Seismic Fragility Assessment of Special Truss Moment Frames (STMF) Using the Capacity Spectrum Method
Gholamreza
Abdollahzadeh
Associate Professor, Faculty of Civil Engineering, Babol University of Technology
author
Mohammad
Sazjini
Ph.D. Student, Faculty of Civil Engineering, Babol University of Technology
author
Azadossadate
Asghari
Ph.D. Student, Faculty of Civil Engineering, Babol University of Technology
author
text
article
2015
eng
Fragility curves represent the probabilities that structural damages, under various levels of seismic excitation, will exceed the specified damage states by means of earthquake intensity damage relations. Conceptual aspects related to seismic vulnerability, damage and risk evaluation are discussed first, together with a short review of the most widely used possibilities for the seismic evaluation of structures. The capacity spectrum method starting from capacity and fragility curves is then discussed. The determination of capacity curves for buildings using a non-linear structural analysis tools is then explained, together with a simplified expeditious procedure allowing the development of fragility curves. Next, the seismic risk of the special truss moment frame (STMF) systems of Tehran, the capital of Iran, is analysed in this paper using the capacity spectrum method. The seismic hazard of the studied area is described by using the reduced 5%-damped elastic response spectra. Significant damage is obtained for mid-rise and high-rise special truss moment frames with a Vierendeel middle panel, because of the buckling and early fracture of truss web members. Special truss moment frames with an X-diagonal middle segment also show a low seismic capacity leading to significant expected damage.
Civil Engineering Infrastructures Journal
University of Tehran
2322-2093
48
v.
1
no.
2015
1
8
https://ceij.ut.ac.ir/article_53703_4fc71a2783acbae075399f4c97135e58.pdf
dx.doi.org/10.7508/ceij.2015.01.001
Particle Swarm Optimization for Hydraulic Analysis of Water Distribution Systems
Naser
Moosavian
Lecturer, Civil Engineering Department, University of Torbat-e-Heydarieh, Torbat-e-Heydarieh, Iran
author
Mohammad Reza
Jaefarzade
Professor, Civil Engineering Department, Ferdowsi University of Mashhad, Mashhad, Iran
author
text
article
2015
eng
The analysis of flow in water-distribution networks with several pumps by the Content Model may be turned into a non-convex optimization uncertain problem with multiple solutions. Newton-based methods such as GGA are not able to capture a global optimum in these situations. On the other hand, evolutionary methods designed to use the population of individuals may find a global solution even for such an uncertain problem. In the present paper, the Content Model is minimized using the particle-swarm optimization (PSO) technique. This is a population-based iterative evolutionary algorithm, applied for non-linear and non-convex optimization problems. The penalty-function method is used to convert the constrained problem into an unconstrained one. Both the PSO and GGA algorithms are applied to analyse two sample examples. It is revealed that while GGA demonstrates better performance in convex problems, PSO is more successful in non-convex networks. By increasing the penalty-function coefficient the accuracy of the solution may be improved considerably.
Civil Engineering Infrastructures Journal
University of Tehran
2322-2093
48
v.
1
no.
2015
9
22
https://ceij.ut.ac.ir/article_53704_481164fab27b0eb989288a80747409a9.pdf
dx.doi.org/10.7508/ceij.2015.01.002
Analysis of the Operational Deficiencies Originating in Design at Wastewater Treatment Plants: A Case Study of the Islamic Republic of Iran
Mansoor
Moradhasseli
Kurdistan Water and Wastewater Company, Shebli Boulevard, Sanandaj, Iran
author
Hermann
Orth
Professor, Institute of Environmental Engineering, Ruhr-Universitat Bochum, 44780 Bochum, Germany
author
text
article
2015
eng
Considerable investments have been made in establishing wastewater treatment plants (WWTPs). However, evaluation of the performance of plants during recent years, when more WWTPs have become operational, shows that effluent quality criteria were not met in many instances. Preliminary assessment of the operational problems of WWTPs in Iran disclosed that numerous factors affect this issue of effluent quality. One reason is the lack of planning knowledge among the local consulting engineering companies, which causes design-related deficiencies. Lack of national standards as well as of practical design manuals are also significant factors. In this study, the effects of the design-related deficiencies on operational practices are investigated in 20 WWTPs around Iran. This is followed by the implementation of solutions in real models that match the most recent innovations in this regard. Consistent methods are then discussed for correcting these deficiencies. It was found that 68% of the operational deficiencies arise from design deficiencies. These are, accordingly, considered in the scope of the solutions presented in this work. The distinctive solutions presented in this study prevent the repetition of the same defects in new designs. Scientific methods for rectifying the detected deficiencies are developed in this study. The results are aimed at supporting experts who undertake the role of rehabilitating WWTPs in the country, through the correction of various deficiencies, so that the final goal of conserving the environment is met. The findings are compared with those of some related national and international works for the purposes of further clarification.
