Can Balkaya

NONLINEAR SEISMIC RESPONSE EVALUATION OF TUNNEL FORM BUILDING STRUCTURES

Abstract The occurrences of (Mw=7.4) Kocaeli and (Mw=7.1) Duzce earthquakes in Turkey in 1999 once again demonstrate the nondamaged and high performance conditions of RC shear wall dominant structures commonly built by using the tunnel form technique. This study presents their seismic performance evaluation based on the nonlinear pushover analyses of two case studies. The contribution of transverse walls and slab-wall interaction during the 3D action, the effects of 3D and 2D modeling on the capacity–demand relation, as well as diaphragm flexibility, torsion and damping effects were investigated. An effort was spent to develop a shell element having closing–opening and rotating crack capabilities. This study shows that the applied methodology has a considerable significance for predicting the actual capacity, failure mechanism, and evaluation of the seismic response of tunnel form buildings.

Finite element analysis and practical modeling of reinforced concrete multi-bin circular silos

Stress resultants in overlapping wall regions (intersection walls) of multi-bin circular silos require a significant computational effort to determine forces due to structural continuity. This paper presents a practical equivalent beam model for computing design forces along the silo walls when subjected to various internal and interstice loadings. The equivalent beam model of intersection wall was developed based on the effective length concept, and verified in a comprehensive series of finite element (FE) analyses of a cluster of four silos for various silo-wall thicknesses. The influence of wall thickness on hoop forces and bending moments acting on interstice and external walls were also examined, and simple empirical expressions were presented for design applications. The proposed beam model yields an accurate estimation of bending moments and hoop forces with a maximum 7% deviation compared with those obtained from detailed FE models.