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


Volume 9 Issue 1 March - May 2020

Research Paper

Study on Some Scale Effects of Two Similar Cylindrical Water Storage Tanks

Silviya Petkova* , Yuji Kohgo**
* Tokyo University of Agriculture and Technology, Tokyo, Japan.
** Graduate School of Agriculture, TUAT, Tokyo, Japan.
Petkova, S., and Kohgo, Y. (2020). Study on Some Scale Effects of Two Similar Cylindrical Water Storage Tanks. i-manager's Journal on Structural Engineering, 9(1), 1-9. https://doi.org/10.26634/jste.9.1.16522

Abstract

This work presents a study of the relationship between the dynamic characteristics of a full-size structure and its scaled version. By understanding the similitude laws and suitably scaling material properties, one can utilize an efficient scale model to obtain realistic structural performance. The main goal is to identify whether the natural frequencies of a coupled fluid-structure system follow the same similitude law as the full-size structure and its scaled prototype. The coupled fluid-structure systems are those where the structural behavior affects the fluid response and the fluid behavior affects the structural response so both must be solved, i.e., coupled together, to obtain the interacting solution. Scaling of the structure in specific numerical analysis defines two models that are similar in their geometry and material properties and is considered only in relation to the need for laboratory testing of engineering models. The finite element representation of a laboratory tested physical model is a bridge between this small-scale prototype and the computational model of a real structure. A thin-walled water storage tank with a simple cylindrical geometry is adopted for the analysis as representative of a coupled fluid-structure system whose dynamic behavior is strongly influenced by the presence of fluid and neither the structure nor the fluid alone governs the response.

Research Paper

Study on the Influence of the Methods of Curing on the Strength Properties of Concrete

Challa Datta Karthik* , Gourishetty Ruthvik**, G. Siva Vignan***
*-*** Department of Civil Engineering, St. Martin's Engineering College, Hyderabad, India.
Karthik, C. D., Ruthvik, G., and Vignan, G. S. (2020). Study on the Influence of the Methods of Curing on the Strength Properties of Concrete. i-manager's Journal on Structural Engineering, 9(1), 10-16. https://doi.org/10.26634/jste.9.1.17006

Abstract

Curing is the process of maintaining hardened concrete under moist condition. Curing must be undertaken for reasonable period of time, to ensure that the concrete achieves its potential strength and durability. Efficient and uninterrupted curing contributes to the superior quality of concrete. This paper aims to compare the strength parameters of M40 and M25 grade concrete under various methods of curing. For this study, we adopted curing by Immersion and Surface Curing methods. We also adopted Membrane Curing, in which the curing would be done by the application of pigmented emulsions of linseed oil on the concrete surface. Finally, after the concrete specimens have undergone curing for a certain period of time, they are tested for strength parameters such as Compressive Strength and Flexural Strength and the conclusions are drawn from it.

Research Paper

Evaluation of Fiber Reinforced Polymer Strengthened High Strength Concrete Beams under Cyclic Performance

Sivapriya S.* , Raghunath P. N.**, Suguna K.***
* Department of Civil Engineering, V. R. S. College of Engineering and Technology, Villupuram, Tamil Nadu, India.
**-*** Department of Structural Engineering, Annamalai University, Chidambaram, Tamil Nadu, India.
Sivapriya, S., Raghunath, P. N., and Suguna, K. (2020). Evaluation of Fiber Reinforced Polymer Strengthened High Strength Concrete Beams under Cyclic Performance. i-manager's Journal on Structural Engineering, 9(1), 17-34. https://doi.org/10.26634/jste.9.1.17135

Abstract

This study focuses on the Artificial Neural Network (ANN) model for predicting the performance of Fibre Reinforced Polymer (FRP) strengthened High Strength Concrete (HSC) beams under cyclic load. The data required for ANN modelling is collected from relevant literature. Back propagation network with Levenberg–Marquardt, Bayesian Regularization and Scaled Conjugate Gradient were chosen for the proposed network, which is implemented using the programming package MATLAB. In the present study, the experimental results were obtained for FRP strengthened HSC beams under cyclic load applied by Push pull jack and Actuator. The investigation has been performed by comparing the test results with the results predicted by the neural network and the regression modeling. The accuracy of the proposed model has been ascertained using statistical indicators such as RMSE, R² and MAE. The scatter plots are drawn for ANN and regression results. Comparing the proposed results with existing experimental results exhibits very good convergence.

