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Journal of Central South University 2025年第4期32卷 1503-1519页

作者：陈磊贾朝军雷明锋何艳春施成华李翱 School of Civil Engineering Central South University National Engineering Research Center of High-speed Railway Construction Technology Hunan Road & Bridge Construction Group Co. Ltd.

既有的基于弹性地基梁的管棚计算分析模型，往往忽略梁端外的土体对梁上剪应力的影响，这使得此类模型不能充分反映土体变形的连续性特征。以Pasternak地基-Euler梁模型为基础，通过考虑梁上的广义剪力，来研究梁端外土体对梁上剪力的... 详细信息

既有的基于弹性地基梁的管棚计算分析模型，往往忽略梁端外的土体对梁上剪应力的影响，这使得此类模型不能充分反映土体变形的连续性特征。以Pasternak地基-Euler梁模型为基础，通过考虑梁上的广义剪力，来研究梁端外土体对梁上剪力的影响；基于初参数法推导有限长梁受任意荷载作用的变形及内力解析解，建立了典型隧道开挖循环下超前管棚的弹性地基梁力学模型，得到了管棚纵向响应的解析解。运用已有的测试数据验证了解析模型的可靠性。改进后的模型改良了既有模型的部分缺陷，如松动段的不合理隆起变形和异常的最大挠度位置。此外，还提出了反映管棚和地基土相对刚度的无量纲特征参数。结果表明：特征参数对管棚的变形及内力有显著影响，在一般的范围内，管棚在半对数坐标下的最大变形和内力随土体特征参数的减小呈近似线性衰减。隧道开挖高度对未支护段的管棚受力影响较小，对埋藏于岩土体内的管棚影响较大，而隧道开挖进尺对管棚的影响与之相反。

关键词：弹性地基梁 Pasternak地基广义剪力管棚解析模型

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Named entity recognition for Chinese construction documents based on conditional random field

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Frontiers of engineering Management 2023年第2期10卷 237-249页

作者： Qiqi ZHANG Cong XUE Xing SU Peng ZHOU Xiangyu WANG Jiansong ZHANG College of Civil Engineering and Architecture Zhejiang UniversityHangzhou 310058China School of Management Science and Engineering Central University of Finance and EconomicsBeijing 100081China School of Design and the Built Environment Curtin UniversityPerthWestern Australia 6845Australia School of Construction Management Technology Purdue UniversityWest LafayetteIN 47907USA

Named entity recognition(NER)is essential in many natural language processing(NLP)tasks such as information extraction and document classification.A construction document usually contains critical named entities,and an effective NER method can provide a solid foundation for downstream applications to improve construction management *** study presents a NER method for Chinese construction documents based on conditional random field(CRF),including a corpus design pipeline and a CRF *** corpus design pipeline identifies typical NER tasks in construction management,enables word-based tokenization,and controls the annotation consistency with a newly designed annotating *** CRF model engineers nine transformation features and seven classes of state features,covering the impacts of word position,part-of-speech(POS),and word/character states within the *** F1-measure on a labeled construction data set is 87.9%.Furthermore,as more domain knowledge features are infused,the marginal performance improvement of including POS information will decrease,leading to a promising research direction of POS customization to improve NLP performance with limited data.

关键词： NER NLP Chinese language construction document

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Task-Significance-Aware Meta Learning for Few-Image-Based Structural Damage Recognition 14

Task-Significance-Aware Meta Learning for Few-Image-Based St...

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14th International Workshop on Structural Health Monitoring: Designing SHM for Sustainability, Maintainability, and Reliability, IWSHM 2023

作者： Xu, Yang Li, Yi Fan, Yunlei Zheng, Xiaodong Bao, Yuequan School of Civil Engineering Harbin Institute of Technology Harbin150090 China Bay Area Super Major Bridge Maintenance Technology Center of Guangdong Highway Construction Co. Ltd. Guangzhou510635 China

