PERFORMANS ESASLI DEPREM MÜHENDİSLİĞİNDE TEMEL KAVRAMLAR

Transkript

1 New Generation Seismic Codes and New Technologies, February, Ankara 2015 PERFORMANCE BASED EARTHQUAKE ENGINEERING: BASIC CONCEPTS PERFORMANS ESASLI DEPREM MÜHENDİSLİĞİNDE TEMEL KAVRAMLAR Halûk Sucuoğlu ORTA DOĞU TEKNİK ÜNİVERSİTESİ MIDDLE EAST TECHNICAL UNIVERSITY

2 Performance Based Earthquake Engineering: A structure should display a performance under a specified earthquake excitation as predicted by the engineer, in both deformation distributions, and internal force distributions. If damage is permitted, then these damages should occur; a. in designated locations, b. in specified amounts Prota Sempozyumu Şubat Ankara 2

3 Justification of Performance Based Earthquake Engineering: Performans Esaslı Deprem Mühendisliği nin Gerekçesi: Similar objectives exist implicitly in conventional seismic design. However it is not possible to predict the deformations and internal force distributions fairly accurately with the conventional analysis methods employed. In recent years, there had been significant advancement in a. estimation of seismic hazard, b. modeling of the mechanical properties of structural materials, c. Structural analysis procedures. When these advancements are transmitted into design practice, seismic performance of structure becomes quite predictable Prota Sempozyumu Şubat Ankara 3

4 Comparison of Strength Based (Conventional) and Performance Based (New Generation) Design Approaches Design Parameter Strength Based Design (Current) Tasarım Yaklaşımlarının Karşılaştırılması Performance Based Design (New Generation) Seismic Hazard Performa nce Objectives Seismic Zone Map: 475 year seismic hazard Minor earthquake: No damage Moderate earthquake: limited (repairable) damage Severe earthquake: Permanent damage, life safety (These objectives are not measurable) Seismic Hazard Contour Map : 72, 475 and 2475 year seismic hazard definitions 72 year earthquake: No damage performance 475 year earthquake: Limited damage performance 2475 year earthquake: Stability performance (All of these objectives are measurable) Design Approach 475 year design earthquake: Calculate internal forces under reduced seismic loads (R) Capacity design Strength capacity > Internal force demand 72 year service earthquake : Preliminary design 475 year design earthquake: Verification of limited damage performance 2475 year maximum earthquake: Verification of structural stability Deformation demand < Performance limit Prota Sempozyumu Şubat Ankara

5 Strength based design: Member design under reduced seismic loads. No verification of design objectives under actual seismic loads. Performance based design: Preliminary design under service loads; Verification of performance objectives under actual seismic loads, for each performance level separately. Revision of design if performance objectives are not satisfied. Employing new technologies if conventional structural systems are not sufficient to meet the design objectives (seismic isolation, energy dissipation devices, etc.) Prota Sempozyumu Şubat Ankara 5

6 Definition of Seismic Hazard: Current Seismic Code Deprem tehlikesinin tanımı: Mevcut Deprem Yönetmeliği Deprem Bölgesi A o (g) Yerel Zemin Sınıfı T A (saniye) T B (saniye ) Z Z Z Z Prota Sempozyumu Şubat Ankara

7 Definition of Seismic Hazard: New Generation Seismic Codes Deprem tehlikesinin tanımı: Yeni Nesil Deprem Yönetmelikleri S a S DS constant acceleration constant velocity constant displacement Ss (and S1) S MCE spectral acceleration at T = 0.2s determined from USGS maps of site cl MCE spectral acceleration at T = 1.0s determined from USGS maps of site cl Values of site coefficient Fa * Site Class S S 0.25g S S = 0.50g S S = 0.75g S S = 1.0g S S A (V S30 > 1500 m/s) B (760 m/s < V S m/s) C (360 m/s < V S m/s) D (180 m/s < V S m/s) E (V S30 < 180 m/s) Values of site coefficient Fv * Site Class S g S 1 = 0.20g S 1 = 0.30g S 1 = 0.40g S 1 0 A (V S30 > 1500 m/s) B (760 m/s < V S m/s) C (360 m/s < V S m/s) D (180 m/s < V S m/s) E (V S30 < 180 m/s) T = 0.2 ve 1.0 saniye için Kontur Haritaları (Ss ve S1 ) T = 0.2 and 1.0 second Contour Maps (Ss ve S1 ) T 0 T S 1.0 T L T (s)

8 Comparison of Strength and Deformation Based Performance Objectives Dayanım ve Şekildeğiştirme Esaslı Performans Hedeflerinin Karşılaştırması Prota Sempozyumu Şubat Ankara 8

9 Strength and Deformation Based Performance Objectives Dayanım ve Şekildeğiştirme Esaslı Performans Hedefleri Şekildeğiştirme Kontrolü (Deformation Check): ϕ EQ < ϕ y : No damage ϕ y < ϕ EQ < 0.75 ϕ max : Limited damage (Life Safety Performance) 0.75 ϕ max < ϕ EQ < ϕ max : Stability (No Collapse Performance) Prota Sempozyumu Şubat Ankara 9

