Cover page. Seismic Assessment of Steel Chemical Storage Tanks. Authors:

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1 Cover page itle: Author: Seimi Aement of Steel Chemial Storage ank. Chun-Wei Chang (Preenter and Contat peron Aitant Engineer, ehnial iviion of aipei Water epartment 131, ChangXing Street, aipei 1067, aiwan, R.O.C. Phone: ( Fax: ( Gee-Yu Liu (o-author Aoiate Reearher, Earthquake iater Simulation iviion National Center for Reearh on Earthquake Engineering (NCREE 00, Se.3, Xinhai Rd., aipei 106, aiwan Phone: ( Fax: (

2 Seimi Aement of Steel Chemial Storage ank. Chun-Wei Chang 1, Gee-Yu Liu 1 aipei Water epartment, aiwan National Center for Reearh on Earthquake Engineering, aiwan ABSRAC Water upply i one the ruial lifeline ytem. he eimi afety of ritial water failitie i a pivotal iue in urban earthquake hazard mitigation. hi projet ondut the eimi aement of two typial teel hemial torage tank (one in Zhitan and one in Changxing water purifiation plant of aipei Water epartment. he aement riteria follow aiwan Building Seimi eign Code (011; deign repone petra, JWWA Guideline to and Explanation of Seimi Contrution Method of Water Supply Failitie (009; water pipe bridge and API 650 Welded Steel ank for Oil Storage (11th ed., 01, Appendix E: Seimi eign of Storage ank; teel tank. Major finding inlude: ank No. of Zhitan and ank No. 6 of Changxing do not have uffiient anhorage; alo, the later doen t have enough freeboard while at it highet ontent level. Aordingly, meaure to enhane their eimi integrity or eure their eimi afety have been advied. Keyword: Water failitie, Seimi aement, Steel hemial torage tank, API 650 INROUCION he teel hemial torage tank eleted for tudy under thi projet are No. tank of Zhitan and No. 6 tank of Changxing water purifiation plant. hey are the larget tank of repetive plant with apaity of 300 on and the height are 7.7 meter and 9. meter and for aommodating PAC and NaOH repetively. he hemial (liquid poed remarkable weight, and any damage of the tank ould reult detrimental effet to the purifiation quality. A rational approah to ae the eimi afety of uh tank i greatly needed.. SEISMIC ASSESSMEN PROCEURE OF SEEL CHEMICAL SORAGE ANKS For the deign of thee hazardou liquid torage tank, Appendix E: Seimi eign of Storage ank in API 650 Welded Steel ank for Oil Storage (API, 007 i mot applied. heoretially, it onider two repone mode of a tank and it ontent: impulive and onvetive (Houner, hi proedure applie to anhored teel tank, whih are the mot ommonly ued variety, and i of high eimi onern in aiwan. It i alo inorporated with the ground motion peified in aiwan Building Seimi eign Code (Contrution and Planning Ageny Minitry of the Interior,R.O.C., 011. API 650 laifie tank into three Seimi Uer Group (SUG. SUG III tank are thoe that provide ervie to failitie eential to the life and health of the publi, or thoe that ontain hazardou ubtane, to whih it i greatly important to prevent publi expoure. SUG II tank are 1

3 thoe that provide diret ervie to major failitie, or whih tore material that may poe a publi hazard and lak eondary ontrol. he ret belong to SUG I tank. In thi tudy, a eimi aement proedure for teel liquid torage tank i given, a depited in Fig. 1. Information of target tank Loation and ite ondition of target tank Parameter of deign petral repone aeleration Calulate for impulive and onvetive (lohing mode : 1. Natural period i and. eign petral repone aeleration oeffiient A i and A 3. Effetive liquid weight W i and W 4. Height of enter of ation of variou lateral eimi fore X 5. otal bae hear V 6. Ringwall and lab overturning moment M rw and M 7. otal ombined hoop tre in the hell etermine total bae hear for tank liding failure aement Examine total ombined hoop tre in the hell for wall breaking aement etermine anhor load for anhor bolt and trap failure aement etermine maximum longitudinal hell ompreion tre for wall bukling aement Examine overturning tability ratio for tank overturning aement Fig. 1 Seimi aement proedure for teel liquid torage tank following API 650, App. E requirement. 1. etermine i ( and (, the natural period of vibration for impulive and onvetive (lohing mode of behavior of the liquid. 1 Ci H i t 000 E u H 3.68g tanh where the oeffiient C i a funtion of H / depited in the following hart. i etermine the height of lohing wave for freeboard aement

