j. beap industries, inc.jbeapindustries.com/library_1.pdf · ” there are 59 active fault...

BY

DOMINGO G. LIMETA, JR. A.E. (S.D.T. / I.I.T. / I.E.T. / E.E.)

SR. TECHNICAL CONSULTANT NONSTRUCTURAL HAZARDS MITIGATION - SEISMIC HAZARDS REDUCTION PROGRAM

J. BEAP INDUSTRIES, INC.

The mechanical vibrations and vibration-induced noises being generated by various Mechanical Floor-Mounted Package Equipment are often the major causes of complaints by the building occupants in various modern building structures. Some of these package equipment are mostly being installed at the basement and at the roof-deck of the building structures, while others are being installed at the other floors / levels within the building structures. The vibrations are being transferred to the building’s structural elements and producing disturbing noises inside the building structures. The said vibrations also shorten the life-span or service-life the package equipment due to mechanical fatigues and stresses imparted internal parts, components, and to the associated pipelines attached at the package equipment nozzle-end connections. In order to reduce the effects of vibrations and vibration-induced noises, the resilient Rubber Pads, Rubber Mounts, or Spring-Mounts are being installed underneath the package equipment’s steel base frames as shown below :

FIGURE 1 : Resilient Vibration-Isolator Mounts (Non-Seismic Applications)

FIGURE 2 : Floor-Mounted Package Equipment With Resilient Vibration-Isolator Mounts (Non-Seismic Applications)

Some Floor-Mounted Package Equipment are mounted at the top of the reinforced Housekeeping Concrete Pads, while others are mounted at the top of the Structural Steel Base Frames, Structural Steel Rails, or Concrete Inertia Base Frames, depending on the requirements as per design by the systems design professionals / engineers.

Earthquake Restraints For Floor-Mounted Package Equipment 1

There are also some instances where the Floor-Mounted Package Equipment are supported by a Floating Concrete Base Pad with resilient Rubber Pads underneath The vibrations can be isolated or reduced to a fraction of the original force by utilizing resilient isolator mounts. Usually, it is highly recommended that Isolation Efficiency be achieved by at least 80% or higher. The Static Deflection, Natural Frequency, Transmissibility, and Efficiency can be somehow determined accurately by a Chart as shown below :

So, the reduction of vibrations and vibration-induced noises are strict requirements by the systems design professionals / engineers and to avoid shortening the life-span or service-life of the Floor-Mounted Package Equipment due to fatigues and stresses. Aside from vibrations and vibration-induced noises, there are two influencing factors which are damaging, one is the Wind Forces (Fwind) and the most destructive of all is the Horizontal – Vertical – Rotational Seismic Forces (Fp & Fpv), commonly known as :

“ E A R T H Q U A K E S “ Earthquake Restraints For Floor-Mounted Package Equipment 2

