Abstract:

The jacking force required for the construction of rectangular pipe jacking tunnel should be calculated more accurately, and the variation law of the soil behind the working shaft after superposition of disturbance of jacking force for many times during the construction of smallspacing pipe jacking tunnel group should be revealed. Therefore, the calculation formulas of jacking force applicable to rectangular pipe jacking is deduced based on the existing calculation formula of jacking force, and the measured data of horizontal displacement and earth pressure of the soil behind working shaft in a pipe jacking tunnel group construction is analyzed, so as to prove the correctness and rationality of the calculation formula of jacking force for rectangular pipe jacking. It is concluded that the horizontal displacement of the soil behind working shaft under jacking force are an arched distribution with the maximum value at the center of the tunnel, and the soil will change significantly under the secondary action of jacking force and the residual stress will exist. The empirical formulas of the horizontal displacement and the earth pressure of the soil behind working shaft under the action of jacking force are obtained by processing the data between the jacking force and the horizontal displacement of the soil behind working shaft, and the data between jacking force and the earth pressure by statistical method.

Key words: rectangular pipe jacking tunnel group, soil behind working shaft, theoretical calculation, monitoring data