bluuebunny/crossref_metadata_2025 huggingface dataset:
Modified Differential Transform Method for Solving Vibration Equations of MDOF Systems
Authors: Najafgholipour Mohammadamir , Soodbakhsh Navid
Published: September 2019

Vibration equations of discrete multi-degrees-of-freedom (MDOF) structural systems is system of differential equations. In linear systems, the differential equations are also linear. Various analytical and numerical methods are available for solving the vibration equations in structural dynamics. In this paper modified differential transform method (MDTM) as a semi-analytical approach is generalized for the system of differential equations and is utilized for solving the vibration equations of MDOF systems. The MDTM is a recursive method which is a hybrid of Differential Transform Method (DTM), Pade' approximant and Laplace Transformation. A series of examples including forced and free vibration of MDOF systems with classical and non-classical damping are also solved by this method. Comparison of the results obtained by MDTM with exact solutions shows good accuracy of the proposed method; so that in some cases the solutions of the vibration equation that found by MDTM are the exact solutions. Also, MDTM is less expensive in computational cost and simpler with compare to the other available approaches.
Marine Current Meter Calibration Using GNSS Receivers, a Comparison with Commercial Method
Authors: Rezaali Vahid , A. Ardalan Alireza
Published: September 2019

Getting information from marine current requires that accurate and calibrated current meter is used. Current meter calibration is carried out in accordance with specific standard in calibration laboratories. To evaluate the performance and health of a current meter, one should compares velocity and heading it with a velocity and heading reference. In this paper, the innovative method for evaluate velocity and heading resulted from impeller marine current meter is presented. In this method, current meter is to be attached to buoy that is installed on it tow GNSS receivers; and by towing it in a lake, simultaneous velocity and heading of the current meter are recorded. Also data position of buoy by GNSS is recorded. Accurately calculated velocity and heading of buoy by using GNSS data to be used as a criterion to evaluate the current meter velocity and heading. Finally, the calibration equation that is known as the final result of the calibration process was determined for velocity and heading of current meter with reasonable accuracy. Also, current meter is tested in this paper evaluated commercial method in calibration laboratory. The results were compared with the results of the proposed method. The results indicated the success of the GNSS-based method for the Performance analysis of a marine current meter.
Experimental and Numerical Investigation on Shear Retrofitting of RC Beams by Prefabricated UHPFRC Sheets
Authors: Aghani Kian , Afshin Hassan
Published: September 2019

Different methods are used for retrofitting RC members. One of the new methods in this field is using externally bonded fiber-reinforced Concrete (FRC) sheets in order to increase RC member’s shear and flexural strength. In this study, applicability of ultra-high performance fiber-reinforced concrete sheets in shear and flexural retrofitting of RC beams was investigated. In total, eight RC beams (dimensions 10×20×150 cm) with two different bending capacity and lack of shear strength were used and were tested in 3-points bending test. Of these, four were control beams and four were retrofitted with laterally bonded UHPFRC sheets. Dimensions of the sheets used for retrofitting were (3×15×126 cm). Also FEM analysis was used to model the effect of The method. the results show that this method can be well used for retrofitting RC beams. In this method the way of connecting sheets to beam’s surfaces has a fundamental role in behavior of retrofitted beams.
An Investigation on Mechanical Properties and Durability of Concrete Containing Silica Fume and Fly Ash
Authors: Sadr Momtazi Ali , Tahmouresi Behzad , Kohani Khoshkbijari Reza
Published: September 2019

Nowadays pozzolans are used vastly in civil projects. Pozzolan is a natural or artificial material containing active silica that increase the strength and improves some properties of concrete. In this survey for investigating some important properties of concrete, silica fume and fly ash was used in replacement of cement in different weights. Concrete compositions were made with water-cement ratio of 0.45 and cured under the same conditions. The main focus of this survey is to investigate the individual and combined effect of using Pozzolan on mechanical properties, permeability and shrinkage of concrete. The mechanical properties of concrete in compressive and bending strength at the age of 7, 28 and 90 days, were evaluated. Permeability was investigated with the water absorption test. The drying shrinkage of concrete was monitored for 90 days. Scanning Electron Microscopy (SEM) images was used in concrete cement based matrix morphology. The results showed that the addition of pozzolan increases the mechanical strength and reduce permeability and increase the drying shrinkage in some mixtures.
Effect of Foundation Nonlinearity on Seismic Response of an Existing Arch Dam
Authors: Parsa Mahmoudi Parisa , Mirzabozorg Hasan , Varmazyari Mehdi , Aghajanzadeh Seyyed Meisam
Published: September 2019

