A simplified analysis procedure is developed to consider the beneficial effects of foundation‐mat uplift in computing the earthquake response of multistory structures. This analysis procedure is presented for structures attached to a rigid foundation mat which is supported on flexible foundation soil modeled as two spring‐damper elements, Winkler foundation with distributed spring‐damper elements, or a viscoelastic half space. In this analysis procedure, the maximum, earthquake induced forces and deformations for an uplifting structure are computed from the earthquake response spectrum without the need for nonlinear response history analysis. It is demonstrated that the maxr imum response is estimated by the simplified analysis procedure to a useful degree of accuracy for practical structural design.

Closure of "Simplified Earthquake Analysis of Multistory Structures With Foundation Uplift"

Dynamic tests were done on polytetrafluoroethylene (PTFE) sliding bridge bearings to evaluate their frictional characteristics at frequencies above 1 Hz High frequency seismic responses of PTFE bearings are expected to occur in bridge structures in eastern North America, where the estimated ground motion is well above 1 Hz Three different combinations of PTFE-steel interfaces were tested at frequencies ranging from 002 Hz to 5 Hz, with displacement amplitudes of up to + or - 70 mm and under confining pressures ranging from 5 MPa to 45 MPa

Frictional response of ptfe sliding bearings at high frequencies

This paper introduces a novel element formulation for the dynamic analysis of bridges incorporating posttensioned segmental columns with hybrid sliding-rocking (HSR) joints distributed over...

Numerical Simulation of Hybrid Sliding-Rocking Columns Subjected to Earthquake Excitation

https://research-information.bris.ac.uk/files/183978804/Kashani_et_al_Accepted_Manuscript_1_.pdf

Layered composite entangled wire materials blocks as pre-tensioned vertebral rocking columns

Soil-structure interaction effects on the seismic collapse capacity of steel moment-resisting frame buildings

This paper introduces a novel gradient inelastic beam theory and a corresponding flexibility-based (FB) frame element formulation to treat major weaknesses of existing FB formulations in the presence of softening section constitutive relations (or softening material response). These weaknesses include (1) strain localization and loss of objectivity and (2) instabilities and convergence failures of the numerical solution algorithms. These weaknesses are shown to emanate from the pathogenies of Navier’s beam theory in the presence of softening section constitutive relations. These pathogenies include (1) loss of solution uniqueness; and (2) loss of spatial continuity of the strain field, under a continuous force field. The proposed gradient inelastic beam theory is derived by enriching Navier’s beam theory with nonlocal section deformation variables through gradient-based equations. For the proposed theory, a FB formulation is developed. This FB formulation (1) results in a single set of algebraic e...

A Gradient Inelastic Flexibility-Based Frame Element Formulation

A finite‐strain gradient‐inelastic beam theory and a corresponding force‐based frame element formulation

This paper presents an Enhanced Rayleigh damping model for dynamic analysis of inelastic structures. The conventional Rayleigh damping model has been extensively used to represent inherent ...

Enhanced Rayleigh Damping Model for Dynamic Analysis of Inelastic Structures

This paper advances the gradient inelastic (GI) flexibility-based (FB) frame element formulation, which focused on monotonic loading conditions, to capture member responses to arbitrary (no...

Mohammad Salehi

Papers

A Gradient Inelastic Flexibility-Based Frame Element Formulation

Numerical Simulation of Hybrid Sliding-Rocking Columns Subjected to Earthquake Excitation

A finite‐strain gradient‐inelastic beam theory and a corresponding force‐based frame element formulation

Enhanced Rayleigh Damping Model for Dynamic Analysis of Inelastic Structures

Refined Gradient Inelastic Flexibility-Based Formulation for Members Subjected to Arbitrary Loading