فهرست مطالب

Civil Engineering - Volume:16 Issue: 12, Dec 2018

International Journal of Civil Engineering
Volume:16 Issue: 12, Dec 2018

  • تاریخ انتشار: 1397/08/14
  • تعداد عناوین: 9
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  • Modeling and analysis of the impact of BIM-based field data capturing technologies on automated construction progress monitoring
    Sepehr Alizadeh Salehi, brahim Yitmen * Pages 1669-1685
    Leveraging automated field data capturing technologies and Building Information Modeling (BIM) for site status analysis would play a more significant role in advancing decision-making in construction projects if applied to the traditional progress control. Despite the numerous advances in project progress control technologies, 3D modeling, and BIM execution, there is still a lack of awareness regarding the impact of these technologies on the overall performance of the projects, leading to the use of time-consuming and ineffective monitoring processes by the companies. For this reason, this study proposes a model for BIM-based field data capturing technologies and analyses the impact of field data capturing technologies on automated project progress monitoring comparing 3D model and BIM workflows. The empirical data were collected through a computerized self-administered questionnaire (CSAQ) survey conducted to contracting and engineering consulting companies operating in the Middle East, Mid-Asia, Europe, North America, and the Far East. The structural equation modeling (SEM) method was used to test the hypotheses and develop the skill model. The study confirms the importance of using field data capturing technologies with BIM in two main stages (modeling and execution) to enhance automated project progress monitoring performance. The study highlights the need for further exploration of the role of BIM-based field data capturing technologies in improving automated construction project progress monitoring.
    Keywords: Project progress monitoring , Field data capturing technologies , Building information modeling , Construction industry
  • The Effect of Temperature on Seismic Response of Cu–Al–Mn SMA Braced Frame
    Mehrsa Mirzahosseini , Mohsen Gerami * Pages 1687-1697
    Cu–Al–Mn is a type of shape memory alloy that has been evaluated for seismic applications in recent years. However, the rate-independent behavior of this new material has been proved in seismic applications in previous studies, but dependency on the temperature has been rarely studied. In this paper, seismic response dependency in a steel braced frame was evaluated under five different temperatures: − 40, − 25, 0, 25 and 50 °C. For this purpose, a one-bay one-story Cu–Al–Mn X braced frame was selected. At first, the response of frame was provided under a record scaled with various PGA and then five scaled records were selected for more evaluation. From the results, the axial force and top acceleration of frame increased with enhancing temperature. The difference of top acceleration in the lowest and highest temperature was 30%. In contrast, there was a drop in the maximum drift and maximum strain of brace with increasing temperature. The percentage changes of maximum drift and maximum strain were in the average values of 44 and 47%, respectively. Changes in all cases were almost linear. Results of the frame under seven different scaled records almost showed similar tendency. However, change in environmental temperature affected time history drift angle, especially at a temperature less than 0 °C, but in most earthquakes, maximum drift angle and strain increased with decreasing temperature and there was decline in top acceleration. The percentage of changes varied from 32 to 72% for drift angle and 20–42% for top acceleration.
    Keywords: Shape memory alloy, Cu–Al–Mn alloy, Braced frame, Temperature , Earthquake
  • Evaluating the Response Modification Factors of RC Frames Designed with Different Geometric Configurations
    Hamdy Abou, Elfath *, Emad Elhout Pages 1699-1711
    The response modification factor (R-factor) of reinforced concrete (RC) moment resisting frames (MRFs) designed with adequate ductility in accordance with the Egyptian code is evaluated. Static pushover and earthquake time history analyses are employed to determine the actual R-factors of nine RC-MRFs with different geometric configurations. The geometric configuration parameters considered include the number of stories, the number of bays, the bay-width and the story height. The results obtained in this study indicate that the R-factor value decreases with the increase in the frame height and that the changes in the number and span of bays have a minor effect on the R-factor. The R-factors calculated by earthquake analysis are generally smaller than the corresponding values calculated by static pushover loading. The R-factors calculated for the frames considered in this study vary from 6.18 to 9.85 in case of static analysis and from 5.43 to 8.43 in case of earthquake analysis. The minimum limit of the calculated R-factors is smaller than the R-factor of seven specified by the Egyptian code for the design of RC-MRFs with adequate ductility.
