Stairway In Chongqing’s Old Community Based On The Visual Safety Perception Of The Elderly Luminous Environment Research

This paper relies on the project funded by Chongqing University Innovation Team Construction Plan(team name: health lighting innovation team,No.: cxtdx201601005).Community visual safety perception is related to the vitality of external space and people’s well-being.It is very important to understand the community lighting design factors affecting safety perception and their influence mechanism.The number of stairways in old communities in Chongqing is large,the aging rate is high,and the elderly group has a weak sense of security during night travel.Therefore,from the perspective of visual safety perception of the elderly,this paper looks for strategies to improve the night light environment of the stairway in the old community.The full text is divided into seven chapters.The first chapter introduces the background,purpose,significance,core concepts and current situation at home and abroad.The second chapter mainly introduces the relevant theories.This part summarizes the theory of stairway lighting in old communities,summarizes the relevant theories and measurement methods of light environment safety perception,and summarizes the four principles of safety,guidance,identifiability and sustainability from the perspective of visual safety perception.The third chapter is the weight calculation of safety perception indicators.In this part,the Delphi method and analytic hierarchy process are used to construct the visual safety perception evaluation system of light environment at night in the old community stairway,and the weight vector of each evaluation index to the target layer is determined.The fourth chapter is the investigation on the light environment security perception of the stairway in the old community.This part makes an in-depth investigation on the light environment parameters and security satisfaction of the stairway in three representative communities in Yuzhong District,Chongqing.It is found that the safety evaluation of most community stairways is not optimistic,and the physical parameters are low.The sidewalk standard in the urban road lighting design standard is not referential.It is necessary to put forward a relatively reasonable screening standard for night light environment of risk stairways.The fifth chapter is the ladder supplementary lighting form experiment.This part explores which of the three forms of low-level lighting(step lighting),medium street lighting(3 ～ 4m)and high-level street lighting(5 ～ 6m)is more suitable for supplementary lighting in adverse light environment through on-site experiments.The experimental results show that:(1)median lighting is the optimal strategy,which is suitable for most of the old community stairways.(2)High level lighting is applicable to the stairway near the public activity area,but it is limited by the height and is limited in the type of covered stairway.(3)Low level lighting is not suitable for stairways with low illumination in the original light environment,but it has the characteristics of flexibility,novel and beautiful form.It is suitable for stairways with high illumination but low uniformity.The sixth chapter is the minimum illumination experiment of the supplementary lighting of the stairway.Through the field experiment,it is found that:(1)when there is no shadow in the stairway,it is recommended to use 1.35 lx as the screening index of the risk stairway.(2)When there is a large area of shadow in the stairway,it is recommended to measure the average illuminance values at the two light dark intersection lines.According to the minimum illuminance corresponding to the shadow area of 1.52,1.65,1.75 and 1.79 lx when the illuminance of the bright area is 2.5,5,7.5and 10 lx,or directly substitute it into the fitting equation.(3)When the stairway has a small shadow but does not affect walking,it is recommended to measure the minimum illumination in the non shadow area,and still use 1.35 lx as the screening index of the risk stairway.Finally,the above research results are summarized and analyzed,the future research work is prospected,and some suggestions are put forward for the follow-up research on the lighting environment of the stairway in the old community.