Abstract:
An earth retention system (ERS), whether it is a temporary or permanent, has become a main engineering item in urban setting. The system enables a below grade construction which could go up to several stories deep in the middle of high rise buildings. It also protects adjacent buildings and properties and supporting networks of underground utilities during construction. In order to protect the adjacent buildings and neighboring underground utilities, the ERS system needs to be engineered to meet strength requirement as well as performance criteria to limit the ground movement and settlement. Although the strength design methodology of an ERS system is well defined and established, we cannot say for the same regarding the performance design aspect.Â
The design and engineering of an ERS system to limit and bound the ground movement require a fairly accurate estimation on how the ERS system would perform during construction, especially excavation. The estimation and prediction of the ERS system’s performance often entails a finite element analysis considering non-linearly. It also needs to include construction sequence as staging analysis to capture irreversible deformations and their contributions to the performance of the ERS system, which directly affects the vicinity area settlement during and after the construction.
Two project case histories will be presented to illustrate the author’s design methodology application during design phases. This will include recommendations on analytical representation of an ERS system and what construction stage needs to be included as an analytical stage. Lastly, the ERS system’s performance prediction will be compared with construction monitoring data, which showed very close correlations.