浅埋公路隧道洞口段施工技术探讨（Discussion on construction technology of portal section of shallow buried highway tunnel）.docVIP

浅埋公路隧道洞口段施工技术探讨（Discussion on construction technology of portal section of shallow buried highway tunnel） Discussion on construction technology of portal section of shallow buried highway tunnel Zhou Zebing 1 Chen Anwu 2 (1 Jiangxi Keli consulting Supervision Co. Ltd. Nanchang 330003) (2 、 China Railway eleven Bureau Group Third Engineering Co., Ltd., Shiyan 442000) Abstract: according to the actual construction experience of the Peach Garden tunnel, according to the shallow buried depth and poor geological condition of tunnel portal area, Put forward some effective and reasonable solutions to ensure the construction safety and quality of the hole. Key words: highway tunnel; shallow buried; portal section; construction technology 0 Preface The Peach Garden tunnel is located in Jiangxi province Jiujiang County, is the control project of Mount Lu ring phase two project in Nanshan Road, highway is a road (mountain), with separate one-way traffic two lane tunnel (up and down), the design speed of 60km/h. Tunnel width 10.45m, height 7.10m, the excavation width 12.50m, height 10.25m. The tunnel entrance is a weak link in the construction of the tunnel, the the Peach Garden tunnel left line has a length of about 500m in the valley, the geological conditions are very complicated, the above is strong weathering argillaceous siltstone, mainly for slope soil and alluvial soil, wind Ling broken, mud volume, most of the water rich and some become saturated, in the rain season catchment is very large, the surface vegetation due to small debris flow after the destruction of the construction, soil and water loss is very easy, but the cover is thin, the left arch waist covering layer is only 90cm thick, and there is a bias phenomenon, most positions covering the thickness of about 10m, the shallow buried section length more than 80m, is a typical shallow buried tunnel. The surrounding rock is weathered, mud, and hillside catchment area is quite large, after the excavation of surface