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Influence of water quality and slag on the development of mechanical properties of self compacting mortar

Materials Today: Proceedings 2022年 57卷 892-897页

作者： Aldabagh, Inas S. Abed, Jasim Mohammed Khaleel, Ban Ahmed Hamah Sor, Nadhim Department of Building and Construction Technology Engineering Engineering Technical College Northern Technical University Mosul41002 Iraq Civil Engineering Department University of Garmian Kurdistan Region Kalar Iraq Department of Civil Engineering Harran University Sanlıurfa Turkey

The present research deals with the impact of the quality of water sources as an alternative to tap water on the hardened and fresh characteristics of self-compacting mortar. Laboratory chemical tests were carried out for water samples collected from four sources- non-potable well water, Tigris river water, untreated wastewater from local factories, and tap water. Water from the four sources was used to pour self-compacted mortar specimens in presence of ground granulated blast furnace slag (GGBFS) as pozzolanic materials up to 30% with 10% increment which replaced with cement by weight. Slump flow diameter, V-shape flow time, compressive strength, flexural strength, and water absorption ratio tests were performed for self-compacted mortar specimens. The experimental results showed a slight improvement in slump flow of self-composted mortar mixtures using non-potable well water in the presence of 10% GGBFS. There is a significant improvement in slump flow for mixtures that used Tigris River water as an alternative to tap water. The compressive strength of self-compacted mortar at 7 and 28 days using Tigris river water, in the presence of10%, 20%, and 30% GGBFS were developed better than non-potable well water and untreated wastewater. © 2022

关键词： Water absorption

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Effect of Submerged Vegetation Density on Flow Hydrodynamics, Bulk Drag Coefficient, and Bed Friction

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Iranian Journal of Science and technology - Transactions of civil engineering 2025年 1-9页

作者： Derakhshan, Sadegh Afzalimehr, Hossein Nazari-Sharabian, Mohammad Karakouzian, Moses Faculty of Civil Engineering Iran University of Science and Technology Tehran 16846-13114 Iran Department of Mathematics Engineering and Computer Science West Virginia State University Institute 25112 WV United States Department of Civil and Environmental Engineering and Construction University of Nevada Las Vegas Las Vegas 89154 NV United States

In a laboratory flume, experiments were conducted to explore bulk flow characteristics in channels with submerged aquatic vegetation patches of finite length and width with varying densities. The experiments aimed to assess the significance of precise drag coefficients and understand the impact of vegetation on bed friction. Wooden rods were used as surrogates for vegetation. Different vegetation densities were featured in six experimental setups. The Boundary Layer Characteristics Method (BLCM) was employed to predict bed shear stress, and a force balance approach was used for calculating bulk drag coefficients. It was found that an increase in vegetation density leads to a rise in the bulk drag coefficient. The presence of vegetation was observed to significantly alter the flow field, causing a redirection of flow from vegetated to unvegetated areas. Contrary to the common assumption in many studies that the bulk drag coefficient equals one, the findings from these experiments suggested this assumption might not be accurate. Additionally, the impact of vegetation on bed friction, often overlooked, was investigated. Two classic bed friction models, which do not account for flow field heterogeneities due to vegetation, and the BLCM, which considers these heterogeneities, were used to estimate bed friction. These estimates were then used in a flow resistance model to predict total friction, including both bed and vegetation friction. The effectiveness of the BLCM over the classic models suggests inaccuracies in the assumption that vegetation does not impact bed friction. © The Author(s), under exclusive licence to Shiraz University 2024.

关键词： Bed friction Boundary layer characteristics method Drag coefficient Force balance Submerged aquatic vegetation

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Innovative approaches in high-speed railway bridge model simplification for enhanced computational efficiency

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Journal of Central South University 2024年第11期31卷 4203-4217页

作者： ZHOU Wang-bao XIONG Li-jun JIANG Li-zhong ZHONG Bu-fan School of Civil Engineering Central South UniversityChangsha 410075China National Engineering Research Center of High-speed Railway Construction Technology Changsha 410075China