In the present paper, the effect of foundation nonlinearity on the seismic response of an existing arch dam is investigated. Luzzone arch dam in Switzerland is selected as a case study. The foundation nonlinearity is originated from opening/slipping of joints between a potential wedge at the left abutment and remaining foundation. Reservoir's water is assumed compressible and the coupled system is solved simultaneously. Also, the foundationis assumed massed medium via viscous boundary on the far-end truncated boundary. Two cases are considered in the analyses; the system applying reservoir pressure on the foundation; the system with no reservoir pressure applied on the foundation. The results reveal that the ignoringreservoir pressure on the foundation overestimates the response of the dam body. Finally, based on the conducted analyses, considering foundation nonlinearity has no significant effect on the results in the considered case due to special design of the body shape.
Application of Hyperstatic Reaction Method for Designing of Tunnel Permanent Lining, Part II: 3D Numerical Modelling
Authors: Hassani Rahim , Basirat Rouhollah
Published: September 2019

Underground structures often have abrupt changes in structural stiffness or ground conditions such as junctions of tunnels, tunnel portal in slopes, and niches in road tunnels. At these locations, stiffness differences may subject the structure to differential movements and generate stress concentrations. Because of adversity in these issues, they need a three dimensional analysis. This paper proposes a numerical approach to the hyperstatic reaction method (HRM) for three dimensional analysis of permanent tunnel linings. In this paper, three dimensional numerical modelling is performed by considering hyperstatic reaction concepts. Designing is done for Manjil-Rudabar freeway project, Tunnel No. 2. The numerical analyses performed for Operational Design Earthquake (ODE) and Maximum Design Earthquake (MDE) loading conditions. Then interaction diagram between axial force and bending moment used for investigating the capacity of tunnel lining. The numerical results show that although more axial forces are created in tunnel lining for ODE condition, but the points in the P-M diagrams are located in the furthest distance to the diagram border (tunnel supporting system); because of less bending moment in this condition. Therefore, the safety factor in ODE condition is more than MDE condition. This numerical processing presented that the HRM is a proper, fast, and practical method for tunnel designers.
Road Pricing Effect on the Emission of Traffic Pollutants, a Case Study in Tehran
Authors: Hadji Hosseinlou Mansour , Zolfaghari Abbas , Yazdanpanah Mahdi
Published: September 2019

Road pricing is one of the main purposes of traffic management policies in order to reduce personal car use. Understanding the behaviour of drivers under the impact of the road pricing policy, can assist transportation planners in making better and more efficient decisions. This research aims at investigating the reactions of private car users to road pricing using stated preference (SP) method on the one hand, and on the other hand, studies the road pricing effect on traffic flow and pollutants. To this aim, the acceptance rate of pricing, which is obtained from modeling of survey data, as well as real traffic flow data in Shahid Hemmat Highway in Tehran, Iran, are applied as the simulation software input. Based on the results of this research, at the lowest price (TN11000), the contribution of toll acceptance is equal to 64/91 percent. The fuel consumption rate at this price decreases to 49/91% and the emission rate of CO2, NOx, particle material (PM) and volatile organic compounds (VOCs) pollutants decrease to 56.82%, 49.46%, 36.8% and 63.17%, respectively. At the highest price (TN10000), toll acceptability, fuel consumption, CO2, NOx, PM and VOC emission rates decrease to 5.47%, 3.57%, 3.98%, 2.85%, 1.22% and 4.86%, respectively.
The Effect of Suffusion Phenomenon in the Increasing of Land Subsidence Rate
Authors: Khaksar Najafi Elmira , Faghihmaleki Hadi
Published: September 2019

Land subsidence is defined as gradually ground surface settlement in an aquifer due to the compaction of unconsolidated sedimentary deposits. Since in an aquifer, deposits consist of cohesive or non-cohesive alluvial soil layers. The consolidation theory cannot be explained as the only reason for land subsidence. According to the susceptibility of alluvial soils to suffusion, internal erosion is also considerable to enhance the rate of the local settlement. Suffusion is explained as a process of soil particle movement in the soil body due to the effect of seepage flow on it. The subsidence rate in southwest and south of Tehran in Iran is very considerable whereby some structures have suffered significant damages due to this phenomenon. In this research, the contribution of suffusion and land subsidence was investigated in damaged building located at Ghale Morghi Street in southwest of Tehran, as a case history. Because of the incapability of available methods, in this article, a probability pattern is also proposed using statistical analysis for determination the likelihood of internal instability in alluvial soils in regard to soil cohesiveness.
Investigation of Separation Non-Persistent Faults in Fracture Mechanism of Rock Bridge
Authors: Nohekhan Hokmabadi Nasim , Sarfarazi Vahab , Moshrefifar Mohamadreza
Published: September 2019

