Shake Map and Seismic Risk Assessment for Dubai (2011-2012)

Installation of strong motion network as part from Dubai seismic network to estimate the distribution of strength of ground shaking to provide detailed maps called shake maps for Dubai for the first time in UAE, in addition to near real time of the seismic risk assessment of existing building stock and different facilities in Dubai.

This project is a part from DM promotion to the disaster countermeasure of DubaiCity for emergency response, loss estimation, and for public information through the media.

SCOPE OF WORK:

Phase 1:EAD Permanent Accelerograph Network

Objective:Furnish and install 5 station strong motion (accelerograph) network as specified herein including sensors, protection enclosures, power supply systems, communication system between remote stations and the data centre and preparation of decided locations for installment.

1.1.1Task Description

  • Selection of about 5 sites in Dubai for deployment of five (5) permanent free-field or free-field like strong motion stations. The locations shall be selected based on seismic hazard zoning and microzoning distribution patterns, compliance of site geotechnical characteristics and distribution of built environment, taking proper account on reclaimed islands and other reclaimed areas being under intensive urban development.

The final selection of 5 sites for deployment of 5 remote strong motion stations shall comply with COSMOS (Consortium of Organizations for Strong-Motion Observation Systems ( recommendations andprinciples: "Guidelines for Installation of Advanced National Seismic System Strong-Motion Reference Station (2001), and Urban Strong-Motion Reference Station Guidelines "Goals, Criteria and Specifications for Urban Strong-Motion Reference Stations".

  • Procurement and installation of 5 remote strong motion stations permanent accelerograph network. The remote strong motion stations shall be deployed dominantly within urban area of Dubai:

Table 5.8.2Required Characteristics of Remote Strong Motion Accelerograph Station
DM Accelerograph Network – Equipment and Installation
REMOTE STRONG MOTION ACCELEROGRAPH STATION
The REMOTE Strong Motion accelerograph station must be able to send real time data to Data centre over any available communication (GPRS/Edge Modem, ADSL, LAN, etc...).
Accelerometer, 5 units
  • Triaxial Force Balance Accelerometer, orthogonally oriented
  • Bandwidth: DC to 200 Hz
  • DynamicRange: > 155 dB (test data published by independent party to be provided)
  • Full scale: User selectable +/-0.5g, +/-1g, +/- 2g
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  • Calibration &test: Calibration Coil Functional and Calibration Coil Resonance Test
  • Protection for ESD, RFI and EMI for all inputs
  • Output: direct connection to the proposed digitizer
  • Power: supplied directly form proposed digitizer
  • Operating temperature: -20° to 70°C
  • Humidity: 0-100% RH

Digitizer, 5 units
  • 24 bits of resolution with ~130dB dynamic range
  • Over sampled delta sigma system with 32-bit digital signal processor performing additional filtering
  • Three channels
  • Frequency response: DC to 80 Hz @ 200 sps, DC to 80% of Nyquist at all sample rates
  • Sampling rate: 1,10,20, 50, 100, 200, 250, 500, 1000, 2000 sps
  • Output: TCP/IP Compatible Data Stream on Ethernet Interface
  • Calibration type: Step test sequence, sine, pulse, RBC, white noise (user selectable)
  • Recording capacity: at least 4 Gbytes
  • Recording Modes: Triggered event recording, continuous data recording, and/or timed event recording.
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  • Timing Type: Disciplined oscillator digitally locked to internal GPS receiver
    with external active 3.3V antenna
  • GPS: Integrates completely with system, providing timing, oscillator frequency correction, and position information. Full diagnostics of GPS system provided, including receiver state, solution type, antenna current, satellite position and SNR
  • Timing Accuracy: <5 microseconds of UTC
  • EMI/RMI protection: All I/O lines are protected from both EMI/RFI emission and susceptibility problems by ferrite filters and transient suppressors. Power lines are protected against lightning induced transients and reversed
  • Environment: Operating temp: -20 C to 70 C, Humidity: 0-100% RH.

Strong Motion Enclosure 5 units
  • Housing Type:
'NEMA 4' equivalent: Mounts on wall or floor with direct bolts into concrete or mounting supports Internal high efficiency switched power supply and battery charger system
  • Communications
  • Ethernet interface: Real Time Telemetry (Multiple destinations TCP/IP Protocol), Parameter set up, and event retrieval (FTP/SFTP)
  • RS-232 interface: Real Time Telemetry (Multiple destinations TCP/IP Protocol), Parameter set up, and event retrieval
  • Modem: Remote access, initiated by user or by the equipment
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  • Power Supply
  • Type: Internal high efficiency switched power supply and battery charger system
  • Input: 8-18 VDC 4W (typical)
  • Int. Charger Operation: 15.5VDC Required
  • Ext. Power Module: Input 100-250 VAC 50/60 Hz Output 15.5 VDC
  • Internal Battery Charger: Digitally temperature compensated output for VRLA battery with reverse protection and deep discharge recovery.
  • Fuses: None uses resettable Polyswitch protection
  • Batteries: External Valve Regulated Lead Acid (VRLA) Battery Optional battery housing.

Phase 2: Ground Shaking Map

Objective: Develop a Ground Shaking Map System for Dubai

-Automatic real time collection of shaking parameters selected for mapping calculated at sensors of deployed strong motion accelerograph network (Phase 1);

  • Internet Web based display of predefined ground motion parameters characterizing spatial distribution of earthquake induced ground shaking within the urban areas of Dubai

1.1.2Task Description

Ground Shaking Map (GSM) System for Dubai should be an Internet-based geographic product for real-time generation, spatial representation and display of potentially very complex shaking within the urban area of DubaiCity.

The overall system is to mathematically derive from acceleration inputs collected automatically at number of seismic instruments constituting the strong motion network: (1)Peak Ground Acceleration Maps; (2)Peak Ground Velocity Maps; (3)Spectral Response Maps; and (4)Rapid Instrumental Intensity Maps from. The calculated parameters are transmitted a central processing site (data centre) where mapping is performed. This mapped information can be used for emergency response/ disaster management, loss estimation, other research and engineering needs, planning, scenario analyses and training, and for public information through emergency response networks, the Internet, and the media.

Locations of Seismic and strong motion stations in Dubai Emirates.

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