摘要:In the construction industry, there are two methods for constructing basements (Top-Down) and (Bottom-UP). The difference between them lies in the sequence of works, since in the (Bottom-Up) method the end of the excavation work is the necessary condition for the beginning of the substructure construction, and this is different from the (Top Down) method where excavation and construction of the substructure and the superstructure are carried out in parallel, which significantly reduces the project duration but at the same time increases the construction cost. Also there is a difference in terms of use for each of these two methods, for example, it is preferable to use the (Top-Down) in dense urban areas, where there is not enough space for the construction and where there are concerns that the adjacent buildings may be deformed as a result of construction, and this is what the (Bottom-Up) method cannot provide. In order to determine the optimal method from a mathematical point of view, 7 main criteria and 25 sub-criteria were identified, and the Analytic Hierarchy Process was used to solve this multi-criteria problem. Using the Expert Choice software, we found that the (Top-Down) method is preferred by 14.8% more than (Bottom-Up), and a sensitivity analysis was performed to determine which criteria dominated our optimal result.