WHAT YOU NEED TO KNOW

Transcription

1 WHAT YOU NEED TO KNOW SEISMIC Tested Solution SEISMIC CEILING INSTALLATION

2 WHAT CAUSES SEISMIC ACTIVITY? The earth s surface is made up of a series of (Tectonic) plates that move in relation to each other. The lines where these plates meet are called fault lines and movement and stresses at these points can send shock waves through the ground. These shock waves are known as seismic waves and result in vibrations that at their most severe can cause immense damage to buildings and other structures, communication networks and indeed lives. Armstrong Seismic Rx System is a fully and independently tested approach to achieving ceiling installations that can withstand the forces associated with significant seismic activity or other severe events.in an earthquake at least two types of damage occur. The first is that the building undergoes major structural damage, is not usable and collapses. The second thing is that even if the building is not severely damaged, the building sustains non-structural damage. This non- structural damage may be caused by a ceiling falling down, or a ceiling causing damage to other systems like lights or sprinklers. This damage may make escape from the building impossible. It is often this non- structural damage that makes the building unusable after an event. WIDER APPLICATIONS In addition to earthquakes, there are several other industries with associated risks (e.g. last protection) where the use of Seismic Rx System will provide additional protection for the ceiling e.g.- Nuclear installations Defence establishments Chemical installations Transport installations (with intermittent vibrations) Another major application area is in hospitals and emergency management facilities (fire brigade, police stations etc.). These are installations where it is important for the facility to be fully functional after an earthquake or other severe event. The Seismic Rx system provides the additional security required for seismic resistance using specifically designed elements for minimised installation complexity with maximum performance. For suspended ceilings, the requirements to resist (as far as is possible) the additional forces associated with seismic events requires us to categorise the associated levels of risk. We are then able to offer suitable solutions to minimise the risk of failure for each of these potential hazard levels: 02

3 HOW SEISMIC DESIGN CATEGORIES ARE DETERMINED The seismic design category must be specified by a professional engineer or registered architect on the project drawings per CISCA 0-2, 3-4. International uilding Code (IC) allows two paths to determine Seismic Design category - IC Section 1613 or ASCE 7 Section The IC states that a Seismic Design Category must be established for each construction project based on: Anticipated ground motion Soil type in a specified geographic area Occupancy category These factors are used to evaluate and establish a Seismic Design Category of A,, C, D, E or F. The installation of ceilings can be divided into three tiers of increasing requirements: Categories A & are installed to meet requirements established in ASTM C636 Category C projects must meet those plus additional provisions listed in the CISCA recommendations for areas subject to moderate risk Categories D, E & F must follow ASTM C636, CISCA guidelines for areas subject to severe earthquake risk and eight additional provisions contained in ASCE 7 Section Note: Seismic categories are determined for the entire building. This is why the Seismic Design Category information is on the structural drawings. Though IC UC IS cannot directly be correlated as the IC also takes into consideration the occupancy category, but for an easier understanding and approximate relation has been depicted below. Z IC Category A Category C Category DEF UC Zone 1 Zone 2 Zone 2A Zone 3 Zone 4 IS Zone 2 Zone 3 Zone 4 Zone 5 ased on the various zones and building occupancy level, Armstrong recommends the following installation. SEISMIC ZONE (INDIA) UILDING IMPORTANCE FACTOR - I ASTM C636 C C-DEF DEF 1.5 ASTM C636- C C-DEF DEF DEF Note: Importance factor is based on Table 35 Part 6 Section, 1 of NC (INDIA). The above are just Armstrong recommendations for IC installation category for various zones corresponding to Importance factor. It is up to design engineer to choose/specify the importance factor and installation category. Various buildings are mentioned below for importance factor 1.0 & 1.5, but can be designed for higher I value depending on economic, strategy & structure requirements. UILDING IMPORTANCE FACTOR - I as per NC (INDIA) 1. Important services and community buildings, such as hospitals, schools, monumental structures, emergency buildings like telephone exchange, television stations, radio stations, railway station, fire station building; large community halls like cinema, 1.5 assembly halls and subway stations, power stations. 2. All other buildings 1 HOW DO WE KNOW IT WORKS? FULL-SCALE SEISMIC TESTED - STATE UNIVERSITY OF NEW YORK, UNIVERSITY AT UFFALO Armstrong has partnered with the University at uffalo to test its standard and non-standard products for seismic performance using: Dynamic Testing Seismic Qualification by Shake Table Testing Static Testing Vertical, Compression and Tension Loads The University at uffalo s (U) Structural Engineering and Earthquake Simulation Laboratory (SEESL) provides research services for the George E. rown, Jr. Network for Earthquake Engineering Simulation (NEES), The Multidisciplinary Centre for Earthquake Engineering Research (MCEER). The Department of Civil, Structural and Environmental Engineering (CSEE), and R&D services for industry: SEISMIC Rx ICC-ES (International Code Council Evaluation Service) the engineering and evaluation arm of the International Code Council (the USA uilding Code authority) recognises the Armstrong Seismic Rx Suspension System as a United States code-compliant solution for severe risk seismic events (as published in ESR-1308). This evaluation and confirmation by ICC-ES provides evidence supporting the Armstrong. Seismic Rx Suspension System as a code-compliant alternative to IC requirements. These tests followed the procedures outlined in the ICC-ES Acceptance Criteria for Seismic Qualification Testing of Non-structural Components, AC 156. The seismic simulation was based on the mapped spectral accelerations (from the International uilding Code, 2006 ed.) at short periods up to 300% gravity. 03

