http://www.hindawi.com The latest articles from Hindawi Publishing Corporation © 2013 , Hindawi Publishing Corporation . All rights reserved. Wed, 08 May 2013 10:38:48 +0000 http://www.hindawi.com/isrn/ce/2013/904180/ A numerical model is developed, validated and applied to the turbulent coastal currents. The currents are driven by the sea surface slope and the radiation stresses of water waves. They are resisted by friction due to turbulent eddies and sea bottom. The k-ε model is used to model the turbulent stresses. Five simultaneous nonlinear partial differential equations govern the depth-averaged dynamics in the surf zone. An implicit finite-difference scheme is used to obtain an accurate numerical solution of the resulting initial-boundary value problem. It is tested against the case of straight coast with uniform bottom slope and a protective jetty. To investigate the actual wave-induced currents, the model is applied to simulate the currents for three real case studies. Results show that the model could be used to compute currents caused by the constructing coastal protection measures and could predict the locations of accretion and scouring. O. Fahmy, K. M. Fassieh, and M. A. Zaki Copyright © 2013 O. Fahmy et al. All rights reserved. Thu, 21 Mar 2013 18:08:37 +0000 http://www.hindawi.com/isrn/ce/2013/916581/ In this paper both the static and dynamic analyses of the geometrically linear or nonlinear, elastic or elastoplastic nonuniform torsion problems of bars of constant or variable arbitrary cross section are presented together with the corresponding research efforts and the conclusions drawn from examined cases with great practical interest. In the presented analyses, the bar is subjected to arbitrarily distributed or concentrated twisting and warping moments along its length, while its edges are supported by the most general torsional boundary conditions. For the dynamic problems, a distributed mass model system is employed taking into account the warping inertia. The analysis of the aforementioned problems is complete by presenting the evaluation of the torsion and warping constants of the bar, its displacement field, its stress resultants together with the torsional shear stresses and the warping normal and shear stresses at any internal point of the bar. Moreover, the construction of the stiffness matrix and the corresponding nodal load vector of a bar of arbitrary cross section taking into account warping effects are presented for the development of a beam element for static and dynamic analyses. Having in mind the disadvantages of the 3D FEM solutions, the importance of the presented beamlike analyses becomes more evident. Evangelos J. Sapountzakis Copyright © 2013 Evangelos J. Sapountzakis. All rights reserved. Tue, 12 Mar 2013 11:03:08 +0000 http://www.hindawi.com/isrn/ce/2013/972020/ This research study focuses on the actual performance of the flexible pavements and its relationship with the in-situ mechanistic and volumetric properties. The data required for the study were obtained using the Long Term Pavement Performance database. Approximately, 116 flexible pavement sections throughout United States were analyzed and discussed. The results indicated that the temperature has a significant affect on the backcalculated modulus of the hot mix asphalt layer. However, no strong relationship was observed between the hot mix asphalt backcalculated modulus and in situ air voids. It was found that fatigue life was a function of tensile strain at the bottom of hot mix asphalt layer, peak surface deflection, hot mix asphalt air voids and maximum specific gravity, and ambient air temperature. Similar relationships between the rut life, mechanistic and volumetric properties were established for wet-freeze and wet-no-freeze climatic zones. The sensitivity analysis revealed that the rut performance in wet-no-freeze sections is mainly affected by higher base and roadbed compressive stresses and strains. On the other hand, the performances in wet-freeze sections are highly depended on roadbed compressive strain and modulus ratio of subbase to roadbed. Mohammad Jamal Khattak and Nagaraju Peddapati Copyright © 2013 Mohammad Jamal Khattak and Nagaraju Peddapati. All rights reserved. Thu, 07 Mar 2013 15:45:00 +0000 http://www.hindawi.com/isrn/ce/2013/348973/ Stone column is often employed for strengthening of an embankment seated on deep soft clay. But in very soft clay having undrained shear strength less than or equal to 15 kPa, stone column may not derive adequate load carrying capacity and undergo large lateral deformation due to inadequate lateral confinement. In such circumstances, reinforcement to individual stone column by geosynthetics enhances load carrying capacity and reduces lateral deformation. This paper addresses parametric study on behaviour of embankment resting on Geosynthetic Reinforced Stone Column (GRSC) considering parameters such as stone column spacing to diameter ratio, deformation modulus of stone column material, geosynthetic stiffness, thickness