i-manager's Journal on Structural Engineering (JSTE)


Volume 4 Issue 3 September - November 2015

Research Paper

A Study on Structural Behavior of Reinforced Cement Concrete Slabs of High Strength Hybrid Fiber Reinforced Self Compacting Concrete

B. Narendra Kumar* , P. Srinivasa Rao**, G. Deepa***
* Associate Professor, Department of Civil Engineering, VNR Vignana Jyothi Institute of Engineering and Technology,Hyderabad, Telangana, India.
** Principal & Professor, Department of Civil Engineering, VNR Vignana Jyothi Institute of Engineering and Technology, Hyderabad, Telangana, India.
*** PG Student, Department of Civil Engineering, VNR Vignana Jyothi Institute of Engineering and Technology, Hyderabad, Telangana, India.
Kumar, B.N., Rao, P.S., and Deepa, G. (2015). A Study on Structural Behavior of Reinforced Cement Concrete Slabs of High Strength Hybrid Fiber Reinforced Self Compacting Concrete. i-manager’s Journal on Structural Engineering, 4(3), 1-9. https://doi.org/10.26634/jste.4.3.3725

Abstract

An experimental program is carried out to evaluate the contribution of hybrid fibers on the structural behavior of high strength hybrid fiber reinforced self compacting concrete slabs. A total of six slabs is cast and tested. The slab dimension is 1200mm x 1200mm and the thickness is 100mm. The slabs are cast with the addition of hybrid fibers (steel and glass fibers) varying from 0% to 1.5% of weight of powder content. The slabs are tested under loading frame to obtain the load and deflection characteristics, first crack load, and the ultimate load. The Reinforced Cement Concrete slabs are designed as per IS: 456 (2000). Addition of hybrid fibers enhanced the first crack load and post cracking behavior. A marginal improvement in the ultimate load carrying capacity is observed. It is observed that, the load carrying capacity of reinforced cement concrete slabs with hybrid fibers (1.0 % steel fibers + 0.75 % glass fiber) showed an improved load carrying capacity compared to all other slabs.

Research Paper

Optimization of Rectangular Box Girder Bridges Subjected to IRC Loading with Volume Minimization

B. Satyanarayana* , A. Mallika**
* PG Student, Department of Civil Engineering, VNR Vignana Jyothi Institute of Engineering and Technology, Hyderabad, Telangana, India.
** Professor, Department of Civil Engineering, VNR Vignana Jyothi Institute of Engineering and Technology, Hyderabad, Telangana, India.
Satyanarayana, B., and Mallika, A. (2015). Optimization of Rectangular Box Girder Bridges Subjected to IRC Loading with Volume Minimization. i-manager’s Journal on Structural Engineering, 4(3), 10-17. https://doi.org/10.26634/jste.4.3.3726

Abstract

In any structural design, safety and economy of the structures are the main objectives therefore, it is necessary to obtain the optimum geometric shape of the structure so that it can carry the imposed load safely and economically. In the present paper, analysis and optimization of the rectangular box girder bridges subjected to IRC loading are presented. The shape optimization of the box girder bridge with volume minimization as the objective are subjected to a constraint on Von-Mises stresses. Numerical examples of single and twin cell box girder sections are considered for analysis and optimization. Ansys 13.0 is used for analysis and optimization. For the single cell box girder bridge, the volume of the structure was reduced by 40 percent and 54 percent volume reduction was obtained for the twin cell box girder.

Research Paper

Investigation on Shear Lag Phenomenon in RCC Framed Tube Structures

G. J. Singh* , S. Mandal**, Rajesh Kumar***
* Research Scholar, Department of Structural Engineering, IIT (BHU), Varanasi, India.
** Associate Professor, Department of Civil Engineering, IIT (BHU), Varanasi, India.
*** Associate Professor, Department of Civil Engineering, IIT (BHU), Varanasi, India.
Singh, G.J., Mandal, S., and Kumar, R. (2015). Investigation on Shear Lag Phenomenon in RCC Framed Tube Structures. i-manager’s Journal on Structural Engineering, 4(3), 18-25. https://doi.org/10.26634/jste.4.3.3727

Abstract

In the present study, a 40 storey RCC framed tube building has been examined. The shear lag phenomenon is analysed in the framed tube structures, by various methods and are reported. The detailed investigation of the phenomenon in the tubular buildings is lacking. As the height of the buildings increases, the lateral load (wind load) becomes governing factor for design. Positive and negative shear lag occur in the bottom and top portion of the building, respectively. As the height increases, axial force in column is immediately adjacent to the corner column increase and with further increase in height, it shifts towards central column. Some column of compression flange may also develop tension right from the support depending upon height of the structure. Columns in upper storeys are critical columns for the designer as they may develop tension. The quantitative estimate will help in the design to fix preliminary section dimensions of different structural members.

