investigation of an instrumented deep tieback-nailed hybrid excavation in tehran alluviums

By increasing population and development of large cities, underground space necessity and deep excavation are felt more than ever. in some parts of tehran alluvium, due to appropriate geotechnical conditions, it is possible to excavate deeper than 20 m. these excavations cause horizontal deformation and settlement more than the permitted range. considering the implementation of these projects in urban areas and the presence of sensitive residential buildings in the vicinity of it justifies more detailed examination of these project’s designs. in most cases, designers use combinational methods to maintenance the excavation wall in order to prevent faults and control deformations within the permissible range. few studies on these cases make it difficult to design them and estimate the deformations. in this research, by investigating the deep and large-scale instrumented excavation in tehran's alluvium, which has been used a combination of nailing, anchorage, and piles system to stabilize walls. the effect of various structural and geotechnical parameters on deformation has been dealt with. this study was carried out using the finite element method by (2d&3d) numerical modeling with plaxis software. finally, the results of modeling are compared with instrumentation data. the outputs indicate the precise approximation by modeling results with the values that obtained from the tools. as a result of parametric analysis, the factors affecting the deformation of the deep excavation was divided into four categories, including very high impact, high impact, medium impact, and low impact.

Investigation of An Instrumented Deep Tieback-Nailed Hybrid Excavation in Tehran Alluviums

by increasing population and development of large cities, underground space necessity and deep excavation are felt more than ever. In some parts of Tehran alluvium, due to appropriate geotechnical conditions, it is possible to excavate deeper than 20 m. These excavations cause horizontal deformation and settlement more than the permitted range. Considering the implementation of these projects in urban areas and the presence of sensitive residential buildings in the vicinity of it justifies more detailed examination of these project’s designs. In most cases, designers use combinational methods to maintenance the Excavation Wall in order to prevent faults and control deformations within the permissible range. Few studies on these cases make it difficult to design them and estimate the deformations. In this research, by investigating the deep and large-scale instrumented excavation in Tehran's Alluvium, which has been used a combination of nailing, anchorage, and piles system to stabilize walls. The effect of various structural and geotechnical parameters on deformation has been dealt with. This study was carried out using the finite element method by (2D&3D) numerical modeling with PLAXIS software. Finally, the results of modeling are compared with instrumentation data. The outputs indicate the precise approximation by modeling results with the values that obtained from the tools. As a result of parametric analysis, the factors affecting the deformation of the deep excavation was divided into four categories, including very high impact, high impact, medium impact, and low impact.