International Journal of Advance Engineering and Research Development PERFORMANCE OF INTEZ TANK UNDER NEAR FAULT AND FAR FIELD EARTHQUKE MOTION

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1 Scientific Journal of Ipact Factor (SJIF): 4.14 e-issn (O): p-issn (P): International Journal of Advance Engineering and Research Developent Volue 3, Issue 4, April -216 PERFORMANCE OF INTEZ TANK UNDER NEAR FAULT AND FAR FIELD EARTHQUKE MOTION Pankita L. Patel 1, Prof. Uang Parekh 2 1 P.G. Student Structure Engineering Departent, L.J. Institute of engineering & technology, Ahedabad, Gujarat, India 2 Assistant professor, Structure Engineering Departent, L.J.Institute of engineering & technology,ahedabad, Gujarat, India Abstract -Elevated water tank are one of the ost iportant lifeline structures in the earthquake region. As water tanks required to provide water for drinking and fire fighting purpose. This type of structure has large ass concentrated at the top of slender supporting structure. So extreely vulnerable under lateral forces due to an earthquake. At near fault region water tank daages ore during earthquake. Elevated water tanks collapsed or daaged during earthquakes because of unsuitable design and wrong selection of supporting syste. The ai of the study is analyses seisic effect on different shape and types elevated water tank due to near fault and far field earthquakes. So it is very iportant to select proper supporting syste and shape of tank according to codal provisions. For this purpose study, Intez types of elevated water tanks with different Height 12, 16, 2 and different capacity. Here odel two different profiles such as shaft and frae and siulated to near fault and far field ground otion with STAAD.PRO. Software. Here analysis tie history records fro past earthquake ground otion records. Seisic responses including base shear have been observed under different earthquake tie history records. Key Words :- Elevated water tank, Staging, Seisic response, Tie history, near fault far field earthquakes, Staad Pro. I. INTRODUCTION In the 21st century, it is inconceivable to think of a water distribution syste without water tank. Water being the basic need for huanity is required to store and distribute water to areas far away fro water reservoirs with the expansion of cities and growth of population Elevated water tank is the only econoical alternative available to distribute water under natural head to the axiu possible area. Elevated water tank should be located at the highest level and at the center of the pipeline syste. It has been noted that, several elevated tanks are daaged or entirely collapsed during the past earthquakes in all over the world.so there is need to focus on seisic safety of lifeline structure is required. Earthquakes pose a real threat to India with 59% of its geographical area vulnerable to seisic disturbance of varying intensities including the capital city of the country. Figure 1 Seisic zones of India (Source: IS All rights Reserved 525

2 International Journal of Advance Engineering and Research Developent (IJAERD) Volue 3, Issue 4, April -216, e-issn: , print-issn: Literature Survey Tavakoli. H. R, Naeej. M, and Salari. A (211) [7]Their objective for study was to investigate the effect of near fault and far fault earthquake otions on the response of reinforced concrete structures considering soil structure interaction. For this purpose, a series of linear tie-history analysis was carried out for three exaple buildings. For all buildings tiehistory analysis were perfored under 3 exaple earthquake otions: Tabbas, Kobe and Loa Prieta. The ain evaluated paraeters were period of structure, base shear. BabakAlavi and Helut Krawinkler (2) :The study done by the is concerned with the elastic and inelastic response of SDOF systes and MDOF frae structures subjected to near-fault ground otions. The global objective of the study is to acquire quantitative knowledge on near-fault ground otion effects. Moreover they concluded that, equivalent pulses are capable of representing the salient response features of near-fault ground otion. M. Davoodi, M. Sadjadi& P. Goljahani and M. Kaalian(212) :They addressed the influence of near-fault and far-fault earthquakes with consideringsoil-structure interaction on the axiu response of SDOF syste. For thatpurpose, a siplified discrete odel was used to represent the real soil-structuresyste, They concluded that at low stiffness ratios, the ean value of axiu dynaic responses of equivalent SDOF syste subjected to far-field ground otions are higher than fault noral coponent of near-field ground otions with forward directivity effect and near-field ground otions with fling-step effect. Durgesh c. Rai[9] Figure 1.4 shows the water tank in Bhachau pulleddown due to severe daage in. Brace and colun ebers of tanks in Manfera and Bhachau do not eet the ductility and toughness requireents for earthquake resistance. 1.2 Active fault region Figure 2 Collapsed water tank in Bhachau (Source: Rai, 23) After Loa Prieta 1989 earthquake, Mohraz has divided earthquakes in 3 groups: Near-field earthquakes: the distance between site and fault is less than 2 k Mid-field earthquakes: the distance between site and fault is between 2 k to 5 k. Far-field earthquakes: the distance between site and fault is larger than 5 k. Near-field earthquakes have soe characteristics that differs the fro far-field ones. i. These earthquakes have higher accelerations and restricted frequency content in higher frequencies than far-field ones. ii. Also their records have pulses in beginning of record with high period and high doain. These pulses are uch considerable when the Forward directivity takes place, therefore the records change fro Board-Band condition to Pulse- Like ones. II. MODELLING OF STRUCTURE AND EARTHQUAKE RECORDS In this study, odels of Intez shape tank with 1 lac liters, 12.5 lac liters and 15 lac liters storage capacity have been investigated. Variations are ade in tanks,, both in height and pattern. Adapted heights are 12, 16, 2 and 24 and for each height two pattern, frae and shaft are taken under consideration. All the structures are ade of RCC and grade of concrete is M25. Tanks are designed with perfect accordance to the Indian Standard criteria for liquid retaining structure located in seisic zone IV. Other structural configurations are as per Table 1. Figure 3 shows the finite eleent odels of the tanks prepared in All rights Reserved 526

