One of the methods for retrofitting reinforced concrete moment frames is the use of steel braces. In this research, the seismic performance of a double-skinned concrete framing system reinforced with two concentric (CBF) and eccentric (EBF) steel bracing, was investigated under seven near-fault earthquake records of varying intensity. For this purpose, two ten-story concrete frames with five sp...

The utilization of the lining type in pressure tunnels is highly dependent on the geological and hydraulic conditions. There are two types of lining, namely concrete and steel lining but steel lining is one of the most expensive arrangements. To decrease the length of steel lining in these tunnels, the concrete lining, which prevents water seepage from the surrounding rock mass, is the appropri...

Bridges are often built in locations susceptible to multiple extreme hazards. Meeting some or all of these constraints drives the development of innovative multi-hazard design concepts. This paper presents the results of research conducted to develop and experimentally validate such multi-hazard bridge pier concepts. The first concept is a pier-bent made of concrete filled steel tube columns. F...

The utilization of unbounded external reinforcing bars is one of the strengthening methods used after loading stage and before failure. The method has been used in different forms to strengthen members of reinforced concrete structures. To investigate the effect of utilization of post-tensioned reinforcing bars in this method of strengthening, a number of reinforced concrete beams was tested. S...

The present study concerns compressive and flexural constitutive models incorporated into an isoparametric beam finite element scheme for fiber reinforced polymer (FRP) and concrete composites, using their multi-axial constitutive behavior. The constitutive behavior of concrete was treated in triaxial stress states as an orthotropic hypoelasticity-based formulation to determine the confinement ...

Article history: Received: 11. 09. 2013. Received in revised form: 01. 10. 2013. Accepted: 15. 10. 2013. Researches into the constitutive relation of the super high strength and high performance concrete and the stress strain relationship of the ultrastrength concrete-filled steel columns are rare. Therefore, this paper based on continuous mechanics presents the relationship of mathematical des...

Many existing reinforced concrete structures were constructed with substandard characteristics. Low quality concrete, poor transverse reinforcement details and insufficient flexural strength are among the most common deficiencies. While substandard structures are in need of retrofitting, particularly in seismic areas, problems such as high costs and disturbance to occupants are major obstacles ...

Externally bonded carbon-epoxy fiber-reinforced polymers (CFRPs) have been widely used to restore or increase the capacities of reinforced concrete beams (Meier et al., 1992; Neale and Labossière, 1997; Varastehpour and Hamelin, 1997). A typical reinforced concrete bridge deck may experience up to 7x10 stress cycles during the course of a 120year life span (Barnes and Mays, 1999), while an over...

In the context of nonlinear finite element (FE) method, this paper presents a computational framework for ‘exact’ response sensitivity analysis of soil-structural interaction (SSI) systems based on the direct differentiation method (DDM). The DDM requires analytically differentiating the FE algorithm for the response computation with respect to material, geometry or loading parameters, involvin...