A Temporal And Spatial Variation Of The Safety Efficiency In Restricted Space Of Chinese Cities

The acceleration of the urbanization in China has led to the bulge ofpopulation, heavy traffic and bad environment. Though limited ground spacehas been over-developed, the situation is still intolerable so people turn to usethe underground space and infrastructure and commercial real estate arespeeding up. When the scale is small, massive input without considering costcan level up the management, but within the time and space changes, theshape and area of the underground space is increasing. So there is a conflictbetween the cost and input and safety efficiency and its quantization model arebecoming important and urgently needed.The paper is discussing the safety problem in Chinese cities by the pointof temporal and spatial variation, and expanded it to restricted space bothabove the ground and underground. Based on the safety economics andinput-output theory, the author tried to explain the safety efficiency and relatedmodel and reflected the difference from the view of government andenterprises. The author analyzed the safety efficiency in some major fields,such as overhead cable lines, subway stair armrest, safe escape in undergroundcommercial street, as well as examine the quantifiable and operability of theevaluation model The model is helpful to the decision-making when balancethe security and efficiency so as to effectively manage the project and funduse.