    Keywords: Response modification factor , RC frame , Geometric configuration , Static pushover , Earthquake
  • Study on Explosion Effects of a Spherical Reticulated Shell Under Internal Explosions
    Lihui Le , Xuanneng Gao *, Wenbao Wang Pages 1713-1724
    Due to the propagation characteristics of explosion shock waves, the stiffness of the structure and its components has an important influence on the explosion effects of the reticulated shell. However, the current research on this problem is insufficient. In this paper, a parametric model for the numerical simulation of spherical reticulated shell structure under internal explosion was established using the finite-element software. Based on the built model, the dynamic responses of a spherical reticulated shell under internal explosion were numerically simulated and analyzed. In addition, the influence of the stiffness of the reticulated shell bars, the stiffness of the connectors, and the stiffness of the roof panels on the explosion effects of the spherical reticulated shell structure under internal explosions were researched. The results show that with an increase in the flexural stiffness of the reticulated shell bars, the kinetic energy and the maximum node displacement responses of the spherical reticulated shell are reduced. However, the magnitude of these decreases gradually decline. The results also reveal that the greater the stiffness of the connectors, the greater the internal energy, the kinetic energy and the maximum node displacement responses. The increase in the stiffness of the connectors is disadvantageous to the anti-explosion properties of the spherical reticulated shell structure. In addition, the research indicated that there is a threshold value to the stiffness (thickness) of the roof panels with regard to the influence of the explosion effects of the spherical reticulated shell, in the case of a certain amount of explosives. With an increase in the stiffness (thickness) of the roof panels, the displacement responses of the spherical reticulated shell under internal explosion decrease if the stiffness (thickness) of the roof panels exceeds the threshold value. Finally, some suggestions for explosion proof and anti-explosion design of the long-span spherical reticulated structures are proposed.
    Keywords: Internal explosion , Explosion effects , Spherical reticulated shell, Dynamic response, Stiffness
  • Turbo Roundabout Usage in Lieu of Conventional Roundabouts for the Jordanian Traffic Conditions
    Mohammad Ali Khasawneh *, Nael Muwaffaq Alsaleh Pages 1725-1738
    The main objective of this study is to check the possibility of upgrading at-grade roundabouts to Turbo roundabouts considering the Jordanian driving conditions. It is also to check how such upgrade is going to affect performance measures of the studied areas including safety, capacity, queue length, delay, and level of service (LOS). Thus, three roundabouts were selected and analyzed using SIDRA software under off-peak, morning peak and evening peak traffic conditions to obtain the actual capacity, queue length, delay, and LOS values under the current design. Then two designs were applied for each roundabout according to Dutch design guideline manual using TORUS software by changing inner radius and opening width. The generated designs were analyzed using VISSIM software under the original traffic conditions, to evaluate the effect of introducing turbo roundabout system as a replacement to the conventional roundabout system. The results of this study indicate that turbo roundabouts offer higher capacities, less delays and better LOS compared to existing intersections. In addition, introducing turbo roundabouts might offer higher safety levels than conventional roundabouts; as conflict points were reduced from 32 on two-lane conventional roundabouts to only 12 on the proposed turbo roundabouts. Consequently, reconstruction of intersections was warranted.
    Keywords: Turbo roundabout , Conventional roundabout , Performance measures , Safety , VISSIM , Microsimulation
  • Experimental Study and Comparative Analysis of a Geiger-Type Ridge-Beam Cable Dome Structure
    Mingmin Ding , Bin Luo *, Jie Pan , Zhengxin Guo Pages 1739-1755
    Cable domes have widely been used in membrane-roof structures in recent years. A broader range of applications are expected if rigid-roof cable dome structures can be implemented. This study focuses on the static behavior of a new typed Geiger-type ridge-beam cable dome structure (Geiger-type RBCD). By changing the ridge cables of the conventional cable dome to hinged ridge beams, this structure can potentially support heavy rigid-roofing systems. A 6-m specimen is built and tested to investigate the static behavior of Geiger-type RBCD in full-span and half-span uniform loading conditions, and a finite-element model is utilized to compare the experimental results. The modified fractional-step finite-element method (FSFEM) is then introduced to obtain the proper structural parameters and initial pretensions of the conventional cable dome, suspen-dome, and Geiger-type RBCD structures. Based on the modified FSFEM, parametric studies of self-weight, support reactions, initial pretensions, and static behaviors of these three structures are conducted. The results show that the Geiger-type RBCD combines the characteristics of increased local stiffness attributed to its similarity to the suspen-dome, and good integrity characteristics attributed to its similarity to the conventional cable dome. This renders it capable of resisting relatively larger roof loads with fewer support requirements and tensioning apparatuses. Meanwhile, the use of ridge beams in the Geiger-type RBCD significantly reduces the pretension level, provides a relatively higher emergency capacity for the entire structure, and makes the Geiger-type RBCD able to meet the mechanical requirements of various loading cases.