ISBN: (纸本)9781605956930

Recently, structural damage recognition has gained significant progress using deep learning and computer vision techniques. However, massive training images, the interclass balance and completeness of damage categories are essential to ensure recognition accuracy. In addition, the generalization ability for new damage categories and robustness under real-world scenarios are limited. This study proposes a task-aware meta-learning paradigm using limited images for universal structural damage segmentation. First, a novel task generation strategy instead of random sampling is designed based on feature density clustering. A synthetical metric of Jaccard distance and Euclidean distance is established to measure the feature similarity among multitype damage images. The class separability discovered in the high-level feature space of multi-type structural damage enhances the interpretability of randomly-generated tasks for conventional meta-learning. Second, a dual-stage optimization framework is built based on Model-Agnostic Meta-Learning (MAML), comprising an internal optimization stage of the semantic segmentation model (U-Net) and an external optimization stage of the meta-learning machine. Third, a set of core samples around the cluster center is selected to form an additional query pool and evaluate the tasksignificance scores of different tasks within a meta-batch by the same criteria. The task-significance scores are utilized in the external optimization to control the orientation of gradient updates towards more significant tasks. To verify the effectiveness and necessity of the proposed method, ablation experiments are performed using a multi-type structural damage dataset, including concrete crack, steel fatigue crack, and concrete spalling. The proposed method outperforms directly training the original U-Net and the conventional MAML algorithm using only a handful of training samples with improvements in segmentation accuracy. In addition, the improvement in rec

关键词： Steel corrosion

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Evaluating the flooding level impacts on urban metro networks and travel demand:behavioral analyses,agent-based simulation,and large-scale case study

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Resilient Cities and Structures 2022年第3期1卷 12-23页

作者： Bingyu Zhao Yili Tang Chaofeng Wang Shuyang Zhang Kenichi Soga Institute of Transportation Science TU WienViennaAustria Department of Civil and Environmental Engineering University of CaliforniaBerkeleyUSA Faculty of Engineering and Applied Science University of ReginaSKCanada College of Design Construction and PlanningGainesvilleFloridaUSA School of Transportation and Logistics Engineering Wuhan University of TechnologyWuhanChina

With urban residents’increasing reliance on metro systems for commuting and other daily activities,extreme weather events such as heavy rainfall and flooding impacting the metro system services are becoming increasingly of *** for such emergency interruptions require a thorough understanding of the potential outcomes on both the system and individual component ***,due to the complex dynamics,constraints,and interactions of the elements involved(e.g.,disaster,infrastructure,service operation,and travel behavior),there is still no framework that comprehensively evaluates the system performance across different spatiotemporal scales and is flexible enough to handle increasingly detailed travel behavior,transit service,and disaster information *** on an agent-based model(ABM)framework,this study adopts a data-driven ABM simulation approach informed by actual metro operation and travel demand data to investigate the impact of flood-induced station closures on travelers as well as the overall system response.A before-after comparison is conducted where the traveler behaviors in disaster scenarios are obtained from a discrete choice model of alternative stations and routes.A case study of the Shanghai Metro is used to demonstrate the ability of the proposed approach in evaluating the impacts of flood-induced station closures on individual traveler behavior under normal operation and a series of water level rise scenarios of up to *** was found that,when the flood-induced station closures only affect a few river-side stations in the city center,the travelers experience only minor disruptions to their trips due to the availability of unaffected stations nearby as a ***,as the water level increases and more stations(mainly in the suburban area)are affected,up to 25%of trips are no longer being fulfilled due to the loss of entrances,exits,or transfer *** system experiences overall less crowdedness in terms of passenger volume and

关键词： Metro flooding Infrastructure resilience Extreme climate events Agent-based simulations

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Performance evaluation of construction project by earned value management system in Amhara waterworks construction enterprise

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Discover civil engineering 2025年第1期2卷 1-25页

作者： Reda, Shumet Getahun Belachew, Ketema Teshome Demiss, Belachew Asteray Ali, Samson Kebede Department of Civil Engineering Bahir Dar University Bahir Dar 26 Ethiopia Amhara Water Works Construction Enterprise Bahir Dar 26 Ethiopia Department of Civil Engineering Addis Ababa Science and Technology University Addis Ababa Ethiopia

This study aims to evaluate the construction project performance by the earned value management system in the Amhara Water Works construction enterprise. The study was conducted using a questionnaire survey, interviews, and document review at Amhara Water Works construction Enterprise projects. The study was conducted on 12 projects to measure project performance. A total of 44 respondents participated in the quantitative study and six in qualitative data. The study focused on the assessment of the practice of the earned value management system and factors that hinder its implementation in construction. Based on the study, one project was incurred over cost, two projects were completed at planned cost, and the other three were performed under the budget. These projects were needed over cost to complete the project due to improper resource planning, inflation, and poor employee management. Poor managers' commitment to practicing EVMS, a lack of support from team members, and a lack of common understanding and proper training are the main barriers hindering the practice of EVMS. Training project practitioners have a vital role in implementing an earned value management system. An earned value management system enables project managers to track potential cost challenges and time delays earlier than project progress. It is also vital to enhance the communication between contract parties and develop the productivity of machineries and labour by optimizing resource allocation. Integrating EVMS with BIM and lean construction concepts is vital to boost the Ethiopian construction industry.