As a reminder, the Philippine Institute Of Volcanology & Seismology (PHIVOLCS), United States Geological Survey (USGS), and Japan Meteorological Agency (JMA) attested that the Philippine archipelago is located in one of the most seismically active regions of Asia. The country has 3-major seismic generators, namely : PHILIPPINE FAULT, PHILIPPINE TRENCH, and MANILA TRENCH. Each seismic generator is capable to unleash a major earthquake with a surface magnitude of 8.0 in the Richter Scale (Ms = 8.0Ri). These are also being attested by our fellow countryman Engr. Ribelito Torregosa, together with his colleagues, Prof. Masata Sugito & Prof. Nobuoto Nojima of the Civil Engineering Department of Gifu University in Yanagido, Gifu, Japan. Complete data can be found on their two case studies entitled “Assessment Of Seismic Hazard And Microzoning In The Philippines & Strong Motion Simulation For The Philippines Based On Seismic Hazard Assessment.” There are 59 Active Fault Parameters (Fault Lines) in the Philippines. In the heart of Metropolitan Manila, the posing threat is the Marikina Valley Fault System which is always being reiterated by the PHIVOLCS. “During an earthquake, a series of wave like motions and vibrations of varying magnitude impart horizontal, vertical, and rotational forces or loads on structures. Equipment, components, and systems feel the effects of an earthquake through earth movement at the foundation which is imparted to the structural frame of the building and then to the equipment, components or systems by way of their support from the structural frame. Once this occurs, a dynamic interaction between the movements and acceleration of the structural frame and those equipment, components, and systems takes place. The loads / forces that develop, therefore, become a function of their relative acceleration and mass (weight); ie., The Load / Force (F) = some portion (%) of Mass x Acceleration (A).” In year 1995, I’ve started to explore and investigate the damaging effects of Major Earthquakes (Seismic Forces) to the various Nonstructural Elements within the commercial / industrial building structures. By year 2000 up to year 2010, I’ve found out that so many Floor-Mounted Package Equipment are simply supported by Non-Seismic Resilient Isolator Mounts as shown in Figure - 1 of Page 1. Since the Floor-Mounted Package Equipment belongs to the Mechanical – Electrical – Plumbing (MEP), I’ve personally asked several Professional Mechanical Engineers and they simply told me that seismic restraints and protections for Nonstructural Elements “Mechanical & Electrical Equipment - Components - Systems” were indeed overlooked. I told them the damaging effects of the Horizontal Seismic Force (Fp) and the Simultaneous Vertical Up & Down Seismic Force (Fpv), and at last they were all enlightened. But to the Structural Engineers, the effects of Horizontal Seismic Force (Fp) and the Simultaneous Vertical Up & Down Seismic Force (Fpv) is nothing new to them. The Structural Engineers told me that “If the building structures can be severely damaged or eventually collapsed due to Major Earthquakes, definitely the Nonstructural Elements are also susceptible to severe damages.” While some Civil Engineers told me “Yes, the Nonstructural Elements can be severely damaged too, in-fact even the strongly-built skyways and elevated railways can be damaged too by Major Earthquakes, and others eventually collapsed like the 1996 Kobe Earthquake in Japan and Major Earthquakes in the State Of California and Turkey.” I decided to get some seismic engineering statements from one of the world’s most trusted manufacturer of resilient isolator mounts – THE VMC GROUP, U.S.A.


Since the Philippines is prone to major earthquake disturbances which may strike at any moment without signs and warnings, the considerations for destructive effects of Seismic Forces (Fp & Fpv)) to the Floor-Mounted Package Equipment were overlooked. Why it was overlooked . . . ? Because, I have personally found out that the National Building Code Of The Philippines (NBCP) has no detailed and definite seismic provisions for the Nonstructural Elements “Mechanical / Electrical – Equipment, Components, & Systems.” I have already informed various professionals who are engaged in the designs and constructions of commercial and


industrial building structures about these issues. Also, the Fire Code Of The Philippines (FCP) has no detailed and definite seismic provisions concerning the critical Fire-Pumps associated with Fire-Hydrant / Automatic Fire Sprinkler Piping Systems. I have met various systems design professionals, consultants, project managements, and contractors who built various building structures and installed various Floor-Mounted Package Equipment and they emphasized that their finished projects complied to the applicable Building Codes & Standards, like the National Structural Codes Of The Philippines (NSCP), 1997 Uniform Building Code (UBC), 2000 / 2003 / 2006 International Building Code (IBC), SMACNA, ASHRAE, and to include the National Fire Protection Association (NFPA-13 Standards). But when it comes to the seismic provisions, it is MISSING. How come it was overlooked in the Philippines where they have said that they have complied from the above mentioned applicable Building Codes & Standards . . . ? This is a very clear reality under the bright sunlight that the Floor-Mounted Package Equipment’s protections against destructive major earthquakes were not given an utmost emphasis or considerations. So, various professional / registered / associate engineers / certified technicians simply told me that their installed Floor-Mounted Package Equipment will withstand Seismic Forces (Fp & Fpv) for the building structures were strongly-built and even designed to withstand severe earthquakes. I replied to them “Sir, no matter how strong the building structures were built, it will move and will be jolted by major earthquakes and the Seismic Forces (Fp & Fpv) will be transferred into the various Floor-Mounted Package Equipment and other Nonstructural Elements.” If they feel that a contention may arise, well they may verify it to PHIVOLCS / NSCP, and also why the seismic provisions are being stipulated by the UBC, IBC, SMACNA, ASHRAE, and NFPA-13 where they are referencing from these codes and standards . . . ? Since year 1995 and most of all during the span of year 2000 up to this present time, I was deeply fascinated as to why the various installed Floor-Mounted Package Equipment in the Philippines have no protections at all to resist or withstand Seismic Forces (Fp & Fpv)). Could it be that the considerations made by some systems design professionals, consultants, project managements, contractors, and the equipment suppliers were intended only for noises & vibrations . . . ? And the effects of Seismic Forces (Fp & Fpv) were not included and sometimes including the effect of Wind Loads (Fwind) were somehow overlooked too . . . ? Whereas, the Philippine archipelago is always being hit by strong storms and super-typhoons starting from the month of July up to November. The Floor-Mounted Package Equipment being discussed herein are : • Air-Cooled Condensers • Air Handling Units • Boilers & Steam Generators • Centrifugal Fans • Chillers • Compressors • Cooling Towers • Pumps • Engine Driven Generator Sets • Power Plant’s Turbines • Other Types Of Huge & Heavy Package Equipment There are four basic types of restrained Floor-Mounted Package Equipment : • RIGIDLY MOUNTED NON-ISOLATED EQUIPMENT • DIRECT MOUNTED EQUIPMENT SUPPORTED BY ISOLATORS WITH BUILT-IN RESTRAINTS • BASE MOUNTED EQUIPMENT SUPPORTED BY ISOLATORS WITH BUILT-IN RESTRAINTS • BASE MOUNTED EQUIPMENT USING ISOLATORS WITH SEPARATE SEISMIC SNUBBERS