Research Paper

Push Over Analysis of Plan Irregular Reinforced Concrete Buildings with and without a Lead Rubber Base Isolator

M. Rakesh* , B. Narendra Kumar**
* PG Student, Department of Civil Engineering, VNR Vignana Jyothi Institute of Engineering and Technology, Hyderabad,Telangana, India.
** Associate Professor, Department of Civil Engineering, VNR Vignana Jyothi Institute of Engineering and Technology, Hyderabad,Telangana, India.
Rakesh, M., Kumar, B.N. (2015). Push Over Analysis of Plan Irregular Reinforced Concrete Buildings with and without a Lead Rubber Base Isolator. i-manager’s Journal on Structural Engineering, 4(3), 26-33. https://doi.org/10.26634/jste.4.3.3728

Abstract

Earthquakes are one of the natural disasters that occur due to the sudden violent movement of earth's surface which releases energy and has high destructive power which can cause significant loss of life. On the other hand, earthquakes cause severe damage to property, especially to man-made structures and it provides architects and engineers with a number of important design criteria foreign to the normal design process. As many researchers studied and reviewed that seismic isolation is the best solution for the earthquake resistant of the structures and its application is the most constructive technique to protect structures against destruction from the earthquake strike and has gained growing majority during past decades. This is because base isolated confines the effects of the earthquake strike, a workable base largely separating the structure from the ground motion, and the structural counter accelerations are usually less as compared to the ground acceleration. The aim of the present study is to know the effect of the Lead rubber bearing base isolator on the seismic behaviour of plan irregular RC buildings i.e., (L Shaped, T Shaped and U Shaped) with different building heights. Static Pushover Analysis has been carried out using SAP2000 version 17 to know the seismic behaviour of buildings with and without Base Isolator.

Research Paper

Black Spot Identification and Audit Analysis for Heterogeneous Traffic Conditions in Hyderabad City – a Case Study

T. Sri Lakshmi Sowmya* , A. Ramesh**, B.N.M. Rao***, M. Kumar****
* PG Student, Department of Civil Engineering, VNR Vignana Jyothi Institute of Engineering and Technology, Hyderabad, Telangana, India.
** Associate Professor, Department of Civil Engineering, VNR Vignana Jyothi Institute of Engineering and Technology, Hyderabad, Telangana, India.
*** Professor and Head, Department of Civil Engineering, VNR Vignana Jyothi Institute of Engineering and Technology, Hyderabad, Telangana, India.
**** Professor, Department of Civil Engineering, University College of Engineering, Osmania University, Telangana, India.
Sowmya, T.S.L., Ramesh, A., Rao, B.N.M., and Kumar, M. (2015). Black Spot Identification and Audit Analysis for Heterogeneous Traffic Conditions in Hyderabad City – a Case Study. i-manager’s Journal on Structural Engineering, 4(3), 34-42. https://doi.org/10.26634/jste.4.3.3729

Abstract

Accident black-spot is the place where road traffic accidents have historically been concentrated. In these locations, accidents are not a random event but are common due to varying factors like road environment, traffic factors, and vehicle conditions. In metropolitan cities like Hyderabad in India, road traffic is heterogeneous and vehicular movement is highly influenced by surrounding vehicular traffic which is resulting in frequent accidents. In order to overcome the increasing number of road accidents, the present study helps to analyze the black-spot locations in the city where the major road accidents take place. Accident data for the past three years (2012-2014) in Hyderabad city was collected from police records in terms of time, date of occurrence, details of accidents such as fatal, injury, and property damage, and type of vehicles involved. This data is analyzed using accident frequency method and accident severity method for identification of black-spot locations. These identified black-spot locations are ranked in terms of severity of occurrence and analyzed to bring out the accident contributing factors for each location. Audit studies were conducted at black-spot locations for achieving improvement measures for reduction in cause of road accidents. A black-spot model was also developed using multiple linear regression analysis. Narrow roads, steep curves, improper illumination, improper traffic signals, and lack of speed sign boards were observed as a few major causes for road accidents at highly ranked black- spot locations. From the study, it was also observed that rash driving, and signal jump play a vital role for increasing accident rates in the city.