3 International Journal of Advance Engineering and Research Developent (IJAERD) Volue 3, Issue 4, April -216, e-issn: , print-issn: Table -1:Diension of intez elevated water tank capacity of 1 lac litter Frae Shaft Diaeter of top doe () Thickness of top doe ().1.1 Diension of top ring bea () Height of cylindrical wall() Thickness of wall ().3.2 Diension of iddle ring bea () Thickness of conical doe () Diaeter of botto doe () Height of conical doe () Thickness of botto doe () Diension of botto ring bea () Colun diaeter () Bracing bea diensions () Shaft thickness () Table -2:Diension of intez elevated water tank capacity of 125 lac litter Frae Shaft Diaeter of top doe () Thickness of top doe ().1.1 Diension of top ring bea () Height of cylindrical wall() Thickness of wall () Diension of iddle ring bea () Thickness of conical doe () Diaeter of botto doe () Height of conical doe () Thickness of botto doe () Diension of botto ring bea () Colun diaeter () Bracing bea diensions () Shaft thickness () Table -3:Diension of intez elevated water tank capacity of 15 lac litter Frae Shaft Diaeter of top doe () Thickness of top doe ().1.1 Diension of top ring bea () Height of cylindrical wall() Thickness of wall () Diension of iddle ring bea () Thickness of conical doe () Diaeter of botto doe () Height of conical doe () 9 19 Thickness of botto doe ().5.1 Diension of botto ring bea () Colun diaeter () Bracing bea diensions () Shaft thickness () All rights Reserved 527

4 International Journal of Advance Engineering and Research Developent (IJAERD) Volue 3, Issue 4, April -216, e-issn: , print-issn: (a) frae type (b) shaft type Figure 3Staad pro odel of elevated intez type tank 2.1 Kobe earthquake record Table -4:Seisic Characteristics Of Kobe Earthquake Seisic Characteristic Near fault Far feild Magnitude (Mw) 6.9 Station Nishi-Akashi Kakogawa EpicentralDistanc(k) PGA (g) PGV (c/sec) PGD (c) To study the effect of far-field and near-fault earthquake on elevated water tank, here Kobe earthquake (1995) are taken into consideration. Acceleration tie histories for these earthquakes are collected frop PEER NGA database for two stations, i.e. one located in near-fault region and the other in far-field region. Table 4 shows the seisic characteristics of Loa Prieta (1989) tie history data, regarding location of the record station, Peak Ground Displaceent (PGD), Peak Ground Velocity (PGV), Peak Ground Acceleration (PGA). III. RESULT AND CONCLUION In this research attepts are ade to study the seisic behavior of Elevated water tank of different storage capacity and syste, subjected to far-field and near fault ground otion. Tanks of four different capacities have been taken to enhance the insight regarding the behavior regarding the storage capacity. Tie history analysis is perfored for all the odels taking three KOBE earthquake records. 3.1 Base shear results For all the water tanks considered here base shear value for tie history analysis is high in case of near-fault earthquake than far-field earthquake. Figures shows the base shear values for intez type frae and shaft supported water tank of different height and capacity. Fro graph shows that base shear value is ore at near fault earthquake than far field once. Base shear value decrease as height decrease in frae water tank in both type of shape. But in shaft type base shear value increase as height of tank All rights Reserved 528

