DRAFT ----FOR COMMITTEE USE ONLY! Proposed Appendix E April 2004 Printed 4/2/ :52 AM Page 1

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1 Propoed Appendix E April 00 Printed //00 : AM Page Propoed Reviion APPENDIX E - SEISMIC DESIGN OF STORAGE TANKS Prepared by Stephen W. Meier, PE SE Tank Indutry Conultant

2 Propoed Appendix E April 00 Printed //00 : AM Page PART I - PROVISIONS... E. SCOPE... E. DEFINITIONS AND NOTATIONS... E.. DEFINITIONS... E.. NOTATIONS... E. PERFORMANCE BASIS... E.. SEISMIC USE GROUP... E... Seimic Ue Group III... E... Seimic Ue Group II... E... Seimic Ue Group I... E... Multiple ue... E. SITE GROUND MOTION... E.. MAPPED ASCE METHOD... E.. SITE-SPECIFIC SPECTRAL RESPONSE ACCELERATIONS...0 E... Site-Specific Study...0 E... Probabilitic Site-pecific MCE Ground Motion...0 E... Determinitic Site-pecific MCE Ground Motion... E... Site-pecific MCE Ground Motion... E.. SITES NOT DEFINED BY ASCE METHODS... E.. MODIFICATIONS FOR SITE SOIL CONDITIONS... E.. STRUCTURAL PERIOD OF VIBRATION... E... Impulive Natural Period... E... Convective (Slohing) Period... E.. DESIGN SPECTRAL RESPONSE ACCELERATIONS... E... Spectral Acceleration Coefficient.... E. SEISMIC DESIGN FACTORS... E.. DESIGN FORCES... E... Repone Modification Factor... E... Importance Factor... E. DESIGN...0 E.. DESIGN LOADS...0 E... Effective Weight of Product... E... Center of Action for Effective Lateral Force... E... Vertical Seimic Effect... E... Dynamic Liquid Hoop Force... E... Overturning Moment... E... Soil-Structure Interaction... E.. RESISTANCE TO DESIGN LOADS... E... Anchorage... E... Maximum Longitudinal Shell Membrane Compreion Stre... E... Foundation... E... Hoop Stree... E. DETAILING REQUIREMENTS... E.. ANCHORAGE... E... Self-anchored... E... Mechanically-anchored...

3 Propoed Appendix E April 00 Printed //00 : AM Page 0 E.. FREEBOARD... E.. PIPING FLEXIBILITY... E... Method for Etimating Tank Uplift... E.. CONNECTIONS... E.. INTERNAL COMPONENTS... E.. SLIDING RESISTANCE... E.. LOCAL SHEAR TRANSFER... E.. CONNECTIONS WITH ADJACENT STRUCTURES... E.. SHELL SUPPORT... E..0 REPAIR, MODIFICATION OR RECONSTRUCTION...

4 Propoed Appendix E April 00 Printed //00 : AM Page Propoed Reviion APPENDIX E - SEISMIC DESIGN OF STORAGE TANKS Part I - Proviion E. SCOPE Thi appendix provide minimum requirement for the deign of welded teel torage tank that may be ubject to eimic ground motion. Thee requirement repreent accepted practice for application to welded teel flat-bottom tank upported at grade. The fundamental performance goal for eimic deign in thi Appendix i the protection of life and prevention of catatrophic collape of the tank. Application of thi tandard doe not imply that damage to the tank and related component will not occur during eimic event. Thi Appendix i baed on the allowable tre deign (ASD) method with the pecific load combination given herein. Application of load combination from other deign document or code i not recommended, and may require the deign method in thi Appendix be modified to produce practical, realitic olution. The method ue an equivalent lateral force analyi that applie equivalent tatic lateral force to a linear mathematical model of the tank baed on a rigid wall, fixed baed model. The ground motion requirement in thi Appendix are derived from ASCE which i baed on a maximum conidered earthquake ground motion defined a the motion due to an event with a % probability of exceedance within a 0 year period (a recurrence interval of approximately 00 year). Application of thee proviion a written i deemed to meet the intent and requirement of ASCE. Accepted technique for applying thee proviion in region or juridiction where the regulatory requirement differ from ASCE are alo included. The peudo-dynamic deign procedure contained in thi Appendix are baed on repone pectra analyi method and conider two repone mode of the tank and it contentimpulive and convective. Dynamic analyi i not required nor included within the cope of thi Appendix. The equivalent lateral eimic force and overturning moment applied to the hell a a reult of the repone of the mae to lateral ground motion are determined. Proviion are included to aure tability of the tank hell with repect to overturning and to reit buckling of the tank hell a a reult of longitudinal compreion. The deign procedure contained in thi appendix are baed on a % damped repone pectra for the impulive mode and 0.% damped pectra for the convective mode upported at grade with adjutment for ite pecific oil characteritic. Application to tank upported on a framework elevated above grade i beyond the cope of thi Appendix. Seimic deign of floating roof i beyond the cope of thi Appendix. Optional deign procedure are included for the conideration of the increaed damping and increae in natural period of vibration due to oil-tructure interaction for mechanically anchored tank.

5 Propoed Appendix E April 00 Printed //00 : AM Page Tank located in region where S i le than or equal to 0.0 and S S le than or equal to 0., or the peak ground acceleration for the ground motion defined by the regulatory requirement i le than or equal to 0.0g, need not be deigned for eimic force; however, in thee region, tank in SUG III hall comply with the freeboard requirement of thi Appendix. Dynamic analyi method incorporating fluid-tructure and oil-tructure interaction are permitted to be ued in lieu of the procedure contained in thi Appendix with Purchaer approval and provided the deign and contruction detail are a afe a otherwie provided in thi Appendix. E. DEFINITIONS and NOTATIONS E.. Definition ACTIVE FAULT: A fault for which there i an average hitoric lip rate of mm per year or more and geologic evidence of eimic activity within Holocene time (pat,000 year). CHARACTERISTIC EARTHQUAKE: An earthquake aeed for an active fault having a magnitude equal to the bet-etimate of the maximum magnitude capable of occurring on the fault, but not le than the larget magnitude that ha occurred hitorically on the fault. MAXIMUM CONSIDERED EARTHQUAKE (MCE): The mot evere earthquake ground motion conidered in thi Appendix MECHANICALLY-ANCHORED TANK: Tank that have anchor bolt, trap or other mechanical device to anchor the tank to the foundation. SELF-ANCHORED TANK: Tank that ue the inherent tability of the elf-weight of the tank and the tored product to reit overturning force. SITE CLASS: A claification aigned to a ite baed on the type of oil preent and their engineering propertie a defined in thi Appendix. E.. Notation A i Impulive deign repone pectrum acceleration coefficient, %g A c Convective deign repone pectrum acceleration coefficient, %g A v C i d c d i d D E F a F c Vertical earthquake acceleration coefficient, % g Coefficient for determining impulive period of tank ytem Total thickne (00 - d ) of coheive oil layer in the top 0 m (00 ft). Thickne of any oil layer i (between 0 and0 m [00 ft]). Total thickne of coheionle oil layer in the top 0 m (00 ft) Nominal tank diameter, m ( ft) Elatic Modulu of tank material, MPa (pi) Acceleration-baed ite coefficient (at 0. ec period). Allowable longitudinal hell membrane compreion tre, MPa (pi)