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Numerical Study of Nonlinear Rayleigh wave detection Of Closed Cracks

Numerical Study of Nonlinear Rayleigh wave detection Of Clos...

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SPAWDA Symposium on Piezoelectricity, Acoustic Waves, and Device Applications

作者： Hongzhao Li Chengzhong Luo Mengfei Cheng Weiwei Zhang Hongwei Ma School of Mechanics and Construction Engineering Jinan University Guangzhou China School of Environment and Civil Engineering Dongguan University of Technology Dongguan China

ISBN: (数字)9798331523732

ISBN: (纸本)9798331523749

The detection of closed cracks on structural surfaces is investigated using nonlinear Rayleigh waves through finite element numerical simulation. The location of closed cracks was achieved using single-point excitation and multi-point reception. A relationship was established between the acoustic nonlinearity parameter, crack length, and crack depth. The results indicate that although the acoustic nonlinearity parameter of the transmitted wave varies at different receiver position, its trend with crack size remains generally consistent. This method can detect cracks as small as 0.7 times the wavelength of the second harmonic. However, when the crack depth exceeds the detection wavelength, further depth assessment becomes challenging. This study provides a reference for detecting surface closed cracks.

关键词： Location awareness Sensitivity Surface acoustic waves Receivers Piezoelectricity Harmonic analysis Market research Numerical simulation Surface cracks Testing

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Water and ions transport in calcium silicate hydrate: a molecular dynamics study 7

Water and ions transport in calcium silicate hydrate: a mole...

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7th International Conference on Durability of Concrete Structure, ICDCS 2022

作者： Zhang, Wei Yang, Qingrui Hou, Dongshuai Zhang, Xingliang Zhang, Yongmin Pang, Kai Diao, Xiaoxiang Department of Civil Engineering Qingdao University of Technology China Ronghua Construction Group Co. Ltd. China China State Construction Port Engineering Group Co. Ltd. China Tianjin Housing Group Construction Engineering General Contraction Co. Ltd. China

Transport properties of water and ions in calcium silicate hydrate (C-S-H) greatly affect the durability of cementitious materials. In this study, molecular dynamics (MD) technique is used to investigate the transport behaviors of NaCl solution in C-S-H nanopores with different sizes (from 0.5 nm to 5 nm), and the hindering effect of C-S-H on the diffusion of water molecules and Cl ions is further explored in the case of a 5 nm pore. Results show that the diffusion coefficients of water molecules and Cl ions in C-S-H nanopores increase with the expansion of nanopore. At the atomic scale, the Ca-rich C-S-H forms Ca-O and Ca-Cl clusters with water molecules and Cl ions, respectively, and the Si-O tetrahedra on silicate chains can also build hydrogen bonding interactions with water molecules, which constrain the transport behaviors of water and ions. From the molecular perspective, this study innovatively investigates the effect of C-S-H pore size on the diffusion capacity of water and ions, and reveals the chemical bonding mechanism between water molecules, Cl ions and C-S-H, which provides a theoretical basis for studying the resistance of concrete to ionic attack. © 2022 7th International Conference on Durability of Concrete Structure, ICDCS 2022. All rights reserved.

关键词： Calcium silicate

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Delayed Building Schedule Control Using Milestones 1

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4th International Scientific Conference on Environmental Challenges in civil engineering, ECCE 2020

作者： Przywara, D. Rak, A. Faculty of Civil Engineering and Architecture Department of Civil Engineering and Construction Processes Opole University of Technology Opole Poland

ISBN: (数字)9783030638795

ISBN: (纸本)9783030638788

A feasibility study is a measure of the quality and reliability of construction schedules. In the course of construction projects, there are a number of external factors that generate time delays and cost variances. Their detailed monitoring and identification allows managers to implement improvement measures. The purpose of the research is to build a decision model that controls the distribution of the resulting time and cost variances identified on the given day of the work registration report. The works assortment processes burdened with the variances in the preceding activities, foreseen to be performed after the selected inspection day were subjected to the improvement measures. Delayed schedule control using milestones allows for the division of time slips by setting priority working deadlines. These deadlines initially eliminate time reserves, making all activities critical. © 2021, The Author(s), under exclusive license to Springer Nature Switzerland AG.

