Corporación de Desarrollo Tecnológico

Corporación de Desarrollo Tecnológico

Asegurando continuidad de operaciones: diseño sismo-resistente

para equipamiento mecánico de edificios e industrias

James Tauby

www.cdt.cl

25 mayo 2010

“Restricción sísmica para equipamiento mecánico”

1 de 51 págs.

Control de RuidoControl de VibracionesRestricción Sísmica para Restricción Sísmica para equipamiento Mecánico

charla: Restricción Sísmica para Equipamiento Mecánico_charla: Restricción Sísmica para Equipamiento Mecánico

James Tauby, BSc. Ingeniero Mecánico24 de mayo 201024 de mayo, 2010

1

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“SEISMIC RESTRAINT OF MECHANICAL SYSTEMS”

BY JAMES R. TAUBY P.E.

ASHRAE SEISMIC RESTRAINT MANUAL RP 812RP-812

COMPARISON OF “G” FORCES

NEW YORK CITY HOSPITAL

SANTIAGO,CHILEHOSPITAL

SAN FRANCISCO HOSPITAL

Rigidly Mounted Boiler on Grade 0.18 G 0.5 G 0.45 GRigidly Mounted Rigidly Mounted Boiler on Roof 0.29 G 0.79 G 0.72 GSpring Vibration Isolated P mp 0 29 G 0 83 G 0 75 GIsolated Pump on Grade

0.29 G 0.83 G 0.75 G

Spring Vibration IsolatedPump on Roof

0.87 G 2.48 G 2.25 G

Ss Value 0.425 1.65 1.50s

SPECIFICATIONS“The Engineers Most Important Tool”“The Engineers Most Important Tool”

The most important way to insure that a project in aThe most important way to insure that a project in aseismic area is constructed as planned.Requires a properly prepared set of constructiondocuments (drawings and spec’s), detailed review,approval of shop drawings and field enforcement.Seismic restraint systems should be looked at as anSeismic restraint systems should be looked at as anengineered system, not as a selection of hardware.The complete load path from the equipment to thet t t b t k i t t b th i istructure must be taken into account by the seismic

restraint system.

CONNECTION TYPESSteel to Steel connections with boltsSteel to Steel connections with bolts

Bolts should be designed to handle the Bolts should be designed to handle the appropriate shear and vertical forcesBolts should be a minimum of Class 4 8 or Bolts should be a minimum of Class 4.8 or ASTM –A-307 quality

CONNECTION TYPESSteel to Concrete with Post Installed AnchorsSteel to Concrete with Post Installed Anchors

Post Installed Anchors include Wedge Undercut Post Installed Anchors include Wedge, Undercut and Adhesive AnchorsAnchors must have been tested to the Guideline Anchors must have been tested to the Guideline for European Technical Approval of Metal Anchors for Use in Concrete ETAG-001 or American Concrete Institute’s ACI -355.2 to insure seismic capability

CONNECTION TYPESCONNECTION TYPES

WeldingWeldingSteel to Wood using lag boltsL b lt t b d i d i d ithLag bolts must be designed in accordance withthe “National Design Specification for WoodConstruction”Construction

HouseKeeping PadsHouseKeeping Pads

Called Plynth’s or Plinth’s in parts of the worldCalled Plynth’s or Plinth’s in parts of the worldThe most overlooked portion of equipment installation is the housekeeping padsinstallation is the housekeeping padsThey provide load transfer between the equipment anchorage and the structure of the equipment anchorage and the structure of the buildingHousekeeping pads need to be reinforced and p g pattached to the structural slab

HouseKeeping PadsHouseKeeping Pads

HouseKeeping PadsHouseKeeping Pads

HouseKeeping PadsHouseKeeping Pads

HouseKeeping PadsHouseKeeping Pads

HouseKeeping PadsHouseKeeping Pads

HouseKeeping PadsHouseKeeping Pads

Fp up to 0 5 “G”Fp up to 0.5 GHousekeeping Pad

AreaM2 (FT2)

Reinforcing Steel

300 mm (12”)

PerimeterDowel Size

600mm

Interior Dowel Size

900mm (36”)

Maximum Combined

Weight ( ) ( )O.C.E.W. (24”) O.C.