6 Propoed Appendix E April 00 Printed //00 : AM Page F v F y Velocity-baed ite coefficient (at.0 ec period). Minimum pecified yield trength of bottom annulu, MPa,(pi) g Acceleration due to gravity in conitent unit. m/ec (ft/ec ) G Specific gravity G e effective pecific gravity including vertical eimic effect = G(-0.A v ) H Maximum deign product level, m (ft) H S J K L n A N N N ch N i N c N h PI P AB P A Thickne of oil, m (ft). Anchorage ratio Coefficient to adjut the pectral acceleration from % to 0.% damping =. unle otherwie pecified. Required minimum width of the bottom annulu meaured from the inide of the hell m (ft) Number of equally paced anchor around the tank circumference. Standard penetration reitance, ASTM D-. Average field tandard penetration tet for the top 0m (00 ft)). Average tandard penetration of coheionle oil layer for the top 0m (00 ft) Impulive hoop membrane force in tank wall, N/mm (lbf/in) Convective hoop membrane force in tank wall, N/mm (lbf/in) Product hydrotatic membrane force, N/mm ( lbf/in) Platicity index, ASTM D-. Anchor deign load, N (lbf) Anchorage attachment deign load, N (lbf) Q Scaling factor from the MCE to the deign level pectral acceleration; equal / for ASCE R Force reduction coefficient for trength level deign method R wi R wc S 0 S S a * S a * S a0 Force reduction factor for the impulive mode uing allowable tre deign method Force reduction coefficient for the convective mode uing allowable tre deign method Mapped, maximum conidered earthquake, -percent-damped, pectral repone acceleration parameter at a period of zero econd (peak ground acceleration for a rigid tructure), %g Mapped, maximum conidered earthquake, -percent-damped, pectral repone acceleration parameter at a period of one econd, %g. The -percent-damped, deign pectral repone acceleration parameter at any period baed on mapped, probabilitic procedure, %g. The -percent-damped, deign pectral repone acceleration parameter at any period baed on ite-pecific procedure, %g. The -percent-damped, deign pectral repone acceleration parameter at zero period baed on ite-pecific procedure, %g

7 Propoed Appendix E April 00 Printed //00 : AM Page S DS The deign, -percent-damped, pectral repone acceleration parameter at hort period (T =0. econd) baed on ASCE method, %g. S D S P S S The deign, -percent-damped, pectral repone acceleration parameter at one econd baed on the ASCE method, %g. Deign level peak ground acceleration parameter for ite not addreed by ASCE method. Mapped, maximum conidered earthquake, -percent-damped, pectral repone acceleration parameter at hort period (0. ec), %g. u Undrained hear trength, ASTM D or ASTM D0. u t t a t b t t u T T i T C T L T 0 Average undrained hear trength in top 0m (00 ft). Thickne of the hell ring under conideration, mm (in) Thickne of the bottom plate under the hell extending at leat the ditance,l, from the inide of the hell, le corroion allowance, mm (in) Thickne of tank bottom le corroion allowance, mm (in) Thickne of bottom hell coure le corroion allowance, mm (in) Equivalent uniform thickne of tank hell, mm (in) Natural period of vibration of the tank and content, econd Natural period of vibration for impulive mode of behavior, econd. Natural period of the convective (lohing) mode of behavior of the liquid, econd Regional-dependent tranition period for longer period ground motion, econd. 0. F v S / F a S S T S F v S / F a S S. v v V i V c V w w AB w int w L w r w t W c Average hear wave velocity at large train level for the oil beneath the foundation, m/ (ft/). Average hear wave velocity in top one 0m (00 ft), m/ (ft/) Deign bae hear due to impulive component from effective weight of tank and content, N (lbf) Deign bae hear due to the convective component of the effective lohing weight, N ( lbf). Total deign bae hear, N (lbf) Moiture content (in percent), ASTM D-. Calculated deign uplift load on anchor per unit circumferential length, N (lbf) Calculated deign uplift due to product preure per unit circumferential length, N/m (lbf/ft) Reiting force of tank content per foot of hell circumference that may be ued to reit the hell overturning moment, N/m (lbf/ft) Roof load acting on the hell, including pecified now load N/m (lbf/ft) Tank and roof weight acting at bae of hell, N/m ( lbf/ft) Effective convective (lohing) portion of the liquid weight, N (lbf)

