- Seismic Analysis of Soil-Structure Interaction.
- Soil Dynamics and Geotechnical Earthquake Engineering.
- Seismic Performance Design of Buildings.
- Numerical Modeling and Simulation.
- Deep Excavation and Earth Retaining Structures.
- Use of Precision Instruments in Excavation Projects.
- Building Damage Assessment for a Building Adjacent to Excavation.
Yeganeh, N., Bolouri Bazaz, J. & Akhtarpour, A. 2015, 'Seismic analysis of the soil-structure interaction for a high rise building adjacent to deep excavation', Soil Dynamics and Earthquake Engineering, vol. 79, pp. 149-170.View/Download from: Publisher's site
© 2015 Elsevier Ltd. Soil-structure interaction is referred to the process in which the soil response is influenced by the structure motion while the latter is influenced by the soil motion. It is of note that the excavation adjacent to the buildings can intensify the effects of soil-structure interaction. In the current research, the soil-structure interaction model and the building-excavation interaction model along with the fixed-base structure model were analyzed on the basis of finite difference method using FLAC 2D , which is capable of analyzing the soil-structure interaction issues. Furthermore, the modified Mohr-Coulomb constitutive model was employed for the soil medium, allowing the implementation of dependency of stiffness on stress as well as the materials unloading behavior by means of the powerful programming language FISH (short for FLACish). Validation of the numerical model was accomplished based on the data extracted from the Tiltmeter installed on one of the columns of the building adjacent to the excavation and the Load Cells placed on the anchors of the excavation wall. The results illustrated that due to the high stiffness and rigidity of the retaining structure system, modeling of the building adjacent to the excavation, whether as surcharge or structural frame, would only influence the settlement profile of the building foundation under static conditions. On the other hand, in the seismic analysis, the type of modeling of the building adjacent to the excavation exerted a remarkable impact on the pile deformation, the bending moment of the pile, the condition for connection of the anchors and soil, the criteria for estimating the probable damage of the structure adjacent to the excavation, and the permanent settlement profile.
Yeganeh, N & Fatahi, B 2018, 'Seasonal Effects on Seismic Performance of High Rise Buildings Considering Soil-Structure Interaction', 16th European Conference on Earthquake Engineering, Thessaloniki, Greece.View/Download from: UTS OPUS
The Seismic Soil-Structure Interaction (SSSI), which is a tangled phenomenon, is concerned with the shear waves in preference to the longitudinal waves on account of a prevalent greater energy content in the former. The need for the high rise buildings in the megalopolises results in the paramountcy of the seismic soil-foundation-building interaction analysis in order to achieve the reliable predictions and mayhap curtail the severe damage and probable partial or total collapse of the superstructures. The seasonal effects could influence the soil moisture content particularly in the vadose zone near the surface, exacerbated by the climate change effects, inducing more frequent floods and drought. Wherefore, a soil-structure model was evaluated in this study, subjected to the soil moisture variations in the vadose zone, by utilizing the 3D finite difference modeling technique through the fully nonlinear dynamic analysis in the time domain considering SSSI during the 1994 Northridge earthquake. In particular, the objective was probing the possible effects of the selected degree of saturation (Sr) values, i.e., 5%, 17.5%, 60%, and 100%, for the noncohesive soil, named 'Glacier Way Silt', in conjunction with the small-strain shear moduli on the seismic performance and its corresponding damage of a 20-story reinforced concrete moment-resisting building frame. It is of note that the said values of Sr were employed for the common 4-m zone of influence in Australia, being a sequel of the natural and artificial wetting-drying cycles. Get to the point, it was concluded that the season, in which an earthquake befalls, is stark prominent insomuch as it is potent to impact the extend of the damage in a superstructure.
Yeganeh, N, Fatahi, B & Terzaghi, S 2017, 'Effects of Shear Wave Velocity Profile of Soil on Seismic Response of High Rise Buildings', International Conference of the International Association for Computer Methods and Advances in Geomechanics, International Association for Computer Methods and Advances in Geomechanics (IACMAG), Wuhan, China.View/Download from: UTS OPUS
There is, nowadays, a conspicuous demand for the high rise buildings in the high-density dwellings of the urban areas; in consequence, harnessing the whiz-bang numerical simulations plus conducting the rigorous experimental studies so as to design and construct such prodigious structures would be essential. Thus, the appropriate parameters for modeling the structure and the soil medium in the Soil-Structure Interaction (SSI) system should be selected. The soil-structure interaction is referred to the process in which the soil response is told on by the structure motion whilst the latter is affected by the soil motion. The current research zeroed in on the soil shear wave velocity and its influence on the superstructure performance. Invoking the weighted average shear wave velocity with the aim of calculating the soil shear modulus, which is closely related to the strength and deformation characteristics of the soil, has been a hotly debated issue since the aforesaid parameter was posited by a plethora of codes and regulations to obtain the soil site classification required for the earthquake design. To that end, the numerical model, having two assorted profiles associated with the shear wave velocity, namely, the in situ non-uniform profile (Case A) and the equivalent uniform profile (Case B), was built by means of FLAC3D, capable of analyzing the complex interaction issues via the direct method whereby the entire system of the structure-foundation-soil is modeled and analyzed in one single step. To put it in a nutshell, employing the weighted average shear wave velocity for the entire soil mass in parsing of the 3D seismic soil-structure interaction problems would be accused for ending up with somewhat unreliable results, e.g., underestimated drift ratio and building deformation, which might be the culprit of the damage to the building and possibly the death of the residents residing in the earthquake-prone zones.