Beijing Metro Application of Glass Fiber Reinforcement to Shield Tunneling Construction Safety Risk of Collapse
Shield method is one of the most commonly used construction methods in Beijing (real estate) subway construction. The reinforced concrete structure must be manually broken before the arrival and arrival of the shield and the tunnel. There is a large construction safety risk and the construction period is relatively high. Long, the outer layer after the breakout is directly exposed, and it is prone to water inrush and collapse, resulting in settlement of the surrounding stratum, or even collapse, which may cause the shield to fail to originate and receive normally. Such accidents have occurred in areas such as Nanjing (real estate), Beijing, Shanghai (real estate), Changsha (property), and Tianjin (real estate).
In order to solve the risk and construction period impact of the reinforced concrete structure that broke the hole, the method of directly cutting the hole reinforcement structure by shield cutter is studied. The Municipal Housing and Urban Construction Committee and the Municipal Major Office entrusted Beijing Urban Express Railway Company and Beijing Jianzhu University to carry out the project. Application research of glass fiber ribs in shield origination and arrival and crossing engineering. Glass Fiber Reinforced Polymer Rebar (GFRP) is a glass fiber reinforced composite material that is heat-fused with glass fiber and resin and can be processed into the same form and size as steel. Compared with steel bars, GFRP bars have the advantages of high tensile strength, light weight, good cuttability, good corrosion resistance, low heat conduction and electrical conductivity, and can be used to replace steel bars in reinforced concrete structures. In the shield construction, the use of glass fiber instead of the steel bars at the hole to achieve direct cutting is a trend of shield launching and receiving, eliminating the safety risks caused by the removal of reinforced concrete, which simplifies construction. The process speeds up the construction schedule and reduces construction risks.
At present, the research work of this subject has been completed, and the results have been successfully applied in the Beijing Metro Line 15 project, which has achieved extremely obvious economic and social benefits. The next step will be comprehensively promoted in other projects such as Beijing Metro Line 16.