关键词： Delayed schedule Milestones Time anchors

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Flexural and free vibration responses of thick isotropic bridge deck using a novel two variable refined plate theory

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Structural engineering and Mechanics 2022年第6期82卷 725-734页

作者： Djidar, Fatima Zohra Hebali, Habib Amara, Khaled Tounsi, Abdelouahed Bendaho, Boudjema Ghazwani, M.H. Hussain, Muzamal Smart Structures Laboratory University of Ain Témouchent Faculty of Science and Technology Civil Engineering Department Algeria Material and Hydrology Laboratory Civil Engineering Department Faculty of Technology University of Sidi Bel Abbes Algeria Civil Engineering Department Faculty of Science and Technology University of Mascara Algeria Engineering and Sustainable Development Laboratory University of Ain Temouchent Ain Temouchent46000 Algeria Yonsei University Seoul Korea Republic of Department of Civil and Environmental Engineering King Fahd University of Petroleum and Minerals Eastern Province Dhahran31261 Saudi Arabia Interdisciplinary Research Center for Construction and Building Materials KFUPM Dhahran31261 Saudi Arabia Department of Mechanical Engineering Faculty of Engineering Jazan University P.O Box 45124 Jazan Saudi Arabia Department of Mathematics Govt. College University Faisalabad Faisalabad38000 Pakistan

This work presents a simple exponential shear deformation theory for the flexural and free vibration responses of thick bridge deck. Contrary to the existing higher order shear deformation theories (HSDT) and the first shear deformation theory (FSDT), the proposed model uses a new displacement field which incorporates undetermined integral terms and involves only two variables. Governing equations and boundary conditions of the theory are derived by the principle of virtual work. The simply supported thick isotropic square and rectangular plates are considered for the detailed numerical studies. Results of displacements, stresses and frequencies are compared with those of other refined theories and exact theory to show the efficiency of the proposed theory. Good agreement is achieved of the present results with those of higher order shear deformation theory (HSDT) and elasticity theory. Moreover, results demonstrate that the developed two variable refined plate theory is simple for solving the flexural and free vibration responses of thick bridge deck and can achieve the same accuracy of the existing HSDTs which have more number of variables. Copyright © 2022 Techno-Press, Ltd.

关键词： Shear stress

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Effect of wind barrier on aerodynamic characteristics of twin parallel decks for rail-cum-road bridge and train

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Journal of Railway Science and engineering 2025年第3期22卷 1144-1153页

作者： Zou, Yunfeng Liu, Zhenghua He, Xuhui Liu, Lulu Yang, Jiafeng School of Civil Engineering Central South University Changsha410075 China National Engineering Research Center of High-speed Railway Construction Technology Changsha410075 China Key Laboratory for Disaster Prevention and Mitigation of Rail Transit Engineering Structures of Hunan Province Changsha410075 China

The installation of wind barriers is an effective measure to ensure the safety of train operation on bridges under strong wind conditions. However, the impact of wind barriers on the aerodynamic characteristics of the train-bridge system is significantly influenced by the structural form of the train’s lower part. To this end, through sectional model force measurement and pressure measurement wind tunnel tests, this article investigated the influence of wind barriers on the aerodynamic characteristics of China’s first large-span, double-deck bridge with both rail and road layers-the train system. The results show that the effect of wind barriers on the average aerodynamic force coefficients of the railway main beam is basically similar under different wind direction angles. At a wind direction angle β =0°, the wind barrier mainly affects the fluctuating lift coefficient of the railway main beam. While at a wind direction angle β=180°, the wind barrier can mainly affect the fluctuating drag coefficient of the railway main beam. At a wind direction angle β=0°, the wind barrier has a minor impact on the fluctuating aerodynamic force coefficients of the highway main beam. While at a wind direction angle β = 180°, the wind barrier can mainly affect the fluctuating drag coefficient and fluctuating lift coefficient of the railway main beam. At a wind direction angle β=0°, the wind barrier has a greater impact on the average drag coefficient of the train than at a wind direction angle β=180°. While at a wind direction angle β=180°, the wind barrier has a greater impact on the fluctuating drag coefficient of the train than at a wind direction angle β=0°. At a wind direction angle β =0°, the wind barrier mainly affects the average wind pressure coefficient at the windward side and the transition section between the windward side and the bottom arc, while at a wind direction angle β=180°, the wind barrier mainly affects the average wind pressure coefficient at the windward sid

关键词： Aerodynamic drag

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