Civil Engineering Infrastructures Journal
University of Tehran
2322-2093
48
v.
1
no.
2015
23
33
https://ceij.ut.ac.ir/article_53705_172f8156f1de9f9e0a27b8cb8debf808.pdf
dx.doi.org/10.7508/ceij.2015.01.003
Use of Numerical Simulation to Measure the Effect of Relief Wells for Decreasing Uplift in a Homogeneous Earth Dam
Farzin
Salmasi
Water Engineering Department, Faculty of Agriculture, University of Tabriz, Tabriz, Iran.
author
Behnam
Mansuri
M.Sc. Student of Hydraulic Structures, University of Tabriz, Tabriz, Iran
author
Amir
Raufi
M.Sc. Student of Hydraulic Structures, University of Azad Ahar, Ahar, Iran.
author
text
article
2015
eng
Relief wells are used extensively to relieve excess hydrostatic pressure in pervious foundation strata overlain by impervious top strata, conditions which often exist landward of levees and downstream of dams and hydraulic structures. Placing well outlets in below-surface trenches or collector pipes helps dry up seepage areas downstream of levees and dams. Relief wells are often used in combination with seepage control measures, such as upstream blankets, downstream seepage berms, and grouting. Draining seepage water into relief wells decreases uplift and prevents piping. This study examined the effect of relief wells with different diameters at different distances downstream of a homogeneous earth dam using Seep/W software. Also the effect of upstream water level of reservoir on seepage flow to each well was carried out. Results show that by decreasing the distance between relief wells and increasing the diameter of the relief wells, total uplift pressure decreases. The optimum distance between relief wells to decrease uplift pressure was found to be 5 m. The proposed method is recommended in designing relief wells by providing optimum diameter and distance of wells for the sustained yield.
Civil Engineering Infrastructures Journal
University of Tehran
2322-2093
48
v.
1
no.
2015
35
45
https://ceij.ut.ac.ir/article_53706_26ada4b851b1250988c31851c7c83ad9.pdf
dx.doi.org/10.7508/ceij.2015.01.004
Seismic Performance Reliability of RC Structures: Application of Response Surface Method and Systemic Approach
Hossein
Shahraki
Ph.D. Candidate, Department of Civil Engineering, Faculty of Engineering, University of Sistan and Baluchestan, Zahedan, Iran
author
Naser
Shabakhty
Assisstant Professor, Department of Civil Engineering, Faculty of Engineering, University of Sistan and Baluchestan, Zahedan, Iran
author
text
article
2015
eng
The present study presents an algorithm that models uncertainties at the structural component level to estimate the performance reliability of RC structures. The method calculates the performance reliability using a systemic approach and incorporates the improved response surface method based on sampling blocks using the first-order reliability method and conditional reliability indices. The results of the proposed method at different performance levels were compared to bound techniques and the overall approach. It was shown that the proposed algorithm appropriately estimates the reliability of the seismic performance of RC structures at different damage levels for the structural components. The results indicated that performance reliability indices increased when then on-performance scenarios were examined for high levels of components damage.
Civil Engineering Infrastructures Journal
University of Tehran
2322-2093
48
v.
1
no.
