Despite the fact that applying constructability concepts in building designs have led to savings estimated within a range of 1% to 14% of the capital cost, the construction industry still lacks an advanced tool to ass...Despite the fact that applying constructability concepts in building designs have led to savings estimated within a range of 1% to 14% of the capital cost, the construction industry still lacks an advanced tool to assess and check for constructability implementations in designs. Therefore, the objective of this research is to propose a quantitative assessment of building constructability, which transforms the subjective assessment of constructability knowledge to a quantified value so that it is easy to analyze and improve building design. The proposed methodology uses the advancement of object oriented Building Information Model (BIM) and 4D simulation model to serve as a data repository models for the constructability assessment platform. Factors affecting constructability of building designs have been identified and relatively weighted using Analytical Hierarchy Process (AHP) technique based on a questionnaire survey collected throughout the Canadian provinces. Evaluation criteria are also developed to assist the designer to evaluate the design proposals. The outcome shows that the proposed method provides the designer an accurate and faster mode in evaluating project constructability by using the parametric features from BIM and taking the advantage of spatial relationship between building components.展开更多
Buried water pipelines are vulnerable to fail or break due to excessive loading or ground displacements.Accurate evaluation of pipe performance and serviceability relies on the proper understanding of pipe-soil intera...Buried water pipelines are vulnerable to fail or break due to excessive loading or ground displacements.Accurate evaluation of pipe performance and serviceability relies on the proper understanding of pipe-soil interactions(PSI).Analytical methods are important approaches to studying PSI.However,a systematic and thorough literature review to analyze the existing research trends,technological achievements and future research opportunities is not available.This work investigates analytical methods that analyze the stress and deformation of pipes in terms of cross-sectional,transverse and longitudinal PSI problems.First,scientometric analysis is performed to acquire relevant research works from online databases and analyze the existing data of influential authors,productive research sources and frequent key word occurrence in the fields of interest.Second,a qualitative discussion is performed in the three categories of PSI:(1)cross-sectional,including ovalization and circumferential behaviours;(2)transverse,including seismic fault crossing,weak soil zones,ground settlement and pipe uplift;and(3)longitudinal.Third,six research opportunities are discussed,including the role of friction in cross-sectional deformation,combined effects of bending and compression,choice of soil reaction models and calibration of key parameters,effect of pipe flaws,soil spatial variability and behaviours of curved pipes.This study helps beginners familiarize themselves with PSI analytical methods and provides experienced researchers with ideas for future research directions.展开更多
Smart cities and decarbonization of the transportation sector provoked significant environmental policy reforms,shifting the urban environment away from car-centric planning to non-mechanized transportation.Thus,walki...Smart cities and decarbonization of the transportation sector provoked significant environmental policy reforms,shifting the urban environment away from car-centric planning to non-mechanized transportation.Thus,walking and cycling became natural alternatives due to their zero-carbon operation and health benefits.Computer vision(CV)techniques offer promising capabilities for analyzing and improving pedestrian sidewalk infrastructure and usage.Despite the current efforts,the literature lacks a comprehensive synthesis of studies applying CV to sidewalks,casting a shadow on the utilization of further artificial-based algorithms in this domain.Hence,this study provides a state-of-the-art analysis of CV applications on sidewalks by presenting 1)a scientometric analysis of existing studies,2)systematic discussions of CV applications and architectures,3)proposal of a framework for applying CV in sidewalk studies,and 4)existing gaps and future research opportunities.The publication trend analysis indicated accelerated growth in sidewalk-focused CV research since 2018,with peaks in the last five years,indicating rising scholarly interest.The keyword analysis revealed seven clusters,where"pavements","computer vision",and"deep learning"are the top keywords based on their degree centrality.The systematic analysis identified and discussed CV applications to sidewalk accessibility,path conditions,and user behaviors,showing that convolutional neural networks are the most adopted architecture in this domain.This study offers academics and industry professionals essential perspectives into the developing research area of leveraging CV for analyzing diverse facets of sidewalks.It highlights the imperative to tackle identified research gaps via innovative techniques and collaborative efforts,in addition to openly sharing datasets and source code.展开更多
文摘Despite the fact that applying constructability concepts in building designs have led to savings estimated within a range of 1% to 14% of the capital cost, the construction industry still lacks an advanced tool to assess and check for constructability implementations in designs. Therefore, the objective of this research is to propose a quantitative assessment of building constructability, which transforms the subjective assessment of constructability knowledge to a quantified value so that it is easy to analyze and improve building design. The proposed methodology uses the advancement of object oriented Building Information Model (BIM) and 4D simulation model to serve as a data repository models for the constructability assessment platform. Factors affecting constructability of building designs have been identified and relatively weighted using Analytical Hierarchy Process (AHP) technique based on a questionnaire survey collected throughout the Canadian provinces. Evaluation criteria are also developed to assist the designer to evaluate the design proposals. The outcome shows that the proposed method provides the designer an accurate and faster mode in evaluating project constructability by using the parametric features from BIM and taking the advantage of spatial relationship between building components.
