CAP in Earthquake Damage 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 No Damage Slight Damage Moderate Damage Severe Damage A Validated Approach - Imperial Valley 1979 CSMIP Project - Imperial Valley County Services (CSMIP ID = 01260) IDR Probability
A Validated Approach - Northridge 1994 Earthquake CSMIP Project - The Van Nuys 7-Story Hotel (CSMIP ID = 24386) Farzad Naeim et.al 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 Building installations GSense Operator Agency #2 GSense Remote Administration EDXL-DE CAP Alert 3 3 Real time acceleration data 2 2 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 Event detection using STA/LTA algorithm on real time acceleration data GSense Operator Agency #1 Network 1 1 Other CAP Consumer application 5 5
GSense Node
Pilot Installations Technological Educational Institute of Crete, Chania Central 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 Trigger 1) 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 Trigger Earthquake 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 Service and 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
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