No abstract

Pedestrian merging flows are common in a stairs evacuation process, which involves complex interactions among pedestrians that substantially restrict the efficiency of the stairs evacuation process. Analyzing the pedestrian merging flows process and improving the efficiency of stairs evacuation are urgent and essential tasks. A novel simplified stairs evacuation model for simulating and analyzing the stairs evacuation process, which considers the impact of merging flows, is proposed in this process. The dynamic pedestrian output rate of a floor platform is calculated by the number of pedestrians on the floor platform. The merging ratio determined by the design size of stairs is adopted to determine the ratio between the stairs pedestrian flow and the floor pedestrian flow in the pedestrian output rate of the floor platform. To evaluate the stairs evacuation process is divided into three stages based on the pedestrian merging flows process, and the evacuation time at each stage is computed by the dynamic pedestrian output rate of the floor platform. The stairs evacuation capacity is calculated by the evacuation time and the number of pedestrians. A case study of a six-floor building evacuation is investigated, and the reliability and feasibility of the proposed model is verified. By establishing different merging ratios, the optimal merging ratio is obtained by comparing the evacuation capacities of different merging ratios, which provides a reference of stairs design for designers.

Improving the poor sustainability of the construction industry requires long-term actions, especially in developing countries such as China. Regional sustainability assessment plays an indispensable role, contributing to a better understanding of the state of development in various regions. However, few studies have focused on the overall sustainability of regional construction industries, and occupational safety is generally ignored. To fill these gaps, an input-output system is established to evaluate regional sustainable performance of the construction industry (SPCI), which is made to include occupational safety by introducing the number of fatalities as an undesirable output. An evaluation model is constructed by combining window analysis with a super-slack-based measure data envelopment analysis (windows-super-SBM DEA). The SPCI in China’s 30 provinces from 2010 to 2017 is dynamically evaluated, and regional differences are further analyzed, with eight regions being defined. The results indicate that (1) the overall SPCI in China has fluctuated smoothly around a slight downward trend. By comparison, the integration of occupational safety refreshes the relative performance of most provinces; (2) dividing China into eight regions presents more detailed information because of those regions’ smaller coverage areas, and more attention should be given to the northeast, northwest, Middle Yellow River region and east coast because of the decrease in the SPCI; and (3) vigorously developing of the construction industry does not necessarily result in a large number of byproducts if the relevant policy is sufficiently strong. The findings of this study are conducive to rationally allocating resources and formulating targeted policies.

As one of the most high-risk sections, the construction industry has traditionally been the research hotspot. Yet little attention has been paid to macro-level accident situations of the entire industry. Therefore, this study develops a comprehensive assessment model on accident situations of Chinese building industry, aiming at assisting the government to better understand and improve accident situations of the entire industry. Based on China conditions, six indicators related to accident situations are firstly selected to establish an indicator system; then structure entropy weight method is proposed to determine indicator weighs, with dynamic classification method to explore the characteristics of accident situations. The results demonstrate that the provinces with poor accident situations account for 53% of all provinces, and they are mainly distributed in the central and western regions of China where there exist the underdeveloped economy. Meanwhile, some provinces experience poor accident situations that could be out-of-control, especially for Hebei. Provinces in the southeastern and northeastern regions of China perform relatively well, but they still have much improvement room for accident situations. The findings validate the rationality of the developed model and can provide valuable insights of safety regulation strategies for the government from the macro-level perspective.