Key Issues And Basic Strategies For The Civil Use Of Urban Deep Underground Space

With the accelerating process of urbanization,the population of the city is increasing,and the capacity of the ground space construction is increasing rapidly.Problems such as waste of land,space congestion,inadequate infrastructure,traffic congestion and other problems have deteriorated in the city.Under the background of three-dimensional urban development,making full use of underground space has become an important measure to improve urban capacity,relieve urban traffic pressure,improve urban environment and develop urban economy.In order to make more rational planning of underground space deployment,strengthen the coordination of the relationship between it and the city,in recent years,our country has introduced policies related to the planning of underground space at the national level.Besides,many cities have also carried out policies related to underground planning with the guidance of national policy in the process of new towns,guiding and controlling underground space with normative regulations.The development and utilization of deep underground space has become a hot topic based because of the saturated development and utilization of subsurface underground space in many cities.In the planning of underground space,each city has also made a corresponding division of the level and depth of the underground space and plans for the short term and long term development.Entering the deep underground space is the inevitable trend of the further expansion of urban land resources,the expansion of functions and regeneration of urban environment.Because of its special space environment of the deep underground space,traditional planning often reserved it for military or municipal facilities.However,in recent years,there has been many domestic and overseas projects that puts civil functions into deep underground space,such as subway stations,teaching buildings and garage,which poses new challenges to the construction standard of underground space.Firstly,this paper analyzes the relationship between underground space depth and civil function from the perspective of policy and phenomenon by sorting through the development process of underground space function and depth.The paper then analyzes on the existing deep underground civil projects,and divides them into new civil projects and non newly-built projects,summarizing the realistic background causes of different types of projects.Based on this phenomenon and policy background,this paper focuses on the key issues of civil projects in deep underground space,and puts forward three aspects: safety,psychological perception and spatial connection.Firstly,regarding the core issue of safety,the paper starts from the existing underground space fire safety regulations and high-rise building fire safety regulations,fully analyzing the similarities and differences between deep underground space and the two,and extracting some points worth learning from.Then some defects of the traditional evacuation methods used in the deep underground space are analyzed.Secondly,as for psychological perception,the paper analyzes the influence of deep underground space on people’s physical and mental health and the differences of influencing factors between deep underground space and shallow underground space.The last issue is the connection of underground space.Based on the status present underground space connections and the trend of networking development,the necessity of deep underground space networking is put forward in order to relieve urban pressure,facilitate safe evacuation and enhance the function of civil air defense.Finally,as to each key problem,the adaptive designing strategy is put forward based on the existing projects and regulations.Taking Chongqing HongTudi rail transit station as an example,the paper puts forward the designing strategy for the fire safety issue of the underground subway stations.