4 . etermine A i (g and A (g, the impulive and onvetive deign petral repone aeleration oeffiient. I I Ai S a ( i R A K S a ( wi R w where I i et by Seimi Uer Group (SUG, and K 1. 5unle otherwie peified. he value of fore redution oeffiient R wi and R w for the impulive and onvetive mode uing allowable tre deign method are 4 and, repetively, for mehanially-anhored tank. 3. eterminev (N, the total bae hear, fromw i (N andw (N, the effetive impulive and onvetive portion of the liquid weight, repetively. Examine the poibility of tank liding. where V V i V tanh H V i Ai ( W Wr W f Wi Wp / H H W W 0.30 tanh W V AW H H Wp / H H he alulated value ofv hould not exeed the liding reitanev (N alulated by: V W W W W ( A ( r f p v i p 4. etermine the ringwall overturning moment M rw (N-m ating at the bae of tank hell perimeter and the lab overturning moment M (N-m ued for lab and pile ap deign. M rw A W X W X W X A ( W X i ( i i r r M ( ( Ai Wi X i W X Wr X r A W X where X and X refer to the height from the bottom of the tank hell to the enter of ation of variou lateral eimi fore from liquid, tank hell and roof. 3

5 3.67H 0.375H / H oh 1 X i H / H X 1.0 H H 3.67H 3.67H inh H 3.67H 1.0 H / H oh X i tanh X 1.0 H H 3.67H 3.67H inh H / H H 5. etermine, the total ombined hoop tre in the hell (MPa. Nh Ni N ( Av Nh ( t where the produt hydrotati membrane fore N h (N/mm, and the impulive and onvetive hoop membrane fore N i (N/mm and N (N/mm in tank hell, repetively, are alulated by: 9.81GY N h Y Y 8.48Ai GH 0.5 tanh0.866 H H H / H Y Y N i 5.Ai G / H and Y Ai G / H and Y N 3.68( H Y 1.85AG oh 3.68H oh 6. Examine P AB, the anhor load (N. 1.73M rw PAB wt (1 0.4Av na he alulated value of P AB hould not exeed 80% of the yield trength of anhor bolt. 7. Examine, the maximum longitudinal hell ompreion tre (MPa. 1.73M rw 1 wt ( 1 0.4Av 1000t he alulated value of hould not exeed the allowable longitudinal hell-membrane ompreion tre F C (MPa alulated by: 4

6 F C 83 t 83 t / /( GH F ty GH GH / t / t Examine that the overturning tability ratio i.0 or greater. 0.5 ( W p W f W M W fd Wg.0 9. etermine, the height (mm of lohing wave above the produt deign height. Examine the uffiieny of tank freeboard to aommodate the alulated value of. where KS A f KS 1 1I 4 1I 4 4 A f KS KS L 0.5A f L L Nomenlature A v : vertial earthquake aeleration oeffiient (g, taken a 0.14SS or greater for the ASCE 7 method : nominal tank diameter (m E : elati modulu of tank material (MPa F : yield trength of hell (MPa ty G : produt peifi gravity g : aeleration due to gravity (m/e H : maximum deign produt level (m I : importane fator oeffiient; I = 1.0, 1.5 and 1.5 for SUG I, II and III, repetively K : oeffiient for adjuting petral aeleration (from 5 to 0.5% damping L : regional-dependent tranition period for longer period ground motion ( t : thikne of hell ring under onideration (mm t : thikne of bottom hell (mm t : equivalent uniform thikne of tank hell (mm u W : weight of the tank bottom (N f W fd : total weight of tank foundation (N W g : weight of oil over tank foundation footing (N W p : total weight of the tank ontent (N W r : total weight of fixed tank roof (N W : total weight of tank hell and appurtenane (N n A : number of anhor around the tank irumferene W : total weight of tank hell, roof, framing, knukle, S a ( : deign earthquake petral repone aeleration produt, bottom, attahment and appurtenane (N oeffiient for trutural period w t : tank and roof weight ating at bae of hell (N/m S 1 : deign (5% damped petral repone aeleration Y : ditane from liquid urfae to any point (poitive parameter at one eond down (m S S : deign (5% damped petral repone aeleration : frition oeffiient for tank liding (max. 0.4 parameter at hort period (0. : denity of fluid (kg/m 3 5

