Asian journal of civil engineering
Volume:7 Issue: 2, April 2006

This paper explores the potential of geographic information system environment indeveloping a construction project information system for rate analysis, safety and qualitycontrol recommendations for different activities. Geographic Information Systems (GIS) is arelatively new branch of information technology for managing the spatial and non-spatialdata and can effectively be used to develop a database related to construction resource and safety and quality control recommendations for possible construction activities. ArcView 3.2, which stores all data sets in tabular format, is used in present study. Resource data for materials, labours, equipments, recommendations for safety and quality control are stored in the different tables and separate tables are used for each construction project for rate analysis. Scripts using avenue language are added to the GIS software enabling the planner to access and manipulate the available database, which finally helps in speeding up the decision making process. This paper suggests that the proposed GIS based methodology may replace the manual methods to extract the information from the available database and can easily be updated as most of the information is in digital format.

In this paper, a unified method is developed for calculating the eigenvalues of the weighted adjacency and Laplacian matrices of three different graph products. These products have many applications in computational mechanics, such as ordering, graph partitioning, and subdomaining of finite element models.

Geotechnical investigations were carried out to establish the bearing capacity of thegeological materials that occur at the site. The investigations involved an analysis of theproperties of the materials in the area using soil mass characterization, river depth analysis,geotechnical testing and slope stability analysis. The investigations identified several keystability issues such as the depth to the firm foundation, the bearing capacity of thefoundation rock, liability to liquefaction and the stability of the slopes.

Wind velocity closed to the earth surface is quite close to zero and it increases with increase in height. However, construction of tall buildings in a locality of low-rise buildings alters the street level wind environment. The wind which strikes tall building surface get deflected towards the ground causing high speed winds on the windward side as well as near the corners of the buildings at street / pedestrian level. This leads to discomfort to the pedestrian walking and also to the cyclists and two wheeler drivers. This paper describes the comfort criteria for pedestrians within a built environment and also enumerates the recent research work done in this area.

Fast Wavelet Transforms (FWT) and Discrete Wavelet Neural Networks (DWN) are usedfor dynamic analysis of structures. A filter bank is used for the FWT and the number ofpoints of the earthquake record is reduced. The DWN is used for approximating the dynamic responses of the structures. By such approximation, the dynamic analysis of the structure is not necessary if the structural properties are changed. Both feedforward neural networks and wavelet decompositions inspire this network. An algorithm of backpropagation type is proposed for training the network. In this network, the input is the damping ratio and the angular natural frequency of the structure and the output is the responses of the structures against these reduced points. After training the network, using the inverse wavelet transform, the results of the dynamic analysis are obtained for the original earthquake record from the output of the network. Some numerical examples are solved by the proposed method and the results are compared with those of the original record.

This paper provides an overview of the design of thread reinforced soil structures with aparticular emphasis on the influence of the strength criterion. Due to the heterogeneity of the material a macroscopic strength criterion is determined and discussed for thread reinforced soil using the homogenization method for periodic medium in the yield design range. Various types of potential failure mechanisms are analyzed and pointed out by using the failure design theory which allows the stability analysis of a reinforced embankment. An account of the results are presented and compared with recent test results. Current evidence on the feasibility of this type of reinforcing is discussed along the variation of different parameters. Conclusion bears on general design and defines some considerations to be included in such analysis.

This paper presents the results of an experimental investigation carried out to evaluate the shrinkage of High Strength Concrete. High Strength Concrete is made by partialreplacement of cement by flyash and silica fume. The shrinkage of High Strength Concretehas been studied using the different types of coarse and fine aggregates i.e. Sandstone and Granite of 12.5 mm size and Yamuna and Badarpur Sand. From the test results of the above investigation it can be concluded that the shrinkage strain of High Strength Concrete increases with age. The shrinkage strain of concrete with replacement of cement by 10% of Flyash and Silica fume respectively at various ages are more (6 to 10%) than the shrinkage strain of concrete without Flyash and Silica fume. The shrinkage strain of High Strength Concrete is also compared with that of normal strength concrete. Test results show that the shrinkage strain of high strength concrete is less than that of normal strength concrete.

Reinforced concrete structures are made up of two materials with different characteristics,namely, concrete and steel. The typical stage in the load-deformation behavior of areinforced concrete simply supported beam is highly nonlinear and the response can beroughly divided into three ranges of behavior: the uncracked elastic stage, the crackpropagation stage and the plastic (yielding of steel or crushing of concrete) stage. The stressstrain relation of concrete is not only nonlinear, but is different in tension than incompression. A nonlinear numerical model has been developed considering material andgeometric nonlinearities. Material nonlinearity is simulated by considering parabolic stressstrain relationship of concrete and bilinear relationship of reinforcing steel which can model both elastic-perfectly plastic and plastic strain hardening. The modified Newton-Raphson technique has been used for the solution of the nonlinear equations. The load-deformation behavior of the over-reinforced high strength concrete beams has been carried out with the model. From the analyses it is observed that for the high strength concrete the increase in steel content increases the strength and stiffness but decreases the ductility.

Iran Strong Motion Network (ISMN) that runs under the authority of Building and HousingResearch Center (BHRC) of Iran, start its activity since 1973. At the present day it consistsof more than 1000 digital (SSA-2) and 61 analog (SMA-1) accelerographs. The recordedearthquake accelerograms are downloaded, controlled and processed and then added to the accelerograph comprehensive data bank, which is too useful for scientists and engineers. Here in the recorded accelerograms and causal earthquakes are briefly described and more detailed information is presented in Table 1 and also available on the web page of BHRC (http://www.bhrc.ac.ir).