Abstract:In Tender A2 of right line of Xiamen Xiang¢an subsea tunnel,weathered slot F1 is needed to cross through. The feasible tunnel construction scheme to cross F1 weathered slot is important to the subsea tunnel construction. The subsea tunnel project has characteristics of difficult construction,limited construction time,large construction risk and higher construction quality. With consideration of Xiamen Xiang¢an subsea tunnel engineering geology characteristics,the general construction scheme for crossing through weathered slot F1 is proposed. The emphasis is made on the prediction and investigation of engineering geology,the rock mass excavation and lining scheme,the curtain grouting,the construction drainage system,the tunnel lining construction and the preparation scheme. The TSP203 geology prediction method is applied to the approach of the weathered slot F1,which gives guidance to determine the strength parameters of rock mass and underwater pressure. The improved double-side guiding whole tunnel-lining scheme is proposed to replace the original tunnel-lining scheme. Both the advantages and disadvantages of the improved tunnel-lining scheme are discussed. The rock grouting method is used to strengthen the rock mass from water permeation. Grouting schemes for the left and right guided holes,the guidance holes strengthening region and the forward grouting for central hole are discussed. The drainage system is illustrated,and the drainage system location,waterproof strobe are presented. The detailed construction scheme for crossing weathered slot F1 is proposed,which can provide some references to the engineering case.