of soft clay, and height of embankment by 3D numerical analysis. Finally, equation for Settlement Improvement Factor (SIF), defined as ratio between settlement of embankment without treatment and with geosynthetic reinforced stone column, is proposed that correlates with the major influence parameters such as stone column spacing to diameter ratio, deformation modulus of soft clay, and geosynthetic stiffness. Yogendra K. Tandel, Chandresh H. Solanki, and Atul K. Desai Copyright © 2013 Yogendra K. Tandel et al. All rights reserved. Wed, 06 Mar 2013 15:00:10 +0000 http://www.hindawi.com/isrn/ce/2013/282743/ Capillary rise is an important cause of deterioration for plaster in building. This phenomenon has been studied by the tensiometric experimental technique. Structural and hydric characteristics of plaster have been determined. Decane, a perfectly impregnate fluid, has been used to calculate the porous constant characteristic called and other structural parameters like pore radius and specific surface. Evaluation of the sensibility of plaster for water has been evaluated in a second time. The angle constant and the capillary moisture content have been determined. A comparison between results for plaster and composite plaster with fiber has been done. The addition of glass and hemp fiber does not have important effect on hydric properties (angle constant), but we have observed influence on structural charecteristics (pore radius, porosity, and degree of heterogeneity). Serge Gassita, Laurent Marmoret, Anne Perwuelz, and Hassen Beji Copyright © 2013 Serge Gassita et al. All rights reserved. Tue, 26 Feb 2013 08:23:41 +0000 http://www.hindawi.com/isrn/ce/2013/176029/ Timely rehabilitation and preservation of pavement systems are imperative to maximize benefits in terms of driver’s comfort and safety. However, the effectiveness of any treatment largely depends on the time of treatment and triggers governed by treatment performance models. This paper presents the development of rutting model for overlay treatment of composite pavement in the State of Louisiana. Various factors affecting the rutting of overlay treatment were identified. Regression analysis was conducted, and rut prediction model is generated. In order to better predict the pavement service life, the existing condition of the pavement was also utilized through the model. The developed models provided a good agreement between the measured and predicted rut values. It was found that the predictions were significantly improved, when existing pavement condition was incorporated. The resulting rutting model could be used as a good pavement management tool for timely pavement maintenance and rehabilitation actions to maximize LADOTD benefits and driver’s comfort and safety. Mohammad Abdullah Nur, Mohammad Jamal Khattak, and Mohammad Reza-Ul-Karim Bhuyan Copyright © 2013 Mohammad Abdullah Nur et al. All rights reserved. Mon, 25 Feb 2013 13:21:28 +0000 http://www.hindawi.com/isrn/ce/2013/901652/ An accurate assessment of the fatigue life of hot mix asphalt (HMA) mixtures depends on the criteria used in the fatigue analysis. In the past, various studies have been conducted on crack initiation and crack propagation of the HMA mixtures. Most of these studies were focused on the beam samples with or without a sawed crack at the bottom. This paper presents and discusses two different fatigue life criteria for two-dimensional problems represented by cylindrical samples. One criterion is based on the rate of accumulation of the tensile horizontal plastic deformation (HPD) as a function of the number of load repetitions. The second criterion is based on fracture mechanics, stress intensity factor, and the rate of crack growth with respect to the number of load repetitions. It was found that, because of three-dimensional nature of the crack growth in cylindrical samples, the Paris' law was violated. It is shown that the rate of crack growth criterion provides higher values of fatigue life relative to the rate of accumulation of HPD criterion. Although a trend could be established among the fatigue lives obtained by using the two criteria, it was found that the fatigue lives obtained from the rate of accumulation of HPD were consistent and based on the actual measurement of HPD for HMA mixtures. Mohammad Jamal Khattak and Gilbert Y. Baladi Copyright © 2013 Mohammad Jamal Khattak and Gilbert Y. Baladi. All rights reserved. Sun, 30 Dec 2012 08:59:58 +0000 http://www.hindawi.com/isrn/ce/2012/197170/ The behavior of connections associated with the thin-walled steel members is distinctly different from that of hot-rolled steel connections, primarily because of the flexibility of the plates. A typical cold-formed steel structural construction may entail such numerous connections. The incorporation of large number of such connections in an analysis and design, using sophisticated finite element models, is very tedious and time consuming and may present computational difficulties. The objective of this investigation is to create simplified, yet