8 Propoed Appendix E April 00 Printed //00 : AM Page Weff Effective weight contributing to eimic repone W f W fd Wg W i W p W r W r W T X c X i X r X X i X c Y y u σ c σ σ h σ T Weight of the tank floor, N (lbf) Total weight of tank foundation, N (lbf) Weight of oil directly over tank foundation footing, N (lbf) Effective impulive weight of the liquid, N (lbf) Total weight of the tank content baed on the deign pecific gravity of the product, N (lbf) Total weight of fixed tank roof including framing, knuckle, any permanent attachment and participating now weight, if pecified, N (lbf) Total roof load acting on the tank hell including the pecified now load, N (lbf) Total weight of tank hell and appurtenance, N (lbf) Total weight of tank hell, roof, framing, knuckle, product, bottom, attachment, appurtenance, participating now load, if pecified, and appurtenance, N (lbf) Height from the bottom of the tank hell to the center of action of lateral eimic force related to the convective liquid force for ringwall moment, m (ft) Height from the bottom of the tank hell to the center of action of the lateral eimic force related to the impulive liquid force for ringwall moment, m (ft) Height from the tank of the tank hell to the roof and roof appurtenance center of gravity, m (ft) Height from the bottom of the tank hell to the hell center of gravity, m (ft) Height from the bottom of the tank hell to the center of action of the lateral eimic force related to the impulive liquid force for the lab moment, m (ft) Height from the bottom of the tank hell to the center of action of lateral eimic force related to the convective liquid force for the lab moment, m (ft) Ditance from liquid urface to analyi point, (poitive down), m (ft) Etimated uplift for elf-anchored tank, mm (in) Maximum longitudinal hell compreion tre, MPa (pi) Hoop tre in the hell due to impulive and convective force of the tored liquid, MPa (pi) Product hydrotatic hoop tre in the hell, Mpa (pi) Total combined hoop tre in the hell, MPa (pi) µ Friction coefficient for tank liding ρ Ma denity of fluid, kg/m (lbm/in ) E. PERFORMANCE BASIS E.. Seimic Ue Group The Seimic Ue Group (SUG) for the tank hall be pecified by the purchaer. If it i not pecified, the Seimic Ue Group hall be aigned to be SUG I.

9 Propoed Appendix E April 00 Printed //00 : AM Page E... Seimic Ue Group III Seimic Ue Group III tank are thoe providing neceary ervice to facilitie that are eential for pot-earthquake recovery and eential to the life and health of the public; or, tank containing ubtantial quantitie of hazardou ubtance that do not have adequate control to prevent public expoure. E... Seimic Ue Group II Seimic Ue Group II tank are thoe toring material that may poe a ubtantial public hazard and lack econdary control to prevent public expoure, or thoe tank providing direct ervice to major facilitie. E... Seimic Ue Group I Seimic Ue Group I tank are thoe not aigned to Seimic Ue Group III or II. E... Multiple ue Tank erving multiple ue facilitie hall be aigned the claification of the ue having the highet Seimic Ue Group. E. SITE GROUND MOTION Spectral lateral acceleration to be ued for deign may be baed on either mapped eimic parameter (zone or contour), ite-pecific procedure, or probabilitic method a defined by the deign repone pectra method contained in thi Appendix. A method for region outide the USA where ASCE method for defining the ground motion may not be applicable i alo included. A methodology for defining the deign pectrum i given in the following ection. E.. Mapped ASCE Method For ite located in the USA, or where the ASCE method i the regulatory requirement, the maximum conidered earthquake ground motion hall be defined a the motion due to an event with a % probability of exceedence within a 0 year period. The following definition apply: S S i the mapped, maximum conidered earthquake, -percent-damped, pectral repone acceleration parameter at hort period (0. econd). S i the mapped, maximum conidered earthquake, -percent-damped, pectral repone acceleration parameter at a period of econd. S 0 i the mapped, maximum conidered earthquake, -percent-damped, pectral repone acceleration parameter at zero econd (uually referred to a the peak ground acceleration). Unle otherwie pecified or determined, S 0 hall be defined a 0.S S when uing the mapped method.

10 Propoed Appendix E April 00 Printed //00 : AM Page E.. Site-pecific Spectral Repone Acceleration The deign method for a ite-pecific pectral repone i baed on the proviion of ASCE. Deign uing ite-pecific ground motion hould be conidered where any of the following apply: The tank i located within 0 km of a known active fault. The tructure i deigned uing bae iolation or energy diipation ytem, which i beyond the cope of thi Appendix. The performance requirement deired by the owner or regulatory body exceed the goal of thi Appendix. Site-pecific determination of the ground motion i required when the tank i located on Site Cla F type oil. If deign for an MCE ite-pecific ground motion i deired, or required, the ite pecific tudy and repone pectrum hall be provided by the Purchaer a defined thi Section. However, in no cae hall the ordinate of the ite-pecific MCE repone pectrum defined be le than 0% of the ordinate of the mapped MCE repone pectra defined in thi Appendix. E... Site-Specific Study A ite-pecific tudy hall account for the regional tectonic etting, geology, and eimicity. Thi include the expected recurrence rate and maximum magnitude of earthquake on known fault and ource zone, the characteritic of ground motion attenuation, near ource effect, if any, on ground motion, and the effect of uburface ite condition on ground motion. The tudy hall incorporate current cientific interpretation, including uncertaintie, for model and parameter value for eimic ource and ground motion. If there are known active fault identified, the maximum conidered eimic pectral repone acceleration at any period, S * a, hall be determined uing both probabilitic and determinitic method. E... Probabilitic Site-pecific MCE Ground Motion The probabilitic ite-pecific MCE ground motion hall be taken a that motion repreented by a -percent-damped acceleration repone pectrum having a percent probability of exceedence in a 0 year period. E... Determinitic Site-pecific MCE Ground Motion The determinitic ite-pecific MCE pectral repone acceleration at each period hall be taken a 0 percent of the larget median -percent-damped pectral repone acceleration computed at that period for characteritic earthquake individually acting on all known active fault within the region. However, the ordinate of the determinitic ite-pecific MCE ground motion repone pectrum hall not be taken lower than the correponding ordinate of the repone pectrum where the value of S S i equal to.f a and the value of S i equal to 0.F v.

