Research on Effect of Grouting Circle on Seepage Field of Subsea Tunnel

According to a real project of Jiaozhou Bay subsea tunnel, the effect of grouting circle on the seepage field was discussed. The calculation results showed that the principle of "to block mainly, to emit limitedly" should be taken in the waterproofing and drainage of subsea tunnel. If the grouting circle effect was used on the condition of the same effect of water plugging, the thinner the thickness of grouting circle and the smaller permeability coefficient of grouting circle required. The role of grouting circle was that decreasing the gushing water quantity by means of blocking the seepage paths of groundwater, so as to achieve a smaller discharge could significantly reduce the external water pressure of lining. When the tunnel gushing water quantity was equal to the control discharge, it was considered as free drainage and the lining could not bear the water pressure.