In the realm of high-speed railway bridge engineering,managing the intricacies of the track-bridge system model(TBSM)during seismic events remains a formidable *** study pioneers an innovative approach by presenting a simplified bridge model(SBM)optimized for both computational efficiency and precise representation,a seminal contribution to the engineering design *** to this innovation is a novel model-updating methodology that synergistically melds artificial neural networks with an augmented particle swarm *** neural networks adeptly map update parameters to seismic responses,while enhancements to the particle swarm algorithm’s inertial and learning weights lead to superior SBM parameter *** via a 4-span high-speed railway bridge revealed that the optimized SBM and TBSM exhibit a highly consistent structural natural period and seismic response,with errors controlled within 7%.Additionally,the computational efficiency improved by over 100%.Leveraging the peak displacement and shear force residuals from the seismic TBSM and SBM as optimization objectives,SBM parameters are adeptly ***,the incorporation of elastoplastic springs at the beam ends of the simplified model effectively captures the additional mass,stiffness,and constraint effects exerted by the track system on the bridge structure.

关键词： high-speed railway bridge engineering track-bridge system model simplified bridge model artificial neural networks particle swarm optimization seismic analysis

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Fire Evacuation and Management Model Based on Building Information Modeling and Virtual Reality 39

Fire Evacuation and Management Model Based on Building Infor...

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39th International Symposium on Automation and Robotics in construction, ISARC 2022

作者： Gao, R.-J. Wang, K.-C. Lai, X.-H. Hung, W.-H. Department of Civil and Construction Engineering Chaoyang University of Technology Taiwan

ISBN: (纸本)9789526952420

Fire management is a key aspect of building management. During a fire, the primary reason why evacuees cannot evacuate in time and causalities occur is their lack of familiarity with the evacuation route. In practice, two dimensional images or videos are used as aids for firefighting educational training. However, they can only display a partial view of an evacuation route (not a 360° panorama) and thus have limited effectiveness in helping evacuees to understand the evacuation route. We proposed a fire evacuation management model that combines building information modeling (BIM) and virtual reality (VR) to support fire evacuation. The model is divided into two modules, namely (1) the evacuation route, and (2) educational training modules. The evacuation route module is used to analyze the shortest evacuation route from a room (where evacuees are located) to an exit and to estimate the shortest evacuation time. To verify whether the simulated route generated by the VR fire management system is applicable to evacuations, we further calculated the allowable evacuation time with the empirical equation provided in the Building Fire Refuge Safety Verification Technique Manual. The VR-based educational training module helps evacuees to evacuate from a building by providing a firstperson perspective simulation. The immersive characteristic of a VR environment allows people to view an evacuation route from a 360° perspective, which deepened their impression of an environment. In this study, the proposed model was introduced and tested in a case study, which verified its ability to assist management units with fire management assessments and support fire evacuation training for users of buildings. © 2022 International Association on Automation and Robotics in construction.

关键词： Virtual reality

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Influence of asymmetric blockage of the drainage system of a deep-buried tunnel on water gushing

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Journal of Mountain Science 2022年第7期19卷 2075-2085页

作者： FU He-lin AN Peng-tao WU Yi-min LI Jie CHEN Long School of Civil Engineering Central South UniversityChangsha410075China National Engineering Laboratory for Construction Technology of High Speed Railway Central South UniversityChangsha410075China

Asymmetric blockage of drainage systems occasionally occurs,which seriously threatens the safety of tunnel *** on theoretical analysis,a calculation expression of tunnel water inflow involving clogging parameters was *** of the analytical solution was analysed with the Taylor equation and series expansion theorem,and a tunnel under construction was considered to conduct field tests to verify the rationality of the established model and correctness of the derived *** have demonstrated that with increasing drainage system blockage degree,the amount of water inflow in the nonblocked area slowly increases,and the total amount of water in the tunnel gradually *** hydrodynamic pressure in the blocked area non-linearly decreased,and the water inrush velocity and hydraulic gradient in the non-blocked area gradually *** the drainage system was not blocked,the result of tunnel water inflow calculated by the formula derived in this paper was 8.3% higher than the measured *** the drainage system was blocked,the theoretical water inflow was 10.5% higher than the measured *** difference between the measured value and the theoretical value is small,which verifies the effectiveness of the calculation formula of water inflow deduced in this paper.

关键词： Drainage system Asymmetric blockage Water inflow Field test

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A Coupled Flow Deformation Model for Expansive Soil with Temperature Change 5th

A Coupled Flow Deformation Model for Expansive Soil with Tem...

