International Journal of Civil Engineering
Volume:15 Issue: 7, Oct 2017

Construction industries are among the most hazardous and high-risk occupations that involve mild-to-severe accidents and bodily injuries. The aim of this study is to explore the causal factors contributing to the accident severity rate (ASR) in 13 of the biggest Iranian construction industries. In this analytical cross-sectional study, the data of registered accidents from 2009 until 2013 were obtained from an official database. Data of HSE risk management systems and HSE training were also gathered from comprehensive accident investigation reports. Data analysis and regression modeling were done using the SPSS statistical software (version 22). The ASR mean and SD of studied construction worksites were 257.52 ± 1098.95. The results show that the system associated with HSE and HSE risk management established only 41.8 and 18.4%, respectively. Results of multiple linear regressions indicated individual and organizational factors (IOFs), HSE training factors (HTFs), and Risk Management System factors (RMSFs) to be significantly associated with ASR (p 

The gap acceptance behavior of drivers at U-turn median openings is studied by considering the critical gap which cannot be obtained directly by field measurements. A thorough investigation on critical gap estimation is carried out by collecting the data sets from median openings at 4-, 6-, and 8-lane roads of Hyderabad City, India. Wide difference (10–42%) among the critical gap values estimated by the application of existing methods shows the limitation to consider for the mixed traffic situations. To address this issue, recently developed method Influence Area for Gap Acceptance (INAFOGA) which is based on clearing behavior of drivers at unsignalised intersections is modified and applied considering the merging behaviour of U-turn vehicles at median openings and named ‘Modified INAFOGA’ method. Modified INAFOGA method is compared with probability equilibrium method through paired-sample hypothesis (t test), and result revealed that difference in mean values 0.009 signifies that both methods are comparable. Difference in critical gap values obtained from the box plots and radar charts indicates that probability equilibrium method is not suitable to address the behavior of U-turn vehicles at median openings under mixed traffic conditions. These observations coupled with higher critical gap values validate the fact that ‘modified INAFOGA’ method is indeed appropriate under mixed traffic conditions.

This study presents methods for numerical modelling and the static computer analysis of steel decks fixed on scaffoldings. The main problem raised here is the method of creating models of a single deck and determination of the accuracy of every model for various design situations: the analysis of state stress in components of decks, the strength analysis of scaffolding, where decks can be loaded by untypical the arrangement of materials, and the strength analysis of full scaffoldings. The analysis of a state stress in components of a deck requires a detailed model. The analyses of scaffoldings with load by materials have to be performed with using more simple models of platforms. The static-strength analysis of full scaffoldings with many frame elements can be performed if the simplest models of decks are used. In this paper, the sets of truss elements replace the stiffness of scaffolding decks.

The present paper addresses the comparative study of two adjacent single-degree-of-freedom structures for elastic and inelastic systems with and without pounding. The study is also carried out in the presence and absence of tuned mass damper under (TMD) seismic excitations. The tuned mass damper considered for the present study is a passive device attached to single main structural unit in the simplest form as soft storey at the top of main system. Total eight models have been considered depending upon the presence and absence of pounding as well as TMD in the analysis. The entire numerical simulation is carried out in time domain form by considering the inputs of four real earthquake ground motions. Outcome of the present study indicates that elastic adjacent structural system always overrates the pounding forces than the inelastic adjacent structural units. The use of TMD reduces the pounding forces in the adjacent structures. During pounding, the results show that the structural displacement response is much more sensitive for inelastic systems mostly under consideration or ignorance of TMD. One of the observations is that there is large amount of variation in the structural energy formation of adjacent structures while considering or ignoring the pounding as well as TMD.

A more proactive approach toward the repair method for a friction-deficient pavement surfaces would be to test the hot mix asphalt in the laboratory during its initial mix design stage to ensure that aggregate combinations will provide adequate friction over the life of the pavement. Toward this objective, the polishing behavior of laboratory-prepared HMA specimens made of eight different job mix formulas has been studied in terms of friction values. In addition, a robust statistical analysis of the obtained surface friction values has also been carried out in an attempt to verify the success in developing this new asphalt polisher that is used to simulate the tire–pavement interaction. Furthermore, polishing behavior (i.e., polishing trend, rate of friction loss and absolute and percent values of decrease) was all fully investigated to capture surface frictional deterioration of HMA specimens. In conclusion, the new asphalt polisher showed a good degree of repeatability. Additionally, it has been concluded that the decrease in polish number is maximum during the first hour of polishing. With the passage of time the drop in friction decreases and stabilizes.

In this paper, the scour hole dimensions around submerged and emerged spur dike in a 90° bend along with the mean and turbulent flowfield were investigated experimentally. Two types of re-circulating flow at the downstream of the spur dike and around the spur dike wing were observed. A direct relation between the estimated bed shear stress using TKE and the scour process prevails. More attentions is needed in estimating the bed shear stress using vertical velocity fluctuations. The scour hole dimensions increase by increasing the ratio of radius of channel bend to channel width, the Froude number of the spur dike, ratio of the length of spur dike to channel width and ratio of the approach mean flow velocity to the approach flow velocity at threshold condition. However, vice versa trends were observed by increasing ratio of the spur dike length to the median sediment size, ratio of the wing length of spur dike to the length of spur dike and the submergence ratio. A particular location of the spur dike in the sharp bend was specified beyond which the scour hole dimensions increase. The ratio of the spur dike length to the median sediment size has a secondary effect on the scour hole dimensions. New equations are proposed for prediction of the scour hole dimensions considering the submergence ratio along with other effective parameters.