    Keywords: Geiger-type ridge beam, Cable dome , Model experiment, Static behavior, Comparative analysis
  • Field Investigation of Service Performance of Concrete Bridges Exposed to Tropical Marine Environment
    Woraphot Prachasaree *, Suchart Limkatanyu , Ornkamon Wangapisit , Somchai Kraidam Pages 1757-1769
    A preliminary field inspection by the DRR (Department of Rural Roads, Thailand) revealed deficient significantly deteriorated highway bridges, damaged by exposure to the tropical marine environment along the southern coastline of Thailand. To assess the causes of deterioration, the damages, and the residual structural performance, a long-term research program was launched by the DRR to resolve and review deterioration from corrosion effects. An initial effort within this program was to investigate and evaluate by field testing 19 concrete bridges in poor or critical condition. It was observed that the concrete strength and covering depth in the current design specifications were insufficient to sustain the targeted 50-year service life. Based on these field data, a simplified model was developed to predict the residual capacities of bridge structural members. The model for concrete bridge beams predicts that the design service life is reduced by 25% by this specific marine environmental exposure. The structural performance of columns and piles in axial bending decreases significantly, which may seriously impair the overall bridge structure.
    Keywords: Bridge , Concrete , Corrosion , Marine , Tropical, Service life , Deterioration
  • Failure Sensitivity Analysis of Tall Moment-Resisting Structures Under Natural Fires
    Behrouz Behnam * Pages 1771-1780
    A series of sensitivity analyses of structural fires are performed, focusing mainly on the possibility of structural failure during the cooling phase. To investigate this, two tall ten-story steel moment-resisting buildings, with two different span lengths, 6000 and 7500 mm, but identical story height of 3500 mm, are designed for two different load combinations: gravity loads, and seismic loads. Assuming different opening ratios in a range between 0.02 and 0.2, different fire curves are created, using the EN 1991-1-2 procedure. The cases are then subjected to the fire curves to monitor their structural responses when interactions between the opening ratios, span lengths, and load combinations are considered. The results show that all of the cases meet their required FRR under all of the fire curves. The results, however, also show that, in the structures designed for gravity loads, while the span length increases, the structural vulnerability increases during the cooling phase. As well, opening ratios of more than 0.1 are seen to cause more vulnerability to the structures during the cooling phase. In the seismically designed structures, even though they are shown to be sensitive to opening ratios more than 0.1, no collapse is observed throughout the analyses.
    Keywords: Tall structures , Span length , Opening ratio, Structural collapse , Fire resistance rating , Cooling phase
  • General Survey of Construction-Related Complaints in Recent Buildings in Spain
    Manuel J. Carretero, Ayuso, Alberto Moreno, Cansado, Jorge de Brito* Pages 1781-1796
    In Spain the construction sector and specifically the building area, is one of the sectors with the greatest number of complaints coming from the users and clients. Sometimes these complaints are important enough to be taken to court. This study, the first of its kind in the literature, is based on the final rulings of these court cases (involving 1166 buildings) to analyze quantitatively and qualitatively the anomalies, their causes and elements in which they occur. The results show the construction zones with the greatest damage and the most frequent anomalies, which will facilitate all intervening actors in the building process access to the knowledge about the anomalies-prone zones and their future prevention. The most frequent pathological processes, their climatic zone distribution and a prediction tool in function of population are also included in the presentation. Some design and execution procedures are proposed to solve the problems detected.
    Keywords: Complaints , Pathology , Spain , Damage diagnosis, Statistical analysis , Current buildings