Rock mass is a heterogeneous material included joints, fractures and faults. The necessity of rock mechanics studies in conducting constructional issues has become important due to the increase in constructional works and the expansion of the structure’s dimension and especially creating underground spaces in rock masses. Faults are the most important discontinuous fractures in the earth's crust in which the two sides of the fracture have moved relative to each other. The purpose of this research is that if the non-persistent faults were situated adjacent to each other, how would be the shear failure mechanism of Rock Bridge surrounded between the faults. For this purpose, physical model consisting two horizontal edge faults and a surrounded angled fault was built; angularity of the central fault varies from 0° to 60° with increasing the 30°. The central fault places in 3 different positions. Along the lateral faults, 1.5 cm vertically far from the edge faults and 3 cm vertically far from the edge faults. All samples tested by uniaxial test machine so that shear load was distributed in the specimens due to special geometry of specimen. The results show that the failure pattern was mostly influenced by configuration of central joint, while the shear strength was linked to the failure pattern and failure mechanism.
Utilization of Soft Computing for Risk Assessment of a Tunneling Project Using Geological Units
Authors: Shaffiee Haghshenas Sina , Shaffiee Haghshenas Sami , Barmal Milad , Farzan Niloofar
Published: September 2019

Soft computing is one of the most efficient tools for analysing risk taking in civil engineering projects. Therefore, in this paper, using Fuzzy C-means (FCM) technique as one of the most efficient and important classification methods in the area of soft computing, risk in the tunnelling project was evaluated and analysed. For this reason, considering three mechanical and physical parameters influencing the design and execution of the tunnelling project including overburden (H), internal friction angle (Phi) and cohesion (C), geological units were classified along the project's route. The present study has been conducted on the third section of Ghomrud tunnel as one of the greatest tunnelling projects in the centre of Iran. Results obtained from the evaluation of geological units along the tunnelling project's route after the validation of drilling rate index’s results show the appropriate evaluation of the project’s risk through fuzzy clustering technique.
Comparison of Coupled and Uncoupled Consolidation Equations Using Finite Element Method in Plane-Strain Condition
Authors: Baqersad Mohamadtaqi , Eslami Haghighat Abbas , Rowshanzamir Mohammadali , Mortazavi Bak Hamid
Published: September 2019

In the current paper, the consolidation settlement of a strip footing over a finite layer of saturated soil has been studied using the finite element method. In Biot’s coupled consolidation equations, the soil deformation and excess pore pressure are determined simultaneously in every time step which refers to the hydro-mechanical coupling. By considering a constant total stress throughout the time and by assuming that volume strain is a function of isotropic effective stress, uncoupled consolidation equations can be obtained using coupled consolidation equations. In these uncoupled equations, excess pore pressure and deformation are determined separately. In this approach, the excess pore pressure can be identified in the first stage. Using the calculated excess pore pressure, the soil deformation is determined through effective stress-strain analyses. A computer code was developed based on coupled and uncoupled equations that are capable of performing consolidation analyses. To verify the accuracy of these analyses, the obtained results have been compared with the precise solution of Terzaghi’s one-dimensional consolidation theory. The capability of these two approaches in estimation of pore water pressure and settlement and to show Mandel-Crayer’s effect in soil consolidation is discussed. Then, the necessity of utilizing coupled analyses for evaluating soil consolidation analysis was investigated by comparing the coupled and uncoupled analyses results.
Prediction of Hydro-mechanical Stability of Dam: Using Calibrated Model from Back Analysis and Monitoring Data
Authors: Narimani Samad , Davarpanah Seyed Morteza , Sattarvand Javad
Published: September 2019

Earth-fill dam safety and stability control during service period is important at the view point of economics and social security. Monitoring is very important to control dam security, to compare real action with predicted planning and to make good experience and opportunity for future planning. In this paper, water pore pressure and settlements in different parts of Sattarkhan dam during service period was studied. So at first, according to instrument data installed in the body of dam, calibration of numerical model done and by doing back analysis real properties of materials of dam defined. Then by using the calibrated model, pore water pressures and settlements of dam studied. Analysis carried out by Flac2D Finite Difference software. The constitutive model used was Mohr-Coulomb at the state of plane strain. Results showed that dam will be safe during service period at the view point of hydro-mechanical behaviour. Finally, stability of dam studied from the view of rapid depletion of the reservoir, which results showed safety conditions.
Finite Element Modeling of Axially Loaded CFRP-Confined Rectangular Reinforced Concrete Columns
Authors: Akbarpour Hamed , Akbarpour Masoumeh
Published: September 2019

This paper investigates numerically the behaviour of rectangular RC columns strengthened with carbon fiber reinforced polymer (CFRP) composites under uniaxial loading. For this a reason, a parametric study is conducted and the effects of CFRP layers number, compressive strength of unconfined concrete, and fiber orientation on the behaviour of such columns have been studied. The number of CFRP layers has been changed from one to five layers while the fibers are oriented transversely. Compressive strength of unconfined concrete has been increased from 26 MPa to 45 MPa. In addition, three different fiber orientations are considered. The results show that an increase in the number of CFRP layers would enhance the ultimate strength of specimens. Although increasing the number of layers would not increase the ultimate strength of specimens exponentially, but the rate of strength gain would also decrease. Moreover, it is shown that lateral strains increase as the layer number increases. The effect of unconfined concrete strength on the ultimate strength is less for low strength concrete than high strength concrete. Evaluating the effect of fiber orientation shows that the maximum ultimate strength is obtained from transverse orientation and as the angle of orientation increases, the ultimate strength decreases.
Numerical Modeling of Flow Field in Morning Glory Spillways and Determining Rating Curve at Different Flow Rates
Authors: Enjilzadeh Mohammad Reza , Nohani Ebrahim
Published: September 2019

