大直径盾构隧道盾构井顺作法与逆作法受力分析对比

Comparison of Forces Applied on the Working Shafts of Large-Diameter Shield Tunnels by the Bottom-Up and Top-Down Methods

基坑工程顺作法施工工艺简单,在浅基坑和中小基坑中受到广泛应用;逆作法工艺虽然复杂,但对于深大基坑安全性好,在结构受力和对基坑变形的控制上,逆作法的优势比顺作法更加明显。文章以长沙南湖路过湘江大直径盾构隧道南线盾构接收井为例,对盾构井采用顺作法和逆作法的围护结构及主体结构进行了受力分析对比,根据对比结果得出大直径盾构隧道盾构井宜推荐采用逆作法施工的结论,并通过实例验证了推荐工法的合理性和优越性。

Compared with the bottom-up method, which is widely used in the construction of shallow, medium and small foundation pits, the top-down method is more complex but has obvious advantages in controlling struc- tural performance and deformation, which contribute to the safety of construction of deep and large foundation pits. Using the receiving shaft on the south line of the river-crossing large-diameter shield tunnel on Nanhu Road of Changsha City as an example, this paper compares and analyzes the forces applied on shafts constructed by the bottom-up and top-down methods, indicating that it＇s better to choose the top-down method for the working shaft construction of large-diameter shield tunnels.