Analysis of building on Sloping Ground subjected to Seismic Forces

— In the current scenario appealing architecture along with high rise buildings is not limited to plain terrain but also extended to the hilly terrain keeping in mind the problems aroused and their effects. This paper presents the comparative analysis of various configurations of 15 storied building with to be found on varying slope with different plan and different structural arrangements situated on seismic zone III. This study compares various reinforced concrete models framed and analyzed their response against dynamic loading to identify and struggle the worst possible scenario. The study is carried out for a combination of four different slopes and different building configuration by response spectrum analysis method and various parameters are compared against various constraints and results obtained from various building cases illustrates that the most optimum case is building C1 and C2 for both step back and step back set back configurations.


I. INTRODUCTION
Seismic history of India shows that the zones of higher seismic activity and higher magnitudes are mostly presents in hilly terrains of northern and north-eastern regions. As well these places are more likely attracts peoples from plains for different purposes varying from adventure, tourism, religious and also for resolving problem of habitat due to decrease in habitable land in the urban areas. These all purposes may lead to resolve the problem of migration of peoples from hilly regions due to lack of res ources which may provide aids to comply their basic needs.
But tendency towards sloping terrain may raise the load on these places and to accomplish this load we need to accommodate more buildings but due to the topography of hilly terrain we could not effortlessly use space everywhere. So we have to move towards multistoried high-rise building to resolve this problem. Also structural stability of the structure will be next problem in the arena to combat various constraints either it may be the typical topographical conditions or it may be the seismic proximity of the area which will be variable from place to place.
These glitches may be sorted by adopting proper and suitable building configuration as per need keeping in mind the economy of the project and the construction practices which will be the ultimate concluding factor that may leads to stability or proximity to the building.

II. CONFIGURATION OF BUILDING IN HILLY
TERRAIN Configuration of the structure infers that the structural and architectural arrangement building might possesses in the sloping regions. Depending upon the arrangement of bays fundamentally there are two prominent types of configurations consisting of: i) Step back type of configuration: The building arrangement in which horizontal plane remains same but on the lower part it will maintain slope as per terrain or topography of the area. ii) Setback and step back type of configuration: In this building configuration the structure is arranged in stepping pattern in which the horizontal plane is not remains same along with lower part of the structure.

III.
OBJECTIVES OF THE PRESENT STUDY Research review from various papers provides that the construction on hilly terrain is not a daily task but needs the firm structural arrangement especially for variable slope. So the building is analyzed for four different slopes 10˚, 20˚, 30˚ and 40˚ along with a regular building rested on flat terrain against various parameters. The key objectives set for the analysis are: 1. To analyze and determine the maximum displacement in longitudinal and transverse directions. 2. To find and compare base shear in both X and Z direction. 3. To compare the maximum of axial forces in column at base. 4. To compare and analyze the shear force and bending moment. 5. To explore the optimum case among various structural arrangements to resist the seismic hazard and structural irregularities.

IV. METHODOLOGY AND MODELING
A 15 Storied multistoried building is configured comprising of 5numbers of equally spaced bays in both th e direction of 4 m with a constant floor height of 3.66m and ground floor of 4.58m. Total of 5 cases in step back and 5 cases for step back set back cases including building rested on flat ground as well as sloping ground as illustrated in in tables mentioned below along with figures of structural arrangements. All the cases are analyzed and studied as per Indian Standard Code IS 1893 (Part1): 2016 against various seismic parameters and constraints for earthquake Zone III by response spectrum analysis metho d by "STAAD Pro V8i" software to explore the possibilities to resist the deformation and withstand against seismic and structural hazards.  Following are the cases taken for analysis against various parameters possess following building and seismic data used for analysis of the step back configuration are tabulated below:

D1 40 degree
Following are the cases taken for analysis against various parameters possess following building and seismic data used for analysis of the step back configuration are tabulated below:

V. RESULTS AND DISCUSSION
In this research study various cases are analyzed as per IS 1893:2016 (part-1) by response spectrum method for seismic zone V against all constraints as mentioned in the objectives. Dynamic analysis was performed against various seismic parameters for multiple load combination for all the models consist of structure on normal ground, step back configuration and step back & setback configuration. The parameters taken for comparative examinations for individual cases are maximum nodal displacement, maximum axial force, maximum shear force, maximum bending moment, maximum torsional moment, and base shear by tabular and graphical form.   /dx.doi.org/10.22161/ijaers.71.18  ISSN: 2349-6495(P) | 2456-1908(O) www.ijaers.com Page | 145