reasonably accurate, finite element models for the analysis of screw connections and bolted connections associated with thin-walled sheet steel construction. The primary plates were modeled using quadrilateral shell elements, and nonlinear stress-strain relationship was established based on experiments. The fasteners were modeled as an elastic medium. The plate-to-plate interactions and the plate-to-screw interactions were incorporated using contact elements. The study considered two finite element models of different complexity. The performance of these models was established through comparisons with the corresponding experimental results. The finite element analysis results exhibit reasonably good agreement with the test results in terms of connection stiffness, screw tilting, end curling, and average longitudinal strain. The recommended simplified connection model is capable of reproducing the behavior of sheet steel screw and bolt connections. Sandesh R. Acharya and K. S. Sivakumaran Copyright © 2012 Sandesh R. Acharya and K. S. Sivakumaran. All rights reserved. Thu, 27 Dec 2012 17:22:36 +0000 http://www.hindawi.com/isrn/ce/2012/271414/ The seismic behavior of steel tanks is relevant in industrial risk assessment because collapse of these structures may trigger other catastrophic phenomena due to loss of containment. Therefore, seismic assessment should be focused on for leakage-based limit states. From a seismic structural perspective, damages suffered by tanks are generally related to large axial compressive stresses, which can induce shell buckling near the base and large displacements of unanchored structures resulting in the detachment of piping. This paper approaches the analysis of seismic response of sliding, nonuplifting, unanchored tanks subject to seismic actions. Simplified methods for dynamic analysis and seismic demand estimation in terms of base displacement and compressive shell stress are analyzed. In particular, attention is focussed on some computational issues related to the solution of the dynamic problem and on the extension of the incremental dynamic analysis (IDA) technique to storage tanks. Antonio Di Carluccio and Giovanni Fabbrocino Copyright © 2012 Antonio Di Carluccio and Giovanni Fabbrocino. All rights reserved. Sun, 16 Dec 2012 08:28:25 +0000 http://www.hindawi.com/isrn/ce/2012/475751/ Lightweight concrete application in construction field is growing rapidly in these recent years due to its advantages over ordinary concrete. In this paper, pumice breccia which can be found abundantly in Indonesia is proposed to be utilized as the coarse aggregate. In spite of its benefits, lightweight concrete exhibits more brittle characteristics and lower tensile strength compared with normal concrete. On the other hand, fiber addition into concrete has become widely used to improve its tensile properties. Furthermore, the utilization of hybrid fiber in a suitable combination may potentially improve the mechanical properties of concrete. This paper experimentally examines the effects of hybrid polypropylene-steel fiber addition on some hardened properties of pumice breccia aggregate lightweight concrete. Five groups of test specimens with fixed volume fraction of polypropylene fiber combined with different amounts of steel fiber were added in concrete to investigate the density, compressive strength, modulus of elasticity, splitting tensile strength, and the modulus of rupture of the concrete mixtures. Test results indicate that hybrid fiber addition leads to significant improvement to the compressive strength, modulus of elasticity, splitting tensile strength, and the modulus of rupture of the pumice breccia lightweight aggregate concrete and meet the specification for structural purposes. Slamet Widodo, Iman Satyarno, and Sri Tudjono Copyright © 2012 Slamet Widodo et al. All rights reserved. Mon, 10 Dec 2012 11:48:12 +0000 http://www.hindawi.com/isrn/ce/2012/926412/ Uncertainties in predictive models for concrete structures performance can influence adversely the timing of management activities. A methodology has been developed that uses data obtained through proactive health monitoring to increase the confidence in predicted performance by reducing the associated uncertainties. Due to temporal and spatial variations associated with climatic changes, exposure conditions, workmanship, and concrete quality, the actual performance could vary at different locations of the member. In this respect, the use of multiple sensors may be beneficial, notwithstanding cost and other constraints. Two distinct cases are identified for which an updating methodology based on data from multiple sensors needs to be developed. In the first case the interest lies in improving the performance prediction for an entire member (or a structure) incorporating spatial and temporal effects. For this purpose, the member is divided into small zones with the assumption that a sensor can be located in each zone. In the second case, the objective is to minimise uncertainties in