Morning glory spillways with drop inlets are normally employed in dams built on narrow valleys or placed on steep slopes. In Iran, morning glory spillways have been commonly used in large Dam projects such as Sefidrood dam, Alborz dam, and Haraz dam. Physical models should be built to accurately determine hydraulic parameters of the flow and flow field in spillways. Establishment of a physical model involves extravagant costs and conditions that cannot be justified in some cases. Therefore, suitable numerical models can be proposed for such circumstances. Using FLOW3D numerical models, 3-dimensional numerical modelling of the flow was calibrated and validated by experimental information associated with morning glory spillway of Alborz dam and accuracy of numerical modelling was determined by relative error of numerical model. So it was attempted to determine flow pattern and control conditions of morning glory spillways in different modes using boundary conditions, inlet conditions and grid spacing of flow field and project rating curve of morning glory spillways. According to the results of numerical model, relative error of numerical modelling equals 6.4% for calculating discharge rate of the spillways. Numerical modelling error is 7.6% for determining depth parameter of the flow in spillway crest in comparison with experimental results.
Numerical Modeling of Local Scour at the Junction of Open Channels in Flow3D Numerical Model
Authors: Shamohamadi Behnam , Mehboudi Ali
Published: September 2019

At the junction of channels, the two corresponding flows of the main and submain channels are diverted from their main alignment and the form and the flow properties change at the junction. Changes in water level profile and depth of flow, velocity distribution, stagnation zone, constriction of public channel, energy loss and also formation of hydraulic jump are among the most important hydraulic variables in this location. For accurate recognition of hydraulic properties of flow and local scour at the junction of channels, physical models are made and constructed. Setting up a physical model requires many conditions and high costs which sometimes are not justifiable, hence appropriate numerical models could be proposed for such options. In this research using Flow3D numerical model, the numerical modelling of the flow has been performed in 3D form utilizing the available laboratory information which is calibrated and validated and accuracy of the numerical modelling, and the corresponding relative error are determined. The calibration and validation of the numerical model results demonstrate that the maximum relative error of the numerical model when simulating for maximum values of scour depth at the flow junction is equal to 8.2%. Also using the numerical model it was found that with passage of time in numerical model, from .....
Investigation of Ready Mixed Concrete Transportation Problem Using Linear Programming and Genetic Algorithm
Authors: Albayrak Gulcag , Albayrak Ugur
Published: September 2019

Ready-mixed concrete (RMC) is one of the most common building material for construction industry for nearly all developed and developing countries. Generally, because of the technical requirements, concrete must be mixed in a batch plant and transported to the construction site. There are two important factors affected the cost of RMC: raw material cost and transportation cost. Additionally, transportation cost is also included when determining the unit price of RMC. However, profitability affects adversely in the case of long distance between the plant and construction site. For these reason, distribution of RMC from supply to the demand points with minimum cost is aimed in this study. This work contributes to both modelling and dispatching of RMC as an optimization problem by applying linear and heuristic methods. For this purpose, as an example, an urban area which divided into 7 districts and contained 4 concrete batch plants is discussed. Linear programming and genetic algorithm were applied to solve this problem and compared each other under the same conditions. The result shows linear programming is more efficient for this application because of the limited constraints and variables.
Analyzing Parameters Influencing Scour Bed in Confluence Channels Using Flow3D Numerical Model
Authors: Shamohamadi Behnam , Mehboudi Ali
Published: September 2019

Channels junction is a phenomenon which is used in most of irrigating and drainage networks and in hydraulic engineering in general. In two channels junction, main and secondary channels encounter with each other and move to the channel downstream. Scour holes and sedimentation zones are created in channels bed. 3D simulation of scour hole created in these channels is influenced by various factors. The ratio of main channel width to secondary channel width is one of the most important influencing factors. This parameter is the main focus of the present research. In the present study, a model calibrated with laboratory results has been simulated. The numerical model results have revealed that decreasing the ratio of main channel width to secondary channel width causes the secondary channel flow encounters to the front wall of the secondary channel. Also, it leads to creating scour near the front wall and the main hole is drawn towards the wall. Furthermore, in the present research, topographical changes of the bed with running time of the numerical model for the middle channel axis has been extracted and presented.
Influence of Polypropylene Length on Stability and Flow of Fiber-reinforced Asphalt Mixtures
Authors: Bayat Ramin , Talatahari Siamak
Published: September 2019