7 SEISMIC ASSESSMEN OF SEEL CHEMICAL SORAGE ANKS Seimi Aement atabae of ank he eimi aement databae of No. ank in Zhitan and No. 6 ank in Changxing purifiation plant are given below a able 1: N0. of ank Addre. Coordinate ype of Chemial Shape and dimenion of tank body able 1 Seimi Aement atabae of ank Zhitan Purifiation Plant No. Storage Changxing Purifiation Plant No. 6 ank Storage ank No., Zhitan Road, Xindian it. New No. 131, Changxing Street, aan it. aipei City aipei City N N E E NaOH olution, onentration 45%, Sp.G: 1.48 Cylinder Retangular O: 7.6 m Height : m Effluent height: m(from bottom up Shell thikne: 6 mm Bottom plate thikne: 6 mm Capaity : 300 M Poly Aluminum Chloride olution, Sp.G 1.15 Cylinder Retangular O: 6.8 m Height: 9.16 m Effluent height: 8.66 m Effluent height: 8.66 M(from bottom up Shell thikne: mm Bottom plate thikne: 6 mm Capaity : 300 M Building material of tank Plaing Manner Loation plaed Steel W/inner lining:ye ( FRP Elevated Height of bottom plate:.80 m RC Bae:ye Foundation pile: nil Anhored with bolt:ye Number of Anhoring Bolt: 18 Spe. of bolt: M0 Outdoor W/O effluent pond/ hannel Steel W/ Inner Lining:ye ( FRP Ground RC Bae:ye Foundation pile: ye Anhored with bolt:ye Number of Anhoring Bolt::16 Spe. of bolt: M5 Outdoor W/O effluent pond Year ompleted 013 No eimi reitane reinforement 007 No eimi reitane reinforement 6

8 Seimi Aement atabae SS 0.6 S ; ( ( N a =1.0 N v =1.0; ( ype Crut, F a 1.1 ( F v 1.4 ; SS 0.66 S ; A v 0.14SS ; 0 S 1 / SS 0.74 ; Steel elatiity modal E 07,000 MPa; g 9.81m/ ; H / 0.887, C i 6. 1; i (proedure 1; I 1.5 ; K=1.5 Rwi=4(mehanially-anhored Rw=(mehanially-anhored Ai=0.187 A=0.97 (proedure ; ρs=7850kg/m 3 W= N ; Wr= N Wf= N ; Wp= N Wi= N ; W= N (proedure 3 ; Mrw= N-m;M= N-m (proedure 4 ; SS 0.6 S 1 SS ; A v 0.14SS ; ; S a 0.6 ; Steel elatiity modal E 07,000 MPa; g 9.81m/ ; H / 1.7, C i 6. 6 ; i ; (proedure 1; I 1.5 ; K=1.5 Rwi=4(mehanially-anhored Rw=(mehanially-anhored Ai=0.5 A=0.675 (proedure ; ρs=7850kg/m 3 W= N ; Wr= N Wf= N ; Wp= N Wi= N ; W= N (proedure 3 ; Mrw= N-m;M= N-m (proedure 4 ; Photo 7