Minimum reinforcement ratios provided in the standards remain at very low levels especially at large systems subject to the effects of earthquakes. Thus, arranging the reinforcement ratios intended for preliminary design can provide significant ease and safety in project design phase, and speed and simplicity in the project control phase. Moreover, a more realistic limitation is thus ensured compared to general minimum reinforcement ratios given in the standards. System characteristics which may affect the reinforcement ratios can be specified by general and simple parameters. As the result of many extensive studies, expressions for reinforcement ratios intended for preliminary design which will cover systems with different parameter values can be composed. Today, thanks to the development levels of finite elements programs which can perform reinforced concrete modeling, meeting this requirement is much more possible compared to the past. Structure of parameters should neither be very special nor very general. Otherwise, reinforcement ratios intended for preliminary design will either be valid for a single system or they will remain at very low limits such as the minimum reinforcement ratios given in the standards. For this reason, in this study a route in between these two extreme conditions was followed. Today, it is possible to perform many studies on the systems with different and comprehensive inclusive parameters and to determine practical ratios which will constitute a recommendation for the project designs. For this purpose, an eight storey reinforced concrete system with single spacing whose shear wall cross-section is 25 × 250 cm, column cross-section is 25 × 30 cm, and beam cross-section is 25 × 50 cm was addressed, and its non-linear planary analyses under static earthquake loads were performed through the ANSYS finite elements program for 13 different reinforcement cases. The reinforcement ratios to be recommended for the system at hand and similar systems were tried to be revealed. The examined system was arranged so as to get the most critical and extreme values for many parameters which can be considered, but it was tried for the reinforcement ratios to be recommended to be valid not only for this system but also for the general system network with similar properties to this system. In future studies, expressions of general and inclusive preliminary design reinforcement ratios can be obtained as per the results of many studies to be made on systems with different parameter values. Thus, the tables for preliminary design reinforcements of examined systems can be created. For preliminary design, reinforcement ratios based on the values of system elements’ parameters can be determined from these tables. In this case, the design process will be greatly reduced and it will be more reliable. These ratios can be called as the minimum reinforcement ratios for the preliminary design.

The present study demonstrates the influence of operating speed on capacity of a midblock section of urban road. Speed–flow data collected at 12 midblock sections of 6-lane and 4-lane divided urban arterials in four metropolitan cities of India are analyzed to determine their capacity. Lane capacity was found to vary from 1482 to 2105 PCU/h. This variation is explained on the basis of city size and driving behavior, which would influence the free flow speed on the road. Free flow speed was also measured at each section and these speed data were used to determine operating speed 85th percentile of free flow speed of standard car) on the road. Lane capacity was found to be strongly related to operating speed on a road and a second-degree polynomial model is developed between the lane capacity and operating speed. This model is further validated by collecting speed flow data at two new sections and their capacity was estimated from field data and from the model developed in the study. The predicted capacity was found to be matching with field capacity and the maximum error was 0.10 percent. Operating speed on a road can vary due to road surface condition, side friction or similar other factors. All these will have influence on capacity of the road. The capacity model suggested in the present study can be a useful tool to determine capacity of an urban road from its operating speed data.

This paper deals with both global and local versions of an energetic analytical model to quantify the damage caused to reinforced concrete (RC) structures under monotonic, cyclic, or fatigue loading. The proposed model closely represents the damage to structures, and presents a damage index (DI) formulation for the RC members. The model is based on the cumulative energy absorbed by the structure. The data required to apply the model can be obtained either from numerical simulation or from experimental test. A computer program has been developed to simulate numerically the response of RC members under cyclic loading. In the program, the non-linear behavior of the materials and the structure involved are taken into account. The proposed numerical simulation model was verified by comparison with practical tests undertaken by other researchers on over 20 full-scale RC columns. The comparison demonstrates that the model provides a realistic estimation of the damage of the RC structural members. The comparison between values of the proposed DI calculated based on experimental test data and numerical simulation results shows that to calculate DI, it is not necessary to perform expensive experimental tests, employing a non-linear structural numerical simulation program is sufficient. The proposed DI is also compared to a damage model proposed by Meyer.

The present study aims at the divination of the speed ranges of level of service (LOS) categories of urban traffic facilities. Free flow speed, congested travel speed, geometric, and surrounding environmental conditions are considered to define LOS criteria for urban street in Indian context. Cluster analysis is found to be a powerful tool to delineate LOS criteria. Hard competitive learning method is used to classify large number of speed data obtained using global positioning system. Six cluster validation parameters are used to classify the urban streets as well as the LOS categories. It can be confirmed from the above research work that the LOS categories for different urban street class are lower than that of the values proposed by HCM 2000 and the average travel speed of LOS categories expressed in percentage of the free-flow speed is lower than the values mentioned in HCM 2010.