Although ground vibration standards have been available for at least some vibration sources (e.g. blasting) since at least the 1970's in the U.S., many
U.S. states and most municipalities still have limited or no regulation of damage-causing
vibration. Yet, the sheer amount of damage done in construction settings alone (see below) suggests a keen need for such regulation.
Here, I'll discuss some considerations in establishing meaningful vibration regulations which, if followed, can head
off most damage from construction vibration, saving untold money and annoyance for homeowners, contractors and project sponsors. Such commonsense regulation can help reduce damage-related litigation and maintain good relationships with
nearby property owners at minimal cost.
Why Regulation Is Needed
Property owners need special consideration in the regulatory process because
they usually lack the knowledge, experience, scientific understanding, money and legal
power to approach damage incidence on a par with those who may be responsible
for it. Home and building owners with legitimate damage claims are too often left with no other option but to seek recourse
in the legal system. It's a good bet that, if there is
substantial damage to one home, there will be damage to others, further burdening the legal system.
consider the rights of the uninvolved third party (the home or building owner) to
proper evaluation and mitigation of risk of damage to his property, as well as
issues perhaps more properly characterized as nuisances (noise, non-damaging
vibration, disruption of lifestyle, blockage of streets, etc.). They must balance the homeowner's rights to use and enjoyment of his property against the very considerable economic, governmental and societal pressures to
complete projects as cheaply, quickly and, yes, profitably, as possible. Construction vibration damage is a worldwide problem (see map distribution of CVDG downloads at right) that regulators can reduce by setting and enforcing
standards which reflect the true risk to existing structures posed by construction.6
The Role of Ground Vibration Standards
Vibration standards are, by nature, a regulatory concern, as they provide the means by which
scientifically-defensible regulation can be carried out. As discussed at length in the CVDG chapter,
Vibration Standards, some national, state and municipal governmental and industry groups around the world have set ground vibration standards in at least
some vibration settings.1 National standards are usually science-based, even if they don't cover well all potential vibration sources and environments.2
Vibration Standards has an extensive analysis of the meaning, limitations, interpretation and proper use of
existing vibration standards
in various ground vibration settings. It also provides a summary of the national standards in place around the world and discusses that subset of ground vibration standards which are most influential in research and most used worldwide. Reading
that chapter is essential for anyone who will set or use ground vibration standards in their work. The CVDG's Vibration and Damage chapter provides information on human perception of vibration, its
effect on structures and the ways in which vibration damage is characterized and categorized.
State and Local Regulation of Vibration
State and municipal standards, when they exist at all, are highly variable
in their coverage and value. Yet, it is those standards which can have the most impact in avoiding vibration damage, since compliance can be more readily ensured locally. Sadly, there are too few states, cities and
towns which have set meaningful, reliable and scientifically-defensible ground vibration standards, which recognize and take into account both the damage potential differences between vibration sources and variations in vibration propagation from locale to locale.
Some of the few local entities which have some vibration regulations may have arrived at them on weak or improper scientific grounds. They may not enforce, or even have any means to enforce, the ones they have. The relative scarcity of state and municipal standards in the U.S. significantly limits how much
how much can be done to
prevent damage meaningfully. The result is unnecessary
damage, expensive litigation and loss of citizen goodwill.
Regulation of Construction Vibration
Well-researched, properly chosen and applied vibration standards are an important part
of the regulatory picture. However, effective regulation must
accurately reflect scientific understanding of risks and, more importantly in
the construction vibration case, the considerable differences between construction vibration characteristics and those of the better-studied blasting vibration. Too
many times, standards are chosen which are simply inappropriate for construction
vibration (e.g. use of blasting standards in non-blasting construction
environments) and for which there is little or no defensible scientific basis. Often, these are based mostly or solely on input from "experts" whose livelihood
depends to a large degree on the construction industry or whose real expertise is in blasting vibration, not construction vibration.
