CAP in Earthquake CAP in Earthquake Damage MessagingDamage Messaging

Presentation Outline

• Automated Post-earthquake Building Damage Assessment

• The GSense system at a glance

• Architecture and Information Flow

• CAP Router and CAP Alerts

• G-Sense Operator Software

Drift-based Fragility Curves and Damage Assessment

Farzad Naeim et.al. 2005

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CSMIP Project - Imperial Valley County Services (CSMIP ID = 01260)

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A Validated Approach - Northridge 1994 Earthquake CSMIP Project - The Van Nuys 7-Story Hotel (CSMIP ID = 24386)

Farzad Naeim et.al. 2005

Drift-based Fragility Curves and Damage Assessment

GSense System at a Glance

• A network of sensor nodes installed in different floors of a building measuring acceleration.

• The nodes include a low noise MEMS tri-axial accelerometer, a 16bit ADC, a power control (UPS) unit, an integrated processing unit enabling on-board processing, GPS option for time synchronization and a gateway (mini PC) for real-time data acquisition, analysis and archiving.

• The gateway is calculating damage probabilities for every floor following an earthquake event and sends damage alerts through CAP to a central command and control software (GSense Operator).

• The GSense Operator visualize the alerts, monitors all Gsense installations in different buildings, the nodes state of health and manages the nodes and gateway configuration remotely when required.

Information Flow

CAP Router

GSense Node

GSense Gateway

Buildinginstallations

GSense OperatorAgency #2

GSense Remote Administration

44

66

EDXL-DECAP Alert

33

Real time acceleration dataReal time acceleration data

22

Real time On-Site Analysis

•Interstory Drift•Shear Wave velocity•Base Shear•PGA , PGV

Real time On-Site Analysis

•Interstory Drift•Shear Wave velocity•Base Shear•PGA , PGV

CAP Alert message containing information

of detected event

CAP Alert message containing information

of detected event

Event detection using STA/LTA algorithm

on real time acceleration data

Event detection using STA/LTA algorithm

on real time acceleration data

GSense OperatorAgency #1

Network

11

Network

Other CAP Consumer application

Other CAP Consumer application

55

GSense Node

Pilot Installations

Technological Educational Institute of Crete, ChaniaCentral Administration building of Aristotle

University, Thessaloniki

Time Synchronization (<50 μsec)

Earthquake Recording Example

GSense Gateway

GSense Gateway is a Mini-PC used for:

•Real Time Data Acquisition from GSense Nodes

•Data Archiving and Storage

•On-Site Data Analysis (Shear Wave Velocity, Base Shear, PGA , PGV, Interstory Drift)

•Real Time Event Detection using STA/LTA Algorithm

•Damage Probabilities Calculation for every Floor and Direction

•CAP Alert Generation

•CAP Router interconnection

On-Site Analysis Software

Event Detection

STA/LTA Algorithm:

Channel Trigger1) Averages of signal amplitudes are calculated for a short and a long time window

2) A ratio of both values - STA/LTA ratio - is calculated

This ratio is continuously compared to STA/LTA trigger threshold level.

If the ratio exceeds this threshold, a channel trigger is declared.

When the current STA/LTA ratio falls below STA/LTA detrigger threshold level the channel detriggers.

Event TriggerEarthquake event is considered if a predefined number of channels are triggered at the same time

Trigger Threshold

Detrigger Threshold

Event Data

Inter-Story Drift Calculation

CAP Alert Example

4 Parameters (Value Pairs) Per Floor and Direction to Display Damage Assessment.

The CAP Router (1)

• A software service which enables messages to be routed according to their header information

• Based on EDXL-DE (Distribution Element) and an Event Driven Architecture (EDA)

• Each agency or organization is seen is registered to the CAP Router as an “endpoint”

• Endpoints can be both message publishers and/or message consumers

The CAP Router device consists of four main services. These are as follows:

1. Registration Service– Each endpoint has a responsibility to announce themselves to the Message Router along with their reachability attributes:•URN•Descriptive Name•Attributes and methods of communication with the end-point (currently only via a Message Broker)•The messages they wish to receive based on

• Message Type• Geographical areas of interest• Keywords

The CAP Router (2)

The CAP Router (3)

2. Message Service – Each publisher endpoint or any generator of information contacts the consumer and hands over the message for delivery specifying the recipients. The following process will be followed on reception:•Check if the publisher and consumer are valid•Check if the consumer endpoint is available•Analyze the Distribution Element information•Send message to consumer endpoint(s) which match the EDXL-DE info•Cache message should the consumer endpoint not be available

The CAP Router (4)

3. Query Service – The Query service interfaces the Persistence Serviceand allows endpoints to query:•which endpoints have been registered in the Router•Available consumer Roles•Available consumer keywords•Available consumer areas

This allows the publisher endpoints to insert the appropriate recipient information in the EDXL-DE envelope.

For the GSense system the Query service is accessed by the Gateway Remote Administration application is order to setup the selection of the CAP Alert consumers.

GSense Operator

• Multi-user and Multi-agency installation• Visualization of sensors and gateways• Interconnection with the CAP Router• Management of equipment (sensors

and gateways)

• Tabular list of CAP alerts• Graphical depiction of damage

probabilities• Intuitive 3D Map Visualization

GSense Remote Administration

3 Chr. Lada Str., Athens, GreeceTel: +30-210-6840036Fax: +30-210-6840037Web: www.satways.netEmail: info@satways.net