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Numerical Analysis Considering the Dynamic Installation Effects of Stone Column on Soft Clay Response

Jordan Journal of civil engineering 2025年第3期19卷 486-502页

作者： Rashwan, Saleh I. Nasr, A.M. Azzam, W.R. Department of Structure Engineering Faculty of Engineering Tanta University Tanta Egypt Civil Engineering Department Faculty of Engineering Horus University-Egypt New Damietta34517 Egypt

This study investigates installing stone columns and their influence on the behaviour of soft clay, with a particular focus on both lateral and dynamic changes induced during the installation process, focusing on two distinct installation methods established on Cylindrical Cavity Expansion (CCE) in the Finite Element (FE): a traditional approach and a dynamic installation technique. Stone columns are commonly used to enhance soil properties, including increasing bearing capacity, reducing settlement, and improving overall soil stability. Through (FE) modeling, the research examines the changes in key factors, such as lateral stress and soil stiffness, which are key factors in soil reinforcement. In the traditional method, the lateral pressure coefficient K reached values up to 2.25 for the most significant expansion ratio, while the normalized stiffness improved by 2.3 times the initial value. These changes enhanced the bearing capacity within a localized zone of 1 to 3 times the column diameter (r/D), diminishing the effects beyond this range. However, the dynamic method showed even more significant improvements, with K exceeding 3.4 and stiffness reaching over 3.2 times the initial value for the same expansion ratio. This method resulted in a more controlled build-up of lateral stress, extending the bearing capacity improvements to 6 times the column diameter. The results indicate that while both techniques strengthen the bearing capacity and stabilize the surrounding soil, the dynamic installation technique offers a more pronounced and extended effect, making it a superior choice for capturing the dynamic impact. The study provides valuable insights into stone column installation methods for geotechnical projects requiring dynamic implications. © 2025, Jordan University of Science and Technology. All rights reserved.

关键词： Clay

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Structural behavior of non-prismatic reinforced concrete frames using hybrid concrete under repeated load

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Asian Journal of civil engineering 2024年第5期25卷 3865-3877页

作者： Al-Saffar, Dhurgham H. Dawood, Mustafa B Habeeb, Ghalib M Civil Engineering/Structure Department College of Engineering Babylon University Najaf Iraq Civil Engineering Department College of Engineering Babylon University Najaf Iraq

This study deals with the experimental investigation of the behavior of a non-prismatic reinforced concrete frame ade of Normal Strength Concrete (NSC) and hybridized with Glass fiber Reactive Powder Concrete (GRPC) under repeated loading. The requirements of construction projects are for concrete members with a small cross-section, and high durability at the lowest cost. Because of the high price of high-performance concrete (GRPC), it is used in specific regions with high stress concentrations. In this research, five specimens with NSC and hybridized with GRPC at different locations (shear and flexural) and proportions (25%, 50%, and 100%) are tested under repeated loading. The results showed that using GRPC in any region selected and at any percentage improves the behavior of the concrete frame in varying percentages where the ultimate load of the hybrid frame increases by (28–59%) compared to the non-hybrid frame. The best hybridization location that gives the best results and the lowest percentage of hybridization is in the lower half of the beam, where the ultimate load increases by 56%. It also makes the crack width constant throughout the loading cycles, and the crack width also remains constant with the loading cycles, and this does not exist in the non-hybrid frame as well as in the other hybrid specimens. Hybridization in the lower half of the beam also changes the mode of failure from shear failure to flexural failure. © The Author(s), under exclusive licence to Springer Nature Switzerland AG 2024.

关键词： Concrete frame GF-RPC Hybrid Repeated load

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Analytical Investigation into the Rotational Performance of Glulam Bolted Beam-Column Connections under Coupled Bending Moment and Shear Force

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Journal of Renewable Materials 2023年第4期11卷 2033-2054页

作者： Xiaofeng Zhang Lisheng Luo Youfu Sun Xinyue Cui Yongqiang Zhang Department of Wooden Structure Construction College of Materials Science and EngineeringNanjing Forestry UniversityNanjingChina Department of Civil Engineering College of Civil Engineering and ArchitectureHainan UniversityHaikouChina

Considering the glulam beam-column connection form and the number of bolts,monotonic loading test and finite element analysis was carried out on 9 connection specimens in 3 groups to study the rotational performance and failure mode of the *** test results revealed that compared with U-shaped connectors,T-shaped connectors can effectively improve the ductility of connections,and the increase in the number of bolts can reduce the initial stiffness and ductility of *** theoretical analysis,formulas for calculating the initial stiffness and ultimate moment of connections were ***,the moment-rotation theoretical model of connections was established based on the formulas,which were validated according to the test data and simulation *** proposed model can not only improve the current theoretical system of heavy-duty glulam beam-column structure but also provide a theoretical basis for calculating the mechanical properties of the glulam beam-column connection.

