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Journal of Wuhan University of Technology(Materials Science) 2024年第5期39卷 1229-1245页

作者： SHANG Minggang FENG Qiong ZHANG Yunsheng HE Zhongmao QIAO Hongxia XUE Cuizhen WANG Jinpen HAN Yuehui School of civil engineering Lanzhou University of TechnologyLanzhou 730050China Gansu Advanced civil engineering Materials engineering Research Center Lanzhou 730050China college of Science&Technology Ningbo UniversityNingbo 315211China

Municipal solid waste incineration tailings were used as lightweight aggregate(MSWIT-LA)in the preparation of specified density concrete to study the effects on compressive strength,axial compressive strength,flexural strength,microhardness,total number of pores,pore area,and pore *** results showed that the internal curing and morphological effects induced by an appropriate quantity of MSWIT-LA improved the compressive response of specified density concrete specimens,whereas an excessive quantity of MSWIT-LA significantly reduced their mechanical *** analysis of pore structure indicated that the addition of MSWIT-LA increased the total quantity of pores and promoted cement hydration,resulting in a denser microstructure than that of ordinary *** results of a principal component analysis showed that the mechanical response of specified density concrete prepared with 25%MSWIT-LA was superior to that of an equivalent ordinary *** was therefore concluded that MSWIT-LA can be feasibly applied to achieve excellent specified density concrete properties while utilising municipal solid waste incineration tailings to protect the environment and alleviate shortages of sand and gravel resources.

关键词： municipal solid waste incineration tailings X-ray computed tomography lightweight aggregate microhardness principal component analysis

Restraint effect of partition wall on the tunnel floor heave in layered rock mass

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Journal of Mountain Science 2024年第7期21卷 2462-2479页

作者： YANG Yunyun HUANG Da ZHONG Zhu LIU Yang PENG Jianbing School of civil and Transportation engineering Hebei University of TechnologyTianjin 300401China college of Geology engineering and Geomatics Chang’an UniversityXi’an 710054China college of civil engineering&Architecture China Three Gorges UniversityYichang 443002China.

The presence of horizontal layered rocks in tunnel engineering significantly impacts the stability and strength of the surrounding rock mass,leading to floor heave in the *** study focused on preparing layered specimens of rock-like material with varying thickness to investigate the failure behaviors of tunnel *** results indicate that thin-layered rock mass exhibits weak interlayer bonding,causing rock layers near the surface to buckle and break upwards when subjected to horizontal *** an increase in the layer thickness,a transition in failure mode occurs from upward buckling to shear failure along the plane,leading to a noticeable reduction in floor heave *** primary cause of significant deformation in floor heave is upward buckling *** address this issue,the study proposes the installation of a partition wall in the middle of the floor to mitigate heave deformation of the rock *** results demonstrate that the partition wall has a considerable stabilizing effect on the floor,reducing the zone of buckling failure and minimizing floor heave *** is crucial for the partition wall to be sufficiently high to prevent buckling failure and ensure *** simulation calculations on an engineering example,it is confirmed that implementing a partition wall can effectively reduce floor heave and enhance the stability of tunnel floor.

关键词： Layered rock Floor heave Horizontal compression test Failure behavior Partition wall

Design and evaluation of the traveling wave piezoelectric beam actuators

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Acta Mechanica Sinica 2024年第7期40卷 152-163页

作者： Yuanshuai Ding Zengyao Lv Hangyu Li Yuyang Lin Yongmao Pei Department of Mechanics and engineering Science College of EngineeringPeking UniversityBeijing100871China Department of civil and Environmental engineering Northwestern UniversityEvanstonIL60208USA

Traveling wave piezoelectric beam actuators(TWPBAs)present an advantageous structural configuration for self-moving actuators and hold significant promise for operation in confined ***,current research on TWPBAs faces several limitations,including deficient design methods of excitation and structural parameters,inadequate evaluation metrics,and lack of a quantitative relationship between these parameters and evaluation *** study presents a systematic approach to determining TWPBAs'structure and excitation parameters,proposes criteria for determining the excitation parameters through an established analytical model,and introduces an effective evaluation method for TWPBAs'*** the analytical model and evaluation metrics,we reveal:(1)the coupling relationship between excitation parameters and structural parameters,(2)the influence of participating mode pairs on vibration response,(3)the quantitative relationship between the evaluation metrics and excitation parameters is also *** conclusions are substantiated by the results of finite element analysis,laser vibration measurements,and motion test ***,the practical application of TWPBAs in pipeline operations underscores their potential for use in endoscopy and precision instruments.

