Abstract: To investigate the mechanical characteristics and sealing property of the rubber ring of a rectangular pipe jacking tunnel joint, the critical state value of the joint in case of waterproof failure is calculated using the joint detail dimension relation expression. Then, the joint′s installation model is established using finite element software, and the joint′s installation clearance and pipe section′s deflection angle are quantitatively changed. Finally, the simulation and theoretical calculation results are compared. The comparative results show the following. (1) The mounting force of the rubber ring increases to the peak value first and then decreases to a constant value with an increase in the mounting distance, and the mounting gap′s size significantly affects the mounting force. (2) When the compression height of the rubber ring ranges from 8 to 14 mm, the rubber ring has a good waterproof performance, whereas the rubber ring does not meet the requirements of the specification when the height is <8 or >14 mm due to contact pressure <0.3 MPa and excessive compression. (3) The maximum allowable deflection angle is 0.02 rad when the pipe joint is deflected. When the deflection angle further increases, the leakage damage due to insufficient contact pressure, contact damage between the steel sleeve ring and socket pipe joint, separation damage between the steel sleeve ring and rubber ring, and damage due to excessive compression of the rubber ring occurs successively.

Key words: rectangular pipe jacking tunnel, joint rubber ring; finite element, installation gap, pipe joint deflection angle