5 International Journal of Advance Engineering and Research Developent (IJAERD) Volue 3, Issue 4, April -216, e-issn: , print-issn: (a) Frae Kobe Near Fault Figure 4. Base shear for 1 lac lire capacity frae type intez tank Kobe Near Fault Kobe Far Fault Figure 5. Base shear for 12.5 lac lire capacity frae type intez tank Kobe Near Fault Kobe Far Fault Figure 6.Base shear for 15 lac lire capacity frae type intez All rights Reserved 529

6 International Journal of Advance Engineering and Research Developent (IJAERD) Volue 3, Issue 4, April -216, e-issn: , print-issn: (b) Shaft Kobe Near Fault Kobe Far Fault Figure 7.Base shear for 15 lac lire capacity shaft type intez tank Figure 8. Base shear for 15 lac lire capacity shaft type intez tank Kobe Near Fault Kobe Far Fault Kobe Near Fault Kobe Far Fault Figure 9.Base shear for 15 lac lire capacity shaft type intez tank IV. CONCLUION STAAD.Pro analysis results are copared to do a paraetric study for the structural responses of water tanks with change in type, shapes and Height. The conclusions are ade based on the coparison of the results generated by tie history analysis for three different types of earthquake All rights Reserved 53

7 International Journal of Advance Engineering and Research Developent (IJAERD) Volue 3, Issue 4, April -216, e-issn: , print-issn: base shear increase with increase in storage capacity in shaft and frae for near fault and far field region earthquakes. With increase in Height for shaft type and both shape of water tanks base shear also increase. But in frae type base shear decrease with increase in Height generally. Only few cases it was increase. Response of the elevated water tank subjected to Near-Fault ground otion is very high as copared to Far-field ground otion for each odel. Due to syste frae type base shear value is ore than shaft type. REFERENCES [1] Tehrani Zade. M, Haj Najafi. L, Assessing seisic behavior of eccentrically braced fraes (ebfs) due to near-field ground otions. The 14th World Conference on Earthquake Engineering, china, 28. [2] Gareane A. Algreane. Dynaic behaviour of elevated concrete water tank with alternate ipulsive ass configurations. [3] IITK-GSDMA guidelines (27), Seisic design of liquid storage tanks, provisions with coentary and explanatory exaples. [4] I.S 1893:22, Criteria for earthquake resistant design of structures, Bureau of Indian Standards, New Delhi. [5] IS 337 (Part II) : 29, Code of practice for concrete structures for the storage of liquids part II reinforced concrete structures, Bureau of Indian Standards, New Delhi. [6] IS 456:2, Plain and Reinforced Concrete, Code of Practice, Bureau of Indian Standards, New Delhi. [7] Tavakoli.H.R, Naeej.M, Salari.A Response of RC structures subjected to near-fault and farfault earthquake otions considering soil-structure interaction, international journal of civil and structural engineering Volue 1, No 4, 211 [8] Dr. Suchita Hirde,Mr. Uesh L, Raygandhi- Shaha. Effect of Staging Height on Seisic Perforance of RC Elevated water G. P. Marvroeidis, A.S Papageorigion, Near-fault ground otion and its relation to the fault rupture process, 14WCEE [9] Durgesh C Rai, Perforance of elevated tanks in Mw 7.7 Bhuj earthquake of January 26th, 21. Indian Acad. Sci. (Earth Planet. Sci.), 112, No. 3, pp , (23). [1] Pavan.S. Ekbote, Seisic Behavior of RC Elevated Water Tankunder Different Types of Staging Pattern Journal of Engineering, Coputers & Applied Sciences (JEC&AS) ISSN No: Volue 2, No.8, August All rights Reserved 531