Chile Observatories Earthquake Preparedness Workshop Atacama Large Millimetersubmillimeter

Chile Observatories Earthquake Preparedness Workshop Atacama Large Millimeter/submillimeter Array ALMA Eduardo Donoso December 2007 Chile Observatories Earthquake Preparedness Workshop 1

Table of Contents • Present status of ALMA Construction • Seismic Requirements – Buildings – Antenna foundations – Computers – Instruments racks • November 14, 2007 Earthquake December 2007 Chile Observatories Earthquake Preparedness Workshop 2

ALMA Site status December 2007 Chile Observatories Earthquake Preparedness Workshop 3

December 2007 Chile Observatories Earthquake Preparedness Workshop 4

AOS December 2007 OSF Site San Pedro de Atacama, Atacama Desert, Northern Chile Observatories Earthquake Preparedness Workshop 5

ALMA Sites AOS (43 km) OSF Site (15 km) December 2007 Chile Observatories Earthquake Preparedness Workshop 6

Operations Support Facility December 2007 Chile Observatories Earthquake Preparedness Workshop 7

ALMA Offices ALMA Camp December 2007 Chile Observatories Earthquake Preparedness Workshop 8

OSF Technical Facilities December 2007 Chile Observatories Earthquake Preparedness Workshop 9

AEM Contractor Area December 2007 Chile Observatories Earthquake Preparedness Workshop 10

MELCO Contractor Area December 2007 Chile Observatories Earthquake Preparedness Workshop 11

MELCO : August 2007 December 2007 Chile Observatories Earthquake Preparedness Workshop 12

Vertex Contractor Area December 2007 Chile Observatories Earthquake Preparedness Workshop 13

Vertex #1: August 2007 December 2007 Chile Observatories Earthquake Preparedness Workshop 14

Contractors Camp December 2007 Chile Observatories Earthquake Preparedness Workshop 15

Road: OSF-AOS: Transporter December 2007 Chile Observatories Earthquake Preparedness Workshop 16

ALMA Transporter December 2007 Chile Observatories Earthquake Preparedness Workshop 17

Transporter – May 2007 December 2007 Chile Observatories Earthquake Preparedness Workshop 18

December 2007 Chile Observatories Earthquake Preparedness Workshop 19

Chajnantor Plateau – looking north V. Licancabur AOS Technical Building December 2007 Cº Chajnantor Pampa La Bola Center of Array Chile Observatories Earthquake Preparedness Workshop 20

AOS Technical Building December 2007 Chile Observatories Earthquake Preparedness Workshop 21

December 2007 Chile Observatories Earthquake Preparedness Workshop 22

ACA December 2007 Chile Observatories Earthquake Preparedness Workshop 23

ALMA + ACA Atacama Large Millimeter/submillimeter Array December 2007 Chile Observatories Earthquake Preparedness Workshop 24

December 2007 Chile Observatories Earthquake Preparedness Workshop 25

Santiago Central Office December 2007 Chile Observatories Earthquake Preparedness Workshop 26

ALMA Seismic Requirements December 2007 Chile Observatories Earthquake Preparedness Workshop 27

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 December 2007 Chile Observatories Earthquake Preparedness Workshop 28

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): • • • December 2007 Seismic response factor 1 – no damping; accel. assumed directly to structure No yield No evacuation No damage Construction cost higher, but no operation stop Chile Observatories Earthquake Preparedness Workshop 29

Permanent Buildings Special Features Rock anchors December 2007 Chile Observatories Earthquake Preparedness Workshop 30

Insulation for permafrost December 2007 Chile Observatories Earthquake Preparedness Workshop 31

Robust structure December 2007 Chile Observatories Earthquake Preparedness Workshop 32

Seismic requirements 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 December 2007 Chile Observatories Earthquake Preparedness Workshop 33

Foundation embedded in rock December 2007 Chile Observatories Earthquake Preparedness Workshop 34

Rock anchor design December 2007 Chile Observatories Earthquake Preparedness Workshop 35

Massive concrete design December 2007 Chile Observatories Earthquake Preparedness Workshop 36

Seismic requirements Computers – Instruments • Seismic design anchoring to foundations December 2007 Chile Observatories Earthquake Preparedness Workshop 37

Racks seismic design December 2007 Chile Observatories Earthquake Preparedness Workshop 38

Effects November 14, 2007 Earthquake December 2007 Chile Observatories Earthquake Preparedness Workshop 39

Nothing happened • No photos – no damage - December 2007 ☺ Chile Observatories Earthquake Preparedness Workshop 40

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 2007 Chile Observatories Earthquake Preparedness Workshop 41