SEISMIC EVALUATION OF INFILLED REINFORCED CONCRETE FRAMES STRENGTHENED WITH FRPS
There is an urgent need to retrofit the deficient mid-rise reinforced concrete frame buildings in Turkey. For this purpose, an efficient FRP retrofit scheme was developed, in which hallow clay brick infill walls are utilized as lateral load resisting elements. The main premise of this practical retrofit scheme is to limit interstory deformations by FRP strengthened infill walls that are integrated to the boundary frame members through FRP anchors. Based on failure modes and measured deformation limits obtained from a large database of experiments, a diagonal compression-strut and tension-tie model is developed. The model is verified with a number of reinforced concrete frame test results with and without upgrades. Furthermore, results of a case study conducted on a typical building frame revealed that strength levels similar to that of a RC shear wall retrofit scheme can be obtained through the FRP retrofit alternative resulting in a displacement ductility of about four.
In-Plane Behavior of Structural Clay Tile Infilled Frames
Large-scale structural clay tile infilled steel frames were tested under in-plane loading. All infills failed through corner crushing, and the failure load was relatively insensitive to framing characteristics. An analytical procedure was proposed in which the peak strength of the infill for the corner crushing limit state is a function only of fm′ and the thickness of the infill. This simple method predicted the strength better than any other analytical method. A piecewise linear equivalent strut was used to model the stiffness of the infill. The behavior of the structural clay tile infills (cracking, tile failure, and stiffness) was better correlated with actual displacements, than with nondimensional story drift (displacement divided by height). Bending moments and axial forces in the bounding frame were examined, with the infill having little effect on the moments in the columns. The results of several other configurations, including a repaired infill, an eccentric infill, an infill with column gaps, ...
The microscale obstacle-resolving meteorological model MITRAS v2.0: model theory
Abstract. This paper describes the developing theory and underlying
processes of the microscale obstacle-resolving model MITRAS version 2. MITRAS
calculates wind, temperature, humidity, and precipitation fields, as well as
transport within the obstacle layer using Reynolds averaging. It explicitly
resolves obstacles, including buildings and overhanging obstacles, to
consider their aerodynamic and thermodynamic effects. Buildings are
represented by impermeable grid cells at the building positions so that the
wind speed vanishes in these grid cells. Wall functions are used to calculate
appropriate turbulent fluxes. Most exchange processes at the obstacle
surfaces are considered in MITRAS, including turbulent and radiative
processes, in order to obtain an accurate surface temperature. MITRAS is also
able to simulate the effect of wind turbines. They are parameterized using
the actuator-disk concept to account for the reduction in wind speed. The
turbulence generation in the wake of a wind turbine is parameterized by
adding an additional part to the turbulence mechanical production term in the
turbulent kinetic energy equation. Effects of trees are considered
explicitly, including the wind speed reduction, turbulence production, and
dissipation due to drag forces from plant foliage elements, as well as the
radiation absorption and shading. The paper provides not only
documentation of the model dynamics and numerical framework but also a solid
foundation for future microscale model extensions.
