Earthquake Response AndEarthquake Response And Its Application to Energy Its Application to Energy

Supply System Supply System

JIN XingJIN XingGUO Xun LI ShanyouGUO Xun LI Shanyou

Institute of Engineering Mechanics (IEM) Institute of Engineering Mechanics (IEM) China Seismological BureauChina Seismological Bureau

www.iem.net.cnwww.iem.net.cn29 Xuefu Rd Harbin29 Xuefu Rd Harbin

Contents

1. Earthquake activities and seismic disasters in China last century

2. Situation of Early Warning System in China

3. Introduction to Earthquake Response System in the near future

4. Application to energy lifeline system

Earthquake Hazard in the Last CenturyEarthquake Hazard in the Last Century

Earthquake with magnitude 6.0-6.9Earthquake with magnitude 6.0-6.9 ： ：380380Earthquake with magnitude 7.0-7.9Earthquake with magnitude 7.0-7.9 ： ：6565Earthquake with magnitude great than 8.0Earthquake with magnitude great than 8.0 ： ：77Earthquake with magnitude great than 8.5Earthquake with magnitude great than 8.5 ： ：22Left total deaths: 590,000Left total deaths: 590,000Total woundedTotal wounded ： ：760,000760,000Collapsing RoomCollapsing Room ： ： more than more than 60,000,00060,000,000Direct Economic Loss: thousands of million RMBDirect Economic Loss: thousands of million RMBIndirect Economic Loss: tens of thousands of Indirect Economic Loss: tens of thousands of million RMBmillion RMB

6.0-7.0

7.0-8.0

≥8.0

The Distribution Strong Earthquake (M≥6.0) In 20th Century

MsMs ： ： 7.87.8

DateDate ： ： July, 28, 1976July, 28, 1976

DeathsDeaths ：： 242,000242,000

LossLoss ：： 13,275 13,275 million RMBmillion RMB

Tang Shan Railway Cars FactoryTang Shan Railway Cars Factory

Earthquake Activity TrendEarthquake Activity Trend

1990

Peak Acceleration Zoning Map of China (2000)

2. Situation of Earthquake Warning

System in China (1)

• Daya Bay Nuclear Power Plant (Shenzhen, Guangdong Prov.)

From 1991, Instruments include: 6 units of 3-component

accelerometer, 2 units of 3-D Trigger, 4 units of peak acceleration

recorder and control unit.

Distribution: around the center, both on ground surface and on

key structures.

Alarm Philosophy: S-wave alarm.

Functions: warning to control center during a earthquake

providing useful information after the earthquake

for facilities maintenance

2. Situation of Earthquake Warning

System in China (2)

• Administrative Center of Daqing Oil Field

From 1992, 8 detecting units (seismometer and

accelerograph, ground surface and downhole)

connected by digital communication network,

S-wave alarm Criteria.

• Ertan Hydropower Station (Sichuan Province)

From 1996, SQC-III accelerograghs

• Qinshan Nuclear Power Station (Zhejiang Province)

From 1994, 4 digital accelerographs

3. Introduction to Earthquake Response System in the Future

Earthquake Response System

Earthquake Warning System Earthquake Emergency System

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General Considerations About Earthquake

Warning System (EWS) • National EWS:

• Earthquake Monitoring Network

Strong Motion Network: 2000 Digital Accelrographs

• Special Communication & Information Network

• Control Center: China Earthquake Disaster Prevention

And Reduction Center (Beijing)

Objective: Large Earthquake Reporting ≤10 min

Emergency Response ≤25 min

Seismometers:636 Fixed and 1000 Mobile

(2). EWS for Major Monitoring Cities:

Such as Beijing, Tianjin, Kunming,

Lanzhou, Urumchi etc., to establish regional

dense earthquake intensity quickly reporting

network.

(3). EWS for Important Infrastructures:

Such as Nuclear Power Plant, Hydropower Station,

Highway and High Railway, to establish dense

telemetered accelarograph network.

The Distribution of Digital Seismic StationsThe Distribution of Digital Seismic Stations

State Digital Seismic Station Net

Regional Digital Seismic Station Net

(Up to the end of the tenth five year Plan (2005))

The Distribution of State Digital AccelerograghsThe Distribution of State Digital Accelerograghs( To be completed before 2005)

First-class Monitoring AreaSecond-class Monitoring Area

4. Application to Energy Lifeline System

(1) Basic Idea: to build earthquake monitoring system including accelerographs, communication system and control center.

