_1721806815 20240724111015000 CMV Verlag khoffman@cmv-verlag.com Dr. Morteza Jamshidi Journal of Civil Engineering Researchers jcer 2538-516X 2538-516X 06 01 2024 6 2 Reza Molavi https://orcid.org/0000-0002-3172-1252 Due to the damage that occurred in the unreinforced welded flange (WUF) connections during the 1994 Northridge earthquake, the use of reduced beam section (RBS) connections and subsequently the reduced web section (RWS) connections became common to prevent premature brittle failure in the welded connections. The RWS connections are created to provide a controlled weak point for the formation of a plastic hinge, which can prevent stress concentrations in the groove welds of the connection. This method, where the transfer of the plastic hinge is achieved by weakening the beam web and without the need to remove the concrete slab, is proposed as a suitable solution for the rehabilitation of connections. In this paper, the effect of different beam web weakening patterns on the seismic performance of the connection is investigated analytically and numerically. Seven beam web weakening designs were studied and compared with the uniform web slotting pattern, and the seismic behavior of the mentioned connections was simulated using the Abaqus software, and the effect of using each of them on the distribution of equivalent plastic strains and the moment-rotation curve was examined. The results showed that the appropriate beam web weakening pattern plays an effective role in reducing the plastic strain in the penetration weld of the direct beam-to-column connection and preventing their premature tearing and failure, so that one of the perforation designs studied can reduce the maximum equivalent plastic strain in the upper penetration weld of the direct beam-to-column connection by an average of 48% compared to the uniform web slotting pattern as the reference connection. 06 27 2024 60 67 https://creativecommons.org/licenses/by/4.0 10.61186/JCER.6.2.60 https://www.journals-researchers.com/ojs/index.php/jcer/article/view/135 https://www.journals-researchers.com/ojs/index.php/jcer/article/download/135/120 https://www.journals-researchers.com/ojs/index.php/jcer/article/download/135/120 Journal of Civil Engineering Researchers jcer 2538-516X 2538-516X 06 01 2024 6 2 Sarwah Othman https://orcid.org/0009-0000-0557-3770 Shuokr Qarani Aziz https://orcid.org/0000-0002-6689-8146 Up to now, there is no central wastewater treatment plant (WWTP) in Erbil City, Kurdistan Region Iraq. Erbil Municipal waste water (EMWW) discharges directly to the environment, or sometimes it used for irrigation, without treatment. This research focused on the EMWW characteristics, treatment using solar energy technique and reusing. Data were collected from published works since 1994 and visiting the site. Some EMWW quality parameters such as total suspended solids (TSS), chemical oxygen demand (COD), and five day biochemical oxygen demand (BOD5) topped the effluent standards. Accordingly, treatment process like solar energy is essential. Quantity of solar energy in Erbil City is A Unit. Application of solar energy for EMWW treatment led to removal of (80-98) % of BOD, (75-95) % COD, and (85-98) % of TSS. Treaded WW is safe for irrigation. Solar energy can be used for EMWW treatment and it regards as efficient and economic technique. 06 27 2024 49 59 https://creativecommons.org/licenses/by/4.0 10.61186/JCER.6.2.49 https://www.journals-researchers.com/ojs/index.php/jcer/article/view/132 https://www.journals-researchers.com/ojs/index.php/jcer/article/download/132/123 https://www.journals-researchers.com/ojs/index.php/jcer/article/download/132/123 Journal of Civil Engineering Researchers jcer 2538-516X 2538-516X 06 01 2024 6 2 Saeed Fallahian https://orcid.org/0009-0006-7046-0215 Seyed Mohammad Seyedpoor https://orcid.org/0000-0003-1242-6191 Eshagh Norouzi https://orcid.org/0009-0005-1337-6132 Sara Ghasemi https://orcid.org/0009-0004-5807-2151 A multi-stage gravitational search algorithm (MSGSA) is proposed here to solve the optimization-based damage detection of structural systems. Natural frequency changes of a structure are considered as a criterion for damage occurrence. Finite element method and structural dynamic principles are also employed to evaluate the required natural frequencies. The structural damage detection problem is first transformed into a standard optimization problem dealing with continuous variables, and then the MSGSA is utilized to solve the optimization problem for finding the site and severity of damage. In order to assess the performance of the proposed method for damage identification, an example with experimental data and two numerical examples with considering measurement noise are considered. All the results demonstrate the effectiveness of the proposed method for accurately determining the site and extent of multiple structural damage. Also, the performance of the MSGSA for damage detection compared to the standard gravitational search algorithm (GSA) is confirmed by examples. 