酸刺沟隧道出口水平旋喷桩施工技术

主要介绍水平旋喷桩在隧道软弱围岩中施工工艺及加固效果的应用。酸刺沟煤矿铁路专用线隧道出口施工时,经现场核实均与设计图纸相符,泥岩与粘性土经地下水长期浸泡饱和后形成稳定性极差的软塑-流塑状地层,即形成泥岩与粘土的互化层,隧道在开挖施工中极易滑坍。为解决通过这种隧道地质的施工方法,保证隧道永久质量和施工中的安全,采取新工艺、新材料和新方法,着重考虑隧道超前预加固,通过对超前小导管、超前小导管预注浆、大管棚、深孔注浆、水平旋喷桩、水平搅拌桩和水平固结等方案比选,决定采取水平旋喷桩施工技术,主要研究软弱围岩隧道施工中如何应用水平旋喷桩,初步拟选桩直径、桩长、外插角和循环距离等技术参数,通过现场施工,顺利通过该隧道软弱围岩段,在该隧道软弱围岩段成功地应用了水平旋喷桩,值得推广和借鉴。

Construction Technology of Horizontal Rotary Jet Grouting Pile In Suancigou Tunnnel Exit

The application of construction technology and reinforcement effects of horizontal rotary jet grouting piles used in the tunnel with soft rocks around were mainly introduced.When the tunnel exit construction of Suancigou mine special railway was conducted,the actual conditions were in line with the design drawings after verification on site and it was found that mudstones and clay soil had formed a soft plastic-fluid plastic like formation with poor stability after long-term immersion by groundwater,which was the inter-layer of shale and clay,as a result,the tunnel was liable to collapse during excavation stage.In order to find a construction method through this tunnel soil and ensure the quality and safety of tunnel construction,new technology,new materials,new methods were adopted,which focused on the advanced pre-reinforcement of tunnel.Through comparing the plans of advanced small catheter,pre-grouting of advanced small catheter,big pipe shed,deep-hole grouting,horizontal jet grouting pile,horizontal mixing pile and hrizontal consolidation,the construction technology of horizontal rotary jet grouting pile was applied finally.How to use horizontal jet grouting piles in soft rock tunnel construction was mainly analysed and the technical parameters of pile diameter,pile length,outside angle and cycle distance were preliminarily determined.Through the construction on site,the soft surrounding rock of this tunnel was passed through eventually and the horizontal jet grouting pile was successfully applied,which was worth popularizing and reference.