DEMONSTRATION PROJECT OF EARTHQUAKE HAZARD FOR CHIA-I CITY OF TAIWAN

Transcription

1 13 th World Conference on Earthquake Engineering Vancouver, B.C., Canada August 1-6, 2004 Paper No.??? DEMONSTRATION PROJECT OF EARTHQUAKE HAZARD FOR CHIA-I CITY OF TAIWAN Tzung-Wu Lai 1 Pai-Mei Liu, Kao 2 Maw-Shyong Sheu 3 SUMMARY The purpose of this paper is to demonstrate the direct economic loss of building structures and the death and injured toll of population due to different peak ground acceleration at Chia-I City, Taiwan. Chia-I City with 250,000 population, located at a very strong seismic Zone with two active faults is selected as the demonstration city of the project. All the building data are provided by the revenue center of the local government. The building structural systems are classified into 7 categories. Each structural category is classified again into 7 different use types. The fragility curves are calculated by the typical building structure for different category and different use type of the buildings. Finally, the probabilities of slight damage, moderate damage and sever damage are calculated for each category, each use type of building for each small administration community under different PGA. The soil liquefaction potential of site is considered as a damage weight. The direct economic loss of structure is converted from damage probability. The computer soft ware is HAZ-TAIWAN, which is modified from the HAZUS. Using the soft ware HAZ-TAIWAN, the damage probabilities for different category and different use type of building may be quickly calculated for different PGA at different community of Chia-I City. The analytical results are compared to 3 big historic earthquakes with magnitude larger than 7.0. The comparison shows reasonable agreement. INTRODUCTION Taiwan is located in seismicity active area. It is very important to estimate the direct economic loss of building structures and the death and injured toll of population that due to different peak ground acceleration at Taiwan. Chia -I City has a population of 250,000 and located at a very strong seismic Zone with two active faults. It is selected as the demonstration city of the project. [1,2,3] 1 Assistant, Professor, Kao Yuan Institute of Technology, Taiwan. lai0214@seed.net.tw 2 Assistant, Professor, Kao Yuan Institute of Technology, Taiwan. pmliu@cc.kyit.edu.tw 3 Professor, National Cheng-Kung University, Taiwan, mssheu@mail.ncku.edu.tw

2 HAZARD-TAIWAN PROGRAM Hazard-Taiwan[4], developed and integrated with geographic information system, is an earthquake scenario-simulative PC program modified from the HAZUS[4] by National Center for Research on Earthquake Engineering, Taiwan. When an earthquake occurs, the losses due to building damage are estimated. Direct economic, social losses and casualties are included. For analyzing the losses due to building damage, 7 building occupancy classes, 7 building structure types and 4 seismic design levels are considered. (Table 1~3) The damages of each building structure can be defined in 4 states, such as: Light Structural Damages (D2), Moderate Structural Damages (D3), Extensive Structural Damages (D4) and Complete Structural Damages (D5). RC structure is shown as: [5] 1.Light Structural Damages (D2) Flexural or shear type hairline cracks in some beams and columns near joints or within joints. 2. Moderate Structural Damages (D3) Most beams and columns exhibit hairline cracks. In ductile frames some of frame elements have yield capacity indicated by larger flexural cracks and some concrete spalling. 3. Extensive Structural Damages (D4) Some of the frame elements have reached their ultimate capacity indicated in ductile frames by large flexural crack, spalled concrete and bucked main reinforcement. 4. Complete Structural Damages (D5) Structure is collapsed or in imminent danger of collapse due to brittle failure of nonductile frame elements or loss of frame stability. The results provide the damage state probability of all the building occupancy classes, all the building structure types, economic loss and casualties. Economic losses are including cost of structure damage, cost of non-structure damage, inventory loss, relocation loss and rental income loss. Stages of injury classification scale are shown as: [5] 1. Severity 1: Injuries requiring basic medical aid without requiring hospitalization. 2. Severity 2: Injuries requiring a greater degree of medical care and hospitalization, but not expected to progress to a life threatening status. 3. Severity 3: Injuries those pose an immediate life threatening condition if not treated adequately and expeditiously. The majority of these injuries are a result of structural collapse and subsequent collapse or impairment of the occupants. 4. Severity 4: Instantaneously killed or mortally injured. Label RES1 RES2 COM1 COM2 COM3 COM4 COM5 IND1 Table 1: Building Occupancy Classes Occupancy Class House Hotel Department, Market, Bazaar, Store, Warehouse Offices Restaurants, Bars, Theaters Hospital Garages Industrial

3 AGR1 REL1 GOV1 EDU1 EDU2 Label W1 S1L S1M S1H S3 C1L C1M C1H PCL RML RMM URML SRC1L SRC1M SRC1H Agriculture Religion Government Schools Library, Museum, Commemoration Hall, Gymnasium, Assembly Hall Table 2: Building Structure Types Description Wood Steel Moment Frame, Low-Rise (1~3 storys) Steel Moment Frame, Mid-Rise (4~7 storys) Steel Moment Frame, Hight-Rise (8+ storys) Steel Light Frame Concrete Moment Frame, Low-Rise (1~3 storys) Concrete Moment Frame, Mid-Rise (4~7 storys) Concrete Moment Frame, Hight-Rise (8+ storys) Precast Concrete Reinforced Masonry Bearing Wall, Low-Rise (1~3 storys) Reinforced Masonry Bearing Wall, Mid-Rise (4~7 storys) Unreinforced Masonry Bearing Wall Steel Concrete Moment Frame, Low-Rise (1~3 storys) Steel Concrete Moment Frame, Mid-Rise (4~7 storys) Steel Concrete Moment Frame, Hight-Rise (8+ storys) Table 3: Seismic Design Level Seismic Design Level Description Pre-Code ~1974 Low-Code 1975~1982 Moderate-Code 1983~1997 High-Code 1998~ DATABASE OF CHIA-I CITY Chia-I City, with 110 tracts, covers an area of 60 square kilometers. All the building data are provided by the revenue center of the local government and the established building data shows Table 4~5 and Figure 1. Combining the established building data of each tract with the other databases that is including the peak ground acceleration, response spectra, probability of liquefaction, fragility curves and capacity curves, the loss estimation is analyzed.