11 Propoed Appendix E April 00 Printed //00 : AM Page E... Site-pecific MCE Ground Motion The % damped ite-pecific MCE pectral repone acceleration at any period, S * a, hall be defined a the leer of the probabilitic MCE ground motion pectral repone acceleration determined in Section E... and the determinitic MCE ground motion pectral repone acceleration defined in Section E... The repone pectrum value for 0.% damping for the convective behavior hall be. time the % pectral value unle otherwie pecified by the Purchaer. The value for ite claified a F may not be le than 0% of the value for a ite cla E ite. E.. Site Not Defined by ASCE Method In region outide the USA, where the regulatory requirement for determining deign ground motion differ from the ASCE method precribed in thi Appendix, the following method may be utilized:. A repone pectrum complying with the regulatory requirement may be ued providing it i baed on, or adjuted to, a bai of % and 0.% damping a required in thi Appendix. The value of the deign pectral acceleration coefficient, A i and A c, which include the effect of ite amplification, importance factor and repone modification may be determined directly. A i hall be baed on the calculated impulive period of the tank (ee Section..) uing the % damped pectra, or the period may be aumed to be 0. econd. A c hall be baed on the calculated convective period (ee Section E...) uing the 0.% pectra.. If no repone pectra hape i precribed and only the peak ground acceleration, S P, i defined, then the following ubtitution hall apply: S =. Eqn () S S P S =. S P Eqn () E.. Modification for Site Soil Condition The maximum conidered earthquake pectral repone acceleration for peak ground acceleration, hall be modified by the appropriate ite coefficient, F a and F v from Table E.-A and E.-B. Where the oil propertie are not known in ufficient detail to determine the ite cla, Site Cla D hall be aumed unle the authority having juridiction determine that Site Cla E or F could apply at the ite or in the event that Site Cla E or F i etablihed by geotechnical data. Table E.-A Value of F a a a Function of Site Cla Mapped Maximum Conidered Earthquake Spectral Repone Acceleration at Short Period Site Cla S < 0. S =0.0 S = 0. S=.0 S>. A B C

12 Propoed Appendix E April 00 Printed //00 : AM Page D E F * * * * * * Site Specific geotechnical invetigation and dynamic ite repone analyi i required. Table E.-B - Value of F v a a function of Site Cla Mapped Maximum Conidered Earthquake Spectral Repone Acceleration at Sec Period Site Cla S < 0. S = 0. S = 0. S = 0. S > 0. A B C..... D E..... F * * * * * SITE CLASS DEFINTIONS The Site Clae are defined a follow: A Hard rock with meaured hear wave velocity, v >,000 ft/ec (00 m/) B Rock with,00 ft/ec < v,000 ft/ec (0 m/ < v 00 m/) C Very dene oil and oft rock with,00 ft/ec < v,00 ft/ec (0 m/ < v 0 m/) or with either N > 0 or u >,000 pf (00 kpa) D Stiff oil with 00 ft/ec v,00 ft/ec (0 m/ v 0 m/) or with either N 0 or,000 pf u,000 pf (0 kpa u 00 kpa) E A oil profile with v < 00 ft/ec (0 m/) or with either N <, u <,000 pf, or any profile with more than 0 ft ( m) of oft clay defined a oil with PI > 0, w 0 percent, and u < 00 pf ( kpa) F Soil requiring ite-pecific evaluation:. Soil vulnerable to potential failure or collape under eimic loading uch a liquefiable oil, quick and highly enitive clay, collapible weakly cemented oil. However, ince tank typically have an impulive period of 0. ec or le, ite-pecific evaluation are not required but recommended to determine pectral acceleration for liquefiable oil. The Site Cla may be determined in accordance with Sec. E..., auming liquefaction doe not occur, and the correponding value of F a and F v determined from Table E.- and E.-.. Peat and/or highly organic clay (H S > 0 ft [ m] of peat and/or highly organic clay, where H = thickne of oil). Very high platicity clay (H S > ft [ m] with PI > ). Very thick, oft/medium tiff clay (H S > 0 ft [ m]) The parameter ued to define the Site Cla are baed on the upper 00 ft (0 m) of the ite profile. Profile containing ditinctly different oil layer hall be ubdivided into thoe layer deignated by a number that range from to n at the bottom where there are a total of n ditinct layer in the upper 00 ft (0 m). The ymbol i then refer to any one of the layer between and n. where:

13 Propoed Appendix E April 00 Printed //00 : AM Page v i = the hear wave velocity in ft/ec (m/). d i = the thickne of any layer (between 0 and 00 ft [0 m]). v where = n i= n i= n i= d i d i d v i i i equal to 00 ft (0 m). N i = the Standard Penetration Reitance determined in accordance with ASTM D, a directly meaured in the field without correction, and hall not be taken greater than 00 blow/ft. (.-) N = N ch n i= n i= = d i di N m i= i d di N i (.-) (.-) where m di = d. i= Ue only d i and N i for coheionle oil. d = the total thickne of coheionle oil layer in the top 00 ft (0 m). ui = the undrained hear trength in pf (kpa), determined in accordance with ASTM D or D 0, and hall not be taken greater than,000 pf (0 kpa). u = k k dc d i= i ui where di = dc. i= d c = the total thickne (00 - d ) of coheive oil layer in the top 00 ft (0 m). PI = the platicity index, determined in accordance with ASTM D. w = the moiture content in percent, determined in accordance with ASTM D. (.-)

14 Propoed Appendix E April 00 Printed //00 : AM Page STEPS FOR CLASSIFYING A SITE: Step : Check for the four categorie of Site Cla F requiring ite-pecific evaluation. If the ite correpond to any of thee categorie, claify the ite a Site Cla F and conduct a ite-pecific evaluation. Step : Check for the exitence of a total thickne of oft clay > 0 ft ( m) where a oft clay layer i defined by: u < 00 pf ( kpa), w 0 percent, and PI > 0. If thee criteria are atified, claify the ite a Site Cla E. Step : Categorize the ite uing one of the following three method with v, N and u computed in all cae ee Table E.-C: a) v for the top 00 ft (0 m) (v method) b) N for the top 00 ft (0 m) ( N method) c) N for coheionle oil layer (PI < 0) in the top 00 ft (0 m) and average u for coheive oil layer (PI > 0) in the top 00 ft (0 m) ( u method) Table E.-C Site Claification Site Cla v N or N ch ua E < 00 fp ( < 0 m/) < <,000 pf ( < 0 kpa) D 00 to,00 fp (0 to 0 m/) to 0,000 to,000 pf (0 to 00 kpa) C,00 to,00 fp (0 to 0 m/) > 0 >,000 ( > 00 kpa) B,00 to,000 fp (0 m/ to 00 m/) A >,000 fp (00 m/) Note: a If the u method i ued and the N ch and u criteria differ, elect the category with the ofter oil (for example, ue Site Cla E intead of D). Aignment of Site Cla B hall be baed on the hear wave velocity for rock. For competent rock with moderate fracturing and weathering, etimation of thi hear wave velocity hall be permitted. For more highly fractured and weathered rock, the hear wave velocity hall be directly meaured or the ite hall be aigned to Site Cla C.