关键词： Beam-column connection mechanical properties stiffness ultimate moment

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Stiffness and Shear Stress Distribution of Glulam Beams in Elastic-Plastic Stage:Theory,Experiments and Numerical Modelling

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Journal of Renewable Materials 2023年第2期11卷 791-809页

作者： Lisheng Luo Xinran Xie Yongqiang Zhang Xiaofeng Zhang Xinyue Cui Department of Civil Engineering College of Civil Engineering and ArchitectureHainan UniversityHaikouChina Department of Wooden Structure Construction College of Materials Science and EngineeringNanjing Forestry UniversityNanjingChina

Traditional methods focus on the ultimate bending moment of glulam beams and the fracture failure of materials with defects,which usually depends on empirical *** is no systematic theoretical method to predict the stiffness and shear distribution of glulam beams in elastic-plastic stage,and consequently,the failure of such glulam beams cannot be predicted *** address these issues,an analytical method considering material nonlinearity was proposed for glulam beams,and the calculating equations of deflection and shear stress distribution for different failure modes were *** proposed method was verified by experiments and numerical models under the corresponding *** showed that the theoretical calculations were in good agreement with experimental and numerical results,indicating that the equations proposed in this paper were reliable and accurate for such glulam beams with wood material in the elastic-plastic stage ignoring the influence of mechanic properties in radial and tangential directions of ***,the experimental results reported by the previous studies indicated that the method was applicable and could be used as a theoretical reference for predicting the failure of glulam beams.

关键词： Glulam beams load-deflection relationship shear stress distribution elastic-plastic stage numerical model

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Experimental study of the structural behavior of non-prismatic reinforced concrete frame using different types of concrete under static and repeated load

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Asian Journal of civil engineering 2023年第8期24卷 3387-3398页

作者： Al-Saffar, Dhurgham H. Dawood, Mustafa B. Habeeb, Ghalib M. Civil Engineering/Structure Department College of Engineering Babylon University Hillah Iraq Civil Engineering Department College of Engineering Babylon University Hillah Iraq

This paper experimentally investigates the behavior of a non-prismatic concrete frame using different types of concrete under static and repeated loads. The parametric study includes changing the type of concrete (conventional concrete, steel fiber reactive powder concrete (SF-RPC) and glass fiber reactive powder concrete (GF-RPC)) and loading type (static and repeated). The results were presented and discussed the effect of SF-RPC and GF-RPC on frame behavior, and compared with the conventional concrete frame through the first crack load, ultimate load and failure mode, load–deflection curve, and the frame-deflected shape. There were evidences of improvement in the frame properties, such as a change in the failure mode, an increase in the ultimate load, as well as an increase in the stiffness of the frame in all the types of loading. The ultimate static load increased by 45.9 and 40.5% for SF-RPC and GF-RPC frames, respectively. Using RPC improves fatigue resistance, as the ultimate load decreases by only 2% under the influence of repeated load. In comparison, the conventional concrete frame decreases by 27%. The use of RPC in the specimens improves the shear strength and stiffness of the frame. The RPC is environmentally friendly through the use of recycled materials in mixtures (silica fume, steel fiber, and glass fiber), and also the structural sections are small;thus, the gasses emitted (CO₂) are few. As well as, it eliminates the need to consume new materials and impede construction for the public, because of the extension of the structural life. © 2023, The Author(s), under exclusive licence to Springer Nature Switzerland AG.

关键词： Concrete frame GF-RPC Repeated load SF-RPC

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Evaluation of the compressive strength of autoclaved aerated concrete in existing masonry

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ce/papers 2023年第2期6卷 142-149页

作者： Drobiec, Lukasz Jasiński, Radoslaw Mazur, Wojciech Department of Building Structure Silesian University of Technology Gliwice Poland Department of Building Structure and Laboratory of Civil Engineering Faculty Silesian University of Technology Gliwice Poland

Sclerometric method, commonly used in reinforced concrete structures, have also found application in masonry structures, mainly in the diagnosis of brick masonry walls or testing mortar in joints. This article presents a proposal for determining the compressive strength of autoclaved aerated concrete masonry elements with the use of the Schmidt OS-120 PT pendulum hammer. The test was carried out on masonry elements with a nominal density class of 400 and 600. Additional tests were also carried out on samples with different levels of humidity, in order to consider the influence of humidity on the change in rebound number and changes in compressive strength. © 2023 Ernst & Sohn GmbH.