I have seen various package equipment with Importance Factor = 1.0 & 1.50 were only equipped with Neoprene Rubber Isolator Mounts and Free-Standing Spring Isolator Mounts w/out Restraints. This is a clear indication that the systems design professionals, installation contractors, and equipment suppliers are only concern about the effects of noises & vibrations. They do not see that the Seismic Forces (Fp & Fpv) which may come from any directions will damage or destroy the above mentioned isolators and also by the Wind Loads (Fpwind). They only considered the equipment’s Static Loads without serious considerations to the effects of Dynamic Loads (seismic / wind loads) and the generated Reactive Loads. In Seismic Zone 4, seismic restraints are stringent requirements better known as CODE COMPLIANCE. TESTIMONIAL ACCOUNT - 1 In year 2006, I have seen a huge and heavy diesel-engine driven Gen-Sets equipped only with Free-Standing Spring Isolator Mounts w/out Restraints located at ground-floor of 3-storey industrial building structures. The site location is within the Seismic Zone 4, with Ground Acceleration of 0.4G as per UBC seismic provisions or 1.65 Site Spectral Response Acceleration as per IBC seismic hazard map and tabulation. The Gen-Set may accommodate the Static Loads and induced vibrations, but not Seismic Forces (Fp & Fpv). The Free-Standing Spring Isolator Mounts w/out Restraints can be damaged by seismic forces and the Gen-Set units could be dislocated from its original mounting position. Also, I saw cracks at the structural concrete floors due to equipment vibrations and the effects of the past earthquakes. TESTIMONIAL ACCOUNT - 2 Last year, I received an inquiry that a huge and heavy Chiller Toners will be installed at the roof-deck of a high-rise building structure. The site location is within the Seismic Zone 4, with Ground Acceleration of 0.4G and at the roof-deck will be 2.12G as per 1997 UBC, plus the effect of Wind Load (Fwind). The equipment supplier and contractor were only highly concerned about the attenuation of noises & vibrations to be generated by the Chiller Toner itself. The Chiller Toner’s operating weight is 12,333.00 KG. ÷ 10-Mounts = 1,233.30 KG. per Neoprene Rubber Isolator Mounts. Each of the Neoprene Rubber Isolator Mount has a loading capacity of 1,818.00 KG. x 10-Mounts = 18,180.00 KG. 18,180.00 KG. - 12,333.00 KG. = 5,847.00 KG. O. K. PASSED . . . . ! NOT O. K. (In Reality) – Failure . . . . ! The equipment supplier and the contractor thought what they have done is already O.K., and that is what they thought. They never realized if a major earthquake and strong aftershocks suddenly strikes . . . ! Their supplied and installed Neoprene Rubber Isolator Mounts will be destroyed and that the equipment itself could be dislocated from its proper mounting position. They did not realize a worst scenario might occur. I have performed an initial Seismic Load Calculations using the Static Analysis Method referenced from the seismic provisions of the 1997 UBC, as specified by the project management / systems design professional in-charged at the on-going building construction project. Below is what I have found out as per results of the calculations and not yet included the effect of Wind Loads. Shear Load Imparted To Each Isolator Mount = 2,618.00 KG. / 5,759.00 LBS. Tension & Compression Load imparted To = 5,786.00 KG. / 12,729.00 LBS. Each isolator Mount The above calculated Reactive Loads does not yet include the Imbalanced Load which should be combined with the calculated Shear Load, a form of conservative approach and considering all possible worst case scenarios. The Moment Of Inertia was also calculated as Ixx = 20,161.00 In4., Iyy = 18,598.00 In4. The θ = 53 Degrees “Critical Angle – Max. Tension Occurs” (function of the Inverse Tangent and functions of the Sine & Cosine for the calculated Fp). The calculated Horizontal Seismic Force or Fp = 26,176.00 KG.