15 Propoed Appendix E April 00 Printed //00 : AM Page 0 Aignment of Site Cla A hall be upported by either hear wave velocity meaurement on ite or hear wave velocity meaurement on profile of the ame rock type in the ame formation with an equal or greater degree of weathering and fracturing. Where hard rock condition are known to be continuou to a depth of 00 ft (0 m), urficial hear wave velocity meaurement may be extrapolated to ae v. Site Clae A and B hall not be ued where there i more than 0 ft ( m) of oil between the rock urface and the bottom of the tank foundation. E.. Structural Period of Vibration The peudo-dynamic modal analyi method utilized in thi Appendix i baed on the natural period of the tructure and content a defined in thi ection. E... Impulive Natural Period The deign method in thi Appendix are independent of impulive period of the tank. However, the impulive period of the tank ytem may be etimated by Eqn () C ih ρ Ti = Eqn () tu E D FIgure E.- Coefficient Ci.. Ci H/D

16 Propoed Appendix E April 00 Printed //00 : AM Page E... Convective (Slohing) Period The firt mode lohing wave period, in econd, hall be calculated by Equation () where K i the lohing period coefficient defined in Eqn (c): In SI unit: or, in cutomary US unit; T c =. K D Eqn (a) T c = K D Eqn (b) 0. K =. H tanh D Eqn (c) E.. Deign Spectral Repone Acceleration The deign repone pectrum for ground upported, flat bottom tank i defined by the following parameter: E... Spectral Acceleration Coefficient. When probabilitic or mapped deign method are utilized, the pectral acceleration parameter for the deign repone pectrum are given in the following equation. Unle otherwie pecified by the Purchaer, T L hall be taken a the mapped value found in ASCE. For tank falling in SUG I or SUG II, the mapped value of T L hall be ued to determine convective force except that a value of T L equal to econd hall be permitted to be ued to determine the lohing wave height. For tank falling in SUG III, the mapped value of T L hall be ued to determine both convective force and lohing wave height except that the importance factor, I, hall be et equal to.0 in the determination of lohing wave height. In region outide the USA, where the regulatory requirement for determining deign ground motion differ from the ASCE method precribed in thi Appendix, T L hall be taken a econd. For ite where only the peak ground acceleration i defined, ubtitute S P for S 0 in Eqn () thru (). The caling factor, Q, i defined a / for the ASCE method. Q may be taken equal to.0 unle otherwie defined in the regulatory requirement where ASCE doe not apply. Soil amplification coefficient, F a and F v ; the value of the importance factor, I; and the ASD repone modification factor, R wi and R wc, hall be a defined by the local regulatory requirement. If thee value are not defined by the regulation, the value in thi Appendix hall be ued.

17 Propoed Appendix E April 00 Printed //00 : AM Page Impulive pectral acceleration parameter, A i : I I A = i = S DS.QFa S0 Eqn () Rwi Rwi However, A i Eqn ()and, for eimic deign categorie E and F only, Convective pectral acceleration parameter, A c : When, T C < T L When, T C > T L, A A I I A = i 0.S 0. S P Eqn () Rwi Rwi T TC I I R c = KS D = KQFv S T C R. 0 wc T S I Ai T C R wc Eqn () TST L I KQFv S =. Ai T R 0 C wc Eqn () = L c KS D wc E... Site Specific Repone Spectra When ite-pecific deign method are pecified, the eimic parameter hall be defined by Eqn (0) through (). Impulive pectral acceleration parameter: I * Ai =.Q Sa0 R Eqn (0) wi Alternatively, A i, may be determined uing either () the impulive period of the tank ytem, or () auming the impulive period = 0. ec; I * Ai = Q Sa R Eqn () wi where, S * a i the ordinate of the % damped, ite-pecific MCE repone pectra at the calculated impulive period including ite oil effect. See Section E... Exception: Unle otherwie pecified by the Purchaer, the value of the impulive pectral acceleration, S a *, for flat bottom tank with H/D < 0. need not exceed 0%g when the tank are: elf anchored, or

18 Propoed Appendix E April 00 Printed //00 : AM Page 0 0 mechanically anchored tank that are equipped with traditional anchor bolt and chair at leat inche high and are not otherwie prevented from liding laterally at leat inch. Convective pectral acceleration: I * Ac = QK Sa R Eqn () wc where, S * a i the ordinate of the % damped, ite-pecific MCE repone pectra at the calculated convective period including ite oil effect. See Section E... Alternatively, the ordinate of a ite-pecific pectrum baed on the procedure of E.. for 0.% damping may be ued to determine the value S * a with K et equal to.0. E. SEISMIC DESIGN FACTORS E.. Deign Force The equivalent lateral eimic deign force hall be determined by the general relationhip F = Eqn () AW eff where, A = lateral acceleration coefficient, %g W eff = Effective weight E... Repone Modification Factor The repone modification factor for ground upported, liquid torage tank deigned and detailed to thee proviion hall be le than or equal to the value hown in Table E.-A. Table E.-A, Repone Modification Factor for ASD Method Anchorage ytem R wi, (impulive), R wc, (convective) Self anchored. Mechanically-anchored E... Importance Factor The importance factor (I) i defined by the Seimic Ue Group and hall be pecified by the purchaer. See Section E. and Table E.-B.