As is discussed in many other locations in the CVDG and CVDG Pro, blasting vibration differs
in just about every important way (duration, frequency distribution, and repetition rate) from construction vibration. The diagram at right shows the actual observed dominant Fast Fourier Transform-derived frequencies of vibrations from a road reconstruction
job, along with those peaks in the vibration spectrum which are below 40 Hz in frequency and 1/2 or more in amplitude of the dominant frequency. As the diagram shows, construction vibration often has most of its integrated intensity at
frequencies below 40 Hz, i.e. in the regime most damaging to homes and other structures.7 There are even significant differences between construction blasting and mine blasting. These disparities mean that blasting vibration standards are
generally not useful for construction vibration regulation, nor are their use in such environments defensible scientifically, although the results of some parts of blasting vibration studies can be useful in understanding vibration
effects on homes and other structures.
Locale Vibration Regulations
Most people would probably accept that the goal of vibration regulation is to prevent most, if not virtually all, damage, while allowing vibration-causing
activities (blasting, heavy equipment use, etc.) to proceed without unreasonable burdens, both financial and regulatory. Some financial burdens, e.g. in the range of 0.1-1.0% of the total project cost, should be considered reasonable and part of the cost of
doing business, if they can prevent potentially millions of dollars in damage to surrounding property.5
Existing national standards can be a useful guide in setting local standards. One can even set local or regional standards by referencing the national ones,
so long as the ones referenced are appropriate. For mine and quarry blasting, the OSM standard (shown at right) is widely used in the U.S. For non-blasting construction vibration, the Federal Transit Administration standard, along with the related
"Swiss standards", are most commonly cited. For vibration affecting historic structures, the NCHRP report has much useful information. There are also proposed standards for protection of museums and the artwork contained
in them.8 Carefully review such vibration standards2 to understand their value and their limitations. An analysis of some of the most important of these
in the U.S. and abroad can be found in the CVDG's chapter,
Vibration Standards, along with references to them. Links to download free some of the most important can be found in the CVDG's More Information chapter.
Considerations for Regulating Vibration
While existing standards can be extremely valuable, there are a number of factors which should be considered as potentially relevant to their use in a given situation and locality. Following is a list of important considerations in undertaking some basic regulation of vibration sources:
- Assemble everything that is known about vibration
propagation in the jurisdiction, with particular attention to those variables which can make vibration velocities difficultly predictable (soil type, moisture, underground rock layers and other structures from which vibrations may be reflected). Pay particular
attention to understanding how vibration propagates with distance in the area, as this will have a considerable impact not only on how and what standards are chosen, but how they are applied in a given case.
- Consider the local built environment one is trying to protect from damage. For example, if the area in question has historic or cultural assets which are irreplaceable, this fact should be recognized by setting lower acceptable
vibration velocities, since such structures are well-known to be more susceptible to damage than most modern construction. Many modern vibration standards and recommendations recognize these differences by setting lower acceptable vibration velocities for
historic and cultural structures.2,8,9
- Because some states (e.g. CA, NH, FL, WI, among others) and municipalities (e.g. New York City) have ground vibration standards in place or have done careful analyses of damage potential, review them for relevance to the
locale of interest.3
- Be careful in selecting and using "expert" help. Most "vibration experts" have ties to construction or mining companies, which often bias their views. Insist that any expert support his opinion with more than just
"experience"; ask for scientific references in support of the opinion.
- Base regulatory requirements on examples which are more like the "worst case" than the best case. Because so many factors can influence and enhance vibration amplitudes in structures in any given instance, a "worst case" approach helps
minimize damage, while providing enhanced litigation defense.
- Write the regulatory language with separate discussion of the major vibration sources and separate standards for each. The standards can be drawn from state or national standards, so long as they accurately reflect the
differences in vibrations produced by various sources. Generally speaking, separate standards should be set for blasting, pile driving, traffic (railway and highway) and construction vibration, with particular attention to those vibrations caused by ground
impacts of any sort (including impact-like vibratory compactor vibrations and tracked equipment drive-bys). Any operations to be done within 25 feet of structures should be scrutinized carefully before permitting.
