地铁站域垂直转换空间"步行交通·公共活动"双适应性研究OACHSSCD

As an important vertical transition space connecting urban ground-level areas with underground metro systems,sunken plazas at metro station entrances and exits serve both the dispersion of pedestrian traffic and the accommodation of public activities.They are important interfaces for the expansion of metro station areas to urban public spaces.In the context of Transit-Oriented Development(TOD),such spaces play a crucial role in improving pedestrian efficiency,activating public life,and enhancing the comprehensive utilization of station areas.However,early field investigations indicate that existing sunken plazas are challenged by fragmented spatial organization and functions between traffic and public activities,low spatial utilization efficiency,and conflicts between activity stopover and traffic travel,thus restricting the full development of composite spatial values in station areas. Sunken plazas at metro station entrances and exits are defined as typical vertical transition spaces,which mainly accommodate pedestrian movement and transfer,with the potential to support public activities from the perspective of dual adaptability between"pedestrian traffic and public activities."In this study,11 sunken plazas from seven metro stations in Wuhan were chosen as the empirical samples.Their spatial morphological features,activity patterns,pedestrian adaptability,and public adaptability were analyzed systematically through the quantification of spatial characteristics,behavioral observation,and subjective perception evaluation. Methodologically,an index system of the spatial characteristics of sunken plazas was established from three aspects:ground plane configuration,vertical enclosure,and facility provision.Next,the intensity,type,and spatiotemporal distribution features of pedestrian traffic and public activities in sunken plazas were examined through field observation and behavioral recording.On this basis,a subjective evaluation method based on emotional perception was introduced,and evaluation factors for pedestrian adaptability and public adaptability were screened using the Delphi method.The dual adaptability evaluation results of the chosen sunken plazas were gained through questionnaires and weighted calculation.Correlation analysis was further applied to explore the relationship between spatial characteristics and dual adaptability performance.The results were explained by combining activity distribution features. The results reveal significant differences among sunken plazas in terms of spatial form,activity organization,and adaptability.Generally speaking,pedestrian adaptability tends to be higher than public adaptability,indicating that the traffic flow efficiency in existing sunken plazas is relatively stable,but public activity experience remains insufficient.Dual adaptability analysis shows that only"high-high"plazas,where both pedestrian and public adaptability are strong,achieve true coordination between traffic function and public use."Low-low"plazas represent the most problematic condition,characterized by deficiencies in traffic and public activities.Correlation analysis further indicates that spatial features of sunken plazas like enclosure height,height-to-width ratio,and seating density are closely related to public adaptability,while activity characteristics mainly reflect behavioral responses to spatial conditions,thus explaining and proving the adaptability results. Based on the research conclusions,some spatial optimization strategies for sunken plazas at metro station entrances and exits are proposed from different perspectives of dual adaptability,including reasonable control over spatial enclosure scale,optimization of traffic-stopover zoning,and increasing configuration of resting and barrier-free facilities to promote the collaborative development of pedestrian traffic and public activities. The study argues that improving the dual adaptability of sunken plazas requires the careful integration of public activities under the premise of maintaining the core functions of transportation architecture rather than a simple overlapping of functions.This study deepens understandings of vertical transition spaces in metro station areas in relation to spatial mechanisms.The results provide theoretical references and design supports for spatial renewal and the composite use of metro station areas.