performance prediction, or to increase the redundancy of health monitoring systems, at critical locations. The development of updating methodologies for the above-mentioned scenarios is described in this paper. Its implications on the management activities, for example, establishing the timing of principal inspections, are evaluated and discussed. M. Imran Rafiq Copyright © 2012 M. Imran Rafiq. All rights reserved. Sun, 09 Dec 2012 10:01:29 +0000 http://www.hindawi.com/isrn/ce/2012/287323/ The manufacture of concrete using a polymer instead of a stony coarse aggregate known as gravel is presented. Polyethylene terephthalate (PET) is the polymer used, recycling soft drink containers with sufficient tenacity. PET is a material commonly used by engineers as a structural element, not as an aggregate. The research work revealed that PET aggregate produces good quality mixtures with lower volumetric weight but mechanical behavior similar to that of natural concrete with adequate granulometry. The water/cement (W/C) ratio is lower for light concretes than for natural concrete. Regarding stress and Flexural strength, it was found that for 300 kg/cm3 and higher cement consumption, which may be due to the fact that at low W/C ratios, the coarse aggregate behavior prevails, while at high W/C ratios, the paste behavior prevails. This leads us to the fact that PET aggregate is best applied on low cement consumption up to 300 kg/m3, since expensive mixtures for higher consumption may result from use on higher consumption. Modulus of elasticity for light concretes is lower than for natural concretes. Deformations are lower for light concretes than for natural concretes. A feature of using PET to substitute coarse aggregate is volumetric weight, since it is 68.88% lighter than concrete with natural aggregates. Francisco Casanova-del-Angel and Jorge Luis Vázquez-Ruiz Copyright © 2012 Francisco Casanova-del-Angel and Jorge Luis Vázquez-Ruiz. All rights reserved. Mon, 26 Nov 2012 14:26:17 +0000 http://www.hindawi.com/isrn/ce/2012/436327/ This paper mainly investigates, from a series of laboratory scale bearing capacity tests carried out on a model square footing, the improvement in bearing capacity and reduction in settlement of a geonet reinforced granular bed (RGB) overlying weak soil due to prestressing the reinforcement. The parameters are the strength of the underlying weak soil, thickness of the granular bed, and magnitude and direction of prestressing force. The settlements at the interface are also measured. The addition of prestress to geonet reinforcement results in significant improvement in the load carrying capacity and settlement response of the prestressed geonet RGB. Improvement in bearing capacity is found to be more with biaxial prestressing than with uniaxial prestressing. Experimental results are also used to validate a proposed numerical model. The BCR (bearing capacity ratio) values predicted from this model are found to be in good agreement with the experimentally obtained BCR values. Finite element analyses are also carried out using the programme PLAXIS, to study the effect of prestressing the reinforcement. Results obtained from finite element analyses are also found to be in good agreement with the experimental results. J. Jayamohan and R. Shivashankar Copyright © 2012 J. Jayamohan and R. Shivashankar. All rights reserved. Wed, 14 Nov 2012 10:04:18 +0000 http://www.hindawi.com/isrn/ce/2012/816107/ The application of a reinforced self-compacting concrete jacket for the structural rehabilitation of shear damaged reinforced concrete beams is experimentally investigated. Five beams were constructed and subjected to monotonic loading in order to exhibit shear failure. The damaged specimens were restored using relatively thin reinforced jackets and retested by the same four-point bending loading. The self-compacting concrete jacket applied, encasing the bottom width and both vertical sides of the initially tested beams (U-formed jacketing), has a small thickness (25 mm) and includes small (5) steel bars and U-formed stirrups. Test results and comparisons between the experimental behaviour of the beams indicated that the examined jacketing technique is a reliable rehabilitation method since the capacity of the retrofitted beams was fully restored or ameliorated with respect to the initial specimens. Discussion of the ability of the applied jacket to enhance the overall structural performance of the examined beams and, potentially, to alter their failure mode to a more ductile one is also included. Calculations of the flexural and shear strength of the tested beams and evaluation of the monolithic factors for the capacity at yield and at ultimate of the jacketed beams were also performed and are commented on. Constantin E. Chalioris and Constantin N. Pourzitidis Copyright © 2012 Constantin E. Chalioris and Constantin N. Pourzitidis. All rights reserved. Wed, 14 Nov 2012 09:57:14 +0000 http://www.hindawi.com/isrn/ce/2012/953204/ An exact analytical solution is proposed for the