4 ARMSTRONG SEISMIC R SUSPENSION SYSTEM (ESR-1308) ESR-1308 LIST SPECIFIC ARMSTRONG COMPONENTS AND METHODS OF INSTALLATION The performance of the Armstrong Seismic Rx Suspension System is based on specific combination of components and method of installation. Other manufacturer s components and installation methods were not tested and are not covered in ESR [ An ESR is an engineering evaluation report done by an independent third party that lists all of the engineering data and verifies performance of the systems. These are available at HYPERLINK ] Substitution of other components puts the system at risk and is not allowed by the ESR report. The following Armstrong ceilings and grid systems are included in ESR These systems were tested to withstand seismic forces in all IC categories. All ceilings have test details and summaries to support the demonstrated performance and Silhouette Grid ERC2 integrity Optional (Loose of Screw) the system. ERC2 ERC 2 IC Category C, D, E and F using Armstrong Seismic Rx system Category D, E, F Armstrong Seismic Rx Suspension System ICC Report ESR-1308 Minimum 22mm wall molding Grid must be attached on two adjacent walls opposite walls require ERC2 with 19mm clearance ERC2 maintains main beam and cross tee spacing Heavy-duty systems Category C Armstrong Seismic Rx Suspension System ICC Report ESR-1308 Minimum 22mm wall molding Grid may be cut tight on two adjoining walls Minimum 10mm clearance on two unattached walls Exposed Tee Grid ERC2 on all main beams erc2 Silhouette eam Angle Angle 22 Angle 4" SEISMIC R APPROACH TO CATEGORY D, E, AND F INSTALLATIONS Silhouette Grid Screw tightened through Exposed Tee Grid Silhouette eam ERC2 web of grid, restricting ERC2 ERC 2 separation from wall molding erc2 Attached Wall 22mm Angle Angle Angle 10 ERC2 adow olding mm Max. Interlude eam 11 ERC2 ERC2 Clips 200mm Max. eam 12 ERC2 Clips ERC2 Optional () Prelude Or 200mm Max. eam ERC Angle Attached 22mmSide 13 ERC2 Angle erc " Silhouette Grid Prelude eam Attached Wall ERC Angle Exposed Tee Grid ERC 2 adow lding Interlude eam 15 ERC 2 Unattached Wall eam Screw tightened through ERC2 web of grid, restricting 16 separation from wall molding Armstrong ERC2 22mm Angle mm Max. 17ERC2 Angle Unattached Wall Silhouette Grid ERC Angle 12 Exposed Tee Grid 19mm ERC2 200mm Max. eam 8 Armstrong ERC2 ERC2 Scale: 1:8 22mm 22 Angle ERC2 200mm Max. 19mm Optional () ERC 2 14 Interlude Angle eam Interlude eam 19mm 22mm 200mm Max. 15 ERC2 ERC 2 O.C. eam eam Unattached Wall Hanger Wire ERC or ERC2 Clip P Pop Rivets 16 ERC Prelude Or eam Seismic Rx Solutions are ESR-1308 Code Compliant & following are the benefits: Eliminates the use of 50mm wall molding & hence the installation & aesthetic problems associated with it Incorporates the narrow & sleek 22mm wall molding Provides better access to the plenum Installation is more secure as it eliminates the use of stabilizer bars Eliminates visible pop rivets through the wall angle Perimeter support wires within 200mm Attached suspension system on two adjacent walls with the ERC

