Prediction of Diaphragm Wall Deflection by Using Different Models for Deep Excavation in Sands

The purpose of this investigation is to assess and contrast findings from analyses of deep excavations in an undrained condition using the most used three soil models. In this research, three distinct soil models were employed to predict the ground surface settlement and diaphragm wall deflection for deep excavation in sands. These models included the Mohr–Coulomb model (MC model), the hardening soil model (HS model), and the hardening soil small strain model (HSS model). A case study of a deep excavation that actually takes place in layers upon layers of sand in Kaohsiung city, Taiwan, and had well-documented monitoring data is employed for the analysis in this study, and soil investigation results compiled for the construction project served as the basis for selecting the geotechnical parameters. The results show that the wall deflections predicted by the Hardening soil with small strain model are relatively close to those results, which were derived from field measurements. The hardening soil model produces superior results, when compared to the Mohr–Coulomb model. The ground settlement results predicted by any of the three soil models were poor. To anticipate the wall deflection and compare the results of the 2D analysis, a 3D analysis in PLAXIS was also carried out in this study, and the outcomes of the 3D analyses were nearly identical below the excavated depth to those of the 2D analyses. This research shows that HS and HSS models in numerical calculations are useful for predicting the soil behaviour during excavation, and researchers and engineers can use the findings of this work to improve the accuracy of their numerical studies using constitutive soil models.