4 Figure 1: Area of General Model Building Type (unit : m 2 ) Table 4: Area of Model Building Type (unit : m 2 ) East Area West Area Pre-Code Low-Code Moderate- Code High- Code Pre-Code Low-Code Moderate- Code High- Code W S1L S1M S1H S C1L C1M C1H PCL RML RMM URML SRC1L SRC1M SRC1H Table 5: Area of Building Occupancy (unit : m 2 ) East Area West Area RES RES COM COM COM COM COM IND AGR

5 REL GOV1 0 0 EDU EDU ANALYTICAL RESULTS OF HISTORIC EARTHQUAKES In this investigation, the losses estimation of three large historic earthquakes (Mei-Shan, Zhong-Pu, Chu- Kou) with magnitude larger than 7.0 were analyzed. (Table 6~10, Figure 2~15) Table 6: Structural Damages of Mei-Shan Earthquake Event (unit : quantifier for buildings) D5 D4 D3 D2 WOOD STEEL RC PC RM URM SRC Table 7: Structural Damages of Zhong-Pu Earthquake Event (unit : quantifier for buildings) D5 D4 D3 D2 WOOD STEEL RC PC RM URM SRC Table 8: Structural Damages of Chu-Kou Earthquake Event (unit : quantifier for buildings) D5 D4 D3 D2 WOOD STEEL RC PC RM URM SRC

6 Table 9: Economic Losses (NT$ values in millions) Cost Cost Inventory Accelerationsensitivsensitive Drift- Loss Non- Non- Structure Structure Damage Damage Cost Structure Damage Relocation Loss Rental Income Loss Total Mei-Shan Earthquake Zhong-Pu Earthquake Chu-Kou Earthquake Table 10: Casualties in The Night SEVERITY_4 SEVERITY_3 SEVERITY_2 SEVERITY_1 Mei-Shan Earthquake Zhong-Pu Earthquake Chu-Kou Earthquake Figure 2: Damage State Probability of Wood Structure (Mei-Shan Earthquake)

7 Figure 3: Damage State Probability of RC Structure (Mei-Shan Earthquake) Figure 4: Damage State Probability of RM Structure (Mei-Shan Earthquake) Figure 5: Total Economic Losses (Mei-Shan Earthquake, NT$ values in million)

8 Figure 6: Casualty of Severity_3 (Mei-Shan Earthquake) Figure 7: Damage State Probability of Wood Structure (Zhong-Pu Earthquake) Figure 8: Damage State Probability of RC Structure (Zhong-Pu Earthquake)

9 Figure 9: Damage State Probability of RM Structure (Zhong-Pu Earthquake) Figure 10: Total Economic Losses (Zhong-Pu Earthquake, NT$ values in million) Figure 11: Damage State Probability of Wood Structure (Chu-Kou Earthquake)

10 Figure 12: Damage State Probability of RC Structure (Chu-Kou Earthquake) Figure 13: Damage State Probability of RM Structure (Chu-Kou Earthquake) Figure 14: Total Economic Losses (Chu-Kou Earthquake, NT$ values in million) Figure15: Casualty of Severity_3 (Chu-Kou Earthquake)

11 CONCLUSION The results of this investigation are an important reference resource for Chia -I city to predict the large historic earthquakes with magnitude larger than 7.0 attacks Chia-I city. Shown as the Mei-Shan Earthquake event: 1. Rapid visual screening of 80,000 buildings for potential seismic hazards. 2. Rescuing resident from 1,500 buildings with complete structural damages. 3. Shelter needs for 5,000 building-users. The damage-stages of buildings are complete structural damages or extensive structural damages. 4. Providing medical aids for 400 patients. In a word, if one city that is located in strong seismic zone could estimate the earthquake loss, the results can be used to plan and stimulate efforts to reduce the risk from an earthquake, and prepare for emergency response and recovery. REFERENCES 1. Loh, C.H., Hazard Mitigation Project in Chia-I City (I), Research Report of National Science & Technology for Hazards Mitigation, Taipei, Taiwan, Loh, C.H., Hazard Mitigation Project in Chia-I City (II), Research Report of National Science & Technology for Hazards Mitigation, Taipei, Taiwan, Loh, C.H., Hazard Mitigation Project in Chia-I City (II), Research Report of National Science & Technology for Hazards Mitigation, Taipei, Taiwan, Yen, C.H., Haiwan Earthquake Loss Estimation System - TELES, Research Report of National Center for Research on Earthquake Engineering, NCREE , Taipei, Taiwan, HAZUS Technical Manual, National Institute of Building Sciences, U.S.A..