Engineers are constantly trying to improve the performance of the flexible pavements. The main surface distress types which cause maintenance and disruption are rutting and fatigue cracking. For solving these problems, many studies have been carried out until now, ranged from changing gradation to adding polymers and fibers to asphalt mixture. In this study, polypropylene additive was selected as fiber additive because of low costing and having good correlation with asphalt pavement. Three type of polypropylene additive in the length 6, 12 and 19 mm were selected and used at five different percentages in the asphalt concrete mixture. Asphalt specimens were analysed by Marshall Analysis and finally tested by Marshall Stability apparatus. Adding polypropylene increased Marshall Stability (38%), and decreased Flow (39%). These results show that polypropylene can be helpful for increasing pavement life.
Risk Assessment of Geological Hazards in a Tunneling Project Using Harmony Search Algorithm (Case Study: Ardabil-Mianeh Railway Tunnel)
Authors: Mikaeil Reza , Shaffiee Haghshenas Sina , Shirvand Yakob , Valizadeh Hasanluy Mehdi , Roshanaei Vali
Published: September 2019

During the design and implementation of underground constructions, the risk assessment and management of geological hazards are important due to the hazards such as the water inflow, collision with crushed fault zones, squeezing and instability around excavation zones. In the present research, it is attempted to study and assess the risk of geological hazards in 378+021 km of the route of Ardabil-Mianeh railway tunnel using the harmony search algorithm (HSA). In the first section of research, after studying structural and geological characteristics during 24 sections of the excavation route, the risk relating to geological hazards including the tunnel instability, squeezing, water inflow and swelling was assessed in three separate classes using HSA. In order to study the accuracy of results, geological hazards recorded during the implementation of excavation operations were used. Studies obtained from the comparison of observed and predicted results indicate the high accuracy of HSA in the assessment and prediction of geological risks in the tunnelling project.
Artificial Neural Network-Cuckoo Optimization Algorithm (ANN-COA) for Optimal Control of Khorramabad Wastewater Treatment Plant, Iran
Authors: Khademikia Samaneh , Haghizadeh Ali , Godini Hatam , Shams Khorramabadi Ghodratollah
Published: September 2019

In this study a hybrid estimation model ANN-COA developed to provide an accurate prediction of a Wastewater Treatment Plant (WWTP). An effective strategy for detection of some output parameters tested on a hardware setup in WWTP. This model is designed utilizing Artificial Neural Network (ANN) and Cuckoo Optimization Algorithm (COA) to improve model performances; which is trained by a historical set of data collected during a 6 months operation. ANN-COA based on the difference between the measured and simulated values, allowed a quick revealing of the faults. The method could obtain the fault detection and used in solving continuous and discrete optimization problems, successfully. After constructing and modelling the method, selected performance indices including coefficient of Regression, Mean-Square Error, Root-Mean-Square Error and Aggregated Measure used to compare the obtained results. This analysis revealed that the hybrid ANN-COA model offers a higher degree of accuracy for predicting and control the WWTP.
Analysis of RC Continuous Beams Strengthened with FRP Plates: A Finite Element Model
Authors: Sakr Mohamed A. , Khalifa Tarek M. , Mansour Walid N.
Published: September 2019

Strengthening of reinforced concrete (RC) beams with externally bonded fibre reinforced polymer (FRP) plates/sheets technique has become widespread in the last two decades. Although a great deal of research has been conducted on simply supported RC beams, a few studies have been carried out on continuous beams strengthened with FRP composites.  This paper presents a simple uniaxial nonlinear finite-element model (UNFEM) that is able to accurately estimate the load-carrying capacity and the behaviour of RC continuous beams flexurally strengthened with externally bonded FRP plates on both of the upper and lower fibres. A 21-degree of freedom element is proposed with layer-discretization of the cross-sections for finite element (FE) modelling. Realistic nonlinear constitutive relations are employed to describe the stress-strain behaviour of each component of the strengthened beam. The FE model is based on nonlinear fracture mechanics. The interfacial shear and normal stresses in the adhesive layer are presented using an analytical uncoupled cohesive zone model with a mixed-mode fracture criterion. The results of the proposed FE model are verified by comparison with various selected experimental measurements available in the literature. The numerical results of the plated beams (beams strengthened with FRP plates) agreed very well with the experimental results. The use of FRP increased the ultimate load capacity up to 100 % compared with the non-strengthened beams as occurred in series (S). The major objective of the current model is to help engineers’ model FRP-strengthened RC continuous beams in a simple manner.
Energy Production from Sewage Sludge in a Proposed Wastewater Treatment Plant
Authors: Ayoub Mohamed , Rashed Ibrahim Gar Al-Alm , El-Morsy Ahmed
Published: September 2019