关键词： Pendulums

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Relationships for Evaluating the Seismic Resilience Index of Reinforced Concrete Buildings Built Up with FRP Lying on Different Soil Types under Near-Field Earthquakes

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Iranian Journal of Science and Technology - Transactions of civil engineering 2024年第6期48卷 4215-4231页

作者： Pour, Hooman Barjouie Roshan Saffari, Hamid Department of Civil Engineering Faculty of Engineering Bushehr Branch Islamic Azad University Bushehr Iran Department of Structure and Earthquake Faculty of Civil Water and Environmental Engineering Shahid Beheshti University Tehran Iran

In recent decades, many researchers have focused their attention on seismic evaluation and vulnerability of structures before and after the earthquakes. As recognizing the structure condition after an earthquake is of vital importance, the capability of enduring future earthquakes and continuous serviceability through estimating structural damage is defined using the damage index. In the present research, the seismic resilience assessment before and after strengthening with FRP has been accomplished for low-rise, mid-rise and high-rise buildings with Reinforced Concrete (RC) moment resisting frames in the near-field sites. In this respect, use has been made of nonlinear incremental dynamic analysis with 104 seismic accelerometer records corresponding to 4 different soil types within the near-field sites. Also the results of vulnerability and seismic resilience curves after strengthening with Fiber Reinforced Polymer (FRP) are presented for the 3, 6 and 9-story buildings. The results obtained in the present research well depict that retrofit of RC moment resisting frames with FRP could increase their resilience. The results of the research clearly show that in the moment resisting frames at lower accelerations (about 0.2 g), the vulnerability of mid-rise and high-rise buildings is much higher than that of the low-rise buildings. But there is no significant difference between the mid-rise and high-rise buildings. By increase of the site acceleration, the vulnerability of mid-rise and high-rise buildings would significantly increase with respect to the low-rise buildings, but its severity would decrease with respect to lower accelerations. In other words, by increase of the earthquake acceleration, the percentage of vulnerability in the 6-story and higher buildings would approach that of the 3-story buildings. The retrofitted structure with FRP has a higher resilience at all the levels with respect to the existing structure. But the advantage of strengthening varies in

关键词： Incremental dynamic analysis Near-field earthquakes Reinforced concrete building Seismic resilience Seismic vulnerability

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Optimization of growth medium for microbially induced calcium carbonate precipitation(MICP) treatment of desert sand

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Journal of Arid Land 2023年第7期15卷 797-811页

作者： Monika DAGLIYA Neelima SATYAM Ankit GARG Department of Civil Engineering Indian Institute of TechnologyIndore 453552India Guangdong Engineering Center for Structure Safety and Health Monitoring Shantou UniversityShantou 515063China

Wind-induced sand erosion is a natural process, and can have several negative impacts on human health, environment, and economy. To mitigate the wind-induced sand erosion, an environmental friendly technique that helps to bind soil particles is desirable. The microbially induced calcium carbonate precipitation(MICP) treatment has lately become renowned and a viable alternative to enhance the binding of sand particles(especially against wind erosion). The efficiency of Sporosarcina pasteurii bacteria in inducing calcite formation can be influenced by various factors, including the type of growth media used for bacterial culture. Most of the studies have mainly validated the efficiency of S. pasteurii bacteria usually under single growth media for the MICP treatment. However, the efficiency of S. pasteurii under different growth media on calcite formation is rarely explored. The current study explores the effect of *** bacteria on calcite formation under the presence of three different growth media, namely,molasses(MS), tryptic soy broth(TB), and nutrient broth(NB). The three growth media have been applied in the laboratory with and without bacterial solution(control samples). Altered cementation media concentrations(0.5 and 1.0 M) with different pore volumes(PVs), namely, 0.25, 0.50, and 1.00 PV were used in sand-filled tubes for 7 and 14 treatment cycles(1 cycle=24 h). The pH and EC were measured for 12-h period in every 2 h interval, to monitor values at the time of treatment at room temperature. The calcite precipitation was confirmed using SEM(scanning electron microscope), PXRD(powder X-ray diffraction), and calcimeter tests. It was observed that MS generates lower calcite precipitation as compared with NB and TB. However, MS has the advantage of being more economical and abundant(waste product from sugar mills and refineries) as compared with other growth media(NB and TB). It was observed that the minimum and the maximum calcite precipitation using MS i

