Recursive evaluation of interaction forces of unbounded soil in frequency domain

Mohasseb, Sassan; Wolf, John P.

doi:10.1016/s0267-7261(89)80019-3

Cited by 9 publications

(3 citation statements)

References 7 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…While it is a major simplification of the actual seismic wave field, at the present time, it seems to be the only pragmatic choice . Afterwards, the free‐field motion of the nodes representing the boundary of excavated region (

{\overset{true¯}{V}}_{b}^{0}

) is used to determine their motion following the excavation (Figure B), using Equation , where

{\overset{true¯}{S}}_{bb}^{f}

is the dynamically condensed impedance matrix of the soil‐structure interface for the excavated region and

{\overset{true¯}{S}}_{bb}

represents the counterpart matrix of the same nodes for soil medium prior to excavation (Figure B).

{\overset{true¯}{U}}_{b}^{0} = {({\overset{true¯}{S}}_{bb}^{f})}^{- 1} {\overset{true¯}{S}}_{bb} {\overset{true¯}{V}}_{b}^{0}

…”

Section: Numerical Modelingmentioning

confidence: 99%

Structure‐soil‐structure interaction of adjacent buildings subjected to seismic loading

Bybordiani

Arıcı

2019

Earthq Engng Struct Dyn

View full text Add to dashboard Cite

Summary The problem of the through‐soil coupling of structures has puzzled the researchers in the field for a long while, especially regarding the varied performance of identical, adjacent buildings in earthquakes. The phenomenon of structure‐soil‐structure interaction (SSSI) that has often been overlooked is recently being recognized: The possible effects in urban regions are yet to be thoroughly quantified. In this respect, the goal of this work was to rigorously investigate the interacting effects of adjacent buildings in a two‐dimensional setting. Detailed finite element models of 5‐, 15‐, and 30‐story structures, realistically designed, were used in forming building clusters on the viscoelastic half‐space. Perfectly matched layers were used to properly define the half‐space boundaries. The interaction of the structure and the soil medium because of the presence of spatially varying ground motion on the boundary of excavated region was considered. The effects of the foundation material and the distance between adjacent buildings on the structural behavior of the neighboring buildings were investigated using drift ratios and base shear quantities as the engineering demand parameters of interest. The effects of SSSI, first investigated in the frequency domain, was then quantified in the time domain using suites of appropriate ground motions in accordance with the soil conditions, and the results were compared with the counterpart SSI solution of a single building. The results showed that, for identical low‐rise structures, the effects of SSSI were negligible. Yet, neglecting SSSI for neighboring closely spaced high‐rise structures or building clusters with a large stiffness contrast was shown to lead to a considerable underestimation of the true seismic demands even compared with solutions obtained using the rigid base assumption.

show abstract

{\overset{true¯}{V}}_{b}^{0}

) is used to determine their motion following the excavation (Figure B), using Equation , where

{\overset{true¯}{S}}_{bb}^{f}

is the dynamically condensed impedance matrix of the soil‐structure interface for the excavated region and

{\overset{true¯}{S}}_{bb}

represents the counterpart matrix of the same nodes for soil medium prior to excavation (Figure B).

{\overset{true¯}{U}}_{b}^{0} = {({\overset{true¯}{S}}_{bb}^{f})}^{- 1} {\overset{true¯}{S}}_{bb} {\overset{true¯}{V}}_{b}^{0}

…”

Section: Numerical Modelingmentioning

confidence: 99%

Structure‐soil‐structure interaction of adjacent buildings subjected to seismic loading

Bybordiani

Arıcı

2019

Earthq Engng Struct Dyn

View full text Add to dashboard Cite

show abstract

“…Specifically, in a first iteration the pseudo-forces are taken as zero and equation (4) is integrated in the usual fashion. The time history of the SOIL-STRUCTURE INTERACTION PROBLEM displacements at the soil-structure interface are then used to evaluate the pseudo-forces from equation (5). Using the computed pseudo-forces one solves equation (4) again and so on until some appropriately selected norm becomes equal to or smaller than a certain prescribed tolerance.…”

Section: The Htfd Methodsmentioning

confidence: 99%

A hybrid time frequency domain formulation for non-linear soil-structure interaction

Bernal

Youssef

1998

Earthquake Engng. Struct. Dyn.

