SIMULATIUON OF SEISMIC ACTION FOR TBILISI CITY WITH LOCAL SEISMOLOGICAL PARTICULARITIES AND SITE EFFECTS

Transcription

1 SIMULTIUON OF SEISMIC CTION FOR TBILISI CITY WITH LOCL SEISMOLOGICL PRTICULRITIES ND SITE EFFECTS Paaa REKVV ad Keeva MDIVNI Geoga Naoal ssocao fo Egeeg Sesmology ad Eahquake Egeeg Tbls Geoga

2 OUTLINE Ioduco Sochasc Smulao of Eahquake Goud Moo Paamees Esmao Deemao of Mullaye Goud Moo Based o he Theoy of Mulple Refleced Waves Smulao Resuls fo Tbls Cy Ses Coclusos Paaa Rekvava Keeva Mdva /8

3 Ioduco I he Tbls aea hee s lack of ecods of sog goud moos pacula acceleogams. Dug he las 00 yeas a he eoy of Tbls cy abou huded weak eahquakes wh esy 3-5 degee MSK scale occued. Local sog eahquake occued oly o pl 5 00 ude he ceal pa o he cy wh magude M=4.5 esy 7 degee ad ecoded o he bedock peak hozoal acceleao of 0.g. Whe acceleao me hsoes ae equed as he pu o egeeg desg o aalyss hee basc opos ae avalable: - selec eal acceleogams fom sog moo daabases; - smulae syhec goud moos fom heoecal sesmologcal models of sesmc faul upue; - smulae afcal acceleogams fom sochasc mehods o mach age espose speca (geeally used egeeg). Fo hs easo o povde he goud moos fo dyamc aalyss ad desg Geoga he ma objecve of hs sudy s o smulae he spaal sesmc aco ems of acceleogams ad coespodg espose speca. The poposed mehodology cludes hee ma opcs: () he sochasc smulao of eahquake goud moo a a gve se of he cy of Tbls; () esmao of acceleao me hsoes a a gve se of he cy of Tbls usg he dec mehod of egeeg sesmology based o he heoy of he efleced waves; () calculao of he hozoal ad vecal acceleao elasc espose speca ad coespodg he specal dyamc coeffce fo ma ses of Tbls eoy cosdeg he egoal sesmologcal chaacescs ad local sol codos fo he se of ees. 3 Paaa Rekvava Keeva Mdva 3/8

4 U S a Ioduco Nomalzed acceleao elasc espose specum - cuve of specal dyamc coeffce fo SDOF sysem wh dampg value S ( ) a ( T) () U () ( ) εu () 0 g max ( T ) g ω U () g () 3. ( )exp[- ( - )s( - )]d U ~ U g max ( ) ~ U m j U / m / g j ( gj ) / Paaa Rekvava Keeva Mdva 4/8

5 Euocode 8 Pa-: Geeal ules sesmc acos ad ules fo buldgs: - he elasc espose specum shape he couy o pa of he couy fom he cea couy Naoal aexes ha ae woked ou by local uhoes. - deep geologcal daa of he cosuco se should be cosdeed ad he hozoal ad vecal elasc espose speca should be compued akg o accou he sesmc souces ad he eahquake magudes geeaed fom hem. Geoga Buldg Code "Eahquake Egeeg PN : Tbls s locaed he sesmc zoe of esy 8 degee MSK scale wh a maxmum hozoal acceleao equals 0.7g ad a eu peod of eahquakes 500 yeas (%/ 50 yeas). The specal dyamc coeffce s deemed fo gouds of had (I) medum (II) ad sof (III) caegoes ad s maxmum value fo all hee caegoes gouds equals.5. Fom he eahquake souces 8 zoes of Tbls ego a he eoy of he cy hee ae expeced he eahquakes wh magudes M= ad coespodg sesmc geeaed kemacs of shfg as evese (N37) evese wh ske slp (N458) ad ske slp(n6) (Fg.) (Vaazaashvl e al. 00) Paaa Rekvava Keeva Mdva 5/8