The implemented technologies for sewage sludge processing are still very limited in Egypt. Unfortunately, dealing with the produced sludge is mainly given to the drying process through natural drying beds neglecting quality of the dried sludge. The undertaken work is devoted to provide a design proposal for a typical wastewater treatment plant suitable for the small communities on a very limited area of land compared to that required to construct the conventional treatment plant that serves the same population. The proposed sewage treatment plant is certainly beneficial in reducing the capital costs by 26%, in addition to about 20% reduction in the running costs. On the other hand, electricity generated from energy produced by anaerobic digestion of sewage sludge reduces the electrical power requirements from the main grid network to about 27% in the proposed wastewater treatment plant.
Establishment of a Stochastic Model for Sustainable Economic Flood Management in Yewa Sub-Basin, Southwest Nigeria
Authors: Agbede O.A , Aiyelokun Oluwatobi
Published: September 2019

Of all natural disasters, floods have been considered to have the greatest potential damage. The magnitude of economic damages and number of people affected by flooding have recently increased globally due to climate change. This study was based on the establishment of a stochastic model for reducing economic floods risk in Yewa sub-basin, by fitting maximum annual instantaneous discharge into four probability distributions. Daily discharge of River Yewa gauged at Ijaka-Oke was used to establish a rating curve for the sub-basin, while return periods of instantaneous peak floods were computed using the Hazen plotting position. Flood magnitudes were found to increase with return periods based on Hazen plotting position. In order to ascertain the most suitable probability distribution for predicting design floods, the performance evaluation of the models using root mean square error was employed. In addition, the four probability models were subjected to goodness of fit test besed on Anderson-Darling (A2) and Kolmogorov-Smirnov (KS). As a result of the diagnostics test the Weibul probability distribution was confirmed to fit well with the empirical data of the study area. The stochastic model  generated from the Weibul probability distribution, could be used to enhance sustainable development by reducing economic flood damages in the sub-basin.
Seismic Response Reduction of Steel MRF Using SMA Equipped Innovated Low-damage Column Foundation Connection
Authors: Jamalpour Reza , Nekooei Masood , Sarvghad Moghadam Abdolreza
Published: September 2019

Connections in MRFs are the most important members and seismic behaviour is affected by function of beam column connections as well as column foundation connections. If the connections are able to provide the required ductility and efficiency against the seismic excitation, the seismic capacity of the MRF performed by these connections will be affected. SMAs have recently been used as a tool to dissipate energy in structures. So far, using of them for column foundation connections has been applied much less. In this paper, SMAs have been introduced and an innovated column foundation connection equipped with SMA has been suggested. Micro and macro behaviour of the connection has been studied and it was applied in sample MRF. Seismic response of the MRF under different earthquakes by equipping the connection with steels/SMAs bars have been studied and compared. Finally, results indicated that MRF with this connection showed proper seismic performance.
The Analysis of the Factors Which Affect the Building Costs in Indonesia
Authors: Laksono Taufik Dwi
Published: September 2019

Buildings are the kind of facility needed by everyone. The accuracy in determining the amount of costs required to build a building has become a challenge for all parties involved in the process. This study aims to determine the factors affecting the cost of a building. By using four independent variables, i.e. floor area, number of floors, foundation depth, and project implementation time, and one dependent variable in the form of a contract value of the building project, an analysis to determine the factors that influence the cost of a building has been made. Using 81 samples in several cities in Indonesia and multiple linear regression of stepwise method, the results show three factors that significantly affect the cost of building projects. They are floor area, number of floors, and project implementation time. This is indicated by tcount for floor area of 12.770, tcount for the number of floors of 46.05, and tcount for project implementation time of 2.321.
Diagnostic and Assessment Benefits and Barriers of BIM in Construction Project Management
Authors: Al-Zwainy Faiq , Mohammed Ibraheem A. , Al-Shaikhli Kamil A. K.
Published: September 2019

This paper aims to diagnostic and assessment the benefits and barriers of Building Information Modelling in the construction project management. Both open and closed questionnaire was used to explore the views of a number of Iraqi engineers; in order to investigate the level of BIM implementation in Iraq construction sector. Questionnaire indicated an acceptable awareness of (BIM) in Iraq, especially among the young generation of engineers which indicates the arrival of the evolutionary stream of BIM in the next few years. Moreover, questionnaire showed that the most important advantage of implementing BIM in the Iraqi construction sector was the ability to generate accurate 2D plans at any stage, while the least important advantage was the ability to provide a careful planning of the site facilities, with a relative importance of (82 %) and (33 %) respectively. Furthermore, the most important barrier to its implementation was the unspecified responsibilities for data content, as presented by questionnaire, while the least important barrier was the lack of programs efficiency in data exchange and internal collaboration, with a relative importance of (81 %) and (34 %) respectively.
Modeling of Rainfall-Runoff Correlations Using Artificial Neural Network-A Case Study of Dharoi Watershed of a Sabarmati River Basin, India
Authors: Patel Ajaykumar Bhagubhai , Joshi Geeta S.
Published: September 2019