10 Deformation Based Performance Objectives (RC) Şekildeğiştirme Esaslı Performans Hedefleri (BA) Şekildeğiştirme Ölçüsü: Eğrilik Deformation Parameter: Curvature ϕ EQ < ϕ y : No Damage ϕ y < ϕ EQ < 0.75 ϕ max : Limited Damage (Life Safety Performance) 0.75 ϕ max < ϕ EQ < ϕ max : Stability (No Collapse Performansı) θi = ϕi x Lp Şekildeğiştirme Ölçüsü : Uç Dönmesi (EC8, ASCE 41) Deformation Parameter: Member end Rotation Şekildeğiştirme Ölçüsü : Birim şekildeğiştirme (TDY) Deformation Parameter: Material Strain (Turkish Seismic Code) θ EQ < θ y : No Damage θ y < θ EQ < 0.75 θ max : Limited Damage (Life Safety Performance) 0.75 θ max < θ EQ < θ max : Stability (No Collapse Performansı) Prota Sempozyumu Şubat Ankara 10

11 Observed Performance Under Earthquake Loading and Performance Limits (Chord Rotation) Deprem Etkisi Altında Gözlenen Davranış ve Performans Hedefleri (Kord Dönmesi) 200 No Damage DV1 Analitik Mom. Dön. Akma (EC8) Akma (ASCE41) Min. Hsr. (TDY2007) DV1 Analitik Mom. Dön. Belirgin Hsr. (EC8) Can Güv. (ASCE41) Güv. Snr. (TDY2007) Kord Dönmesi (rad) 6PV1 Analitik Mom. Dön. Akma (EC8) Akma (ASCE41) Min. Hsr. (TDY2007) DV1 Analitik Mom. Dön. Göçme Snr. (EC8) Göçme Snr. (ASCE41) Göçme Snr. (TDY2007) My Taban Momenti (kn-m) Kord Dönmesi (rad) My Kord Dönmesi (rad) 75 Taban Momenti (kn-m) Yönetmeli k uyumsuz kolon PV1 Analitik Mom. Dön. Belirgin Hsr. (EC8) Can Güv. (ASCE41) Güv. Snr. (TDY2007) -125 Kord Dönmesi (rad) Prota Sempozyumu Şubat Ankara Taban Momenti (kn-m) Taban Momenti (kn-m) Taban Momenti (kn-m) Kord Dönmesi (rad) Non Conformi ng Column No Collapse My My Yönetmeli k uyumlu kolon Life Safety My Taban Momenti (kn-m) Code Conformi ng Column My PV1 Analitik Mom. Dön. Göçme Snr. (EC8) Göçme Snr. (ASCE41) Göçme Snr. (TDY2007) -125 Kord Dönmesi (rad) 11

12 Deformation Based Performance Objectives: Non-structural Architectural Components Şekildeğiştirme Esaslı Performans Hedefleri: Yapısal Olmayan Mimari Elemanlar Performance Objective: No damage under frequent earthquakes 475 Year EQ Prota Sempozyumu Şubat Ankara 12

13 Analysis Procedures Hesap Yöntemleri Earthquake Level Deprem Düzeyi Service Level Servis Depremi Design Earthquake Tasarım Depremi Maximum Earthquake Maksimum Deprem Linear Elastic Procedures Doğrusal Elastik Analiz Yöntemleri Internal Force İç Kuvvet Member Deformation Şekil değiştirme Nonlinear Procedures- PO or NRHA Doğrusal Olmayan Analiz Yöntemleri (İtme veya zaman analizi) Internal Force İç Kuvvet Member Deformation Şekil değiştirme Prota Sempozyumu Şubat Ankara 13

14 5 Story Frame 5 Katlı Çerçeve 5CD: Capacity Design Kapasite tasarımı 5R: Relaxed Capacity Design Gevşetilmiş kapasite tasarımı T1 = 1.13 s; T2 = 0.36 s, T3 = 0.20 s Prota Sempozyumu Şubat Ankara 14

15 5 Katlı Çerçeve, Kapasite Tasarımı, T1 = 1.13 s Prota Sempozyumu Şubat Ankara 15

16 12 Story Frame, Capacity Design, T1 = 0.8 s 12 Katlı Çerçeve, Kapasite Tasarımı Prota Sempozyumu Şubat Ankara 16

17 GM: Loma Prieta 10/1/89/; LEX000 (Spectrum matched) Prota Sempozyumu Şubat Ankara 17

18 20 Story Frame-Wall, Capacity Design, T1 = 1.44 s 20 Katlı Perde-Çerçeve, Kapasite Tasarımı Prota Sempozyumu Şubat Ankara 18

19 GM: Northridge, 01/17/94; ORR090 (Spectrum matched) Prota Sempozyumu Şubat Ankara 19

20 Nonlinear analysis procedures in performance based earthquake engineering require a higher level of engineering knowledge compared to standard practice, in: structural modeling, definition of nonlinear response, compilation and interpretation of analysis results. Accordingly, a peer review system is suggested in the design of important structures where these procedures are employed. a) New design: Tall buildings, seismic isolation b) Retrofit design: Hospitals, heritage buildings, etc. In the new Turkish Seismic Code (2015), employing nonlinear procedures is inevitable in the seismic design of important structures, and optional in the design of ordinary structures. Such requirements will lead to an increasing demand for higher quality engineering services in seismic design and more refined engineering education. Thank you for listening, Sabırla dinlediğiniz için teşekkürler Prota Sempozyumu Şubat Ankara 20