( )O.C.

gkg (lbs)

Up to 3.7 (40) T8 (#3) M16 (5/8”) M16 (5/8”) 3,630 (8,000)

3.8 (41) to 9.3 (100) T8 (#3) M16 (5/8”) M16 (5/8”) 6,800 (15,000)( ) ( ) ( ) ( ) ( ) , ( , )

9.4 (101) to 18.6 (250) T12 (#4) M20 (3/4”) M16 (5/8”) 11,340 (25,000)

18.7 (251) to 37 (400) T12 (#4) M24 (1”) M16 (5/8”) 22,675 (50,000)

SUSPENDED PIPINGSUSPENDED PIPING

All piping types require seismic bracingAll piping types require seismic bracingPipe ductility helps decided the seismic performance ofthe pipe systemWeak links are at equipment and valve connectionsSteel and copper piping with welded or brazed joints areextremely ductile and perform well Rp = 9 0extremely ductile and perform well. Rp = 9.0Steel and copper piping with threaded, bonded,compression or grooved joints do not perform as well aswelded or brazed joints. Rp = 4.5Cast iron, plastic or glass piping joints do not performwell. Rp = 3.0well. Rp 3.0

PIPE BRACING TYPES

RIGID PIPE BRACING

USES STEEL SECTIONS OR STRUT CHANNELSCANNOT BE USED WITH VIBRATION ISOLATED VIBRATION ISOLATED SYSTEMSCAUTION MUST BE TAKEN WHEN USED ON TAKEN WHEN USED ON HOT WATER OR STEAM PIPING AS THEY MAY ACT AS ANCHORSLENGTH OF BRACE IS DEPENDENT ON LOADDEPENDENT ON LOAD

RIGID PIPE BRACING

Rigid bracing adds a downward vertical force that adds to the gravity load and tries to pull the oad a d t es to pu t ehanger rod out of the above structure. This does not happen on This does not happen on tension only cable bracing.

RIGID PIPE BRACING

CABLE PIPE BRACING

Cable brace systems use galvanized aircraft cableCan be used for both vibration isolated and vibration isolated and non-vibration isolated systemsC ti h t b t k Caution has to be taken with hot water or steam systems, cables can be installed slack for the anticipated thermal movementsWork in tension only

CABLE PIPE BRACING

PIPE BRACING

PIPE BRACING

PIPE BRACING

PIPE BRACING

DUCT BRACING

All ductwork types (rectangular round and oval) All ductwork types (rectangular, round and oval) require seismic bracing depending on the sizeDuctwork may be braced with either rigid or Ductwork may be braced with either rigid or cable bracingDuctwork that is vibration isolated must use Ductwork that is vibration isolated must use cable bracing

DUCT CABLE BRACING

DUCT RIGID BRACING

DUCT BRACING

DUCT BRACING

SUSPENDED EQUIPMENTQ

All d d i t i All suspended equipment requires seismic bracing depending on the sizeEquipment may be braced with either rigid or cable bracingEquipment that is vibration isolated must use cable bracing

RIGIDLY BRACED SUSPENDED EQUIPMENTEQUIPMENT

CABLE BRACED SUSPENDED EQUIPMENTCABLE BRACED SUSPENDED EQUIPMENT

SUSPENDED EQUIPMENTSUSPENDED EQUIPMENT

FLOOR MOUNTED EQUIPMENTQ

Equipment must be attached to the structureE i t b b lt d d t th t tEquipment can be bolted down to the structureEquipment can be held in position with seismic snubbers snubbers

FLOOR MOUNTED EQUIPMENTQ

FLOOR MOUNTED EQUIPMENT

Springs & seismic snubbers with Springs & seismic snubbers with

Q

anchorage designed for the seismic forcesanchorage designed for the seismic forces

FLOOR MOUNTED EQUIPMENTQ

FLOOR MOUNTED EQUIPMENTQ

FLOOR MOUNTED EQUIPMENTQ

FLOOR MOUNTED EQUIPMENTQ

REFERENCES

A Practical Guide to Seismic Restraint, ASHRAE, 19992007 ASHRAE Handbook, HVAC Applications, ASHRAE,2007ASCE 7-05, Minimum Design Loads for Buildings andOther Structures, American Society of Civil Engineers,Other Structures, American Society of Civil Engineers,20052006 International Building Code, International CodeC il 2006Council, 2006National Design Specification for Wood Construction,American Forest & Paper Association, Inc., 2005p , ,