&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp连拱隧道的开挖方法
连拱隧道是现代高速公路设计与质量最为重要的一项施工。
连拱隧道的开挖方法：
&nbsp&nbsp1)开挖之前,要对照设计图纸认清围岩的种类和设计的施工方法及材料；
&nbsp&nbsp2)Ⅰ、Ⅱ类围岩,应该进行台阶法开挖；
&nbsp&nbsp3)&nbspⅢ、Ⅳ类围岩，进行全断面法开挖。