pressure oscillations within deep coastal aquifers under the action of tidal level time-variations attributable to train of solitary waves originating off-shore. The purpose of the study is to relate the characteristics of the response of the system to amplitude, steepness, and asymmetry of the soliciting waves, in order to assess its vulnerability to events like violent seaquakes and consequent tsunamis. The time needed by the forcing perturbations, approximated by consecutive triangular impulses, to attain their maximum is assumed to be always smaller than the aquifer diffusive time, in order to evaluate the consequences of the sudden raise of water level along the shoreline, typical of those quite extreme phenomena. Marilena Pannone Copyright © 2012 Marilena Pannone. All rights reserved. Wed, 14 Nov 2012 09:49:42 +0000 http://www.hindawi.com/isrn/ce/2012/709157/ Plates are most widely used structural systems to build and/or enclose the space along with some other structural elements, namely, walls, columns, and so forth. in any building. Design procedure for proportioning plates has been recommended in various design codes based upon empirical relations and some factors found on basis of the results of an extensive series of tests and well-established performance record of various plate/slab systems constructed in the past. These guidelines have a number of inherent limitations in the form of assumptions, thereby, forcing the designers to proportion the plate system within the domain of these limitations. A procedure to design reinforced concrete stiffened-plates is presented using an energy-balance concept and it can be used for both a single panel as well as multipanel rectangular plate system with any value of aspect ratio, number of panels, and orthotropy. To validate the results from the proposed design procedure, these are compared with the results from well-established literature on the plate analysis and are found to be in good agreement. Working procedure is illustrated with the help of design examples. Harvinder Singh Copyright © 2012 Harvinder Singh. All rights reserved. Thu, 01 Nov 2012 15:07:48 +0000 http://www.hindawi.com/isrn/ce/2012/629369/ The dynamic analysis process started after any loss of embankment with associated huge damages like cracks during the earthquake. Literature review indicated that the maximum displacement during the earthquake is conducted to the crest and interface between the embankment with water reservoir, and foundations were cased. This paper evaluated the effect of material properties of the foundation for the two conditions so the result is related at the end of construction with supplying water. Numerical analyses of models were performed by finite element with plane strain method and ANSYS13 software. Earthquake recording as Nagan with 5.02 seconds and peak ground acceleration equal to is used. Results indicated that with a comparison of horizontal and vertical displacement, shear strain and shear stress so nonisotropic behavior of embankment especially in the up to part of the structure was obvious. It is required to consider an improvement of dynamic settlement with reinforcement structure in the future. Behrouz Gordan and Azlan Bin Adnan Copyright © 2012 Behrouz Gordan and Azlan Bin Adnan. All rights reserved. Sun, 21 Oct 2012 09:32:20 +0000 http://www.hindawi.com/isrn/ce/2012/565948/ The management of low-volume rural roads in developing countries presents a range of challenges to road designers and managers. Rural roads comprise over 85 percent of the road network in India. The present study aims at development of deterioration models for the optimum maintenance management of the rural roads under a rural road programme namely Pradhan Mantri Gram Sadak Yojana (PMGSY) in India. Visual condition survey along the selected low-volume rural roads considers parameters like condition of shoulders, drainage features, cross-drainage structures, and camber, and pavement distresses, namely, potholes, crack area, and edge break, are collected for a period of three years. The deterioration models have a significant role in the pavement maintenance management system. However, the performance of a pavement depends on several factors. Cluster analysis can be used to group the pavement sections so that the performance of pavements in different clusters can be studied. Nonhierarchical clustering technique of k-means clustering was considered. Separate deterioration models have been developed for each of the clusters. A comparison of the models developed with and without clustered sections reveals that the clustering of pavement sections are preferred for the efficient rural road maintenance management. V. Sunitha, A. Veeraragavan, Karthik K. Srinivasan, and Samson Mathew Copyright © 2012 V. Sunitha et al. All rights reserved. Tue, 16 Oct 2012 10:16:17 +0000 http://www.hindawi.com/isrn/ce/2012/678329/ This paper studies the optimum conceptual design of pile foundations at the initial design stage. A modular method is proposed, which divides the