9 Reult of etail Seimi Reitane Aement Conluding the above databae and analyi, the of No. ank in Zhitan and No. 6 ank in Changxing purifiation plant eimi aement reult are hown in able and able 3. able Reult of etail Seimi Reitane Aement- No. ank in Zhitan Purifiation Plant Item he poibility of tank liding he total ombined hoop tre in the hell he anhor load he maximum longitudinal hell ompreion tre he tability againt overturning he height of lohing wave Reult of etail Seimi Reitane Aement he total bae hear for tank liding V= N he liding reitane VS= N VS > V OK. (proedure 3 σ(+=70.84mpa(tenion,at the bottom of the tank σ(-=-7.807mpa(ompreion,at the liquid urfae SUS304 tainle teel fy=06 Mpa >σ(+ orσ(- OK. (proedure 5 wt= N/m PAB= N 80% of the yield trength of anhor bolt=80% N= N< PAB NG(proedure 6 Anhor bolt do not have uffiient anhorage he maximum longitudinal hell ompreion treσ=10.4 Mpa he allowable longitudinal hell-membrane ompreion tre FC=49.87 Mpa FC >σ OK. (proedure 7 he overturning tability ratio i 5.75 >.0 OK. (proedure 8. he height of lohing waveδs=0.97m he tank freeboard= =0.93m δs OK. (proedure 9. he height of lohing waveδs i lightly higher than the tank freeboard, but i determined a aeptable. able 3 Reult of etail Seimi Reitane Aement- No. 6 ank in Changxing Purifiation Plant Item he poibility of tank liding he total ombined hoop tre in the hell Reult of etail Seimi Reitane Aement he total bae hear for tank liding V= N he liding reitane VS= N VS > V OK. (proedure 3 σ(+=6.33mpa(tenion,at the bottom of the tank σ(-=-14.7mpa(ompreion,at the liquid urfae SUS304 tainle teel fy=06 Mpa >σ(+ orσ(- OK. (proedure 5 8

10 he anhor load he maximum longitudinal hell ompreion tre he tability againt overturning he height of lohing wave wt= N/m PAB= N 80% of the yield trength of anhor bolt=80% N= N< PAB NG(proedure 6 Anhor bolt do not have uffiient anhorage he maximum longitudinal hell ompreion treσ=18.87 Mpa he allowable longitudinal hell-membrane ompreion tre FC=5.96 Mpa FC >σ OK. (proedure 7 he overturning tability ratio i 3.64 >.0 OK. (proedure 8. he height of lohing waveδs=1.46m he tank freeboard= =0.5m<δs NG. (proedure 9. he height of lohing waveδs i higher than the tank freeboard. CONCLUSION AN SUGGESION Bai API650,Appendix E(API, 007 and the bai data a well a ite urvey of the two teel hemial torage tank in water treatment, the reitane againt anhor load of Zhitan No. ank and Changxing No. 6 ank i hown a inuffiient. Under deign eimi ondition, damage to anhoring poition may be reulted. aipei Water epartment ha etablihed plan to reinfore anhoring bolt, either to inreae or to replae o that the anhoring fore will be meeting the need of deign eimi reitane. Beide, the height of lohing wave i higher than the freeboard of Changxing No. 6 ank about 1 meter. hi may lead damage to the top plate due to lohing wave of fluid during earthquake. New requirement ha been et that the liquid level operation height mut be 1 meter or more lower than the uffiieny of tank freeboard. he exiting large apaity teel hemial torage tank imilar to Zhitan No. ank or Changxing No. 6 ank,may be exited with inuffiient anhoring apaity and inuffiient freeboard. hi i probably a ytemati iue and hall be inpeted totally to avoid ourrene of any unneeary damage. REFERENCES [1]API (Amerian Petroleum Intitute, 007, API 650 Welded Steel ank for Oil Storage, 11-th Ed. []Houner, G.W. 1963, ynami Analyi of Fluid in Container Subjeted to Aeleration, Nulear Reator and Earthquake, Appendix F, Report No. I 704, U.S. Atomi Energy Commiion, Wahington.C. [3]Gee-Yu Liu.015, Aement of Steel Liquid Storage ank, National Center for Reearh on Earthquake Engineering (NCREE, aiwan [4]Contrution and Planning Ageny Minitry of the Interior,R.O.C.,011, aiwan Building Seimi eign Code,aipei. [5]aipei Water epartment,014, Seimi Aement of Water Pipe Bridge,Chemial Storage ank,and itribution reervoir,aipei. 9