Research on the Design of Space Renewal under the Urban Viaduct from the Perspective of Public Space ----Taking the Lijiao Section of Guangzhou Ring Expressway as an Example

As urban scales continuously expand, the mileage of roads and rail transit lines has rapidly increased, with various rapid transit facilities often adopting elevated forms. While initially aimed at alleviating urban traffic congestion, these viaducts have also brought numerous issues: they alter the city's original appearance, create negative gray spaces, fragment urban space and cultural continuity, and even breed new social problems. The rational and efficient utilization of the space under urban viaducts can, to a certain extent, effectively meet citizens' growing demand for public space and tap into the potential of urban space. Currently, cities such as Beijing, Guangzhou, Chongqing, Shanghai, and Shenzhen have not only introduced relevant policies but also implemented many successful cases of under-bridge renovation and utilization. However, theoretical research on under-bridge renovation and utilization in China is still in the exploratory and improvement stage. This paper first identifies the space under urban viaducts as the research object. Through basic research on the characteristics of China’s urban viaducts and under-bridge spaces, a systematic study of the current status of under-bridge space renewal in Guangzhou, and an analysis of relevant policies and design guidelines—particularly those in Guangzhou and Beijing, including the Beijing Municipal Under-Bridge Space Utilization Design Guidelines—the study summarizes existing problems and draws on relevant experiences. Furthermore, by examining domestic and international under-bridge project cases, it proposes universal design strategies for urban under-bridge spaces. These strategies cover six aspects: functional reorganization and reuse, spatial remodeling and sequential experience, traffic integration and flow organization, spatial narrative construction and cultural implantation, ecological technology and sustainability, and shared development with orderly management. Finally, the study applies these strategies in a practical context. Focusing on the under-bridge space of the Lijiao section of the Guangzhou Ring Road, and against the backdrop of the Haizhu Innovation Bay (Lijiao Area) planning, the research analyzes the current conditions of the bridge and its surroundings, identifies key issues, and applies the proposed design strategies. In line with Guangzhou’s policy of building a “ring park” under the expressway, and considering the needs of surrounding residents and the environment, the project aims to enhance the quality and functionality of the under-bridge space, reconnect urban fabric, preserve the memory of the original market beneath the bridge, and continue the local cultural lineage of Lijiao. The goal is to create a high-quality public space for residents. A “one axis, six zones” design scheme is proposed: using the Ring Road Viaduct as the axis, a linear spatial sequence is created under the bridge, connecting urban areas along the route and forming six functional zones—children’s recreation, public leisure, commercial bazaar, cultural exhibition, sports, and ecological nature. This scheme aims to promote social interaction between the north and south sides of the viaduct, integrate surrounding urban functions and spatial structures, and, based on the principles of co-construction and sharing, transform the under-bridge space into a high-quality public area with diverse functions, varied spatial forms, good accessibility, and integration of ecological concepts and local cultural elements.