19 Propoed Appendix E April 00 Printed //00 : AM Page 0 Table E.-B - Importance Factor (I) and Seimic Ue Group Claification Seimic Ue Group I I.0 II. III. E. DESIGN E.. Deign Load Ground-upported, flat bottom tank, toring liquid hall be deigned to reit the eimic force calculated by conidering the effective ma and dynamic liquid preure in determining the equivalent lateral force and lateral force ditribution. Thi i the default method for thi Appendix. The equivalent lateral force bae hear hall be determined a defined in the following ection. The eimic bae hear hall be defined a the quare root of the um of the quare (SRSS) combination of the impulive and convective component unle the applicable regulation require direct um. For the purpoe of thi Appendix, an alternate method uing the direct um of the effect in one direction combined with 0% of the effect in the orthogonal direction i deemed to be equivalent to the the SRSS ummation. V = V i + V c Eqn () Where, V = A W + W + W + W ) Eqn () i c i( r f i V = A W Eqn () c c 0 E... Effective Weight of Product The effective weight W i and W c hall be determined by multiplying the total product weight, W p, by the ratio W i /W p and W c /W p, repectively, Equation () through (). When D/H i greater than or equal to., the effective impulive weight i defined in Equation (), D tanh 0. H Wi = W D p Eqn () 0. H When D/H i le than., the effective impulive weight i defined in Equation (),

20 Propoed Appendix E April 00 Printed //00 : AM Page W D =.0 0. H Eqn () i W p The effective convective weight i defined in Equation (), D. H W c = 0.0 tanh Eqn () H D E... Center of Action for Effective Lateral Force The moment arm from the bae of the tank to the center of action for the equivalent lateral force from the liquid i defined by Equation (0) through (). The center of action for the impulive lateral force for the tank hell, roof and appurtenance i aumed to act through the center of gravity of the component. E... Center of Action for Ringwall Overturning Moment The ringwall moment, M rw, i the portion of the total overturning moment that act at the bae of the tank hell perimeter. Thi moment i ued to determine load on a ringwall foundation, the tank anchorage force, and to check the longitudinal hell compreion. The height from the bottom of the tank hell to the center of action of the lateral eimic force applied to W i and W c, X i and X c, may be determined by multiplying H by the ratio X i /H and X c /H, repectively, obtained for the ratio D/H by uing Equation (0) through (). When D/H i greater than or equal to., the height X i i determined by Equation (0), X i = 0. H Eqn (0) When D/H i le than., the height X i i determined by Equation (), X i D = H H Eqn () The height X c i determined by Equation (), X c.h coh D =.0 H.H.H inh D D Eqn ()

21 Propoed Appendix E April 00 Printed //00 : AM Page 0 E... Center of Action for Slab Overturning Moment The lab moment, M, i the total overturning moment acting acro the entire tank bae cro ection. Thi overturning moment i ued to deign lab and pile cap foundation. When D/H i greater than or equal to., the height X i i determined by Equation (), X i D 0. = H. 0 H D H Eqn () tanh 0. When D/H i le than., the height X i i determined by Equation (), X i D = H H Eqn () The height, X c, i determined by Eqn (): X c.h coh. D =.0 H.H.H inh D D Eqn () 0 0 E... Vertical Seimic Effect When pecified, vertical acceleration effect hall be conidered a acting in both upward and downward direction and combined with lateral acceleration effect by the SRSS method unle a direct um combination i required by the applicable regulation. Vertical acceleration effect for hydrodynamic hoop tree hall be combined a hown in Section E... Vertical acceleration effect need not be combined concurrently for determining load, force and reitance to overturning in the tank hell. The maximum vertical eimic acceleration parameter hall be taken a 0.S DS or greater for the ASCE method unle otherwie pecified by the Purchaer. Alternatively, the Purchaer may pecify the ertical ground motion acceleration parameter, A v. The total vertical eimic force hall be: F = ± A W Eqn () v v eff Vertical eimic effect hall be conidered in the following when pecified: Shell hoop tenile tree (ee Section E...)

22 Propoed Appendix E April 00 Printed //00 : AM Page Shell membrane compreion (ee Section E...) Anchorage deign (ee Section E...) Fixed roof component Sliding Foundation deign (ee Section E...) In region outide the USA where the regulatory requirement differ from the method precribed in thi Appendix, the vertical acceleration parameter and combination with lateral effect may be applied a defined by the governing regulatory requirement. E... Dynamic Liquid Hoop Force Dynamic hoop tenile tree due to the eimic motion of the liquid hall be determined by the following formula: For D/H.: In SI unit: Y Y D Ni =.Ai GDH 0. tanh 0. H H H or, in cutomary US unit; Y Y Ni = AiGDH 0. tanh 0. H H For D/H <. and Y < 0.D: In SI unit: D H Eqn (a) Eqn (b) Y Y Ni =.AiGD 0. Eqn (a) 0.D 0.D or, in cutomary US unit; Y Y Ni = Ai GD 0. Eqn (b) 0.D 0.D For D/H <. and Y 0.D: In SI unit:

23 Propoed Appendix E April 00 Printed //00 : AM Page N i =.AiGD Eqn (a) or, in cutomary US unit; Ni =.AiGD Eqn (b) For all proportion of D/H: In SI unit: N N c c.acc =.AcC = c c. SGD coh D.H coh D. SGD coh D.H coh D ( H Y ) ( H Y ) Eqn (0a) Eqn (0b). When the Purchaer pecifie that vertical acceleration need not be conidered (i.e; A v =0), the combined hoop tre hall be defined by Eqn. The dynamic hoop tenile tre hall be directly combined with the product hydrotatic deign tre in determining the total tre. + N h ± Ni Nc σ T = σ h ± σ = Eqn () t. When vertical acceleration i pecified. ( A N ) N h ± N i + N c + v h σ T = σ h ± σ = Eqn () t E... Overturning Moment The eimic overturning moment at the bae of the tank hell hall be the SRSS ummation of the impulive and convective component multiplied by the repective moment arm to the center of action of the force unle otherwie pecified. Ringwall Moment, M rw :

24 Propoed Appendix E April 00 Printed //00 : AM Page Slab Moment, M: rw [ A W X + W X + W X )] [ A ( W X )] M = + Eqn () i ( i i r r c c c [ A W X + W X + W X )] [ A ( W X )] M = + Eqn () i ( i i r r c c c Unle a more rigorou determination i ued, the overturning moment at the bottom of each hell ring hall be defined by linear approximation uing the following:. If the tank i equipped with a fixed roof, the impulive hear and overturning moment i applied at top of hell. The impulive hear and overturning moment for each hell coure i included baed on the weight and centroid of each coure.. The overturning moment due to the liquid i approximated by a linear variation that i equal to the ringwall moment, M rw at the bae of the hell to zero at the maximum liquid level. E... Soil-Structure Interaction If pecified by the Purchaer, the effect of oil-tructure interaction on the effective damping and period of vibration may be conidered for tank in accordance with ASCE with the following limitation: Tank hall be equipped with a reinforced concrete ringwall, mat or imilar type foundation upported on grade. Soil tructure interaction effect for tank upported on granular berm, or pile type foundation are outide the cope of thi Appendix. The tank hall be mechanically anchored to the foundation. The value of the bae hear and overturning moment for the impulive mode including the effect of oil-tructure interaction hall not be le than 0% of the value determined without conideration of oil-tructure interaction. The effective damping factor for the tructure-foundation ytem hall not exceed 0%. E.. Reitance to Deign Load The allowable tre deign (ASD) method i utilized in thi Appendix. Allowable tree in tructural element applicable to normal operating condition may be increaed by % when the effect of the deign earthquake are included unle otherwie pecified in thi Appendix. E... Anchorage Reitance to the deign overturning (ringwall) moment at the bae of the hell may be provided by: the weight of the tank hell, weight of roof reaction on hell W r, and by the weight of a portion of the tank content adjacent to the hell for unanchored tank mechanical anchorage device.