6 Fg.. Eahquake souce zoes of Tbls ego Paaa Rekvava Keeva Mdva 6/8

7 Sochasc Smulao of Eahquake Goud Moo Fo smulao of possble sesmc goud moos o he eoy of Tbls cy s employed he dscee osaoay Gaussa sochasc pocess epeseed as (Rekvava ad Mdva 00) g () = E () X ()= E () x () () (=3) whee g () deemes of goud acceleao he deco of hee pcpal ohogoal axses wh zeo coss coelao bewee of compoes; E () s he deemsc omalzed evelope o modulag fuco; X () epeses a ypcal ealzao of he saoay Gaussa pocess; s a mea squae value of acceleao he deco of pcpal axses ad deoes adom pocess esy ha s defed by s vaace; s deco of he axses. Nomalzed saoay adom fuco x () wh zeo mea ad u-vaace s chaacezed by K() fuco of coelao as K()=e - j (cos j + j / j s j ) () Whee s coelao coeffce chaacezg wdh ad cofguao of he specum of j-h pocess; s ccula j-h pocess fequecy; j epeses a odal umbe of pocess. Paaa Rekvava Keeva Mdva 7/8

8 The modulag fuco E () s defed ems of so-called Belag mpulse ad wh E () max = s gve by () E ε exp( ε) (3) whee cools he shape of he evelope fuco ad effecve duao ad pocess osaoay. deemes he Geealzg he fom Eq. he hozoal ad vecal compoes of he pocess ca be we as g g g ( ) exp( ) x ( ) ( ) exp( ) x( ) 3( ) 3 exp( ) x3( ) whee k ad ae coecve facos of he value of he hozoal ad vecal compoes whch ae accodgly equal o ad 0.7. (4) Paaa Rekvava Keeva Mdva 8/8

9 Paamees Esmao The maxmum macosesmc esy I Tb of he expeced eahquake o he eoy of Tbls cy fom he eahquake souces zoes s defed (Javakhshvl e al. 998) fo small eahquakes (M s <6) I Tb =.5M s 3.4lgR+3. (5) fo sog eahquakes (M s >=6) I Tb =.5M s 4.7lgR+4.0 (6) whee M s s suface-wave magude; R= ( +h ) / s hypoceal dsace; s epceal dsace; h-focal deph. The lage hozoal values of peak hozoal acceleao (Sm e al. 000) log PG h = M s -logr+0.003k+0.8p (7) (8) K h 4.5 whee p s 0 fo 50-pecele values ad fo 84-pecele. The doma peod T of goud moo (Mkhalova ad pkaev 996) lgt=0.5m s +0.5lgR+C +C ±0. (9) Duao of he esve phase of goud moo s compued by lgd=0.5m s +0.50lgR+C+C+C3±0.30 (0) whee C s paamee of faul mechasm; C s paamee of goud caegoy; a mea value of ao C 3 s equal o.3.

10 Table. Quaave Chaacescs of he Pedced Goud Moo o he Bodele of Cy Tbls Tbls Cy Zoe N R (km) Fom focus wh M=5.0 Fom focus wh M=5.5 I TB (deg) T (sec) D (sec) PG h (m/sec ) PG h (m/sec ) PG h3 (m/sec ) Fom focus wh M= Fom focus wh M= Fom focus wh M= Paaa Rekvava Keeva Mdva 0/8

11 Fg.. Locao of he ses o he eoy of he cy N N3 N4 N5 N6 N7 ad N0 II caegoy (medum) N N8 ad N9 - III caegoy (sof) Paaa Rekvava Keeva Mdva /8

12 Fo 0 ses of Tbls cy eoy (350 squae klomees) wee deemed mmum R PG fo % ad % pobables of beg exceeded 50 yeas doma peods ad duao of oscllao. Table. Quaave Chaacescs of he Pedced Goud Moo fo he Cocee Ses of Tbls Cy (%/ 50 yeas) geeaed fom he hgh poeal sesmc souces zoe N3 Paaa Rekvava Keeva Mdva /8