foundation into modules and each module is identified by its characteristics of pile length, diameter, number and layout. Modules with the same characteristics may be packed and represented by a design variable. A minimum-cost optimization model with multiple design constraints based on Chinese code and a cardinality constraint is built to achieve the concurrent optimization of pile size and layout. The model is solved by the improved automatic grouping genetic algorithms to obtain the design with optimal variables and optimal variable grouping. A practical example demonstrates the effectiveness of the proposed approach. Xiaofeng Liu, Gengdong Cheng, Bo Wang, and Shuzhi Lin Copyright © 2012 Xiaofeng Liu et al. All rights reserved. Mon, 15 Oct 2012 13:42:09 +0000 http://www.hindawi.com/isrn/ce/2012/501816/ A finite element simulation for experimental punching shear behavior of reinforced concrete slab is presented in this paper. The numerical simulation is based on previously tested 15 reinforced concrete model slabs. Finite element analysis of reinforced concrete slabs subjected to punching load is evaluated and results are compared with experiments. This study involves development of a nonlinear strategy which implements solution for a realistic description of the deflection, load carrying capacity and crack, pattern related to punching shear of RC slabs for several types of slab thickness, edge restraints, and reinforcement ratio. It has been shown that the load versus. deflection diagram and ultimate load capacity obtained from FE analysis closely match with the experimental results. Comparison of crack pattern of the slab also shows good agreement. It has been shown that using appropriate method and material for numerical simulation, significant benefit can be achieved using finite element tools and advanced computing facilities in obtaining safe and optimum solutions without doing expensive and time-consuming laboratory tests. A. K. M. Jahangir Alam and Khan Mahmud Amanat Copyright © 2012 A. K. M. Jahangir Alam and Khan Mahmud Amanat. All rights reserved. Sun, 14 Oct 2012 15:54:34 +0000 http://www.hindawi.com/isrn/ce/2012/592181/ Tuned liquid column damper (TLCD) has been used extensively to improve the seismic behavior of structures, and different methods have been proposed for optimal design of TLCDs on linear structures. For improving the effectiveness of TLCDs, multiple tuned liquid column dampers (MTLCDs) have been proposed, and each TLCD has different dynamic parameters. In this paper designing optimal MTLCDs and assessment of its effectiveness in mitigating the response of structures under earthquake excitations have been studied. The parameters of TLCDs have been determined based on minimizing the maximum displacement of structure through solving an optimization problem. Genetic algorithm (GA) has been used for solving the optimization problem. For illustration, the method has been used for designing optimal MTLCDs for a ten-storey linear shear frame subjected to a white noise excitation. According to the results of numerical simulations it could be said that the proposed method for designing optimal MTLCDs has been effective regarding the simplicity and convergence behavior of the method. Based on designing MTLCDs for different values of MTLCDs total mass ratio, it has been concluded that MTLCDs total mass affects significantly the performance of MTMDs where its increasing has led to improve MTLCDs performance. Also, testing the optimal MTLCDs structure under different testing excitations has shown that the performance of MTLCDs depends on the characteristics of earthquakes. Parviz Ahadi, Mohtasham Mohebbi, and Kazem Shakeri Copyright © 2012 Parviz Ahadi et al. All rights reserved. Tue, 11 Sep 2012 08:31:42 +0000 http://www.hindawi.com/isrn/ce/2012/459016/ As natural aggregate sources are becoming depleted due to high demand in road construction and the amount of disposed waste material keeps increasing, researchers are exploring the use of alternative materials which could preserve natural sources and save the environment. In this study, steel slag was used as an aggregate replacement in conventional dense graded asphalt mixes (ACW14 and ACB28). Steel slag was selected due to its characteristics, which are almost similar to conventional aggregates, and the fact that it is easily obtainable as a by-product of the steel industry. The same gradations of mixtures were produced using normal crushed aggregate as control samples. The Marshall mix design system was used for sample preparation in accordance with Malaysian specifications. Samples of asphaltic concrete were subjected to the resilient modulus test, creep test and rutting test. Samples made from steel slag show significantly better results than conventional aggregate. Therefore, utilization of steel slag will reduce land fill, save natural resources and improve the strength of pavement to sustain a higher volume of vehicles. This will shift the gear in sustainable pavement construction, which is most