The Neoprene Rubber Isolator Mount having a load capacity of 1,818.00 KG. will not survive against the 2,618.00 KG. Shear Load and also against the 5,786.00 KG. Tension / Compression Loads. They did not saw these effects. The calculated Wind Load is Fwind = 13,960.00 KG. TESTIMONIAL ACCOUNT - 3 Last month of this year (2011), a huge and heavy Gen-Set will be installed at the basement of a medium-rise building structure. The site location is within the Seismic Zone 4, with Ground Acceleration of 0.4G and at the basement is from 0.40G down to 0.31G as per 2003 / 2006 IBC. The equipment supplier was only highly concerned about the attenuation of noises & vibrations to be generated by the Gen-Set. The project management consulted me to evaluate the proposed installation set-up. The Gen-Set operating weight is 9,971.00 KG. ÷ 8-Mounts = 1,246.40 KG. per Free-Standing Spring Isolator Mount w/out Restraints. Each of the spring isolator has a rated load capacity of approximately 1,500.00 KG. Then, 1,500.00 x 8-Mounts = 12,000.00 KG. 12,000.00 KG. - 9,971.00 KG. = 2,029.00 KG. O. K. PASSED . . . . ! NOT O. K. (In Reality) – Failure . . . . ! The calculated Horizontal Seismic Force (Fp) = 4,388.00 KG. and the simultaneous up & down Seismic Vertical Force (Fpv) = 2,194.00 KG. I have performed the initial Seismic Load Calculations using the Static Analysis Method referenced from the seismic provisions of the 2003 / 2006 IBC. Shear Load Imparted To Each Isolator Mount = 1,097.00 KG. / 2,413.00 LBS. Tension & Compression Load imparted To = 3,110.00 KG. / 6,842.00 LBS. Each isolator Mount The Free-Standing Spring Isolator w/out Restraints load capacity is approximately 1,500.00 KG. will not survive against the 3,100.00 KG. Tension / Compression loads. The Testimonial Accounts - 2 & 3, the equipment suppliers / contractor never realized that their procedures were not correct. Their supplied and installed Neoprene Rubber Isolator Mounts and Free-Standing Spring Isolator Mounts will be damaged or destroyed by the seismic generated Reactive Shear / Tension / Compression Loads. If they will pursue their objectives by just merely installing their specified isolator mounts without considering the reality or existence of major earthquakes in the Philippines, the installed equipment will be damaged in an event of major earthquake. This will be a clear indication of negligence and contrary to the advocacies of the safety standards. Where is the CODE COMPLIANCE . . . ? I have also noticed few years ago (2009 / 2010) that many equipment suppliers and contractors have no in-depth knowledge about the stringent requirements and provisions of the various applicable Building Codes & Standards, particularly the SEISMIC LOAD CALCULATIONS. We encountered this scenario during the on-going building constructions here in Manila (embassy building), the manufacturer’s representative for Seismic Restraint Products here in Manila could not perform their very own initial seismic load calculations for almost several months, we were stunned after we have discovered it as per info to us by one contractor engaged in the installations of Fire Sprinkler Piping Systems. We were immediately called and requested by various mechanical contractors to assist them even by initial / representative seismic load calculations. In a matter of 1-Week, we have managed to catch-up and provided them our seismic load calculations based on the seismic provisions of the 2003 International Building Code (IBC). Why is it that the seismic provisions of the applicable Building Codes & Standards are very crucial for the restraints of huge and heavy Floor-Mounted Package Equipment . . . ? Then here we go . . . . . . !


