Abstract:

UShaped shield uses mobile shield to support foundation pit, and propulsion is an important parameter in design and application. In order to solve the design problem of Ushaped shield propulsion, based on the theory of geomechanics and structural mechanics, the causes and components of thrust resistance of Ushaped shield in the process of propulsion are analyzed. The items of thrust resistance of Ushaped shield are established. Based on the model, theoretical model deduction is carried out for the resistance caused by side rock and soil and additional load, the thrust resistance of front push plate, selfweight friction resistance, climbing resistance, friction resistance of shield tail and pipe joints during Ushaped shield driving. The resistance of each component is calculated combined with geological survey and design parameters, and the proportion of each component is analyzed. In practical engineering applications, the total thrust data under two working conditions are tested and counted respectively, and compared with the theoretical calculation. The results show that the calculated data of the theoretical model is basically consistent with the actual measured data under the two working conditions, which verifies the correctness of the calculation model. The analysis method and results provide reference for the design of similar projects.

Key words: Ushaped shield, thrust resistance, active earth pressure, passive earth pressure, mobile support