06 26 2024 33 48 https://creativecommons.org/licenses/by/4.0 10.61186/JCER.6.2.33 https://www.journals-researchers.com/ojs/index.php/jcer/article/view/133 https://www.journals-researchers.com/ojs/index.php/jcer/article/download/133/118 https://www.journals-researchers.com/ojs/index.php/jcer/article/download/133/118 Journal of Civil Engineering Researchers jcer 2538-516X 2538-516X 06 01 2024 6 2 Hossein Nematian jelodar https://orcid.org/0009-0002-7297-5109 Negar Moloukaneh https://orcid.org/0009-0006-2331-7344 Ayda Khazaei poul https://orcid.org/0009-0009-6067-3657 Buildings with masonry materials are one of the weakest buildings against earthquakes, and the importance of proper design and correct construction of these buildings is not hidden. Among The buildings with masonry materials, the buildings with Ring beams are the most common of such buildings. Engineers use internal and external regulations and standards to design ring beam masonry buildings. The two main references for the design and construction of masonry buildings with Ring beams are the Code of Practice for Seismic Resistant Design of Buildings (Standard 2800, Fourth Edition) and the Eighth Topic of the National Building Regulations (2020 Edition) under the title of design and construction of buildings with masonry materials. The Provisions for masonry buildings with Ring beams are given in the fifth chapter of the Eighth Topic of the National Building Regulations and the Seventh Chapter of the 2800 Standard. In this research, an attempt was been made to examine the Provisions of masonry buildings with Ring beams of these two references and to identify the discrepancies and differences in the provisions. The investigation of these two references has shown that there were more than 66 cases of differences in Provisions regarding masonry buildings with Ring beams between the Eighth Topic of the National Building Regulations and the Seismic Resistant Design of Buildings. Most of the differences in the criteria were related to the sections of vertical and horizontal Ring beams, structural walls, and Non-structural walls with 34 cases and 51.5% compared to the total difference. Also, the type of soil is classified in the Eighth Topic of The National Construction Regulations with 3 types of soil and the 2800 Standard of Conduct is classified with 4 types of soil. 06 24 2024 24 32 https://creativecommons.org/licenses/by/4.0 10.61186/JCER.6.2.24 https://www.journals-researchers.com/ojs/index.php/jcer/article/view/130 https://www.journals-researchers.com/ojs/index.php/jcer/article/download/130/116 https://www.journals-researchers.com/ojs/index.php/jcer/article/download/130/116 Journal of Civil Engineering Researchers jcer 2538-516X 2538-516X 06 01 2024 6 2 Hossein Alimohammadi https://orcid.org/0000-0001-7522-2239 Ashfaq Memon https://orcid.org/0009-0004-2152-4740 Sinkholes pose significant risks to infrastructure, requiring detailed investigation and effective repair strategies. This paper details a case study of a persistent sinkhole along a driveway in Nashville, Tennessee, which has caused repeated pavement subsidence despite multiple repairs. The investigation included site visits, drilling operations, soil and rock analysis, and groundwater assessment. Three mitigation approaches were evaluated including conventional inverted rock filter repair, constructing a land bridge, and compaction grouting. After considering technical, situational, and cost factors, compaction grouting was chosen as the optimal solution. The paper outlines the compaction grouting repair strategy, including methodology, materials, and construction specifications. The findings aim to enhance design standards and construction practices for sinkhole repairs in Tennessee and similar geotechnical regions. 06 09 2024 1 16 https://creativecommons.org/licenses/by/4.0 10.61186/JCER.6.2.1 https://www.journals-researchers.com/ojs/index.php/jcer/article/view/123 https://www.journals-researchers.com/ojs/index.php/jcer/article/download/123/115 https://www.journals-researchers.com/ojs/index.php/jcer/article/download/123/115 Journal of Civil Engineering Researchers jcer 2538-516X 2538-516X 06 01 2024 6 2 Niloufar Allahverdi https://orcid.org/0000-0003-3060-1109 Seyed Mohammd Mirhoseini https://orcid.org/0000-0001-7747-1132 Emadaldin Hezavehi https://orcid.org/0000-0001-7098-7232 Vahid Rahimi The occurrence of progressive structural damage during seismic events and nearby explosions presents a significant challenge. Progressive failure refers to the situation in which a localized failure in a structural element triggers the failure of neighboring elements, leading to further collapses within the building. There are limited instances of structures experiencing either partial or complete progressive failure. Notably, such occurrences were observed following the partial collapse of the renowned Ronan Point1 residential building in London in 1968 and the destruction of the World Trade Center buildings on September 11, 2001. The engineering community and various standardization committees have focused their attention on this significant issue and have initiated the implementation of enhanced design methods to mitigate progressive failure. 06 01 2024 17 23 https://creativecommons.org/licenses/by/4.0 10.61186/JCER.6.2.17 https://www.journals-researchers.com/ojs/index.php/jcer/article/view/120 https://www.journals-researchers.com/ojs/index.php/jcer/article/download/120/114 https://www.journals-researchers.com/ojs/index.php/jcer/article/download/120/114