During major earthquake, the low frequency sinusoidal waves of varying magnitudes / amplitudes are traveling under the earth’s surface. The ground shaking will be impacted into the building’s structural foundations and then imparted way-up to the building’s structural framing elements and then transferred into the Floor-Mounted Package Equipment. The seismic waves will then RIDE into the running & idle huge and heavy Floor-Mounted Package Equipment. The seismic waves (shaking) will be transferred into the Neoprene Rubber Isolator Mounts or Free-Standing Spring Isolator Mounts w/out Restraints. The rubber mounts and

particularly the spring mounts will AMPLIFY the seismic waves. If the rubber mounts or spring mounts are not rated for seismic applications without built-in Restraints, it will be damaged or in the worst case it will be completely destroyed and a potential scenario where the equipment will be dislocated from its proper mounting position. That is why the applicable Building Codes & Standards stipulated that all Flexibly-Mounted Equipment with a period of 0.07 Second or higher and supported by Vibration-Isolated Devices shall be treated with utmost importance. All Neoprene Rubber Mounts and Spring Isolator Mounts shall have an all directional restraints with air-gap not to exceed 6MM., or 1/4 Inch. If the all directional restraints with air-gap will be larger than 6MM., or 1/4 Inch., the applicable Building Codes & Standards strictly stipulated that the Horizontal Seismic Force shall be DOUBLED or 2Fp and considering all worst case scenarios the simultaneous vertical up & down Seismic Force (Fpv) should also be DOUBLED or 2Fpv, for we are tackling the effect of

AMPLIFICATION. If the existing / operational huge and heavy Floor-Mounted Package Equipment are already equipped with Neoprene Rubber Mounts or Free-Standing Spring Isolator Mounts, it shall be retro-fitted by an all directional Seismic Snubbers. For those equipment that will be installed / erected for the first time, the Neoprene Rubber Isolator Mounts w/ built in Restraints or Spring Isolator Mounts w/ built-in Restraints shall be implemented, particularly in regions or areas designated under Seismic Zone 4 like the Metropolitan Manila within the 5 to 10- kilometer radius within danger zone of the Marikina Valley Fault System which is repeatedly being warned by PHIVOLCS. Now we all see the danger of Seismic Forces (Fp & Fpv) to all Flexibly Floor-Mounted Package Equipment

equipped with vibration / isolator mounts. The seismic waves will be AMPLIFIED by the vibration / isolator mounts. The most critical locations are those huge and heavy Floor-Mounted Package Equipment installed at the roof-deck and various elevated parts within the building structures. The huge and heavy Floor-Mounted Package Equipment located at the ground level or basement of the building structures will also be affected by the Seismic Forces (Fp & Fpv) which may come from any directions.

FIGURE 3 : These Isolator Mounts With Built-In Restraints Are Rated For Seismic Applications For Seismic Zone 4 It Also Attenuate Vibrations Producing Noises


FIGURE : 4 - All Directional Seismic Snubbers


I have seen a Seismic Load Calculations performed by one well-known building / equipment contractor together with the equipment supplier. It is very surprising that their calculations were merely a Horizontal Seismic Force (Fp). My humble questions were : “ Where Are The Other Calculations . . . . . ? “ Seismic Vertical Force ( Fpv ) = Simultaneous Vertical Up & Down Shear ( V ) = Reactive Load Shear ( V ) Imbalanced Load = Combined To Shear, Where c.g. Is Uncertain Tension ( T ) = Reactive Load Compression ( C ) = Reactive Load Ixx / Iyy = Moment Of Inertia θ = Critical Angle In Degrees For Overturning Function Of Inv Tangent, Cosine, and Sine Ss = Site Spectral Response Acceleration (IBC) Fa = Site Coefficient (IBC) SMS / SDS = 2/3 SMS And Seismic Design Spectral (IBC) G or HLF = % Of Gravity or Horizontal Load Factor (IBC) And The Vertical Load Factor (IBC) Ca Value = 1997 UBC Seismic Source Type = A / B / C 1997 UBC Na Value = 1997 UBC Distance To Nearest Seismic Source = ≤ 2 KM. / 5 KM. / ≥ 10 KM. 1997 UBC Site Soil Class = Class D As Default If Unknown (IBC / UBC) Others are : Response Modification Factor (Rp), Amplification Factor (Ap), Building’s Fundamental Period (Ta)n in second, Equipment Fundamental Period (Tp) in second “Single-Degree-Of-Freedom”. Now, how about the Wind Load (Fwind) for package equipment particularly those which are located at the roof-deck and expose to gusting wind which may also come from any direction. qz = Velocity Pressure (ASCE 7) V = Wind Speed In MPH or KPH (ASCE 7) Kz = Velocity Pressure Exposure At Height z (ASCE 7) Ku = Topographic Factor (ASCE 7) Kd = Wind Directionality Factor (ASCE 7) Note : See the IBC & UBC equivalent Wind Load Calculations. We are not yet finished here, after the calculations of the Horizontal & Vertical Seismic Force Combinations, it will be determined if the Isolator Mounts falls within the Capacity Envelop as shown on next page. Also, the contractor’s Seismic Load Calculations together with the equipment suppliers did not seen the Restraints Capacity Envelope and what exactly is this all about.