基金The authors gratefully acknowledge the Innovation and Technology Support Programme(ITSP)[Grant No.ITS/033/20FP]the Water Supplies Department of Hong Kong,China.Suggestions given by Dr.Andy Y.F.Leung are also appreciated.
文摘Buried water pipelines are vulnerable to fail or break due to excessive loading or ground displacements.Accurate evaluation of pipe performance and serviceability relies on the proper understanding of pipe-soil interactions(PSI).Analytical methods are important approaches to studying PSI.However,a systematic and thorough literature review to analyze the existing research trends,technological achievements and future research opportunities is not available.This work investigates analytical methods that analyze the stress and deformation of pipes in terms of cross-sectional,transverse and longitudinal PSI problems.First,scientometric analysis is performed to acquire relevant research works from online databases and analyze the existing data of influential authors,productive research sources and frequent key word occurrence in the fields of interest.Second,a qualitative discussion is performed in the three categories of PSI:(1)cross-sectional,including ovalization and circumferential behaviours;(2)transverse,including seismic fault crossing,weak soil zones,ground settlement and pipe uplift;and(3)longitudinal.Third,six research opportunities are discussed,including the role of friction in cross-sectional deformation,combined effects of bending and compression,choice of soil reaction models and calibration of key parameters,effect of pipe flaws,soil spatial variability and behaviours of curved pipes.This study helps beginners familiarize themselves with PSI analytical methods and provides experienced researchers with ideas for future research directions.
基金The authors gratefully acknowledge the support from the Smart Traffic Fund(STF)under grant number PSRI/14/2109/RAThe Hong Kong Polytechnic University for Entry Scholarship for the Postgraduate Scheme 2022/23 BRE,and the Presidential Fellowship。
文摘Smart cities and decarbonization of the transportation sector provoked significant environmental policy reforms,shifting the urban environment away from car-centric planning to non-mechanized transportation.Thus,walking and cycling became natural alternatives due to their zero-carbon operation and health benefits.Computer vision(CV)techniques offer promising capabilities for analyzing and improving pedestrian sidewalk infrastructure and usage.Despite the current efforts,the literature lacks a comprehensive synthesis of studies applying CV to sidewalks,casting a shadow on the utilization of further artificial-based algorithms in this domain.Hence,this study provides a state-of-the-art analysis of CV applications on sidewalks by presenting 1)a scientometric analysis of existing studies,2)systematic discussions of CV applications and architectures,3)proposal of a framework for applying CV in sidewalk studies,and 4)existing gaps and future research opportunities.The publication trend analysis indicated accelerated growth in sidewalk-focused CV research since 2018,with peaks in the last five years,indicating rising scholarly interest.The keyword analysis revealed seven clusters,where"pavements","computer vision",and"deep learning"are the top keywords based on their degree centrality.The systematic analysis identified and discussed CV applications to sidewalk accessibility,path conditions,and user behaviors,showing that convolutional neural networks are the most adopted architecture in this domain.This study offers academics and industry professionals essential perspectives into the developing research area of leveraging CV for analyzing diverse facets of sidewalks.It highlights the imperative to tackle identified research gaps via innovative techniques and collaborative efforts,in addition to openly sharing datasets and source code.
