The Construction Technology Discussion Of Huangmeishan Twin-arch Tunnel Under The Condition Of Large Span, Low-burying And Soft Surrounding Rock

Huangmeishan Tunnel is the controlling project of Maanshan-Wuhu Expressway, and also the 1st large span twin-arch tunnel constructed under the condition of shallow burying soft surrounding rocks in Anhui Province.The depth buried at the port of the tunnel is shallow,and it is covered with accumulated and disposal soil. Because of the loose surrounding rock,and its poor bearing capacity,the hidden danger of collapse and top ascending is existed. The construction technology of twin-arch tunnel under the condition of large span, low-burying and soft surrounding rock is fully discussed and deeply studied in engineering analogy methed in the paper.with the study subject of Huangmeishan tunnel of Maanshan-wuhu Expressway. The main contents including:1. The application of the technology of pre-grouting for strengthening in deep hole from surface.2. The application of the technology of long pipe shed construction.3. The construction technologies of cave without top fill and tunnel gate.4. The discussion on the technology of T-cave for twin-arch tunnel and middle separated wall.5. The application of supporting technology in early period and surveying technology.6. Summary on technology and comments...