13 The ma paamee of he goud moo model s deemed based o he Eq.9 usg he expesso: j =π/t j () The value of he coelao degee chaacezg paamee s evaluaed based o he aalyss of he Geoga eahquakes ecods daa depedg o ad fo (x) (y) da 3(z) compoes cosss of j =0.04 j ; j =0.53 j ; j3 =0.4 j ; () The mea squae value of acceleao was acceped cosdeg ha =PG /3 =3 (3) The paamee s deemed o he bass of he gve duao of esve oscllaos above-meoed ecods ad s equal o j = 0.0 j (4) Thus calculaed paamees ae epeseed Table 3.The mea squae values of he hozoal ad vecal acceleaos fo eahquake geeaed fom he hgh poeal sesmc souces zoe N3 ae gve Table 4. Paaa Rekvava Keeva Mdva 3/8

14 Table 3. Paamees fo Geeao Regoal Syhec cceleogams Zoe N j (sec - ) j (sec - ) j (sec - ) j3 (sec - ) j (sec - ) =0.04T j (sec) Fom focus wh M= Fom focus wh M= Fom focus wh M= Fom focus wh M= Fom focus wh M= Paaa Rekvava Keeva Mdva 4/8

15 Table 4. Mea Squae Values of acceleaos fo Cocee Ses fom sesmc souce zoe N3 Mea squae value of acceleao m/sec Pobably of exceedg 50 yeas Se # % / % / % / % / % / % / Paaa Rekvava Keeva Mdva 5/8

16 Deemao of Mullaye Goud Moo Based o he Theoy of Mulple Refleced Waves I s assumed ha he goud s elasc ad waves ae popagaed he vecal deco (Fg. 3). I he fom of sesmc fluece hs case s used ecoded o he bedock acceleogam fom he daabase of goud moos wh kow eahquake. Fg. 3. Desg model of o-homogeeous goud Paaa Rekvava Keeva Mdva 6/8

17 I he Fg. 3 ae acceped followg desgaos: f () s value of he wave fuco a he me o he boom level of he -h laye; () s value of he wave fuco a he me o he op level of he -h laye; ( 0 ) s gve elaoshp of he moveme o he level of bedock. Fo ay -h laye of goud he wave equao of shea oscllaos ca be we as (Napevadze 973) : ( ) ( ) (5) V 0 s y whee () s he dsplaceme of goud laye pacles; s he me; y epeses he coodae of pacle oscllao he vecal deco; V s s he velocy of he shea wave popagao he goud aea. Soluo of he equao (5) o he op of he -h laye a he me s gve by f (6) whee s he faco of efaco ude passg of wave fom --h o -h laye; he faco of wave efleco o he bodele bewee ad - layes; epeses he me of wave passage he -h laye =H /V s whee H ad V s ae accodgly he hckess of goud laye ad he velocy of he shea wave popagao he -h laye. Paaa Rekvava Keeva Mdva 7/8

18 ad facos ae defed by (7) (8) whee s a desy of -h goud laye. Fally soluo of he dec poblem of egeeg sesmology ca be epeseed by he ecue elaos as: (9) Paaa Rekvava Keeva Mdva 8/8 s s s V V V / / s s s s V V V V f f f f f f f f f f

19 Oscllao of he pacles fom he boom of -h laye o he level of y ca be calculaed accodg o (Napevadze 973) y f y / V H y / V s s (0) Smulao Resuls fo Tbls Cy Ses The developed sofwae CCSIM was used fo geeao of he hozoal ad vecal compoes of syhec acceleogams coespodg possble sesmc souce zoes of Tbls ego gve Table. Whe assessg he pobablsc mea elasc espose speca ad he omalzed dyamc coeffce specal cuves fo all ses whch ae peseed Fg. he equed umbe of ealzaos was educed fo each syhec acceleogam up o 0 ealzaos. Paaa Rekvava Keeva Mdva 9/8