desirable in today’s energy deficient world. Mohd Rosli Hainin, Nur Izzi Md. Yusoff, Mohd Fahmi Mohammad Sabri, Mohd Azizi Abdul Aziz, Mohd Anwar Sahul Hameed, and Wasid Farooq Reshi Copyright © 2012 Mohd Rosli Hainin et al. All rights reserved. Sun, 02 Sep 2012 18:03:41 +0000 http://www.hindawi.com/isrn/ce/2012/949070/ During windstorms and hurricanes, architectural glazing is subjected to wind loading and windborne debris impact. Wind-borne debris is categorized into two types. One is small hard missile like roof gravel and the other is large soft missile representing the lumber from wood-framed buildings. Laminated architectural glazing (LAG) is the commonly used glazing in buildings where impact resistance is needed. The prefailure stress response of the LAG due to the combined loading due to wind and windborne debris impact is studied. Following the ASTM standards (E1886 and E1996), a steel ball with an impact velocity of 39.62 m/s and a wooden cylinder with an impact velocity 12.19 m/s were chosen to be representative of small and large missiles, respectively. A lateral pressure that corresponds to a wind speed of 58.11 m/s was used to represent wind loading on LAG. The effect of geometric and material properties on the stress response of a rectangular LAG is studied parametrically. Thinner outer ply would result in better prefailure stress pattern than a thicker outer ply, while thicker interlayer generally results in lower stresses in failure critical areas. The contribution of wind loading to the principal stress is between 5–10% of the combined stress with small missile case having higher percentage. Mahesh S. Shetty, Lokeswarappa R. Dharani, and Daniel S. Stutts Copyright © 2012 Mahesh S. Shetty et al. All rights reserved. Mon, 13 Aug 2012 09:53:09 +0000 http://www.hindawi.com/isrn/ce/2012/716469/ As tall buildings keep becoming taller, they become more susceptible to dynamic excitations such as wind and seismic excitations. In this paper, design procedure and some current applications of tuned mass damper (TMD) are discussed. A symmetrical moment resistance frame (MRF) twenty storey three-dimensional model were modeled in SAP2000 and a TMD was placed on its top and through it to study its effects on the structural response due to seismic excitations and using time history analysis with and without the TMD. The study indicates that the response of structure such as storey displacements and shear force of columns can be dramatically reduced by using TMD (groups of TMDs) devices especially with a specific arrangement in the model. The study illustrates the group of four TMDs distributed on the plan (interior) which can be effective as R.C. core shear wall. Ahmed Abdelraheem Farghaly and Mahmoud Salem Ahmed Copyright © 2012 Ahmed Abdelraheem Farghaly and Mahmoud Salem Ahmed. All rights reserved. Sun, 05 Aug 2012 13:21:02 +0000 http://www.hindawi.com/isrn/ce/2012/984758/ During the first decade of the new millennium, fueled by the economic development in Spain, urban bus services were extended. Since the years 2008 and 2009, the root of the economic crisis, the improvement of these services is at risk due to economic problems. In this paper, the technical efficiency of the main urban bus companies in Spain during the 2004–2009 period are studied using SBM (slack-based measures) models and by establishing the slacks in the services' production inputs. The influence of a series of exogenous variables on the operation of the different services is also analyzed. It is concluded that only the 24% of the case studies are efficient, and some urban form variables can explain part of the inefficiency. The methodology used allows studying the inefficiency in a disaggregated way that other DEA (data envelopment analysis) models do not. Pablo Jordá, Rocío Cascajo, and Andrés Monzón Copyright © 2012 Pablo Jordá et al. All rights reserved. Thu, 26 Jul 2012 09:45:42 +0000 http://www.hindawi.com/isrn/ce/2012/435618/ ITS technologies such as dynamic lane merging (DLM) and variable speed limits (VSL) have been deployed in roadway work zones in an attempt to enhance safety and mobility through vehicular traffic. The DLM system in its two main forms namely the early merge and the late merge was designed to advise drivers on definite merging locations whereas VSL were introduced to work zones to decrease speed fluctuations, variances, and to smoothen traffic through work zones. Up to date, there are no studies that contrast Maintenance Of Traffic (MOTs) plans including a combination of ITS technologies to standard work zones MOTs under matching work zone settings. This study simulates a two-to-one work zone lane closure configuration in VISSIM under six different MOT plans and compares work zone throughputs and travel times across MOTs namely Motorist Awareness System (MAS), early DLM, late DLM, VSL combined with MAS, a VSL and early DLM combination, and a VSL late DLM combination. Results showed that the combination of VSL and DLM or standalone DLM improve work zone throughputs and travel