| dc.description.abstract | ABSTRACT
Diaphragm walls are frequently adopted as soil retaining systems for excavation. However, it is inefficient to excavate in a vast area by using horizontal struts and it is not convenient to do the underground construction work afterward. As a consequence, a double-wall retaining system was developed and used for excavation in a good ground condition.
In this research, centrifuge modeling tests were adopted to simulate the process of excavation to investigate the effects upon adjacent area in various excavation depths and penetration depths by using a single-rail pile wall or a double-rail pile wall as retaining systems.
The results show that the shape of the ground settlement induced by excavation in this study was a triangular one, when a single-rail pile wall or a double-rail pile wall was selected to be the retaining system in sandy layer. The extent of affected area was 1.1 times the pile length behind the wall. Furthermore, the maximum surface settlement can be calculated from the horizontal deformation of the top of pile. Nevertheless, in the same excavation/penetration depth ratio, the horizontal displacement on the top of pile and the maximum surface settlement induced by the single-rail pile wall system were larger than those induced by the double-rail pile wall retaining system. Moreover, the moment and shear force which occurred in the double-rail pile wall system were also less than those in the single-rail pile wall system. Therefore, it would be more stable if the double-rail piles were used as a retaining system. The research also indicated that the front piles and the rear piles would interact with each other during excavation due to the constraint of the cap beam and the distribution of moment and shear force is quite different. According to the research, it may be suitable to assess the stability of the double-rail pile wall system by treating it as a gravity type retaining wall. | en_US |