Excavation Pits: Calculation Methods

摘要

Three methods in engineering practice are mainly implemented to investigate the behavior of excavation walls. In the majority of the cases beam models with classical supports seem to be sufficient. For modelling more accurate the deformation behavior of the foot of the wall it may be worth to improve the prediction of the deformation behavior using a subgrade reaction model. In cases of more complex pit geometries and soil conditions a finite element analysis may be more appropriate. All these three methods of calculation are shortly described in the paper and compared with each other. With the consideration of bound theorems an attempt is made in the paper to discuss the safety issues. All the presented three methods can be used to calculate the wall deformations. It is demonstrated that even a finite element analysis has limitations in cases of deformation predictions induced due to geotechnical installation processes in the vicinity of the wall. Data from field records may be used to estimate the order of magnitude of wall deformations due to installation processes. As an example of using field data in the wall deformation prediction and FEM in a recent research project the vibroinstallation of uplift piles near to the wall has been used. The numerical results show quite satisfactorily that the new developed model may serve as a basis for the prediction of wall deformations due to some installation processes.