关键词： Piezoelectric actuator Exciter-Exciter method Wave propagation Vibration control

Laser welding study of vacuum sintered HUST-1 lunar regolith simulant

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Science China(Technological Sciences) 2024年第9期67卷 2905-2918页

作者： HAN WenBin DING LieYun ZHOU Cheng ZHOU Yan DANG Fen National Center of Technology Innovation for Digital Construction Huazhong University of Science and TechnologyWuhan 430074China School of civil and hydraulic engineering Huazhong University of Science and TechnologyWuhan 730074China

Efforts are underway to establish a permanent lunar base on the Moon. In situ lunar regolith is anticipated to be useful as a building material after sintering. However, sintering lunar regolith into a large-scale structure presents challenges. Therefore, the key to lunar construction lies in assembling multiple small-sized sintered modules into a stable, large-sized structure. This study explored the feasibility of welding the sintered HUST-1 lunar regolith simulant(HLRS) using a laser device and conducted experiments using lasers of varying power. The microstructure, mineral composition, element distribution, and shear strength of the welded joint were investigated. A few low-melting minerals were fused and vaporized during welding, leading to the generation of thermal decomposition gas. Furthermore, the welded joint exhibited numerous micro-cracks, pores, and bubbles,resulting in reduced weld shear strength. Finally, the influence of laser power on weld shear strength was investigated, revealing that the highest shear strength(15.69 N/cm) was achieved at a laser power of 1000 W. This study demonstrates the feasibility of laser welding of sintered HLRS for the first time, with potential applications in lunar base construction.

关键词： lunar regolith vacuum sintering laser welding weld shear strength lunar base

Fractal Study on the Evolution of Micro-Pores in Concrete Under Freeze-Thaw

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Journal of Wuhan University of Technology(Materials Science) 2024年第1期39卷 109-117页

作者：孙浩然邹春霞 XU Deru GUO Xiaosong HUANG Kun college of Water Conservancy and civil engineering Inner Mongolia Agricultural UniversityHohhot 010018China Xi’an HaiTang Vocational college Xi’an 710038China

After exposure to freeze-thaw cycles, scanning electron microscopy(SEM) and nuclear magnetic resonance(NMR) were used to test the four mixtures. The microstructure is qualitatively analyzed from the 2D SEM image and the 3D pore distribution curve before and after freezing and thawing. The fractal dimension is utilized to characterize the two-dimensional topography image and the three-dimensional pore distribution, quantitatively. The results reveal that the surface porosity and volume porosity increase as the freeze-thaw action increases. Self-similarity characteristics exist in micro-damage inside the concrete. In the fractal dimension, it is possible to characterize pore evolution quantitatively. The fractal dimension correlates with pore damage evolution. The fractal dimension effectively quantitatively characterizes micro-damage features at various scales from the local to the global level.

关键词： fractal dimension freeze-thaw cycle concrete SEM NMR

Experimental Study on Vortex-Induced Vibration of Rough Risers with Coupling Interference Effect Under Side-by-Side Arrangement

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China Ocean engineering 2024年第1期38卷 18-28页

作者： HU Ze-bo LIU Zhen LI Peng GUO Hai-yan WANG Shu-bing REN Xiao-hui HOU Hao WANG Ye-shuo college of civil engineering and Architecture Shandong University of Science and TechnologyQingdao 266590China Qingdao Key Laboratory of Marine civil engineering Materials and Structures Qingdao 266590China college of engineering Ocean University of ChinaQingdao 266100China CHEC Dredging Co. LtdShanghai 200136China

A vortex-induced vibration(VIV)experiment of rough risers with coupling interference effect under a side-by-side arrangement was carried out in a wave-current combined *** roughness of the riser was characterized by arranging different specifications of surface attachments on the surface of the *** risers with three different roughnesses were arranged side by side with smooth risers to explore the VIV response of the riser under the combined action of roughness and interference effect,and to reveal the coupling mechanism between roughness and interference *** experimental results show that,compared with that of a smooth riser,the VIV of a rough riser under the coupling interference effect has a wider"lock-in"region,and the displacement decreases more significantly at a high reduced velocity,which is more likely to excite higher-order modes and frequency *** addition,the displacement response and frequency response of the smooth riser are not significantly affected by wake interference from the rough riser,which is caused by the decrease of the wake region due to the delay of the boundary layer separation point of the rough riser.

关键词： marine riser vortex-induced vibration side-by-side arrangement roughness interference effect

Prediction of fracture initiation in cohesive soils based on data mining modelling and large-scale laboratory verification

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Underground Space 2024年第6期19卷 279-300页

作者： Weiping Luo Dajun Yuan Yannick Choy Hing Ng Dalong Jin Ping Lu Teng Wang Department of Geotechnical engineering College of Civil EngineeringTongji UniversityShanghai 200092China Key Laboratory of the Ministry of Education for Urban Underground engineering Beijing Jiaotong UniversityBeijing 100044China Department of civil and Environmental engineering National University of SingaporeSingapore 119077Singapore

Many empirical and analytical methods have been proposed to predict fracturing pressure in cohesive *** of them take into account three to four specific influencing factors and rely on the assumption of a failure *** this study,a novel data-mining approach based on the XGBoost algorithm is investigated for predicting fracture initiation in cohesive *** has the advantage of handling multiple influencing factors simultaneously,without pre-determining a failure mode.A dataset of 416 samples consisting of 14 distinct features was herein collected from past studies,and used for developing a regressor and a classifier model for fracturing pressure prediction and failure mode classification *** results show that the intrinsic characteristics of the soil govern the failure mode while the fracturing pressure is more sensitive to the stress *** XGBoost-based model was also tested against conventional approaches,as well as a similar machine learning algorithm namely random forest ***,several large-scale triaxial fracturing tests and an in-situ case study were carried out to further verify the generalization ability and applicability of the proposed data mining approach,and the results indicate a superior performance of the XGBoost model.