关键词： growth media molasses tryptic soy broth nutrient broth S.pasteurii calcium carbonate

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A CombustionModel for Explosive Charge Affected by a Bottom Gap in the Launch Environment

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Computer Modeling in engineering & Sciences 2024年第2期138卷 1207-1236页

作者： ShiboWu Weidong Chen Jingxin Ma Lan Liu Shengzhuo Lu Honglin Meng Xiquan Song College of Aerospace and Civil Engineering Harbin Engineering UniversityHarbin150001China General Department of Experimental Technology Beijing Institute of Structure and Environment EngineeringBeijing100076China Department of Economics Kunlun Energy Holding Company LimitedBeijing100101China

Launch safety of explosive charges has become an urgent problem to be solved by all countries in the world aslaunch situation of ammunition becomes ***, the existing numericalmodels have differentdefects. This paper formulates an efficient computational model of the combustion of an explosive charge affectedby a bottom gap in the launch environment in the context of the material point method. The current temperatureis computed accurately from the heat balance equation, and different physical states of the explosive charges areconsidered through various equations of state. Microcracks in the explosive charges are described with respectto the viscoelastic statistical crackmechanics (Visco–SCRAM) model. Themethod for calculating the temperatureat the bottomof the explosive charge with respect to the bottomgap is described. Based on this combustionmodel,the temperature history of a Composition B (COMB) explosive charge in the presence of a bottom gap is obtainedduring the launch process of a 155-mm artillery. The simulation results show that the bottom gap thickness shouldbe no greater than 0.039 cm to ensure the safety of the COM B explosive charge in the launch environment. Thisconclusion is consistent with previous results and verifies the correctness of the proposed model. Ultimately, thispaper derives amathematical expression for themaximumtemperature of the COMB explosive chargewith respectto the bottomgap thickness (over the range of 0.00–0.039 cm), and establishes a quantitative evaluationmethod forthe launch safety of explosive *** research results provide some guidance for the assessment and detectionof explosive charge safety in complex launch environments.

关键词： Combustion model explosive charge safety launch environment bottom gap temperature

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Effects of high-pressure activated slightly acidic electrolyzed water on cleaning and sterilization of pig transfer vehicles

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International Journal of Agricultural and Biological engineering 2024年第4期17卷 53-59页

作者： Xuedong Zhao Shengnan Tao Fei Qi Hao Li Zhengxiang Shi Department of Agricultural Structure and Bioenvironmental Engineering College of Water Resources&Civil EngineeringChina Agricultural UniversityBeijing 100083China Key Laboratory of Agricultural Engineering in Structure and Environment Ministry of Agriculture and Rural AffairsBeijing 100083China Beijing Engineering Research Center on Animal Healthy Environment Beijing 100083China

The establishment of biosafety system is of enormous importance to the livestock and poultry production in terms of mitigating the transmission of diseases and implementing regional prevention and control ***,the current sterilization technology presents several drawbacks,including time-consuming procedures,chemical residues,and challenges in treating the sewage after *** this study,a novel cleaning and sterilization method that combines slightly acidic electrolyzed water and high pressure water-jet was *** orthogonal test was conducted to examine the correlation between high-pressure conditions and the various non-structural parameters on the efficacy of sterilization *** a field test,the effectiveness of the technology in cleaning pig transfer vehicles was evaluated by the total plate count and variations of community *** findings revealed that the combination of process parameters,including an available chlorine concentration of 200 mg/L,rinsing pressure of 170 bar,rinsing duration of 10 s,and residence time of 15 min,resulted in a removal rate of colony concentration on the surface of pig transfer vehicles of(96.50±0.91)%.Moreover,it was demonstrated to effectively inhibit a variety of pathogenic *** innovative cleaning system has the potential to replace traditional methods and reduces pollution while saving time and *** introduces a novel approach for sterilization of transportation in livestock and poultry farms as well as the biosafety construction of the animal husbandry.

关键词： slightly acidic electrolyzed water high pressure water-jet sterilization biosafety concentrated animal production

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