Parametric study on performance of laterally loaded drilled shafts in an MSE wall

摘要

Drilled shafts are sometimes built in an MSE wall to support superstructures subjected to lateral loads. However, cuiTent design methodology isolates the interaction between drilled shafts and MSE walls, and the designs are independent. This design practice results in inappropriately designed drilled shafts and MSE walls. A three-dimensional numerical model of drilled shafts within an MSE wall was developed using FLAC3D and was calibrated with published data of a full-scale field study. Then the calibrated model was used for a parametric study to investigate the influence of various parameters on the synergistic performance of the drilled shafts and the MSE wall. The performance was assessed in terms oh' lateral displacement of the drilled shaft and MSE wall, the induced lateral earth pressure, and the induced strain in the geogrid. The investigated parameters in this study included the backfill material properties, the geogrid tensile stiffness and length, the distance between the drilled shaft and the MSE wall, and the length of the drilled shaft. An elastoplastic soil constitutive model, able to consider the compression and shear hardening, was used for the backfill material. The facing of the MSE wall was simulated as an assembly of discrete blocks which interacted with each other through interfaces. It was found that the properties of the backfill material, the distance between the drilled shaft and MSE wall, and the length of the drilled shaft had influence on the deflections, lateral earth pressure and strain in the geogrid. The extent of the influence varied and depended on the loads. The geogrid tensile stiffness and length did not show salient influence. (C) 2015 The Japanese Geotechnical Society. Production and hosting by Elsevier BA/. All rights reserved.