To develop the cost climate survey scale( CCSS) used in construction enterprises,the design concepts,principles and the process diagrams of CCSS are proposed.Through questionnaire investigation and expert interviews,3...To develop the cost climate survey scale( CCSS) used in construction enterprises,the design concepts,principles and the process diagrams of CCSS are proposed.Through questionnaire investigation and expert interviews,314 projects are established and the CCSS that is made up of 7 dimensions framework and 30 levels is preliminarily determined.After categorized merger,pre-test analysis and multiple items refining,16 projects of CCSS are eventually compiled.In order to verify the credibility and validity of the CCSS,200 employees in Qinhuangdao construction company as the samples are tested.SPSS 21.0 is used to analyze the reliability,validity and rationality of level divisions,and Amos 22.0 is for analyzing the degree of model adaptation in this survey.Finally,the current cost climate situation of the construction site in the company is evaluated,the deficiencies of the cost culture of the construction site are pointed out.This study shows that strengthening the cost knowledge training has a significant positive effect on the cost climate cognition of the employees.Nevertheless,accumulation of work experience has a dual impact on that.The CCSS is not only an important foundation for the cost climate research and its theoretical development,but also the premise of the cost climate quantitative research.An appropriate CCSS,to some extent,can reflect the cognitive level of all kinds of employees in one enterprise and cost savings degree of the enterprise in a certain time.The development of CCSS reflects the originality and interactivity,and fills a blank of the CCSS in construction,which is considered to be an effective tool for cost climate research in construction.展开更多
To accurately control the full-span erection of continuous steel box girder bridges with complex cross-sections and long cantilevers, both the augmented finite element method(A-FEM) and the degenerated plate elements ...To accurately control the full-span erection of continuous steel box girder bridges with complex cross-sections and long cantilevers, both the augmented finite element method(A-FEM) and the degenerated plate elements are adopted in this paper. The entire construction process is simulated by the A-FEM with the mesh-separation-based approximation technique, while the degenerated plate elements are constructed based on 3D isoparametric elements, making it suitable for analysis of a thin-walled structure. This method significantly improves computational efficiency by avoiding numerous degrees of freedom(DoFs) when analyzing complex structures. With characteristics of the full-span erection technology, the end-face angle of adjacent girder segments, the preset distance of girder segments from the design position, and the temperature difference are selected as control parameters, and they are calculated through the structural response of each construction stage. Engineering practice shows that the calculation accuracy of A-FEM is verified by field-measured results. It can be applied rapidly and effectively to evaluate the matching state of girder segments and the stress state of bearings as well as the thermal effect during full-span erection.展开更多
基金Natural Science Foundation of Hebei Province,China(No.E2016203147)Science and Technology Research and Development Plan of Qinhuangdao,China(No.201602A040)Construction Science and Technology Research Program of Hebei Province,China(No.2016-124)
文摘To develop the cost climate survey scale( CCSS) used in construction enterprises,the design concepts,principles and the process diagrams of CCSS are proposed.Through questionnaire investigation and expert interviews,314 projects are established and the CCSS that is made up of 7 dimensions framework and 30 levels is preliminarily determined.After categorized merger,pre-test analysis and multiple items refining,16 projects of CCSS are eventually compiled.In order to verify the credibility and validity of the CCSS,200 employees in Qinhuangdao construction company as the samples are tested.SPSS 21.0 is used to analyze the reliability,validity and rationality of level divisions,and Amos 22.0 is for analyzing the degree of model adaptation in this survey.Finally,the current cost climate situation of the construction site in the company is evaluated,the deficiencies of the cost culture of the construction site are pointed out.This study shows that strengthening the cost knowledge training has a significant positive effect on the cost climate cognition of the employees.Nevertheless,accumulation of work experience has a dual impact on that.The CCSS is not only an important foundation for the cost climate research and its theoretical development,but also the premise of the cost climate quantitative research.An appropriate CCSS,to some extent,can reflect the cognitive level of all kinds of employees in one enterprise and cost savings degree of the enterprise in a certain time.The development of CCSS reflects the originality and interactivity,and fills a blank of the CCSS in construction,which is considered to be an effective tool for cost climate research in construction.
基金Project supported by the National Natural Science Foundation of China(Nos.51578496 and 51878603)the Zhejiang Provincial Natural Science Foundation of China(No.LZ16E080001)。
文摘To accurately control the full-span erection of continuous steel box girder bridges with complex cross-sections and long cantilevers, both the augmented finite element method(A-FEM) and the degenerated plate elements are adopted in this paper. The entire construction process is simulated by the A-FEM with the mesh-separation-based approximation technique, while the degenerated plate elements are constructed based on 3D isoparametric elements, making it suitable for analysis of a thin-walled structure. This method significantly improves computational efficiency by avoiding numerous degrees of freedom(DoFs) when analyzing complex structures. With characteristics of the full-span erection technology, the end-face angle of adjacent girder segments, the preset distance of girder segments from the design position, and the temperature difference are selected as control parameters, and they are calculated through the structural response of each construction stage. Engineering practice shows that the calculation accuracy of A-FEM is verified by field-measured results. It can be applied rapidly and effectively to evaluate the matching state of girder segments and the stress state of bearings as well as the thermal effect during full-span erection.