The use of an Artificial Neural Network (ANN) is becoming common due to its ability to analyse complex nonlinear events. An ANN has a flexible, convenient and easy mathematical structure to identify the nonlinear relationships between input and output data sets. This capability could efficiently be employed for the different hydrological models such as rainfall-runoff models, which are inherently nonlinear in nature. Artificial Neural Networks (ANN) can be used in cases where the available data is limited. The present work involves the development of an ANN model using Feed-Forward Back Propagation algorithm for establishing monthly and annual rainfall runoff correlations. The hydrologic variables used were monthly and annual rainfall and runoff for monthly and annual time period of monsoon season. The ANN model developed in this study is applied to Dharoi reservoir watersheds of Sabarmati river basin of India. The hydrologic data were available for twenty-nine years at Dharoi station at Dharoi dam project. The model results yielding into the least error is recommended for simulating the rainfall-runoff characteristics of the watersheds. The obtained results can help the water resource managers to operate the reservoir properly in the case of extreme events such as flooding and drought.
Cost Analysis of RCC, Steel and Composite Multi-Storied Car Parking Subjected to High Wind Exposure in Bangladesh
Authors: Kuddus Mir Abdul , Dey Partha Pritom
Published: September 2019

Steel-concrete composite constructions in Bangladesh are nowadays very popular owing to their advantages over conventional concrete and steel constructions. Concrete structures are massive and allot more seismic weight and less deflection whereas steel structures instruct more deflections and ductility to the structure, which is beneficial in resisting earthquake and wind forces. Composite construction combines the better properties of both steel and concrete along with lesser cost, speedy construction, fire protection etc. The objective of this study was to analysis and design ground floor plus 19 storied R.C.C, Steel and Composite (steel-concrete) multi-storied parking structure’s frame of same plan using ETABS 2013 software and compare their structural parameters with estimated cost for required material. All frames are designed for same gravity and dynamic loadings. The RCC deck-slab is used in steel and composite frame. Beam and column sections are made of RCC, steel or steel-concrete composite sections. The composite construction option provided about 25 % and 18% less cost when compared to RCC and steel structure, respectively. Comparative study concludes that the composite frames are best suited among all the three types of constructions in terms of material cost and benefit added with better structural behaviour.
Ameliorating Precast Concrete Curbs Using Rubber and Nano Material
Authors: Komaki Mohammad Ebrahim , Ghodrati Dolatshamloo Amirreza , Eslami Mahdi , Heydari Sahar
Published: September 2019

Disposal of waste tire rubber has become one of the major environmental issues in each part the World. One of the possible solutions to dispose of scrap tire rubber is using them into concrete curbs. This paper presents a new method to ameliorate the rubber concrete using a particular rubber size and Nano Material. Initially six mix designs were performed to determine the optimized size and percentage of rubber according to compressive strength. Afterwards, the major concrete curbs were made with the optimum mix design. Three different samples were made to determine the effects of rubber and Nano. One of which was made without rubber and Nano, the other was made with rubber and the last with rubber and Nano. Experiments were carried out to determine the durability and strength of specimens according to ISIRI-12728.
Effect of Cyclic Loadings on the Shear Strength and Reinforcement Slip of RC Beams
Authors: Sakr Mohammed A
Published: September 2019

Numerous studies of the response of reinforced concrete members under cyclic loadings, many of which have been summarized and have indicated that, in general, the flexural strength of under-reinforced beams remains unimpaired under cyclic loadings consisting of a reasonable number of cycles. However, there is a body of evidence indicating that their shear strength may suffer under such loadings. The first objective of the current study is to construct an accurate 2D shell finite element model of reinforced concrete beams under cyclic loadings. The second objective is carrying out a parametric study on reinforced concrete beams, using the suggested 2D shell model.  The objective of this study was to observe the effect of the stirrup spacing, steel-to-concrete bond properties on the performance of reinforced concrete beams under cyclic loadings. For this purpose, an efﬁcient and accurate ﬁnite element model was established taking into account the compression and tensile softening introducing damage in the concrete material, the Baushinger effect using nonlinear isotropic/kinematic hardening in the steel and an adequate bond-slip law for the concrete–steel interface. The simulated results of numerical models were veriﬁed by experimental results available in literature in order to validate the proposed model, including hysteretic curves, failure modes, crack pattern and debonding failure mode. The model provided a strong tool for investigating the performances of reinforced concrete beam. The results showed that: Cyclic loadings may change the failure mode of the beam to bond failure even though it has sufficient bond length to resist static loadings. So that under cyclic loadings additional anchorage length must be taken, cyclic loadings also influence the ductility and peak load for beams fail in shear. All these topics are of the utmost importance to RC behaviour to be considered by construction codes.
The Effects of Using Different Seismic Bearing on the Behavior and Seismic Response of High-Rise Building
Authors: Mansouri Saman , Nazari Amin
Published: September 2019