FIGURE 5 : Example Of Isolator Mount’s Capacity Envelope The contractor and equipment supplier thought that the Seismic Load and Wind Load Calculations are just an

easy task, the answer in NO. It is a very complex calculations which sometimes yielded into several sheets of papers and to include the Base-Plate & Anchoring to the structural concrete. The Base-Plate size and strength shall also be detailed, as well as the Anchorages to structural concrete or housekeeping pad concrete.


FIGURE 6 : Example Of Standard Base Plate For Anchor Bolts

The Cast-In Place or Post-Installed Mechanical Anchor Bolt calculations are also very crucial. If uncertainty arises about the locations / spacing of the Cast-In Place Anchor Bolts due changes in the specifications of the concrete slab or Isolator Mounts, the ICC Evaluation Service Report highly recommends the use of Undercutting Post-Installed Mechanical Anchor Bolts as a direct alternative to the Cast-In Placed Anchor Bolts (L-Hook or J-Hook). Other professional engineers (seniors) still uses the Allowable Stress Design (ASD) methodology while the present and younger generations of professional / registered / associate engineers uses Strength Design methodology or known as the Load Reduction Factor Design (LRFD). Both the ASD & LRFD are widely acceptable. However, various manufacturers of vibration-isolator mounts published the load ratings / capacities of their vibration-isolator mounts in ASD.


Let us read below the statements of one well-known manufacturer of vibration-isolator mounts in the United States.


FORCE TAILORING FACTORS A). Isolated Equipment Connection To Steel Using LRFD Bolt Allowable : Lateral Design Load = 2.00 x Fp Vertical Design Load = 2.00 x Fpv B). Isolated Equipment Connection Via Through Bolts Using ASD Bolt Allowable : Lateral Design Load = 2.00 x Fp / 1.4, but increase Bolt Allowable by multiplying 4/3 Vertical Design Load = 2.00 x Fpv / 1.4, but increase Bolt Allowable by multiplying 4/3 C). Isolated Equipment Connection To Concrete With Post-Installed Anchor Bolts using ICBO Anchor Bolt Ratings : Shallow Embedment ( < 8 diameter) Lateral Design Load = 3.90 x Fp / 1.4, but increase Bolt Allowable by multiplying 4/3 Vertical Design Load = 3.90 x Fpv / 1.4, but increase Bolt Allowable by multiplying 4/3 Shallow Embedment ( = 8 diameter) Lateral Design Load = 2.60 x Fp / 1.4, but increase Bolt Allowable by multiplying 4/3 Vertical Design Load = 2.60 x Fpv / 1.4, but increase Bolt Allowable by multiplying 4/3 D). Isolated Equipment Connection To Concrete With Post-Installed Anchor Bolts using ICBO Special Inspection Anchor Bolt Ratings : Shallow Embedment ( < 8 diameter) Lateral Design Load = 3.90 x Fp / 1.4 Vertical Design Load = 3.90 x Fpv / 1.4 Shallow Embedment ( = 8 diameter) Lateral Design Load = 2.60 x Fp / 1.4 Vertical Design Load = 2.60 x Fpv / 1.4


