Asian journal of civil engineering
Volume:7 Issue: 6, December 2006

By carrying out experiments on eight brick masonry walls with pilasters reinforced by glassfiber reinforced polymer (GFRP), a seismic shear capacity of brick masonry wall structuresis studied in detail. First, the interaction coefficient of the pilaster ψ, modified coefficient δgfi statistic coefficient β and effective participation coefficient ζ are determined. Then, based on failure model of brick masonry walls and truss model of fiber reinforced polymer (FRP), the formulae of seismic shear capacity of brick masonry wall with pilaster reinforced by FRP are established, which have an excellent coincidence with the experimental results obtained from the test; Finally, the simplified design formula of seismic shear capacity of brick masonry wall reinforced by FRP has been proposed in this paper. The design formula can be used for further study or for design reference in brick masonry structures.

An important benefit in terms of improving efficient use of resources such as electricity and combustibles, is harnessing renewable resources of energy, mainly solar energy. Solarenergy can effectively be used in regions where solar radiation is very important either inintensity or over a long period yearly. Among these uses, thermal treatment of products like prefabricated concrete elements. Algeria is one place among those rich regions in solarradiation thanks to the beight of sun and the number of days per year of sun shining. The use of heating by evaporation in climatic container having a polyethylene or metal covers permits to improve production capacity. It has been established that during ambient temperature of 25°C and more, the inner temperature of this climatic container can reach 50 to 70°C and the strength of concrete after 8 hours of storage reaches 70 to 75% of the nominal strength. These conditions can tremendously improve the rate of production of prefabricated concrete elements.

This paper deals with the shear strength of simply supported ferrocement rectangular plates subjected to four points loading. Limited literature is available on the shear behavior of ferrocement elements, as the span to depth ratio of these elements is very high. However, studies on the shear response of ferrocement assume importance to understand the material behavior. In the present study, tests on ferrocement elements varying the shear span to depth ratio (a/d) and different layers of mesh are conducted. It is observed that increase in the volume fraction of the mesh reinforcement (number of layers of mesh) increased the shear capacity of the member. It is also found that up to Shear span to depth ratio 3, shear behavior is predominant. Beyond shear span to depth ratio 3, the flexural behavior is predominant and design of the elements based on flexure is sufficient.

Optimum design of singly and doubly reinforced beams with uniformly distributed andconcentrated load has been done by incorporating actual self weight of beam, parabolicstress block, moment-equilibrium and serviceability constraints besides other constraints.Also, this design expertise has been incorporated into a genetically optimized artificialneural network based on steepest descent, adaptive and resilient back-propagation learning techniques. The initial solution for the optimization procedure has been obtained using limit state design as per IS: 456-2000.

An experimental research program was undertaken to ascertain the compressive and shearstrength enhancement of masonry wall panels using steel strips. The study includes eightwall panels, four each for compressive and shear strength evaluation. In each group of four walls, one wall was un-strengthened, the second was single sided coarse steel mesh, the third was double sided coarse steel mesh and the fourth one was single sided fine steel mesh with closely spaced horizontal strips. Separate testing arrangements were made for compressive and shear strength determination. During compression testing only vertical load was applied and for shear strength determination, lateral load with vertical pre-compression was applied. During the test observations were recorded covering all important parameters like stressstrain, vertical load-deflection, lateral load-deflection and behavior of steel strips under vertical and lateral loading. Load carrying mechanisms were observed, varying from the initial, un-cracked state, to the final, fully cracked state. The results demonstrate that a significant increase in compressive and shear strength can be achieved by anchoring steel strips to the surface of masonry walls. It is concluded on the basis of experimental work that the technique / approach is viable for rehabilitation of old deteriorating buildings and strengthening of unreinforcedmasonry structures in seismic zones.

In this study an approximate method based on the continuum approach and transfer matrix method for free vibration analysis of multi bay coupled shear walls is presented. In this method the whole structure is idealized as sandwich beam in this method. Initially thedifferential equation of this equivalent sandwich beam is written then shape functions foreach storey can be obtained by the solution of differential equations. By using boundaryconditions and storey transfer matrices which are obtained by these shape functions, system modes and periods can be calculated. Reliability of the study is shown with a few examples. A computer program has been developed in MATLAB and numerical samples have been solved for demonstration of the reliability of this method. The results of the samples display the agreement between the present method and the other methods given in literature.

Genetic Algorithm is known as a general tool for optimization in the field of discretevariables such as the case of structural problems. For such a search to be efficient andpractical, the genetic parameters should be selected of proper type and should be fine tuned. For this purpose, a direct index coding is utilized in this paper and the corresponding mutation operator is improved in two ways. First, it is modified incorporating simulated annealing concepts to form a generation based genetic algorithm. A dynamic variable band mutation is also developed as the second attempt in order to properly adopt mutation operator with the treated problem during optimization. A number of structural examples are treated by the proposed method to investigate its effect on efficiency and convergence rate of the genetic search.

One of the most distinguished activities in the field of energy conservation, is the provisionof regulations and standards for energy conservation in the building sector.In this paper, the nature of different types of approaches in controlling building designfor energy efficiency purposes are discussed to make an evaluation of the existingregulation. Then, considering the recent international research results related to standardsand regulations, suggestions are made for improving the next version of Code 19 of theIranian Building Regulations.

In the first half of the year 2006, 327 accelerograms (with PGA greater than the trigger level of 0.01g) were recorded by 108 accelerographs, which were triggered by 200 earthquakes with different magnitude. The Silakhor earthquake of 3/31/2006 in Lorestan province was the strongest earthquake in the studied period that triggered 29 accelerographs and the maximum PGA of about 0.524g was occurred in ChalanChoolan station. In this article the most important earthquakes and those with more than three or more accelerograms in the studied time period are discussed in brief and the detailed information is presented in the finale table.