The effects of using different seismic bearings were investigated to reduce the seismic response of buildings by assuming the vulnerability of 20-story regular RC building in this paper. The method of this study was that the studied building was studied in three different models in terms of its connection to the foundation. In the first model, the structures were placed on the rigid bearing and in the second and third models; lead-rubber bearings and friction pendulum bearings were placed at the counter between the structure and foundation, respectively. Then, the dynamic analysis was used to assess the behaviour and seismic response of the mentioned models. The results of the study showed that the structures in the first model functioned like cantilever column that would become uniaxial and biaxial bending under the effects of earthquake around the vertical axis of structure. Due to the tensile (tension) weakness in concrete, seismic loads caused major cracks in the tension part of the structures according to the place of the neutral axis that could lead to the collapse of structure. In addition, the use of mentioned seismic bearings under the earthquake caused the structure like a semi-rigid box slid on this equipment that reduced the structure's stiffness and increased the period of the structure in comparison with the first model. Using the studied seismic bearings caused the displacement of the roof of the first and twentieth stories of the structure become approximately equal and prevented the creation of the bending moment in the first model. The results of non-linear time history analysis showed that using the studied seismic bearings caused the response of the structure reduced significantly when the structure was placed on rigid bearings. It could be very valuable regarding the limitation of the capacity of the structure's members.
Effects of Soil Modulus and Flexural Rigidity on Structural Analysis of Water Intake Basins
Authors: Akbari Hassan
Published: September 2019

A water intake basin is a buried box that functions as a water reservoir near shorelines. Number of these structures has been increased in the recent years and for a safe design, it is necessary to know their behaviour under applied loads. In addition to common dead, live and seismic loads, the bottom of such a basin is usually located below sea water level and endures uplift pressure as well as reaction of supporting soils. Uncertainty of these special loads complicates the structural response of this buried basin to the applied loads. Therefore, the unreliability in the soil parameter and in the rigidity of the basin structure is studied in this research by calculating the generated internal bending moments. Different loads and load combinations have been taken into account and finite element analysis is carried out for modelling nonlinear behaviour of different types of supporting soils. It is concluded that the geometry and flexural stiffness of the basin affects the analysis more than the soil parameters because the contribution of the soil modulus in the total stiffness of the system is negligible than the structural rigidity of the basin structure. In addition, inner walls and geometry of the basin should be modelled in detail to obtain acceptable results.
Procurement of Railway Infrastructure Projects – A European Benchmarking Study
Authors: Eriksson Per Erik , Lingegård Sofia , Borg Lena , Nyström Johan
Published: September 2019

This benchmarking study compares how railway investments are procured in five European countries: Sweden, Norway, Germany, the Netherlands, and the UK. In total, 19 procurement managers and project managers were interviewed. This study compares the national rail clients’ procurement strategies regarding: delivery system, reward system, contractor selection, and collaboration model. Historically, these clients have used in-house production. The first step towards a gradually increased usage of the market was to outsource the construction activities while keeping the design and development competence in-house. All five countries have mainly used Design-Bid-Build contracts in their initial outsourcing. However, the last few years there is a discernible trend in Sweden, Norway, the Netherlands and the UK towards allocating more design and development responsibilities to contractors (i.e. Design-Build contracts) and increasing the strategic focus on cooperation. The UK and the Netherlands are forerunners in this trend that can be viewed as a third step in the transition towards a market oriented railway sector. Norway and Sweden is in the middle of this transition, whereas Germany has not initiated this change. The transition towards a gradually increased usage of the market has two main dimensions; degree of cooperation and degree of contractor freedom, which differs among the countries. The UK and Sweden focus on increasing both these dimensions, while The Netherlands and Norway mostly focus on increasing the degree of contractor freedom. Germany still limits both dimensions by performing design and development in-house and letting contractors compete for construction work in Design-Bid-Build contracts. Due to historical and cultural reasons, Deutsche Bahn in Germany is very hesitant to engage in collaboration with external suppliers; focusing on competition is considered more appropriate and less controversial.
Aerated Concrete Produced Using Locally Available Raw Materials
Authors: Matalkah Faris , Bharadwaj Harsha , Balachandra Anagi , Soroushian Parviz
Published: September 2019

Aerated concrete materials were developed with abundant natural materials. Aerated concrete can provide insulating qualities complemented with secondary structural attributes when used as core in sandwich composites for building construction. A hybrid binder that comprised lime and gypsum was used. Different foaming agents were considered for production of aerated concrete, including saponin that is found abundantly in different plants. Different formulations were considered, and the stability of the foam structure as well as the density and early-age compressive strength of the resulting aerated concrete were evaluated. One formulation comprising lime-gypsum binder with saponin foaming agent, with a density of 0.53 g/cm3, was further characterized through performance of thermal conductivity, split tension, flexure, elastic and shear modulus and sorptivity tests. The results pointed at the satisfactory balance of qualities provided by the aerated concrete when compared with alternative aerated concrete materials.