Research On Suitable Scale Combination Of Underground Commercial Street Based On Virtual Reality

With the development of social economy,the development and utilization of underground space has become an important direction of urban development.The underground commercial street is an important part of the underground space.In this space,people carry out a lot of social activities,and the demand for its environmental quality gradually increases.They begin to consider the impact of scale,cognition and other factors on the space environment.In the underground commercial street,different spatial scales can bring people different cognition.Therefore,it is the premise of forming humanized design to explore the appropriate scale of space by analyzing the relationship between scale and cognition.Based on the three scale elements of scale space,this paper constructs one-dimensional scale combination,two-dimensional scale combination and three-dimensional scale combination,and takes the scale combination of three dimensions as the research object to explore the appropriate scale combination of underground commercial street with the help of virtual reality technology and spatial cognitive theory.Based on the scale measurement of 62 underground commercial streets in Shanghai,Nanjing,Chengdu,Xuzhou and other cities,the length,width and height are determined and combined according to the frequency analysis to form the experimental model of underground commercial street with different scale combinations.The cognitive evaluation experiment(Experiment 1)and three-dimensional scale combination-appropriate length selection experiment(Experiment 2)of scale combination of underground commercial street are carried out by using virtual reality technology,and finally get two rounds of experimental data and explore the appropriate scale combination.In Experiment 1,the cognitive evaluation of different scale combination of underground commercial street is carried out,and the quantitative data of spatial cognition is obtained;in Experiment 2,the appropriate length of fixed width and height underground commercial street is selected,and the appropriate length range of three-dimensional scale combination is obtained.The research results show that: 1)In the combination of one-dimensional scale,the width has a greater influence on the spatial cognition of the underground commercial street.When the width of the local commercial street is about 5.4 meters,the overall spatial awareness is better,indicating that this value can be as the recommended data for the width of underground commercial streets.2)Compared with the one-dimensional scale combination,the two-dimensional scale combination has a greater impact on spatial cognition,among which the aspect ratio L/D,aspect ratio D/H,and positive interface angle V2 are important scale combinations that affect the spatial recognition of underground commercial streets.The suitable range and its variation law corresponding to L/D,D/H and V2 are obtained through analysis.The suitable range of two-dimensional scale combination is: L/D's suitable range is about 7.0-14.3,the most suitable range is about 9.2-10.0;D/H's suitable range is about 1.1-1.6,the most suitable range is about 1.2-1.3;V2's suitable range is about 36.7 °-48.5 °,and the most suitable range is about 43.9 °-44.1 °.The suitable range of L/D decreases with the increase of height,the suitable range of D/H increases with the increase of length,and the suitable range V2 decreases with the increase of length.3)Compared with the two-dimensional scale combination,the three-dimensional scale combination uses three dimensions to limit the space of the underground commercial street,through which we can understand the spatial scale more comprehensively.The suitable range and change rule of 3D scale combination are obtained through analysis.The suitable range of three-dimensional scale combination is: when the width is 3.3m,the suitable length range is about 35-49 m,the most suitable length range is about 35-46m;when the width is 5.4m,the suitable length range is about 42-70 m,the most suitable length range is about 46-66m;when the width is 8.7m,the suitable length range is about 45-70 m,the most suitable length range is about 52-70 m.Among them,the four sets of the most suitable three-dimensional scale combination are: when the width is 3.3 meters,the height is 3 meters,and the most suitable length of underground commercial street is about 43-46m;when the width is 5.4m,the height is 4m and 4.5m,and the most suitable length of underground commercial street is about 50-55 m and 49-53m;when the width is 8.7m and the height is 5m,the most suitable length of underground commercial street is about 52-65 m.The change rule of the suitable range of three-dimensional scale combination is: when the width is 3.3m,the suitable length range first decreases and then increases with the increase of height;when the width is 5.4m,the suitable length range gradually decreases with the increase of height;when the width is 8.7m,the suitable length range gradually decreases with the increase of height.In this paper,virtual simulation experiment is used to study the appropriate scale combination in the underground commercial street,trying to get the important scale combination and its appropriate range and change rule that affect the spatial cognition of the underground commercial street,hoping to provide suggestions for the design of urban underground space.