(2) Basic principle:

a. S-wave Alarm (40 gal, 80 gal, 120 gal);

b. Front Alarm (arrival time difference);

c. P-wave alarm (initial motion).

d. The determination of earthquake parameters

(magnitude, location, time);

e. Evaluation of earthquake damage losses

Analysis and estimation of strong ground motion

along energy supply system

Emergency plan

This is a pipe line with length of 5400 km which will transport gas From Tarimu and Changqing Oil Field to provinces of East China (Anhui, Jiangsu, Shanghai, Zhejiang).

Because of the widely distributed potential earthquake sources, we can not establish a EWS like that in Mexico or in Hualien, Taiwan. S-wave Alarm criteria will be applied by setting detecting units every 50km along the pipeline, some existing instruments operated by different related provinces will included in this Earthquake System.

Considerations on EWS for the Gas Transportation Project

Gas Transporting

Tibet Railway Power Transporting

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Four National Major Lifeline ProjectsFour National Major Lifeline Projects

Conclusion Remarks• China is an earthquake-prone country, energy supply

system suffered severe damages in the past strong

earthquakes;

• The existing Earthquake Warning System is just a

primary step;

• The development of the national economy needs

urgent effective EWS;

• We hope as more as possible cooperation with the

members of APEC on this filed

• Consists of distributed seismic

accelerographs, communication links

and controlling center;

• Can quickly response to seismic

event;

• Losses can be minimized through

promptly countermeasures .

Basic Concept of EWS:

S-wave Alarm : The alert is issued when the acceleration exceeds pre-set levels, such as 40 gal (A), 80 gal (B) and 120 gal (C). Three levels correspond to different countermeasures.

Problems: Alarm is too late to give enough time useful for the countermeasures;

Frequent false alarm is issued for the harmless small earthquake.

Alarm Philosophy （ 1 ）

C

A

B

0 10 20 30 40 50 60 70 80 90 100

s

S-wave Alarm

Front Alarm: The earthquake motions are detected as early as possible near the source to prepare against the earthquake before seismic motion reaches the site, using the difference of transmission velocities of electric signal and seismic wave.

Front Alarm

Margin Time : t2-t1-t1´Focus

Alarm Philosophy （ 2 ）

P-wave Alarm (From UrEDAS, Japan)

Alarm Philosophy (3)

P-wave Alarm: Alarm is issued by the detecting of P-wave. Usually, P-wave alarm is done by the trigger of at least two adjacent accelerometers. If the pre-set threshold level is to low, false alarm occurs very often.

In the case of single station, the epicentral azimuth may be estimated by the amplitude of initial part of two horizontal traces, the epicentral distance may be calculated by the arrival time difference of P and S waves.

As for multi-station, the earthquake location

may be determined using the arrival time of P

waves at 4 stations.

Method for location determination

Alarming system When the state or regional telemetered station network center receives the information of P wave at some stations, they automatically transmit one alarming single to early alarm system center of energy supply system closing to the epicenter.

After the earthquake parameters transmit to the early alarm system center, the alarm system intelligently estimate the damage of energy supply system by use of the earthquake parameters and the information from the dense telemetered accelarograph network , and then take appropriate emergency measures.

What Should We Do in the Near Future

To establish National EWS, some regional EWS and EWS for important infrastructure, New type of earthquake detecting instruments have been produced such as GDQJ-I and GDQJ-II.

Features of GDQJ Accelerograph (1)

• Data Acquisition: 16 bit of A/D converter with 3 channels,

90dB of dynamic range, 62.5, 125, 250 and 500 Hz of

sampling rate

• Sensor: Triaxial Force Balance Accelerometer, ±2g full scale

range, 140 dB of dynamic range and 0~80 Hz of bandwidth

• Trigger: alarm threshold or STA/LTA

• Storage: 4 Mbyte CMOS RAM

• System Control: configure sample rate, filter type, trigger type

and volting, maintains communications and event storage

• User Interface: Full RS-232 interface with modem control

• Intelligent Alerting: Auto initiate communications

when an event is detected

• Timing: Free running oscillator and GPS

• Power Supply: 100~240 Vac 50/60 Hz with 10AH 12V battery

• Driving Software: Windows 98 based and version for DOS

platform

Features of GDQJ Accelerograph (2)