25 Propoed Appendix E April 00 Printed //00 : AM Page E... Self-anchored For elf-anchored tank, a portion of the content may be ued to reit overturning. The anchorage provided i dependent on the aumed width of a bottom annulu uplifted by the overturning moment. The reiting annulu may be a portion of the tank bottom (i.e. t a = t b ) or a eparate butt-welded annular ring (i.e. t a > t b ). The reiting force of the annulu that lift off the foundation hall be determined by Eqn () In SI unit: w = t F HG HDG e Eqn (a) a a y e In cutomary US unit w =. t F HG. HDG e Eqn (b) a a y e Equation () for w a applie whether or not a thickened bottom annulu i ued. The tank i elf-anchored providing the following condition are met:. The reiting force i adequate for tank tability (i.e. the anchorage ratio, J <.).. The maximum width of annulu for determining the reiting force i.% of the tank diameter.. The hell compreion atifie ection E.... The required annular plate thickne doe not exceed the thickne of the bottom hell coure.. Piping flexibility requirement are atified. E... Anchorage Ratio, J Where: J J = D w t M rw ( wt ( 0.Av ) + wa ) Eqn () W + w πd = r Table E.-A - Anchorage Ratio Criteria Criteria Eqn ()

26 Propoed Appendix E April 00 Printed //00 : AM Page anchorage ratio J < 0. No calculated uplift under the deign eimic overturning moment. The tank i elf anchored. 0. < J <. Tank i uplifting, but the tank i table for the deign load providing the hell compreion requirement are atified. Tank i elf-anchored. J >. Tank i not table and cannot be elf-anchored for the deign load. Modify the annular plate if L < 0.0D i not controlling or add mechanical anchorage. E... Annular Plate Requirement The thickne of the tank floor plate provided under the hell may be greater than or equal to the thickne of the general tank floor plate (i.e. t a > t b ) with the following retriction. (Note- In thickening the bottom annulu, the intent i not to force a thickening of the lowet hell coure, thereby inducing an abrupt thickne change in the hell, but rather to impoe a limit on the bottom annulu thickne baed on the hell deign).. The thickne, t a, ued to calculate w a in Equation () the firt hell coure thickne, t, le the hell corroion allowance,. Nor hall the thickne, t a, ued in Equation () exceed the actual thickne of the plate under the hell le the corroion allowance for tank bottom.. When the bottom plate under the hell i thicker than the remainder of the tank bottom (i.e. t a > t b ) the minimum projection of the upplied thicker annular plate inide the tank wall, L, hall be equal to or greater than L: In SI unit: In cutomary US unit L = 0.0t a Fy HGe 0. 0D Eqn (a) L = 0. t F HG, 0.0D (ft) Eqn (b) a y e E... Mechanically-anchored If the tank configuration i uch that the elf-anchored requirement can not be met, the tank mut be anchored with mechanical device uch a anchor bolt or trap. When tank are anchored, the reiting weight of the product hall not be ued to reduce the calculated uplift load on the anchor. The anchor hall be ized to provide for at leat the following minimum anchorage reitance, :

27 Propoed Appendix E April 00 Printed //00 : AM Page M rw wab = wt ( 0. Av ) Eqn () D Plu 0. time the uplift, in N/m (lbf/ft ) of hell circumference, due to deign internal preure. See API 0 Section. for load combination. If the ratio of operating preure to deign preure exceed 0., the purchaer hould conider pecifying a higher factor on deign. Wind loading need not be conidered in combination with eimic loading. The anchor eimic deign load, P AB, i defined in Eqn (0) πd P = AB wab Eqn (0) na where, n A i the number of equally paced anchor around the tank circumference. P AB hall be increaed to account for unequal pacing. When mechanical anchorage i required, the anchor embedment or attachment to the foundation, the anchor attachment aembly and the attachment to the hell hall be deigned for P A, the anchor attachment deign load, P A, hall be the leer of the load equal to the minimum pecified yield trength multiplied by the a-built cro-ectional area of the anchor or three time P AB. The maximum allowable tre for the anchorage part hall not exceed the following value for anchor deigned for the eimic loading alone or in combination with other load cae: An allowable tenile tre for anchor bolt and trap equal to 0% of the publihed minimum yield tre. For other part, % of the allowable tre in accordance with Section.0.. The maximum allowable deign tre in the hell at the anchor attachment hall be limited to 0 MPa (,000 pi) with no increae for eimic loading. Thee tree can be ued in conjunction with other load for eimic loading when the combined loading govern. E... Maximum Longitudinal Shell Membrane Compreion Stre E... Shell Compreion in Self-anchored Tank The maximum longitudinal hell compreion tre at the bottom of the hell when there i no calculated uplift, J < 0., hall be determined by the formula In SI unit:.m rw σ c = wt ( + 0.Av ) + Eqn(a) D 000t or, in cutomary US unit;