Other professionals said that the ASD is easier to use than LRFD. Other professionals said that the LRFD require tedious task calculations. The LRFD has a several strength reduction factor multipliers to the nominal strength of Anchor Bolts, this methodology is also very stringent when it comes to Uncracked & Cracked Concrete, Spacing, Edge Distance, Pull-Out Strength, Shear Failure, and others. The latest 2006 IBC requires that all post-installed Mechanical Anchor Bolts shall be capable of maintaining its holding even in cracked concrete conditions before, during, and aftermath of major earthquakes. The HILTI HDA Undercut Anchor Bolts and the SIMPSON Strong-Bolt Wedge-Type Undercutting Anchor Bolts are examples of best candidates as direct replacements for the Cast-In Place Anchor Bolts. These Post-Installed Mechanical Anchor Bolts maintains its holding power even in cracked concrete conditions and as the package equipment vibrates and under the influence of Seismic Forces / Wind Loads, the stronger and deeper it holds inside the structural concrete and concrete housekeeping pad. For the huge and heavy package equipment, the contractors should not use ordinary (unknown source / locally fabricated / cheap source hardware stores) for seismic applications. The poor-quality and sub-standard anchor bolts maybe brittle and weak, no quality assurance for safety. The use of high-quality anchor bolts from the well-known and industries recognized manufacturers shall be implemented like the HILTI or SIMPSON with supporting ICC-ES Evaluation Report ESR - 1546 (HILTI) and ESR - 1771 & ESR - 3037 (SIMPSON). Below are the examples of the SIMPSON Strong-Bolt Wedge-Type Undercutting Anchor Bolts Tabulated Load Capacities in accordance to the ACI 318-02 Appendix D – LRFD. However, the data shown below and on the next page will be converted into ASD, it can be done. Refer to the complete ESR - 1771 and ESR - 3037.


FIGURE : 7 - Severely Damaged Noise / Vibration Spring Isolators Seen Aftermath Of Major Earthquakes Many Of These Spring Isolator Mounts Are Not Rated For Seismic Applications

If the Floor-Mounted Package Equipment are part of the critical systems and part of essential facilities, then the equipment shall be subject for Nonstructural Hazards Mitigation - Seismic Hazards Reduction Program (NHM-SHRP), as indicated below :


If a particular Floor-Mounted Package Equipment is very crucial to private / government vital operations or the set-up installation is very critical and being life-threatening, the manufacturers of the Seismic / Vibration Isolator Mounts strictly recommends that the Seismic Load Calculations be done using the COMPUTERIZED DYNAMIC MODELING ANALYSIS METHOD rather than the conventional STATIC ANALYSIS METHOD. One well-known manufacturer of seismic / vibration-isolator mounts have a very wonderful explanations about this issue.


Example Of Seismic Load Calculations With Certification Outputs Courtesy Of The Kinetics Noise Control, Inc. - U.S.A.



NOTE : The last edition of the Uniform Building Code (UBC) was the 1997 UBC. It was replaced by the new and more stringent INTERNATIONAL BUILDING CODE (IBC). I am personally not yet certain if the Philippines will adopt the IBC. However, the latest National Structural Code Of The Philippines in terms of Wind Load has adopted the provisions of the ASCE 7-05. The ASCE 7-05 Minimum Design Loads For Buildings & Structures is basically the same and in harmony with the Seismic Provisions of the International Building Code (IBC)

Sample of our initial Seismic / Wind Load Calculations Based On The Static Load Analysis Method Prior To The Seismic Restraint Spring Isolator Mounts Manufacturer’s Computerized Dynamic Analysis Method.


REFERENCES

• Assessment Of Seismic Hazard And Microzoning In The Philippines & Strong Motion Simulation For The Philippines Based On Seismic Hazard Assessment – Torregosa, Sugito, & Nojima of C.E. Dept., of Gifu University, Japan.

• Manual Of Code Compliance Guidelines On Earthquake Resistance Of Architectural, Mechanical & Electrical Components & Systems, 2nd Edition Year 2001 and 3rd Edition Year 2008 - Loos & Co., Inc. U.S.A.

• Kinetics Noise Control, Inc. - Seismic Design Manuals, U.S.A.

• Vibration Mountings & Controls, Inc. (The VMC group) - U.S.A.

• Mason Industries, Inc. - U.S.A.

• Vibration Eliminator Co., Inc. - U.S.A.

• 2000 / 2003 / 2006 International Building Code (IBC), U.S.A.

• ASCE 7-98 (1998) & ASCE 7-05 (2005) Minimum Design Loads For Buildings & Structures, U.S.A.

• 1999 & 2007 National Fire Protection Association (NFPA-13 Standards), U.S.A.

• 2000 & 2003 National Earthquake Hazards Reduction Program (NEHRP / FEMA), U.S.A.

• 1997 Uniform Building Code (UBC), U.S.A.

• American Concrete Institute - ACI 318-02 Appendix D, U.S.A.