2015
47
68
https://ceij.ut.ac.ir/article_53707_0b39d37e86972beba78e217bc5a460e2.pdf
dx.doi.org/10.7508/ceij.2015.01.005
Modelling of Sediment Transport in Beris Fishery Port
Samira
Ardani
Ph.D. Candidate, Texas A & M University, College Station, TX., (Formerly, Graduate Student, K.N. Toosi University of Technology, Tehran, Iran)
author
Mohsen
Soltanpour
Associate Professor, K.N. Toosi University of Technology, Tehran, Iran
author
text
article
2015
eng
In this paper, the large amount of sedimentation and the resultant shoreline advancements at the breakwaters of Beris Fishery Port are studied. A series of numerical modeling of waves, sediment transport, and shoreline changes were conducted to predict the complicated equilibrium shoreline. The outputs show that the nearshore directions of wave components are not perpendicular to the coast which reveals the existence of longshore currents and consequently sediment transport along the bay. Considering the dynamic equilibrium condition of the bay, the effect of the existing sediment resources in the studied area is also investigated. The study also shows that in spite of the change of the diffraction point of Beris Bay after the construction of the fishery port, the bay is approaching its dynamic equilibrium condition, and the shoreline advancement behind secondary breakwater will stop before blocking the entrance of the port. The probable solutions to overcome the sedimentation problem at the main breakwater are also discussed.
Civil Engineering Infrastructures Journal
University of Tehran
2322-2093
48
v.
1
no.
2015
69
82
https://ceij.ut.ac.ir/article_53708_2c23de3d5886c6ce188752f0a869382c.pdf
dx.doi.org/10.7508/ceij.2015.01.006
Optimum Parameters for Tuned Mass Damper Using Shuffled Complex Evolution (SCE) Algorithm
Hessamoddin
Meshkat Razavi
Ph.D. Candidate, Department of Civil Engineering, Faculty of Engineering, Ferdowsi University of Mashhad, Mashhad, Iran
author
Hashem
Shariatmadar
Associated Professor, Department of Civil Engineering, Faculty of Engineering, Ferdowsi University of Mashhad, Mashhad, Iran
author
text
article
2015
eng
This study is investigated the optimum parameters for a tuned mass damper (TMD) under the seismic excitation. Shuffled complex evolution (SCE) is a meta-heuristic optimization method which is used to find the optimum damping and tuning frequency ratio for a TMD. The efficiency of the TMD is evaluated by decreasing the structural displacement dynamic magnification factor (DDMF) and acceleration dynamic magnification factor (ADMF) for a specific vibration mode of the structure. The optimum TMD parameters and the corresponding optimized DDMF and ADMF are achieved for two control levels (displacement control and acceleration control), different structural damping ratio and mass ratio of the TMD system. The optimum TMD parameters are checked for a 10-storey building under earthquake excitations. The maximum storey displacement and acceleration obtained by SCE method are compared with the results of other existing approaches. The results show that the peak building response decreased with decreases of about 20% for displacement and 30% for acceleration of the top floor. To show the efficiency of the adopted algorithm (SCE), a comparison is also made between SCE and other meta-heuristic optimization methods such as genetic algorithm (GA), particle swarm optimization (PSO) method and harmony search (HS) algorithm in terms of success rate and computational processing time. The results show that the proposed algorithm outperforms other meta-heuristic optimization methods.
Civil Engineering Infrastructures Journal
University of Tehran
2322-2093
48
v.
1
no.
2015
83
100
https://ceij.ut.ac.ir/article_53709_744617dc553f1b80dc30f13fdf35991f.pdf
dx.doi.org/10.7508/ceij.2015.01.007
Modification of Displacement Coefficient Method in Estimation of Target Displacement for Regular Concrete Bridges Based on ASCE 41-06 Standard
Seyed Bahram
Beheshti-Aval
Associate Professor, Civil Engineering Faculty, K.N. Toosi University of Technology, Tehran, Iran
author
Ehsan
Jahanfekr
Ph.D. Candidate, Faculty of Technical and Engineering, Hormozgan University, Bandarabas, Iran
author
text
article
2015
eng
Displacement Coefficient Method (DCM) stipulated in the ASCE 41-06 standard is becoming the preferred method for seismic rehabilitation of buildings in many high-seismic-hazard countries. Applications of the method for non-building constructions such as bridges are beyond the scope of this standard. Thus its application to this kind of structure should be approached with care. Target displacement has reasonable accuracy for buildings with strong columns and weak beams, where there is the development of plastic hinges. Due to high stiffness and strength of the deck relative to the piers in most bridges, this mechanism does not occur, and it is necessary to evaluate the accuracy of DCM for such structures. In this research, an attempt is made to evaluate the credibility of DCM in the ASCE/SEI 41-06 standard for estimating target drifts in concrete regular bridges under strong ground motions. To apply the extension of the method to bridge structures, the definition of new correction factor CB, which should be multiplied to previous coefficients, is required. This novel coefficient can improve the accuracy of the mentioned method in accessing seismic displacement demands. The coefficient is presented for soil types A to D based on NEHRP soil classification. The validity of the modified DCM is examined for several bridges with use of nonlinear dynamic analysis. Good correlation is found between both procedures.