关键词： Fracturing pressure Failure mode Cohesive soil Data-mining Large-scale tests

The influences of perforating phase and bedding planes on the fracture deflection in laminated shale

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Petroleum Science 2024年第2期21卷 1221-1230页

作者： Ming-Zhe Gu Mao Sheng Xiao-Ying Zhuang Xin-Yi Li Gen-Sheng Li National Key Laboratory of Petroleum Resources and engineering China University of PetroleumBeijing102249China college of Petroleum engineering China University of PetroleumBeijing102249China college of civil engineering Tongji UniversityShanghai200092China

The perforating phase leads to complex and diverse hydraulic fracture propagation behaviors in laminated shale formations. In this paper, a 2D high-speed imaging scheme which can capture the interaction between perforating phase and natural shale bedding planes was proposed. The phase field method was used to simulate the same conditions as in the experiment for verification and hydraulic fracture propagation mechanism under the competition of perforating phase and bedding planes was *** results indicate that the bedding planes appear to be no influence on fracture propagation while the perforating phase is perpendicular to the bedding planes, and the fracture propagates along the perforating phase without deflection. When the perforating phase algins with the bedding planes, the fracture initiation pressure reserves the lowest value, and no deflection occurs during fracture propagation. When the perforating phase is the angle 45°, 60°and 75°of bedding planes, the bedding planes begin to play a key role on the fracture deflection. The maximum deflection degree is reached at the perforating phase of75°. Numerical simulation provides evidence that the existence of shale bedding planes is not exactly equivalent to anisotropy for fracture propagation and the difference of mechanical properties between different shale layers is the fundamental reason for fracture deflection. The findings help to understand the intrinsic characteristics of shale and provide a theoretical basis for the optimization design of field perforation parameters.

关键词： Shale Propagation Perforating Bedding Structure

Adaptive pandemic management strategies for construction sites:An agent-based modeling approach

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Frontiers of engineering Management 2024年第2期11卷 288-310页

作者： Chengqian LI Qi FANG Ke CHEN Zhikang BAO Zehao JIANG Wenli LIU School of civil engineering Hunan UniversityChangsha 410082China School of civil engineering Central South UniversityChangsha 410004China School of civil and hydraulic engineering Huazhong University of Science and TechnologyWuhan 430074China School of Energy GeoscienceInfrastructureand SocietyHeriot-Watt UniversityEdinburghUK

In the face of sudden pandemics,it becomes crucial for project managers to quickly adapt and make informed decisions that anticipate the consequences of their *** highlights the need for proactive management strategies to enhance epidemic response ***,current research mainly emphasizes the negative impacts of pandemics,often neglecting the development of adaptable management approaches for construction *** study aims to fill this research void by developing strategies tailored to managing pandemics at construction *** agent-based modeling,the study simulates the movement patterns of workers and the consequent spread of an epidemic under different risk scenarios and management *** results indicate that measures such as wearing masks,managing group activities,and enforcing entry controls can significantly reduce epidemic spread on construction sites,with entry controls showing the greatest effectiveness.

关键词： epidemic transmission agent-based modeling safety management management strategy

An extended micromechanical-based plastic damage model for understanding water effects on quasi-brittle rocks

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International Journal of Mining Science and Technology 2024年第3期34卷 289-304页

作者： Qiaojuan Yu Shigui Du Qizhi Zhu Zhanyou Luo Sili Liu Lunyang Zhao Institute of Rock Mechanics Ningbo UniversityNingbo 315211China Ningbo Key Laboratory of Energy Geostructure Ningbo UniversityNingbo 315211China college of civil and Transportation engineering Hohai UniversityNanjing 210098China college of civil engineering Jiangsu Open UniversityNanjing 210036China South China Institution of Geotechnical engineering School of Civil Engineering and TransportationSouth China University of TechnologyGuangzhou 510641China

Water effects on the mechanical properties of rocks have been extensively investigated through experiments and numerical ***,few studies have established a comprehensive link between the microscopic mechanisms of water-related micro-crack and the constitutive behaviors of *** this work,we shall propose an extended micromechanical-based plastic damage model for understanding weakening effect induced by the presence of water between micro-crack’s surfaces on quasi-brittle rocks,based on the Mori-Tanaka homogenization and irreversible thermodynamics *** the physical mechanism,water strengthens micro-crack propagation,which induces damage evolution during the pre-and post-stage,and weakens the elastic effective properties of rock *** proposing a special calibration procedure for the determination of model parameters based on the laboratory compression tests,the proposed micromechanical-based model is verified by comparing the model predictions to the experimental *** model effectively captures the mechanical behaviors of quasibrittle rocks subjected to the weakening effects of water.

关键词： Water Micro-crack Damage Micro-mechanics Constitutive model Cohesive force