C. S. Danee Joycee ¹, M. Helen Santhi ²

Affiliations
1 Faculty of Building and Environment, Sathyabama University, OMR, Chennai – 600119, Tamil Nadu, IN
2 School of Mechanical and Building Sciences, VIT University, Chennai Campus, Chennai – 632014, Tamil Nadu, IN

Abstract

Objectives: To estimate the runoff from the sub basin of Kodayar, Tamilnadu using Natural Resources Conservation Service Curve Number (NRCS-CN) method with GIS and Remote sensing techniques. Methods: The GIS and remote sensing techniques facilitate accurate estimation of surface runoff from watershed. Thematic maps such as soil map, land use and hydrologic soil group (HSG) maps have been generated with GIS environment. Weighted CN value for the basin was obtained and the runoff for the selected rainfall event was estimated. Findings: In the HSG map, the region predominantly comprises of group B (56%) followed by group C (27.4%), group D (12.4%) and A (3.9%) respectively. In order to calculate the CN value of the basin, it is divided into 12 sub basins of which each sub basin has area less than 150km2 which gives more accurate result than considering the whole basin. The CN values for these 12 sub basins are ranging from 69 to 80. Composite curve number value for each sub-basin was calculated by multiplying weights according to the area occupied by each land use class and the corresponding curve number. Weighted CN value and the storage retention (S) for the entire basin are estimated as 75 and 85 respectively. Runoff values are estimated on four different rainfall events selected during the study period in this basin. Conclusion: The study ultimately leads to the development of the rainfall runoff model based on NRCS-CN-GIS technique. The runoff for any rainfall event occurred can be estimated by feeding the inputs into this corresponding model which would in turn be helpful on significant conservation of water in the study area.

Keywords

Curve Number, GIS, Kodayar Basin, NRCS Model, Runoff

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A. C. Lalitha Muthu ¹, M. Helen Santhi ²

Affiliations
1 Sathyabama University, Chennai - 600119, Tamil Nadu, IN
2 School of Mechanical and Building Sciences, VIT University, Chennai - 600127, Tamil Nadu, IN

Abstract

This paper deals with estimation of surface runoff potential from rainfall for Thiruporur Block, Kancheepuram District in Tamil Nadu, India, through Arc GIS version 10.2 by SCS CN number method which is a widely used and efficient method for determining the amount of runoff from a rainfall event in a particular area. The runoff curve number is one of the most widely accepted and frequently used techniques for the estimation of storm runoff. The surface runoff is mapped for whole of Kancheepuram District, from which the runoff of Thiruporur block boundary is delineated in order to obtain higher accuracy of surface runoff. The seasonal variation of rainfall runoff of the study area is also depicted. The surface runoff potential estimated through SCS-CN method can further be used for the management of water resources and land.

Keywords

GIS, Rainfall, SCS-CN, Surface Runoff

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J. S. Arvind ¹, M. Helen Santhi ¹

Affiliations
1 SMBS, VIT University Chennai Campus, Chennai - 600127, Tamil Nadu, IN

Abstract

This paper presents the column shortening effect on the behavior of Tubular, Tube in tube and Bundled tube structure. Frame tube buildings consist of closely spaced column connected by deep spandrel beams placed on the perimeter in plan. A Tube in tube and Bundled tube structure of 50 storeys with storey height of 4 m is considered for the study, RC columns and spandrel beams are modelled with M70 and M110 concrete mix. Models are developed using ETABS software and the effect of elastic shortening of the RC column is included in the analysis to study the behavior by calculating member forces. From the analysis, the effects due to elastic shortening in parameters such as axial force, shear force, bending moment and time period are obtained and compared between the tubular, tube in tube structure and bundled tube structure, there is a variation of about 25%, 20%, 23% and 74% and 23%, 17%, 25% and 57%. 19%, 15%, 31% and 60% respectively, which results in the reduction of member size, which ultimately reduces the dead load and the cost of construction.

Keywords

Bundled Tube Structure, Elastic Column Shortening, Tube in Tube Tall Structure, Tubular Structure

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