the effect of the temperature was not noticeable. XFEM-CZM coupled model provides a suitable numerical tool to represent the rutting tests.

Push–out Test of Timber Concrete Composite Construction

Ihab S. Saleh; Nabeel A. Jasim; Anis A. Mohhamed Ali

Engineering and Technology Journal, 2022, Volume 40, Issue 5, Pages 668-676
DOI: 10.30684/etj.v40i2.2175

In this study, push – out test specimen is proposed to explore the behavior of shear connectors in timber–concrete composite beams. Since there are no standard shapes and dimensions for determining the strength of connectors, push–out specimens such as those used for steel-concrete composite beams are suggested to study the behavior of connectors in timber concrete composite beams. Four specimens are tested. Two of these specimens are with one connector per side. The other two are with two connectors per side. The load and slip are recorded during testing. The results show that the ultimate load per connector ranges from 24.9 kN to 29.4 kN, with an average value of 26.9 kN. An equation is proposed to determine the ultimate load of the connector. Good agreement is achieved between the theoretical and experimental results. An average value of 0.98 is obtained for theoretical to experimental results.

Development of Intensity-Duration-Frequency (IDF) Models for Manually Operated Rain Gauge Catchment: A Case Study of Port Harcourt Metropolis Using 50years Rainfall Data

Francis J. Ogbozige

Engineering and Technology Journal, 2022, Volume 40, Issue 5, Pages 627-635
DOI: 10.30684/etj.2021.131839.1064

Hydraulic structures such as surface drainages and culverts are usually constructed in urban areas with the intention of draining runoff into nearby streams and rivers in order to avoid flooding. However, most of these structures frequently fail to serve the intended use due to the occurrence of high intensity rainfall accompanied with long duration, which produce runoff discharge higher than their designed capacities. This is common in many developing countries as drainages and culverts are most times constructed without considering hydrological analysis of the catchment. Hence, this research considered Port Harcourt city as a case study by utilizing 50years rainfall data to develop rainfall Intensity-Duration-Frequency (IDF) curves that will be used for subsequent design of drainages and culverts within the city and its environs. The IDF curves were developed using Gumbel, Pearson type III and Log-Pearson type III distributions at return periods of 2, 5, 10, 25 and 50years. However, the durations considered were 5, 10, 20, 30, 45, 60, 90, 120, 150, 180, 210, 240, 300, 360 and 420minutes. Results showed that the IDF equations developed for the three frequency distributions highly correlate with the observed intensities since there goodness of fit (R2) ranges from 0.9766 – 0.9865. Also, it was noted that there was no significant difference (p < 0.01) between the predicted rainfall intensities from all the IDF equations and the observed intensities. Notwithstanding, the IDF equation developed for Gumbel distribution was recommended to be given higher priority since it has the highest R2 value.

Effect of Partial Saturation on Ultimate Bearing Capacity of Skirted Foundations

Mahmood R. Mahmood; Saad F. A. Al-Wakel; Muthana S. Mohammed

Engineering and Technology Journal, 2022, Volume 40, Issue 5, Pages 710-721
DOI: 10.30684/etj.v40i5.2259

Skirted foundations are one of the solutions proposed to increase the bearing capacity of the soil. They assist in increasing the load and depth of failure in weak ground or soils with low shear resistance and reducing the foundation settlement if a soil improvement method cannot be applied or the cost of implementing deep foundations increases. This study examined and investigated the extent of soil bearing of skirted foundations on sandy soils and studied the effect of soil saturation cases and three cases of water content reduction to measure the matric suction value of unsaturated soil. A physical model was created to simulate the strip foundation and compare these cases (dry-fully saturated-partially saturated). It was found that the soil load carrying capacity in the case of unsaturated soil is the highest, where matric suction is at a depth of 450 mm, followed by the dry case and then the saturated case as it represents the weakest state of the soil.

Assessment of Future Climate Change Impacts on Water Resources of Khabour River Catchment, North Of Iraq

Lena Haitham; Mustafa Al-Mukhtar

Engineering and Technology Journal, 2022, Volume 40, Issue 5, Pages 695-709
DOI: 10.30684/etj.v40i5.1925

In arid and semi-arid areas, assessing the potential impact of climate change on water availability is of critical importance for achieving better management of future water resources. Iraq as one example of those areas is expected to experience more stress on water due to the climatological characteristics and to the rapid population growth in addition to the policy of the riparian upstream countries. Therefore, the present study aims to quantify the impacts of climate change on the Khabour River catchment north of Iraq, which is one of the riparian catchments between Iraq and Turkey. The HEC-HMS model was firstly calibrated and validated against daily streamflow data measured for the period 01Jan2004-30Jun2009 near the catchment outlet at Zakho station. Thereafter, the future climate changes data from the HadGEM2_ES model was fed into the calibrated HEC-HMS model to quantify the future water resources availability. The impacts of climate change on the water under four possible scenarios of RCPs (RCP2.6, RCP4.5, RCP6, and RCP8.5) of atmospheric greenhouse gas (GHG) concentrations for three future slice periods (2021-2030), (2041-2050), and (2061-2070); was assessed in attribution to that from the period (2000-2009). Results show that the implemented HEC-HMS model was superior in modeling the streamflow data. NSE, R² and RMSE value was 0.871, 0.89 and 26.7, respectively, for calibration and 0.936, 0.9364 and 18.0, respectively for validation. The results also suggest that annual river runoff will likely decrease under all scenarios of RCPs and time stages of the future period.

Evaluation of Predictive Equations for Local Pier Scour in Cohesive Soils

Zahraa F. Hassan; Ibtisam R. Karim; Abdul- Hassan K. Al-Shukur

Engineering and Technology Journal, 2019, Volume 37, Issue 12A, Pages 584-591
DOI: 10.30684/etj.37.12A.436

Wavelet analysis has become a powerful tool for denoising images. It represents a new way to achieve better noise reduction and increased contrast. Here,  experimentally demonstrate the abilities of the discrete wavelet transform with Daubechies basis functions for improving the quality of noisy images. In this research, two methods have been compared to modify the coefficients using a soft and hard threshold to improve the visual fineness of noisy images depending on the Root-Mean-Square error (RMS). The low RMS value and better noise reduction are found in the soft threshold methods based on Daubechies wavelet (db8) for the first image RMS=0.101 and the second example RMS=0.109.