Base Shear Reduction by Using Optimum Size of Beams in Top Floors with Different Grades in Multistoried Building at Different Levels

— The recent development shows that expansion is the key to enlarge the infrastructure not only in horizontal direction but in vertical direction too. For this, tall constructions are favored due to less consumption of the land region for living purpose. With this, the seismic disaster activities in this approach made it more complicated. Indian Standard code of practice 1893:2016 shows the seismic prone zones where the shakes are witnessed. On decreasing the load of the structure decreases the Base Shear on the foundation base without compromising the stiffness of the tall structures. To demonstrate and prove this, six tall structures are prepared using software approach, lessening the beam sizes with grade change in top floors, analyzed it and compared among them. After deep comparative analysis, it has been found out that Building with Base Shear reduction case F1 emerges and hence proved to be the best Base Shear reduction case.


I. INTRODUCTION
The introduction of lessening the weight of the structure is such a difficult task when construction is for high rise structures. This is only done with the help of changing the grade of concrete so that homogeneity of the components of concrete; or by reducing the components of the structures. The later one will compromise the architectural point of view.
Again the solution of this problem is to make the structural components slender, which will reduce the weight of the entire structure. But the lateral shakes of earthquake will not going to implement this. The last solution of this problem to use some special elements or to detect which part of the structure will be reduced to make it economical. This approach will need more case studies and the research will be useful in the growing infrastructure demand.
Similarly, the grade change of concrete in construction industry plays a vital role in terms of economy and providing the strength. The enactment of grade change will affect the presentation of the complete construction. Therefore it should not be unnoticed.

II. OBJECTIVES OF THE PRESENT STUDY
The objectives selection is a very tough task since what we have decided that has to be going to be proved. The use of this kind of system in which base shear will reduce without losing the concept of lateral load stiffening system by using the dual system in which Special Moment Resisting Frames are used in the combination of Ordinary Core Type Shear Wall around the lift area in multistoried building. The objectives of this work are as follows: k. To study and find the maximum nodal displacement in transitional X and transitional Z direction for all Base Shear reduction cases.

III. METHODOLOGY AND MODELING APPROACH
As per the objectives, the Response Spectrum Analysis has been performed on different models consist of Building Case A1 made up of G+17 storey Semi commercial building with all beams are of same sizes. Building Case B1 made up of G+ 17 storey Semi commercial building with all beams are not of same sizes and beam sizes changes above G+17. Building Case C1 made up of G+ 17 storey Semi commercial building with all beams are not of same sizes and beam sizes changes above G+16. Building Case D1 made up of G+ 17 storey Semi commercial building with all beams are not of same sizes and beam sizes changes above G+15. Building Case E1 made up of G+ 17 storey Semi commercial building with all beams are not of same sizes and beam sizes changes above G+14. Building Case F1 made up of G+ 17 storey Semi commercial building with all beams are not of same sizes and beam sizes changes above G+13. All the cases are situated in Earthquake Zone III.   /dx.doi.org/10.22161/ijaers.74.20  ISSN: 2349-6495(P) | 2456-1908(O) www.ijaers.com Page | 173  /dx.doi.org/10.22161/ijaers.74.20  ISSN: 2349-6495(P) | 2456-1908(O) www.ijaers.com Page | 176 size is less. No special displacement reducing components are implemented in these buildings.
2. Again, the maximum displacement in Z direction behaves same as the X direction when no special displacement reducing components are implemented in these buildings.
3. Base Shear in X direction has gradually reduced by implementing lesser size of beams in top floors, subsequently decreases the weight of the structure. For this parameter, Case F1 proves to be an efficient parametric case. Observing all the parameters, the main aim of this work has achieved with lessening the Base Shear parameter in both X and Z direction in Semi-Commercial (G+17) multistoried building under seismic loading. Building Case F1 observed and obtained as efficient case and should be recommended when this type of approach will be adopted in any earthquake zones.