View full text Add to dashboard Cite

SUMMARYMethods that combine frequency and time domain techniques offer an attractive alternative for solving Soil-Structureinteraction problems where the structure exhibits non-linear behaviour. In the hybrid-frequency-time-domain procedure a reference linear system is solved in the frequency domain and the difference between the actual restoring forces and those in the linear model are treated as pseudo-forces. In the solution scheme explored in this paper, designated as the hybrid-time-frequency-domain (HTFD) procedure, the equations of motion are solved in the time domain with due consideration for non-linearities and with the unbounded medium represented by frequency-independent springs and dampers. The frequency dependency of the impedance coefficients is introduced by means of pseudo-forces evaluated in the frequency domain at the end of each iteration.A criterion of stability for the HTFD approach is derived analytically and its validity is sustained numerically. As is often the case, the criterion takes the form of a limit of unity on the spectral radius of an appropriately defined matrix. Inspection of the terms in this matrix shows that convergence can be guaranteed by suitable selection of the reference impedance. The CPU times required to obtain converged solutions with the HTFD are found, in a number of numerical simulations, to be up to one order of magnitude less than those required by the alternative hybrid-frequency-timedomain approach.1998 John Wiley & Sons, Ltd.

show abstract

“…By examining historical earthquakes and studying recorded earthquakes, it is clear that the study area has a high potential from a tectonic seismic point of view and is highly seismic [2]. Meanwhile, the whole province of Tehran is located in an area with a relative earthquake risk of "very high" (In this case, the Peak Ground Acceleration, PGA, is 0.35 g (according to the third edition of the 2800 standard) [Ref.…”

Section: Seismicity and Geotechnical Specifications Of The Areamentioning

confidence: 99%

Design and Implementation of Seismic Retrofitting of a Steel Bridge: Case study of Karim-Khan-Zand bridge in Tehran

Rahmati,

Sebti,

Mohasseb

Proceedings of the Eleventh International Conference on Engineering Computational Technology

View full text Add to dashboard Cite

In order to achieve the maximum utilization of the roadways as well as increasing the service life of the bridges, proper traffic transfer, earthquake resistance and damage resistance of the bridges caused by the passage of time; strengthening and repairing of the bridges are essential. In this study, Karim-Khan bridge was selected as a case study to be repaired and retrofitted. The dynamic response of this bridge was investigated by structural finite element analysis method using SAP2000 software. The three-dimensional geometry of the bridge developed through the software environment and advanced options such as the base contact elements and nonlinear material properties were used to assess the effect of different seismic loads on the structural behavior of the critical bridge components. C / D ratio showed that the columns are not ductile due to geometric configuration when subjected to axial load; while their sections in the longitudinal direction are weak in bending. For this reason, the columns are more vulnerable to collapse during the earthquake. Hence it was concluded that the seismic vulnerability of the bridge is high. Regarding the cost of rehabilitation, which was about 30% of the cost of construction of a new bridge and the traffic problems during the construction of the new bridge, the option of improvement and rehabilitation was approved by the technical and civil deputy of Tehran Municipality.

show abstract

Recursive evaluation of interaction forces of unbounded soil in frequency domain

Cited by 9 publications

References 7 publications

Structure‐soil‐structure interaction of adjacent buildings subjected to seismic loading

Structure‐soil‐structure interaction of adjacent buildings subjected to seismic loading

A hybrid time frequency domain formulation for non-linear soil-structure interaction

Design and Implementation of Seismic Retrofitting of a Steel Bridge: Case study of Karim-Khan-Zand bridge in Tehran

Contact Info

Product

Resources

About