Civil Engineering Infrastructures Journal
University of Tehran
2322-2093
48
v.
1
no.
2015
101
120
https://ceij.ut.ac.ir/article_53710_4da8a6686e932f2e0e70b7a2f5368fd3.pdf
dx.doi.org/10.7508/ceij.2015.01.008
Threat-Independent Column Removal and Fire-Induced Progressive Collapse: Numerical Study and Comparison
Hamidreza
Tavakoli
Assistant Professor, Department of Earthquake Engineering, Babol University of Technology, Babol, Iran
author
Foad
Kiakojouri
M.Sc. of Structural Engineering, Department of Structural Engineering, Islamic Azad University, Takestan Branch, Iran
author
text
article
2015
eng
Progressive collapse is defined as the spread of an initial failure from element to element, eventually resulting in the collapse of an entire structure or a disproportionately large part of it. The current progressive collapse analyses and design methods in guidelines and codes focus on the alternate load path method. This method is suitable especially in the case of blast-induced progressive collapse. In this paper, fire-induced and threat-independent progressive collapse potential is numerically investigated in steel moment resisting frames. Affecting parameters such as location of initial failure and number of floors are considered in this study. Two different mechanisms were observed in threat-independent and fire-induced progressive collapse: while in threat-independent column removal alternative load paths play major role, in fire-induced progressive collapse the weight of the structure above the failure region is the most important parameter.
Civil Engineering Infrastructures Journal
University of Tehran
2322-2093
48
v.
1
no.
2015
121
131
https://ceij.ut.ac.ir/article_53711_58c441ce9f41f554aa9c54ae62c05765.pdf
dx.doi.org/10.7508/ceij.2015.01.009
Two New Quadrilateral Elements Based on Strain States
Mohammad
Rezaiee-Pajand
Professor, Civil Engineering Department, Ferdowsi University of Mashhad, Mashhad, Iran
author
Majid
Yaghoobi
Ph.D. Candidate, Civil Engineering Department, Ferdowsi University of Mashhad, Mashhad, Iran
author
text
article
2015
eng
In this paper, two new quadrilateral elements are formulated to solve plane problems. Low sensitivity to geometric distortion, no parasitic shear error, rotational invariance, and satisfying the Felippa pure bending test are characteristics of these suggested elements. One proposed element is formulated by establishing equilibrium equations for the second-order strain field. The other suggested element is obtained by establishing equilibrium equations only for the linear part of the strain field. The number of the strain states decreases when the conditions among strain states are satisfied. Several numerical tests are used to demonstrate the performance of the proposed elements. Famous elements, which were suggested by other researchers, are used as a means of comparison. It is shown that these novel elements pass the strong patch tests, even for extremely poor meshes, and one of them has an excellent accuracy and fast convergence in other complicated problems.
Civil Engineering Infrastructures Journal
University of Tehran
2322-2093
48
v.
1
no.
