Abstract
Buttress walls are a common construction method in Taiwan for protection of adjacent buildings during excavation but their mechanism in restraining movements was not fully understood. This study performs three-dimensional finite element analyses of two excavation cases with buttress walls to establish the numerical analysis model. Then a series of parametric study were performed by varying the length of buttress walls. Results show that the main restraining effect for rectangular shape buttress walls comes from the frictional resistance between the buttress walls and adjacent soil while the buttress walls were demolished along with the removal of soil. The efficiency of reducing wall deflection will increase with length of rectangular shape buttress wall. If the rectangular shape buttress wall length was less than 2.0 m, the buttress wall was unable to restrain the wall deflection. The restraining effect for T-shape buttress walls comes from the frictional resistance between the buttress walls and adjacent soil and bearing resistance from the flange. Increase of the web length has a slightly better effect in reducing the wall deflection than that of the flange length for T-shape buttress wall.
