隧道横洞进双线正洞交叉口导洞法施工研究

Research on the construction of roof raisingat cross tunnel into double main tunnel intersection

为解决隧道横洞进正洞,考虑到加强超前地质预报及排水,顺坡施工或用辅助坑道排水,在先加固后开挖的原则下,采用导洞法进行施工研究。根据地质情况,保证横洞净空不被侵占的前提下,本着对交接范围内初期支护加厚、加宽、加强的原则施作初期支护。横洞距交叉口采用变截面拱架爬坡挑高拱顶施工,两台阶施工,横洞拱顶依次抬高,挑顶进正洞施工导洞拱部采用圆弧形,导洞门架上横梁按正洞拱顶弧形施作并紧贴开挖面,钢架高程逐榀递增,到正洞拱顶中线位置后拱顶钢架高程递减,且递增递减坡度与正洞拱顶曲率增减吻合形成正洞拱部弧形。相交处加强环及正洞初期支护施工完成后,及时施作交叉口的横洞衬砌,再向正洞方向转序施工。

In order to solve the problem of crossing tunnel into the main tunnel,considering the strengthening of advance geological forecast and drainage,construction along slope or drainage with auxiliary tunnel,under the principle of first reinforcement and then excavation,the construction research is carried out by the guide tunnel method.According to the geological conditions,on the premise of ensuring that the clearance of the transverse tunnel is not occupied,the initial support should be made in accordance with the principle of thickening,broadening and strengthening the initial support within the scope of the connection.The variable section arch horizontal hole distance intersection climbing high dome construction,construction of two steps,horizontal hole vault,in turn,raise,ripping into pilot tunnel arch is hole construction department USES the circular arc form,pilot tunnel vault door frame beams by hole arc applied and close to the excavation face,steel elevation by increasing cross,that it was after the central position of the hole in the vault vault steel elevation decreasing,increasing and decreasing slope with vault is hole curvature increase or decrease in formation is arch department curved hole.After the strengthening ring at the intersection and the initial supporting construction of the main tunnel are completed,the lining of the cross tunnel at the intersection should be applied in time,and then the construction should be carried out in the direction of the main tunnel.