2015
133
156
https://ceij.ut.ac.ir/article_53712_416b84d15e91e08fa5d51ee1ce849362.pdf
dx.doi.org/10.7508/ceij.2015.01.010
Investigation of the Influences of Track Superstructure Parameters on Ballasted Railway Track Design
Javad
Sadeghi
Centre of Excellence in Railway Transportation, School of Railway Engineering, Iran University of Science and Technology, Tehran, Iran
author
Araz
hasheminezhad
Research Assistant, School of Railway Engineering, Iran University of Science and Technology, Tehran, Iran
author
Mohammad
Essmayil Kaboli
M.Sc. Student, School of Railway Engineering, Iran University of Science and Technology, Tehran, Iran
author
text
article
2015
eng
The main design criteria of ballasted railway tracks include rail deflections, rail bending stresses, rail wheel contact stresses, sleeper bending moments and ballast sleeper contact pressures. Numerous criteria have been defined for the design of ballasted railway tracks owing to the various mechanical properties of track components and their complex interaction. Therefore, railway track designing is a difficult and time-consuming process. These complications highlight the need to focus attention on the necessity of a thorough investigation into effect of the track and rolling stock parameters on the design criteria. In an attempt to overcome this problem, sensitivity analysis for the main railway track design criteria was conducted in this study. Consequently, the roles of track and rolling stock parameters (including track modulus, sleeper spacing, train speed and axle load) in the design of railway track were investigated for various track design criteria. The research findings provide new, practical suggestions for consideration in the analysis and design of ballasted railway tracks.
Civil Engineering Infrastructures Journal
University of Tehran
2322-2093
48
v.
1
no.
2015
157
174
https://ceij.ut.ac.ir/article_53713_bfa724c51cbc5b00af372ebafc1828ff.pdf
dx.doi.org/10.7508/ceij.2015.01.011
Design of Riprap Stone Around Bridge Piers Using Empirical and Neural Network Method
Mojtaba
Karimaee Tabarestani
Ph.D. of Water Engineering, Civil and Environmental Department, Amirkabir University of Technology, P.O. Box 15915, Tehran, Iran
author
Amir Reza
Zarrati
Professor, Civil and Environmental Department, Amirkabir University of Technology, P.O. Box 15915, Tehran, Iran
author
text
article
2015
eng
An attempt was made to develop a method for sizing stable riprap around bridge piers based on a huge amount of experimental data, which is available in the literature. All available experimental data for circular as well as round-nose-and-tail rectangular piers were collected. The data for rectangular piers, with different aspect ratios, aligned with the flow or skewed at different angles to the flow, were used in this analysis. In addition, new experiments were also conducted for larger pier width to riprap size ratio, which was not available in the literature. Based on at least 190 experimental data, the effect of important parameters on riprap stability were studied which showed that the effective pier width is the most effective parameter on riprap stability. In addition, an empirical equation was developed by multiple regression analysis to estimate the stable riprap stone size around bridge piers. The ratio of predicted to experiment riprap size value for all experimental data is larger than one with an average value of 1.75, which is less than many other empirical equations. Finally, in order to achieve a higher accuracy for riprap design, the artificial neural network (ANN) method based on utilizing non-dimensional parameters was deployed. The results showed that the ANN model provides around a 7% improved prediction for riprap size compared to the conventional regression formula.
Civil Engineering Infrastructures Journal
University of Tehran
2322-2093
48
v.
1
no.
2015
175
188
https://ceij.ut.ac.ir/article_53714_152badcf667bcf2c2827b6177aa05cc7.pdf
dx.doi.org/10.7508/ceij.2015.01.012
Development and Practical Application of a Bridge Management System (J-BMS) in Japan
Ayaho
Miyamoto
Professor, Yamaguchi University, Ube, Japan
author
Minoru
Motoshita
B.Sc., Kyowa Sekkei CO., LTD., Kobe, Japan
author
text
article
2015
eng
This paper presents a new bridge management system (J-BMS). It is integrated with a concrete bridge rating expert system that can be used to evaluate the serviceability of existing concrete bridges. The proposed J-BMS not only evaluates the performance of bridges, but also offers a rehabilitation strategy based on a combination of maintenance cost minimization and quality maximization. In this system, the genetic algorithm (GA) technique was used to search for an approximation of the optimal maintenance plan. This was constructed using Visual Basic and the C language. Furthermore, this paper examines the results of applying this system to some in-service bridges and the results of questionnaire surveys of experts. A comparison of these results shows that this system can accurately predict optimal maintenance planning, as well as bridge rating.
Civil Engineering Infrastructures Journal
University of Tehran
2322-2093
48
v.
1
no.
2015
189
216
https://ceij.ut.ac.ir/article_53715_47b3963864663ebcad3074ae0d3e62a4.pdf
dx.doi.org/10.7508/ceij.2015.01.013