5 SEISMIC R APPROACH TO CATEGORY C INSTALLATIONS ERC2 Tight screw 22mm Tight Wall ERC2 Tight Wall Tight Wall eam Cross Tee Cross Tee eam Seismic Rx Code Compliant Solutions and enefits (ESR-1308) Meets code requirements Easy to square the system Eliminates stabilizer bars etter access to the plenum Narrow, sleek aesthetic with standard 22mm molding Suspension system can be tight on two adjoining walls can use the ERC2 Intermediate-duty suspension system 22mm 19mm Clearance Wall O.C. Hanger Wire ERC or ERC2 Clip 19mm Clearance Wall PURPOSE OF SEISMIC SEPARATION JOINTS ASCE 7 Section mandates that ceiling areas greater than 232m 2 must have seismic separation joints, closure angles and horizontal restraints. This means 50mm molding, perimeter spacer bars and if the area is greater than 93m 2 lateral force bracing. It is thought that these measures will prevent the accumulated forces from overpowering an individual suspension system connection. ARMSTRONG DELIVERS TESTED SEISMIC SOLUTION Armstrong has done full-scale testing which confirms that a ceiling fitted with our Seismic Joint Clip for eams (SJMR) and Seismic Joint Clip for Cross Tees (G & SCJSI) performs as well as a field fabricated separation joint. Additional benefits to these seismic-tested separation joints are: Seismic Joint Clip - eam (SJMR) Gives architects and designers a clean look (not visible from the floor) Saves contractors time with a reliable installation method Easily installs in minutes at main beam splice tains integrity of ceiling module, unlike field assembled alternatives Allows for full acoustical panel at the joint Easier to keep the ceiling system square Seismic Joint Clip - Cross Tee (G & SI) Gives architects and designers a clean look (not visible from the floor) Saves contractors time with a reliable installation method Installs in minutes, no need to cut the face of the grid to install clip Eliminates the need for additional hanger wires tains integrity of the ceiling module, unlike field assembled alternatives Allows the use of full size panels SEPARATION JOINT LAYOUT GUIDE eam eam SJMR SJMR SJMR Cross Tea Cross Tea eam SJMR Cross Tea eam SJMR SJMR SJMR eam eam eam SJMR SJMR SJMR Tee Cross Tea Cross Tee Cross Tee SJMR in x Layout SJMR and in x Layout SJMR and in x Layout 05

6 RACING AND RESTRAINT FOR SEISMIC INSTALLATION DIFFERENCE ETWEEN RACING AND RESTRAINT Typical post materials are EMT conduit or steel stud (see Figure 2). STEEL STUD COMPRESSION POST Attachment to the wall is considered restraint. racing is a form of 45 OR LESS #12 HANGER WIRE 45 OR LESS restraint (compression post and wires). Typical seismic bracing for a wall-to-wall ceiling consists of clusters of four 12-gauge wires arrayed 90º from one another and attached to the main beam within 50mm of a cross tee intersection. These wires are to be angled no more than 45º from the plane of the ceiling. The compression post is attached to the grid at the cluster of wires and extends to the overhead structure (see Figure 1). TYP. 4'-0" O.C. (3 TIGHT WRAPS) MAIN EAM 4'-0" O.C. CROSS TEES COMPRESSION POST 12 GA. RACE WIRES 2'-0" O.C. Figure 1 The compression post needs to be engineered for the application and the longer its length the more substantial it must be. 45 OR LESS ARMSTRONG CROSS TEE 45 OR LESS ARMSTRONG MAIN EAM Figure 2 The code also allows for the use of rigid bracing. The advantage here is that when a rigid member is used in place of wires it can handle loads in two directions (push and/or pull) so only two diagonals and one vertical are needed at each location. Typical wall-to-wall ceiling restraint is achieved by proximity or attachment to the perimeter angles which are fixed to the walls. Seismic Design Category C allows some movement but limits are established by setting the required clearance at 10mm Seismic Design Categories D, E and F require the ceiling grid to be fixed to the wall molding on two adjacent walls. This attachment to the molding is the first element of restraint. As the ceiling area gets larger and the mass (or weight) of the ceiling increases additional restraint must be applied in the form of lateral force bracing. 06

7 SEISMIC SUSPENSION SYSTEM Item No. Silhouette* - Heavy Duty ( DEF Category) P Description 3 HD eam, White Reveal Dimensions (L x W x H) in mm Rout Spacing Load o/c Spacing 3600 x 15 x P803042G Cross Tee, White Reveal 1200 x 15 x P802042G Cross Tee, White Reveal 600 x 15 x L- Heavy Duty ( DEF Category) P HD eam P Cross Tee P Cross Tee Prelude L- Heavy Duty ( DEF Category) P HD eam 3600 x 24 x P Cross Tee, Center Rout 1200 x 24 x P Cross Tee 600 x 24 x 35 - Silhouette* - Intermediate Duty ( C Category) P ID eam, White Reveal 3600 x 15 x P Cross Tee, White Reveal 1200 x 15 x P Cross Tee, White Reveal 600 x 15 x L- Intermediate Duty ( C Category) P mm ID eam 3600 x 15 x P Cross Tee 1200 x15 x P Cross Tee 600 x 15 x Prelude L- Intermediate Duty ( C Category) P ID eam 3600 x 24 x P313052P Cross Tee, Center Rout 1200 x 24 x P Cross Tee 600 x 24 x * For Silhouette with lack reveal add L in the suffix 07

8 ACCESSORIES Item No. Description Dimensions length (mm) PT 2222H P GM1245A ERC2 Clip Pieces Per Carton P GM1247 P GM1246 Seismic Cross Tee Joint Clip Seismic eam Joint Clip P GM1248 P GM1249 Expansion Sleeve (15mm) Expenssion Sleeve (24mm) P 442 Vector Seismic Clip R TM SEISMIC GRID The performance of the Armstrong Seismic R TM Suspension system is based onspecific combination of components and method of installation. Other manufacturer s components and installation methods were not tested and are not coverd in this evalution. CONTACT US