Project Progress Tracking Using Lidar and 4D Design Models

SPR 811Accurate data collected from on-going construction projects assists project field engineers with tracking the progress of construction work. The comparison of as-planned schedules against the as-built status of construction enables the involved parties to determine project performance. Periodic monitoring of project performance enables timely identification of discrepancies between the schedule baseline and project schedule. The rapid identification of discrepancies allows necessary measures to be taken to minimize the impact of a delay on the construction workflow. In transportation projects, the traditional means of acquiring as-built data from a construction site prevents involved parties from receiving the required information from the site in a timely manner. The delay in the communication of information ultimately causes subsequent delays in implementing necessary courses of action targeted toward improving the workflow. Therefore, this project develops a technology-supplemented progress monitoring approach. The technology accurately records as-built data with a high level of detail from a construction worksite within a reasonable period of time using lidar while ensuring the safety of the data collector. The proposed framework utilizes point cloud data obtained using mobile lidar technology and 4D Design Models to identify deviations of the performed work from the planned work. Percentage of Completion (POC) for the as-built bridge elements are calculated and compared with the as-planned POC. The differences between these two POC values for an element, on a particular scan date, are used for assessing the performance of the proposed framework

Avaliação do cumprimento da NR-18 em função do porte de obra residencial e proposta de lista de verificação da NR-18

O presente trabalho investiga as reais condições dos ambientes de trabalho da indústria da construção, tendo em vista os problemas relacionados à segurança do trabalho nos canteiros de obras. Formulou-se a hipótese de haver discrepância no grau de cumprimento da NR-18 em obras de diferentes portes (pequena, média e grande). Baseado em uma lista de verificação do grau de cumprimento dos requisitos da NR-18, foram avaliados 115 canteiros de obra na cidade de Chapecó - SC. Para cada item da lista de verificação foi atribuída uma nota e, após compilar as informações, estas foram avaliadas conforme os objetivos da pesquisa. Fez-se uma análise crítica para os cinco piores e os cinco melhores itens observados para as obras pequenas, médias e grandes. Analisando-se os resultados é possível afirmar que há uma diferença significativa de aplicação da NR-18 nos diferentes portes de obras, sendo que as obras de grande porte obtiveram uma média final (6,47) significativamente superior em relação às obras pequenas (1,97). Desta forma, foi corroborada a hipótese formulada, podendo se atribuir este resultado a diversos fatores, entre os quais a falta de habilidades gerenciais de segurança e saúde do trabalho nas pequenas empresas. Outra contribuição deste artigo foi a proposta de uma nova lista de verificação para avaliar o grau de cumprimento da NR-18 nos canteiros de obra

Validating DFS concept in lifecycle subway projects in China based on incident case analysis and network analysis

Regardless of potential benefits of design for safety (DFS) concept for lifecycle safety management in construction industry, DFS adoption as an early intervention has been slower than expected. While existing research mainly con­centrates on construction and operation phases, the role of design phase in construction safety management is always ignored. To validate the influence of DFS concept on lifecycle safety performance, this research conducted an incident case analysis (ICA) based on 442 cases collected from lifecycle subway projects, and a subway design-incident classification model (SDICM) was developed to help identify their relationship to DFS concept. Network theory was applied to study the interdependence of 22 subsystems obtained from China’s code for metro design in lifecycle safety performance. Research findings show 236 out of 442 accidents are linked to DFS. Compared with construction phase, operation phase is more susceptible to design work. Station Building (SB), Section Construction (SC), Platform Screen Doors (PSD), Vehicle Systems (VES) and Power Supply Systems (PSS) are identified as having the highest number of accidents. The results of network analysis are consistent with ICA and demonstrate the safety interdependence of subsystems. This research can help improve the cognizance of DFS, and the identified subsystems should be given priority in the design phase