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5th International Conference on Transportation Geotechnics, ICTG 2024

作者： Yu, Miao Gui, Yilin Dawes, Les Korzani, Maziar Gholami Li, Bonan School of Civil and Environmental Engineering Queensland University of Technology Gardens Point BrisbaneQLD4000 Australia Sustainable Engineered Construction Materials Faculty of Engineering Queensland University of Technology Gardens Point BrisbaneQLD4000 Australia

ISBN: (纸本)9789819782321

Expansive soils exhibit significant volume change when experiencing variation of temperature or moisture change. However, previous constitutive models on expansive soil mainly focus on hydraulic conditions, less attention on thermal field. This study delves into the thermo-hydro-mechanical behavior of expansive soils, crucial for applications such as nuclear waste disposal and thermal energy storage. A novel constitutive model, extended from bounding surface plasticity theory, is introduced to simulate the expansive soil behavior under various temperatures. A new approach on effective stress principle considering the effect of temperature is proposed. In this model, changes on suction and temperature are considered, which are in response to mechanical behaviors. Validated by temperature-controlled tests from (Tang et al. in Géotechnique 58:45–54 [1]), the proposed model shows potential in understanding the complex coupling of thermal, hydraulic, and mechanical processes in expansive soils, especially in cyclic environmental conditions. © The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd. 2025.

关键词： Radioactive waste disposal

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Micro-mechanism of Fracture Failure of Fissured Rock Mass under Uniaxial Compression Based on PFC2D

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IAENG International Journal of Applied Mathematics 2025年第5期55卷 1265-1274页

作者： Yang, Zhichen Zeng, Jiajun Wang, Qiyun Shen, Qingqing Zeng, Qiang College of civil and construction engineering Hunan Institute of Technology Hengyang421002 China

The morphology of primary fractures significantly influences the strength and failure characteristics of rock masses. To elucidate the meso-scale fracture mechanisms in fissured rock masses during uniaxial compression failure, specimens with varying dip angles were prefabricated for uniaxial compression testing. This study investigates the mechanical characteristics and crack evolution models of rock mass specimens influenced by different fracture dip angles. In addition, by combining particle flow numerical simulation, the distribution of particle displacement field in the fissured rock mass during loading was explored, revealing the evolution of force chains around the pre-existing fissures. © (2025), (International Association of Engineers). All rights reserved.

关键词： Compression testing

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Stability analysis of karst anti dip rock slope induced by underground coal mining——A case study of Jiguanling landslide, China

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Journal of Mountain Science 2025年第4期22卷 1226-1244页

作者： ZHONG Zuliang LIANG Erwei WANG Nanyun XU Yawei School of Civil Engineering Chongqing UniversityChongqing 400045China State key laboratory of coal mine disaster dynamics and control Chongqing 400044China Key Laboratory of New Technology for Construction of Cities in Mountain Area of Ministry of Education Chongqing 400045China

In recent years,the southwestern region of China has experienced a surge in significant mountain collapses,predominantly linked to underground mining *** investigation targets the Jiguanling area in Wulong,Chongqing,employing the UDEC numerical simulation technique to meticulously examine the deformation and failure characteristics,rock mass movement patterns,fracture evolution processes,and stress transmission mechanisms of anti-dip rock slopes composed of stratified *** slopes are inherently susceptible to bending and tilting due to their own *** findings elucidate that the predominant failure mode of anti-dip rock karst slopes is the inclined sliding(shear)type,which mirrors the fracture evolution mechanism as they extend in a quadrilateral pattern from the top and bottom plates of the mining area to the critical blocks at the rear and front edges of the *** disaster mechanism can be encapsulated as the"initial roof movement phase,direct roof collapse and crack propagation phase,critical block locking and sliding resistance phase,and deterioration phase".The four distinct stages of development and transformation encompass critical block slip(shear)and slope instability *** increase in coal seam thickness enlarges the deformation space in the lower part,while the dip angle of the coal seam influences the length and displacement range of rock fracture *** mining sequence alters the stress failure mode of the underlying critical blocks,and the vertical height of the mining step distance modifies the potential sliding surface and failure mode of the underlying critical ***,the distance between the goaf and the surface,along with the height of the mining impact,impacts the stability of the reverse *** results demonstrate that mining activities are the primary factor inducing the collapse of anti-dip rock slopes,with natural factors playing a secondary role.

关键词： Anti-dip rock slope Mining action Slope deformation mechanism Slope instability mechanism Evolution law of cracks

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Comparative Study on the Personnel Performance Appraisal Systems Between construction and Information technology Industries 7th

Comparative Study on the Personnel Performance Appraisal Sys...