Research Paper

Use of Waste Tyre as a Light Weight Backfill Material for Retaining Wall

Vikash Singh* , Samreen Bano**, Syed Aqeel Ahmad***
* Department of Civil Engineering, Seth Vishambhar Nath Institute of Engineering and Technology, Barabanki, Lucknow, Uttar Pradesh, India.
**-*** Department of Civil Engineering, Integral University, Lucknow, Uttar Pradesh, India.
Singh, V., Bano, S., and Ahmad, S. A. (2020). Use of Waste Tyre as a Light Weight Backfill Material for Retaining Wall. i-manager's Journal on Structural Engineering, 9(1), 35-39. https://doi.org/10.26634/jste.9.1.16040

Abstract

In the present time, waste tyres are increasingly being used in many geotechnical applications like embankment fill, retaining wall, machine foundation, bridge abutment etc. From the previous studies, it had been noted that the tyre chips mixed with soil are used as a backfill material for earth-retaining structures. In the present study, a numerical simulation using OPTUM G2 (finite element based numerical tool) has been adopted to evaluate the effect of waste tyre as a backfill material on total lateral earth pressure for an 8 m high wall. In all the cases, wall backfilled with waste tyres are found to be safer than the wall backfilled with soil. From this study, it has been found that mixing of waste tyre as a backfill material substantially reduces the total earth pressure on the wall in the range of 50-54% as compared to wall backfilled with the soil.

Research Paper

Design of Reinforced Cement Concrete Corbel and Perform Free Vibration and Buckling Analysis

Rahul Bharadwaj* , Mubeen Khan**, Kamal Nath***, K. N. V. Chandrasekhar****
*-**** Department of Civil Enginering, CVR College of Engineering, Hyderabad, Telangana, India.
Bharadwaj, R., Khan, M., Kamalnath, and Chandrasekhar, K. N. V. (2020). Design of Reinforced Cement Concrete Corbel and Perform Free Vibration and Buckling Analysis. i-manager's Journal on Structural Engineering, 9(1), 40-51. https://doi.org/10.26634/jste.9.1.16479

Abstract

The first role of a civil engineer is to perform design and analyze the structure before it is built. The structure should provide a safe and green environment to live in and should take up less cost. Corbel is one of the complex structural members where the load applied is eccentric. Corbels can carry heavy loads under the bridges and must be designed for buckling and vibration analysis. The main focus of this study is to perform the reinforced cement concrete corbel using Midas NFX® and perform the static, buckling and vibration analysis. The results show whether the structure is safe in buckling and vibration. The buckling mode shapes and vibration mode shapes were presented. The topology optimization had been performed to identify the areas which carry loading with minimizing compliance as objective function. The optimal distribution of the material shows a strut and tie model in the design domain.

Research Paper

A Research Paper on Seismic Retrofitting of Pure Masonry Structure

Punit Kumar Tiwari* , Shubharanshu Jaiswal **, Praveen Kumar Yadav***
*-** Department of Civil Engineering, B.B.D. University, Uttar Pradesh, India.
*** Department of Civil Engineering, I.T.S. Engineering College, Uttar Pradesh, India.
Tiwari, P. K., Jaiswal, S., and Yadav, P. K. (2020). A Research Paper on Seismic Retrofitting of Pure Masonry Structure. i-manager's Journal on Structural Engineering, 9(1), 52-59. https://doi.org/10.26634/jste.9.1.16052

Abstract

In India, most of the buildings in rural and urban areas are constructed through the pure masonry structure. At present, retrofitting is a method of providing external strength to a building under lateral loads. In this paper, we have compared different eight models under lateral loading, through response spectrum method and time history method. We used Etabs 2015 software for the analysis of structure. There are different loads such as live load, dead load and seismic load. There are 26 different load combination used in the seismic analysis. The parameters such as maximum story displacement, maximum story drift, overturning moment and story shear are calculated in this present technical paper. We focused on how to make masonry structure better as RC frame structure through retrofitting using bracing system.

Research Paper

A Study of Free Vibration and Forced Vibration Characteristics of Laminated Composite Elliptical Paraboloid Shells

Kondapalli V. Sumala* , K. N. V. Chandrasekhar **
*-** Department of Civil Engineering, CVR College of Engineering, Hyderabad, India.
Sumala, K. V., and Chandrasekhar, K. N. V. (2020). A Study of Free Vibration and Forced Vibration Characteristics of Laminated Composite Elliptical Paraboloid Shells. i-manager's Journal on Structural Engineering, 9(1), 60-76. https://doi.org/10.26634/jste.9.1.16443

Abstract

The study on laminated composite materials is one of the emerging areas of Civil Engineering. Laminates with the desired properties can be used as an alternative material instead of conventional materials such as steel and concrete. This research focuses on the study of free vibration and forced vibration characteristics of laminated elliptical paraboloid shells. The linear strain triangular elements having six nodes is used in the formulation. The fundamental frequencies of the vibrations were determined for different geometry ratios, support conditions, and different lamina. The results obtained for free vibration analysis are compared with those in the literature given by Chakravorthy using eight node quadrilateral elements. Forced vibration analysis is performed for three different types of loading. The deformed shape and the selected nodal displacement results were presented. For an LEPS having SSSS boundary condition, it is observed that for a given set of geometry ratios, 45/-45/45/-45 lamina has the highest NDFF and least deflection shows highest stiffness over any other lamina. For an LEPS with the case of CCCC boundary condition, it is observed that for a given set of geometry ratios, 0/45/0 lamina has the highest NDFF and the lowest deflection showing the highest strength.