28 Propoed Appendix E April 00 Printed //00 : AM Page M rw σ c = wt ( + 0.Av ) + Eqn (b) D t The maximum longitudinal hell compreion tre at the bottom of the hell when there i calculated uplift, J > 0., hall be determined by the formula In SI unit: t ( + 0.Av )) + w a w. a 0.[ J ] 000t w σ c = 0.0 Eqn (a) or, in cutomary US unit; wt ( + 0.Av ) + wa c w. a [ J ] σ = t Eqn (b) E... Shell Compreion in Mechanically-anchored Tank The maximum longitudinal hell compreion tre at the bottom of the hell for mechanicallyanchored tank hall be determined by the formula In SI unit:.m rw σ c = wt ( + 0.Av ) + Eqn (a) D 000t or, in cutomary US unit;.m rw σ c = wt ( + 0.Av ) + D t Eqn (b) E... Allowable Longitudinal Membrane Compreion Stre in Tank Shell The maximum longitudinal hell compreion tre σ c mut be le than the eimic allowable tre F C, which i determined by the following formula and include the % increae for ASD. Thee formula for F C, conider the effect of internal preure due to the liquid content. When GHD / t i greater than or equal to (SI unit) [0 U.S. Cutomary Unit], In SI unit: F C = t / D Eqn (a) Or, in US Cutomary unit: F C = 0 t / D Eqn (b)

29 Propoed Appendix E April 00 Printed //00 : AM Page In SI unit: When GHD / t i le than, F C = t / (.D) +. ( GH) <0.F ty Eqn (a) Or, in cutomary US unit; When GHD It i le than 0, F C = 0 t / (. D) + 00 ( GH) < O. F ty Eqn (b) If the thickne of the bottom hell coure calculated to reit the eimic overturning moment i greater than the thickne required for hydrotatic preure, both excluding any corroion allowance, then the calculated thickne of each upper hell coure for hydrotatic preure hall be increaed in the ame proportion, unle a pecial analyi i made to determine the eimic overturning moment and correponding tree at the bottom of each upper hell coure (See Section E...). E... Foundation Foundation and footing for mechanically-anchored flat-bottom tank hall be proportioned to reit peak anchor uplift and overturning bearing preure. Product and oil load directly over the ringwall and footing may be ued to reit the maximum anchor uplift on the foundation, provided the ringwall and footing are deigned to carry thi eccentric loading. Product load hall not be ued to reduce the anchor load. When vertical eimic acceleration are applicable, the product load directly over the ringwall and footing. When ued to reit the maximum anchor uplift on the foundation, the product preure hall be multiplied by a factor of (-0.A v ) and the foundation ringwall and footing hall be deigned to reit the eccentric load with or without the vertical eimic acceleration.. When ued to evaluate the bearing (downward) load, the product preure over the ringwall hall be multiplied by a factor of (+0.A v ) and the foundation ringwall and footing hall be deigned to reit the eccentric load with or without the vertical eimic acceleration. The overturning tability ratio for mechanically-anchored tank ytem excluding vertical eimic effect hall be.0 or greater a defined in Eqn (). 0.D W [ + W + W + W + W ] p f M T fd g.0 Eqn () Ringwall for elf-anchored flat-bottom tank hall be proportioned to reit overturning bearing preure baed on the maximum longitudinal hell compreion force at the bae of the hell in

30 Propoed Appendix E April 00 Printed //00 : AM Page Eqn (). Slab and pile cap for elf-anchored tank hall be deigned for the peak load determined in Section E....M rw Pf = wt ( + 0.Av ) + Eqn () D E... Hoop Stree The maximum allowable hoop tenion membrane tre for the combination of hydrotatic product and dynamic membrane hoop effect hall be the leer of: The baic allowable membrane in thi tandard for the hell plate materialincreaed by %; or, 0.F y time the joint efficiency where F y i the leer of the publihed minimum yield trength of the hell material or weld material. E. DETAILING REQUIREMENTS E.. Anchorage Tank at grade are permitted to be deigned without anchorage when they meet the requirement for elf-anchored tank in thi appendix. The following pecial detailing requirement hall apply to teel tank mechanical anchor in eimic region where S DS > 0.0g. E... Self-anchored For tank in SUG and located where S DS = 0.g or greater, butt welded annular plate hall be required. Annular plate exceeding / inch thickne hall be butt-welded. The corner weld of the tank hell to bottom annular plate hall be checked for the deign uplift load. E... Mechanically-anchored When mechanical-anchorage i required, at leat ix anchor hall be provided. The pacing between anchor hall not exceed m (0 ft). When anchor bolt are ued, they hall have a minimum diameter of mm ( in.), excluding any corroion allowance. Carbon teel anchor trap hall be ¼ inch minimum thickne and have a minimum corroion allowance of / inch on each urface for a ditance at leat mm ( inche) but not more than 00 mm ( inche) above the urface of the concrete. Hooked anchor bolt (L or J haped embedded bolt) or other anchorage ytem baed olely on bond or mechanical friction hall not be ued when eimic deign i required by thi Appendix. Pot-intalled anchor may be ued provided that teting validate their ability to develop yield load in the anchor under cyclic load in cracked concrete and meet the requirement of ACI.

31 Propoed Appendix E April 00 Printed //00 : AM Page E.. Freeboard Slohing of the liquid within the tank or veel hall be conidered in determining the freeboard required above the top capacity liquid level. A minimum freeboard hall be provided per Table E.-A. See Section E... Purchaer hall pecify whether freeboard i deired for SUG I tank. Freeboard irequired for SUG II and SUG III tank. The height of the lohing wave above the product deign height can be etimated by: δ = 0.Da f Eqn () 0 For SUG I and II, When, T C < When, T C >, For SUG III, T S a = = f KS DI. KQFv S0I TC TC Eqn () T = S a f = KS DI.KQFv S0I TC TC Eqn (0) 0 When, T C < T L When, T C > T L, T S a = = f KS D. KQFv S0 TC TC Eqn () = T L T = STL a f KS D. KQFv S0 T C TC Eqn () TABLE E.-A Minimum Required Freeboard Value of SDS I II III S DS <0.g 0.δ (a) 0.δ (a) δ (c) S DS < 0.0g 0.δ (a) 0.δ (b) δ (c) a A freeboard of 0.δ i recommended for economic conideration but not required. b A freeboard equal to 0.δ i required unle one of the following alternative are provided:. Secondary containment i provided to control the product pill.. The roof and tank hell are deigned to contain the lohing liquid. c Freeboard equal to the calculated wave height, δ, i required unle one of the following alternative are provided:. Secondary containment i provided to control the product pill.. The roof and tank hell are deigned to contain the lohing liquid.