• HILTI U.S.A. Post-Installed Mechanical Anchor Bolts, U.S.A.

• SIMPSON Strong Anchor Bolt, U.S.A.

• The National Structural Code Of The Philippines (NSCP). Philippines. ACKNOWLEDGEMENT My sincere gratitude to Carl L. Strand, M.S. Geology (president of Strand Earthquake Consultants, L.A. CA. U.S.A. and a member of the ASCE 25-97 Committee) who is my mentor concerning Nonstructural Hazards Mitigation - Seismic Hazards Reduction Program since year 1999 up to this present time, as well as to Dianna Mitchell (manager of the Strand Earthquake Consultants). My sincere appreciation to Albert S. Mendiola (managing director of J. BEAP Industries, Inc.) for his untiring support and my partner for earthquake safety advocacies in the Philippines. Also, to Chester Szalaj and Zeke Bochenek of The Metraflex Co. based in Chicago, IL. concerning the versatility and other technical data of the Seismic Spectrum Rated Flexible Loop. Lastly, my appreciation to Dan Duggan, Jr. of the Seismic Solutions, Inc. CA. U.S.A. and to his father Mr. Daniel C. Duggan Sr. (a member of the NFPA-13 Committee / ASHRAE) & president of Fire Sprinkler Design, St. Louis, Missouri, U.S.A.), as well as to Michael E. Werner, P.E. for their wonderful works for the engineering data concerning the UL Listed Pre-Stretched Certified Break Strength Seismic Wire Rope / Cable TM Bracing Systems. ABOUT THE AUTHOR (From Albert S. Mendiola) The author is Mr. Domingo G. Limeta, Jr. He gained 15-years of experience in the field of Nonstructural Hazards Mitigation - Seismic Hazards Reduction Program (NHM-SHRP) since 1995, perhaps the pioneer in the Philippines. His first job experience in this field was handling various Seismic Monitoring & Measuring Precision Instruments and Seismic Gas Shut-Off Valve Systems. He was the first person in the Philippines who introduced and successfully installed various sizes of Seismic Spectrum Rated Flexible Loop manufactured by The Metraflex Co. and the one who designed and calculated the J-FLEX Seismic V-Loops for UHP Gases now installed and operational at the Texas Instruments manufacturing plant in Clark, Pampanga. He was the first guy who conducted a seminar in the Philippines about NHM-SHRP entitled “Earthquake Preparedness” to various safety & engineering organizations like : SEIPI - Semiconductor & Electronics Industries In The Philippines, Inc. held at TESDA Bldg., in Taguig City in year 2002. HEMAP - Hospital Engineering & Maintenance Association Of The Philippines held at U.N. Ave., Manila in year 2003, and at the San De Dios Educational Foundation, Inc. (Hospital) in Pasay City in year 2004, and others.


Since then, he elevated his knowledge and experience in handling Seismic Sway Bracing Systems for suspended nonstructural elements & Seismic Restraints of various mechanical & electrical package equipment and components, including the preliminary seismic load calculations based from the seismic provisions of the applicable Building Codes & Standards. He has also done several Findings & Reports for the Earthquake Safety & Protection of various American semiconductor manufacturing firms here in the Philippines with coordination with the Risk Insurer Firms and closely working together with various professional engineers, systems design engineers, consultants, contractors, and safety engineers. Lastly, he is also the author of several seismic technical articles and one unpublished book about NHM-SHRP. He is highly familiar about the seismic provisions of various Building Codes & Standards. Mr. Limeta is now the Senior Technical Consultant of the J. BEAP Industries, Inc. for NHM-SHRP. ******************************************************************************************************** No part of this material may be reproduced or copied in any forms or by any means – graphic, electronic or mechanical, including photocopying, taping, or information, storage or retrieval systems to be used by other parties for their own purpose or agenda without written permission from the author. This is an intellectual property. All comments or suggestions are welcome for the further improvement of this article. In GOD we trust.

WÉÅ|ÇzÉ ZA _|Åxàt? ]ÜA A.E. (SDT / IIT / IET / EE)

SR. TECHNICAL CONSULTANT FOR NONSTRUCTURAL HAZARDS MITIGATION SEISMIC HAZARDS REDUCTION PROGRAM SEISMIC ENGINEERING


j. beap industries, inc.jbeapindustries.com/library_1.pdf · ” there are 59 active fault...

Documents