December 2007Chile Observatories Earthquake Preparedness Workshop1 Atacama Large...

December 2007 Chile Observatories Earthquake Preparedness Workshop 1

Chile Observatories Earthquake Preparedness Workshop

Atacama Large Millimeter/submillimeter Array

ALMA

Eduardo Donoso


Table of Contents

• Present status of ALMA Construction

• Seismic Requirements– Buildings– Antenna foundations– Computers – Instruments racks

• November 14, 2007 Earthquake


ALMA Site status


San Pedro de Atacama,Atacama Desert, Northern ChileOSF SiteAOS


AOS (43km)

OSF Site (15km)

ALMA Sites


OperationsSupportFacility


ALMA Offices

ALMA Camp


OSF Technical Facilities


AEM Contractor AreaAEM Contractor Area


MELCO Contractor AreaMELCO Contractor Area


MELCO : August 2007


Vertex Contractor Area


Vertex #1: August 2007


Contractors Camp


Road: OSF-AOS: Transporter


ALMA Transporter


Transporter – May 2007


Center of Array

Pampa La BolaV. Licancabur Cº Chajnantor

Chajnantor Plateau – looking north

AOS Technical Building


27 Mar 2007 Full configuration - 192 pads

7446000

7448000

7450000

7452000

7454000

7456000

7458000

7460000

7462000

7464000

618000 620000 622000 624000 626000 628000 630000 632000 634000 636000

UTM-X

UT

M-Y

Central+Inner ArrayY WestACAY SouthY Pampa La Bola


ACA


ALMA + ACA Atacama Large Millimeter/submillimeter Array


Santiago Central Office


ALMA Seismic Requirements


Seismic requirements

Temporary Buildings• Chilean Code

Permanent Buildings

• ALMA special requirements – more stringent: 0.28 g• Chilean Code requirements – 0.20 g• No structural damage design


No structural damage design

• Extremely conservative design: 0.446 g vs 0.28 g– Code written to minimize structural damage and prevent collapse:

• Structure yields• Personnel evacuation• Costly repairs – 5.000 m = $$$

– ALMA designs to minimize damage (loads 5 times higher than required by code):

• Seismic response factor 1 – no damping; accel. assumed directly to structure

• No yield• No evacuation• No damage• Construction cost higher, but no operation stop


Permanent Buildings Special Features

Rock anchors


Insulation for permafrost


Robust structure



Antenna foundations

• Case 1: Embedded into rock• Case 2: Rock anchors – foundation laying on rock• Case 3: Massive concrete standalone

– In all cases stiffness governs design – operational requirement of high weight and fast switching


Foundation embedded in rock


Rock anchor design


Massive concrete design



Computers – Instruments

• Seismic design anchoring to foundations


Racks seismic design


Effects

November 14, 2007 Earthquake


Nothing happened

• No photos – no damage - ☺


www.alma.info

The Atacama Large Millimeter/submillimeter Array (ALMA), an international astronomy facility, is a partnership among Europe, Japan and North America, in cooperation with the Republic of Chile. ALMA is funded in Europe by the European Organization for Astronomical Research in the Southern Hemisphere, in Japan by the National Institutes of Natural Sciences (NINS) in cooperation with the Academia Sinica in Taiwan and in North America by the U.S. National Science Foundation (NSF) in cooperation with the National Research Council of Canada (NRC). ALMA construction and operations are led on behalf of Europe by ESO, on behalf of Japan by the National Astronomical Observatory of Japan (NAOJ) and on behalf of North America by the National Radio Astronomy Observatory (NRAO), which is managed by Associated Universities, Inc. (AUI).

December 2007Chile Observatories Earthquake Preparedness Workshop1 Atacama Large...

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