times compared to work zones with conventional static Florida MOT and work zones with VSL. Zaier Zaidi, Essam Radwan, and Rami Harb Copyright © 2012 Zaier Zaidi et al. All rights reserved. Tue, 24 Jul 2012 07:06:22 +0000 http://www.hindawi.com/isrn/ce/2012/231674/ Fatigue life estimation of metal historical bridges is a key issue for managing cost-effective decisions regarding rehabilitation or replacement of existing infrastructure. Because of increasing service loads and speeds, this type of assessment method is becoming relevant. Hence there is a need to estimate how long these structures could remain in service. In this paper a method to estimate fatigue damage in existing steel railway bridges by detailed loading history analysis is presented. The procedure is based on the assumption that failure probability is a function of the number of predicted future trains and the probability of failure is related to the probability of reaching the critical crack length. Alessio Pipinato, Carlo Pellegrino, and Claudio Modena Copyright © 2012 Alessio Pipinato et al. All rights reserved. Sun, 15 Jul 2012 14:54:08 +0000 http://www.hindawi.com/isrn/ce/2012/103534/ The present research study focused on the high early strength concrete properties that can be produced with large replacement of cement by fly ash. Also, the effects of adding fibres on the compressive strength gain and early age strength gain properties are determined. Tests were conducted on different high strength concrete specimens, where fly ash was substituted for cement up to 50%. Different types of concrete specimens were casted and tested for different fine-to-coarse aggregate ratio, metallic fibre content, cement-to-total-aggregate ratio, and accelerator dosage. The test results indicated that high early strength concrete (50.7 MPa at 7 days) was obtained for higher F/C ratio of 0.8, C/TA ratio of 0.24, and higher dosage level of steel fibre at 1.5%. V. M. Sounthararajan and A. Sivakumar Copyright © 2012 V. M. Sounthararajan and A. Sivakumar. All rights reserved. Thu, 12 Jul 2012 14:10:22 +0000 http://www.hindawi.com/isrn/ce/2012/591450/ This study measured in situ the thermal resistivity of soils at Olorunsogo Gas Turbine Power Station (335 MW Phase 1) which is located in Ogun State, Southwestern Nigeria. Ten pits, each of about 1.5 m below the ground surface, were established in and around the power plant in order to measure the thermal resistivity of soils in situ. A KD 2-Pro was used for the in situ measurement of thermal properties. Samples were also collected from the ten pits for laboratory determination of the physical parameters that influence thermal resistivity. The samples were subjected to grain size distribution analysis, compaction, specific gravity and porosity tests, moisture content determination, and XRD analysis. Also, thermal resistivity values were calculated by an algorithm using grain size distribution, dry density, and moisture content for comparison with the in situ values. The results show that thermal resistivity values range from 34.07 to 71.88°C-cm/W with an average of 56.43°C-cm/W which falls below the permissible value of 90°C-cm/W for geomaterials. Also, the physical parameters such as moisture content, porosity, degree of saturation, and dry density vary from 13.00 to 16.20%, 39.74 to 45.64%, 40.72 to 63.52%, and 1725.05 to 1930.00 Kg/m3, respectively. The temperature ranges from 28.92 to 35.39°C with an average of 32.11°C in the study area. The calculated thermal resistivity from an algorithm was found to vary from 48.43 to 81.22°C-cm/W with an average of 65.56°C-cm/W which is close to the thermal resistivity values measured in situ. Good correlation exists between the in situ thermal resistivity and calculated thermal resistivity with 𝑅=+0.85 suggesting that both methods are reliable. Michael Adeyinka Oladunjoye and Oluseun Adetola Sanuade Copyright © 2012 Michael Adeyinka Oladunjoye and Oluseun Adetola Sanuade. All rights reserved. Thu, 28 Jun 2012 11:54:19 +0000 http://www.hindawi.com/isrn/ce/2012/989785/ A scrutiny of the literature reveals that the free vibration characteristics of stiffened composite hypar shell with cutout are missing. So a generalized finite element formulation for the stiffened hyperbolic paraboloidal shells bounded by straight edges (commonly called as hypar shells) is attempted using an eight-noded curved quadratic isoparametric element for shell with a three-noded beam element for stiffener. Numerical problems of earlier investigators are solved as benchmark problems to validate the approach. A number of problems are further solved by varying the size of the cutouts and their positions with respect to the shell centre for different edge constraints. The results are presented in the form of figures and tables. The results are further analysed to suggest guidelines to select optimum size and position of the cutout with respect to shell centre considering the different practical constraints. Sarmila Sahoo Copyright © 2012 Sarmila Sahoo. All rights reserved.