Shafts by the Sequential Excavation Method: Mechanical vs Hydro-mechanical calculations

The application of the SEM in the vertical direction allows shaft excavations, using the phases shown in Figure 1 and explained below:

i. The 1st phase can involve water table (WT) variations or not and the WT lowering can happen before (as shown in Fig. 1) or while the excavation takes place. At the same time takes place the construction of the capping beam;

ii. Excavation of the 1st ring; iii. Construction of the support of the 1st ring; iv. to vi. Repeat phase ii and iii to the remaining

rings ending with the excavation of the last ring (v) and construction of the respective support (vi).