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7th International Conference on construction, Real Estate, Infrastructure, and Project Management, ICCRIP 2023

作者： Kowshik, Chaithra N. Mahesh, Gangadhar Ingle, Prachi Vinod Patil, Suhas Vijay Patil, Rajkumar Bhimgonda Civil Engineering Department National Institute of Technology Karnataka Surathkal575025 India School of Construction Nicmar University Pune Pune India Department of Civil Engineering D. Y. Patil College of Engineering Akurdi Pune India Department of Mechanical Engineering Dwarkadas J. Sanghvi College of Engineering Mumbai400056 India

ISBN: (纸本)9789819649013

Personnel Performance Appraisal (PPA) involves systematically evaluating the employee’s performance in the workplace. The purpose of PPA is to identify an individual’s strengths and weaknesses, which impact the overall performance of the organization. The construction sector is commonly perceived as an unorganized industry. This paper compares the PPA systems of a construction Organization (CO) and information technology (service-based) organization and explores potential solutions for continuous improvement. The study utilizes case studies and incorporates semi-structured interviews with Information technology (IT) professionals and construction professionals. Documented reviews and semi-structured interviews are meticulously documented, recorded, and transcribed. The gathered data are recapitulated and depicted based on recurring topics. Given that both construction and IT organizations operate within a project-based culture, the disparities, and similarities between their respective PPA practices are identified. It becomes apparent that employees in the IT organization possess a clear understanding of the PPA process and its relevance, whereas this cognizance appears to be deficient within the CO. Notwithstanding the implementation of PPA in the CO, this comparative analysis indicates that there is potential for enhancement. © The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd. 2025.

关键词： construction industry

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An enhanced numerical model for considering coupled strainsoftening and seepage effects on rock masses surrounding a submarine tunnel

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Journal of Rock Mechanics and Geotechnical engineering 2025年第3期17卷 1445-1458页

作者： Lan Cui Wenyu Yang Qian Sheng Junjie Zheng Wengang Zhang Kai Guan Fei Song State Key Laboratory of Geomechanics and Geotechnical Engineering Institute of Rock and Soil MechanicsChinese Academy of SciencesWuhan430071China University of Chinese Academy of Sciences Beijing100049China School of Civil Engineering Chongqing UniversityChongqing400045China School of Civil Engineering Wuhan UniversityWuhan430072China Key Laboratory of New Technology for Construction of Cities in Mountain Area Chongqing UniversityMinistry of EducationChongqing400045China National Joint Engineering Research Center of Geohazards Prevention in the Reservoir Areas Chongqing UniversityChongqing400045China Center for Rock Instability and Seismicity Research School of Resource and Civil EngineeringNortheastern UniversityShenyang110819China School of Aerospace Engineering and Applied Mechanics Tongji UniversityShanghai200092China

The seepage of groundwater and the strain-softening of rock mass in a submarine tunnel expand the plastic region of rock,thereby affecting its overall *** is therefore essential to study the stress and strain fields in the rocks surrounding the submarine tunnel by considering the coupled effect of strainsoftening and ***,the evolution equation for the hydro-mechanical parameters in the existing fully coupled solution is a uniform equation that is unable to reproduce the characteristics of rock mass in *** this study,an updated numerical procedure for the submarine tunnel is derived by coupling strain-softening and seepage effect based on the experimental *** to the hydro-mechanical coupling theory,the hydro-mechanical parameters such as elastic modulus,Poisson's ratio,Biot's coefficient and permeability coefficient of rocks are characterized by the fitting equations derived from the experimental ***,the updated numerical procedure is deduced with the governing equations,boundary conditions,seepage equations and fitting *** updated numerical procedure is verified accurately compared with the previous analytical *** utilizing the updated numerical procedure,the characteristics of stress field and the influences of initial pore water pressure,Biot's coefficient,and permeability coefficient on the stress,displacement and water-inflow of the surrounding rocks are *** of the variations in hydro-mechanical parameters,the stress distribution has a similar *** initial permeability coefficient exerts the most significant influence on the stress *** the increases in initial pore water pressure and Biot's coefficient,the plastic region expands,and the water-inflow and displacement increase *** the fact that the stability of the tunnel is more sensitive to the seepage force controlled by the hydraulic parameters,it is suggested to dewater the ground above the submarine

关键词： Seepage force Strain-softening Submarine tunnel Numerical procedure Coupling effect

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