矩形顶管隧道接头橡胶圈防水安全限值研究

Waterproof Safety Limit of Rubber Rings of Rectangular Pipe Jacking Tunnel Joints

为研究矩形顶管隧道接头橡胶圈的受力特性和密封性,利用接头细部尺寸关系表达式,计算接头在发生防水失效时的临界状态值,通过有限元软件建立接头安装模型,定量改变接头安装间隙和管节偏转角,将模拟结果与理论计算结果进行对比验证。结果表明:1)橡胶圈安装力随安装距离的增加表现为先增大到峰值,后减小到定值,且安装间隙的大小对安装力影响显著;2)橡胶圈压缩高度在8~14 mm时接头防水效果良好,当橡胶圈压缩高度小于8 mm或大于14 mm时,橡胶圈分别因接触压力不足0.3 MPa或过度压缩而不满足规范要求;3)管节发生偏转时,最大允许的偏转角为0.02 rad,当偏转角进一步增大,依次发生因接触压力不足引起的渗漏水破坏、钢套环与插口管节接触破坏、钢套环与橡胶圈的脱离破坏以及橡胶圈过度压缩导致的破坏。

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.