大断面黄土隧道近接下穿古长城遗址设计方案论证

Demonstration of design scheme of large section Loess tunnel passing through the ancient Great Wall site

国道227线老城关经西宁至上新庄段公路尕沟隧道K16+350处下穿明长城遗址,下穿处隧道埋深58m—65m,地质条件复杂,施工风险极高。本文以该工程为依托,通过多方案论证比选及现场实测资料,得出采用水平旋喷桩预加固技术可有效解决洞内涌水及隧道变形问题,研究成果可为今后大跨黄土隧道下穿古长城设计提供借鉴。

The gagou tunnel K16+350 of National G227 old Chengguan passes through Xining to Shangxinzhuang,and goes through the Ming Dynasty Great Wall ruins.The tunnel is buried 58m-65m deep,with complex geological conditions and high construction risks.In this paper,based on the project,through the comparison of several schemes and the field measurement data,it is concluded that the horizontal rotary jet grouting pile pre-reinforcement technology can effectively solve the problems of water inrush and tunnel deformation,and the research results can provide reference for the future design of large-span loess tunnel under the ancient Great Wall.