20 Fg. 4. Thee compoes of acceleogam geeaed fom zoe 3 o he fee goud of he se 8 Paaa Rekvava Keeva Mdva 0/8

21 Table 5. Desg paamees of pobablsc dyamc coeffce ( %/ 50yeas) Zoe # Magude Compoes Se N N N5 N7 N8 N0 ᵦmax T a T b ᵦmax T a T b ᵦmax T a T b ᵦmax T a T b ᵦmax T a T b ᵦmax T a T b x y z x y z Table 6. Desg paamees of pobablsc dyamc coeffce (%/ 50yeas) Zoe # Magude Compoes Paaa Rekvava Keeva Mdva /8 Se N N N5 N7 N8 N0 ᵦmax T a T b ᵦma T a T b ᵦmax T a T b ᵦmax T a T b ᵦmax T a T b ᵦmax T a T b x x y z x y z

22 Fg. 5. Geeaed fom sesmc souces zoe #3 fo se #8 xyz compoes of acceleao espose speca (a) ad specal cuves of dyamc coeffce (%/ 50 yeas) (b) Paaa Rekvava Keeva Mdva /8

23 Usg he sofwae GFRT was suded a fluece of a ypcal eahquake ad local sol codos upo fomg he acceleao elasc espose speca fo he abovemeoed ses. The daa se was seleced fve ecoded o he bedock acceleogams : - EL Ceo-940-M=6.7 T=0.85 sec D=9. sec - Saa Babaa-980-M=6 T=0.4 sec D=4.0sec - Moeego-979-M=7 T=0.5 D=.3 sec - Ful 976-M=6 T=0.3 D=8.88 sec - Tbls-00- M=4.5 T=0. sec D=9.8 sec cceleogams ae dffee fom each ohe by paamees of PG (0.44g 0.46g 0.g 0.6g 0.g) doma peod (T) ad duao (D) bu by he magude ad epceal dsace ae close o pedcable eahquakes chaacescs fo Tbls ego. Paaa Rekvava Keeva Mdva 3/8

24 Tblss 00 wls 5 apls-99w mwszvs samkompoea aqseleogama da eaqcs speqeb. p Fg.6. Thee compoes acceleogam of Tbls (5 pl 00) eahquake ecoded o he bedock Paaa Rekvava Keeva Mdva 4/8

25 Fg.7. Thee compoes acceleogams of Tbls (5 pl 00) eahquake calculaed a he goud fee suface of N8 se fom ecodg acceleogams of he deph -43. m Paaa Rekvava Keeva Mdva 5/8

26 Table 7. Desg paamees of dyamc coeffce Paaa Rekvava Keeva Mdva 6/8

27 Fg. 8. Thee compoes acceleao espose speca (a) ad specal cuves of dyamc coeffce (b) fo se #8 esulg fom he acceleogam calculaed a he fee suface fom ecodg "Tbls- 00" of he deph z=-43.m Paaa Rekvava Keeva Mdva 7/8

28 CONCLUSIONS. The complex appoach of smulao goud moo s poposed. The hozoal ad vecal elasc espose speca ad coespodg dyamc coeffce specal cuves fo II ad III caegoy of he sol ae cosuced. Ths mehod s accoued fo he locao of he eahquake souces zoes he Tbls ego ad s chaacescs ad cocee cosuco ses codos of he cy.. ccodg o he obaed esuls he value of he amplfcao faco (ao of he maxmum acceleaos of he goud suface laye o he bedock) he gve sol popees of he ses ude vesgao ae chaged fom.5 o.6 due o espose of suface sol sedmes. 3. The maxmum values of dyamc coeffce (.6-3.0) deemed ad based o he sochasc goud moo model ude medum ad sof goud codos ae up o.04-. mes lage ha gve Buldg code (.5). 4. The maxmum values of dyamc coeffce (.7-4.0) obaed fom he soluo of he dec poblem of egeeg sesmology ae mes gae ha deemed Buldg code (.5). Paaa Rekvava Keeva Mdva 8/8

29 Thak You fo you aeo