Study On The Top-down Construction Method Of Underground Structures

The top-down construction method is a practical and effective engineering construction technology used in multi-tiered basements of high-rise buildings and in multi-tiered underground structures. The technology has been researched and developed in such developed countries as the United States, Japan, Germany and France for over 60 years. Moreover, it has been extensively utilized in the construction of multi-tiered underground structures, including basements of high-or super-high-rise buildings, underground structures of large-scale malls, underground parking lots, subway, tunnels, large-scale waste-water pools, and has gained satisfactory results.On the basis of current domestic circumstances, the technology has been utilized in many projects and obtained considerable social and economic benefits. However, because there is no corresponding design and construction codes for Top-down Construction method in China, it is inevitable to generate some engineering accidents, especially the collapse of exterior-protected construction. These accidents not only resulted in huge economic losses but also damaged peripheral surroundings.Based on the domestic and foreign factual conditions and documents, this dissertation states the developing process of Top-down Construction technology and related engineering characteristics. Furthermore, by combing current domestic circumstances, the dissertation clarifies the details of its construction process, including engineering survey of soil and rock, design, construction, supervision, measurement, and quality standards. The statement in the dissertation coordinates the relationship between the design and construction of Top-down Construction method, and guarantees the safety, applicability, sophistication in technology and practicability in economy.