- Embody the regulations in the permitting and contracting process to assure that they perform their main function of preventing damage.
- Take into account the past record of a contractor in letting contracts for work. While a few examples of minor damage in a contractor's record should not disqualify or count against a contractor, any examples of
multiple homes damaged or extensive damage should be reflected in the scoring system used to award contracts. Don't depend on the contractor for truthful reporting of such information. Search the Internet for records of
actions against any contractor who may be awarded a contract. If the contractor causes damage, the sponsoring entity will have to pay more, either through settlement or litigation costs.
- Provide guidance on how to mitigate vibrations and prevent damage with the regulations or as an appendix to them. Many contractors are responsible and will follow good practices,
if given the opportunity.
- Mandate at least an exterior pre-construction survey for structures within 500 feet of any project which will involve blasting, vibratory compaction, pile driving or demolition by other than normal and approved
methods. That survey should not be of the "walk-by" or "drive-by" type, as such surveys rarely produce sufficiently detailed documentation of structure condition to be of more than extremely limited value. For projects
where the damage potential is high, a complete interior and exterior survey should be done.
- Some unnecessary and highly damaging construction procedures should be banned: pounding on pavement with various pieces of non-qualified heavy equipment for demolition, driving tracked heavy equipment for more than 10
seconds or 50 feet at a time, using vibratory compactors within 15 feet of structures, and any use of any heavy equipment which violates Operator's Manual instructions for that equipment, directly causing damage. Such bans should be accompanied with
steep fines, since the procedures they would forbid almost always lead to damage to multiple structures.11 A fine of $10,000 per violation occurrence is not unjustified, given that damage to even one structure
typically will cost in that range to repair. Case-by-case exceptions to such rules can be granted prior to work start under well-considered, monitored and
- Setting standards, while a good first step, is not enough, by itself, to satisfy the need or prevent damage. Good standards must be accompanied by requirements which ensure enforcement of the standards, if they are to have any
positive effect. At a minimum, such requirements for construction with heavy equipment should include on-site professionally-supervised vibration monitoring, done by a certified vibration monitoring contractor, for any operation involving pile driving,
compaction, pavement demolition or any operation involving repeated ground impact. That monitoring should be set up to provide real-time feedback to the construction crews, so that they can stop or modify violating
vibrations as they occur (see photo at right for an example setup with a vibration-triggered alert light). While an argument can be made for requiring vibration monitoring during all working periods, paying special attention to the operations
mentioned should provide good protection at minimum cost. Beyond monitoring these particular operations, all operations done within 25 feet of structures should be monitored for vibration for as long as the operation is within
the 25 foot radius.
- Vibration frequency distribution must be taken into account in assessing vibrations, not just the peak particle velocity (PPV). Most modern standards take the greater damage potential of lower frequencies into account by
setting lower allowable PPV's at lower frequencies. Caution is advised when considering frequency effects, since even blasting vibration of short duration is known to produce amplification of ground vibrations by as much as a
factor of eight in the home vibration (see Resonance/Fatigue for more on this). This amplification can take a nominally "safe" ground vibration and turn it into an unsafe house
- Establish a reserve fund, perhaps taken from the contractor's completion bonuses, for every project. If the project completes successfully, without damage claims 30 to 90 days after completion, it is dispersed, with
interest, according to the construction contract. If not, it can be withheld and used to pay legitimate damage claims, without the expense of litigation. Having such a fund in place will provide incentive for contractors to
carry out their work responsibly. In most places, the current "incentives" for on-time completion act to do just the opposite.
Vibration Velocity Estimations
propagation equations are often used to estimate vibration velocities at distance from known or reference data, using multiple explicit and implicit assumptions about the variables affecting vibration propagation. The
calculated velocities are then compared to some standard, too often improperly chosen, to provide "proof" of vibration safety. Unfortunately, because meaningful validating data are only infrequently available for a given locale,
such calculations often do not accurately predict vibration velocities.
The propagation equations can be quite useful where the local soil and geological environment has been thoroughly studied and the attenuation of the vibration
with distance is well-understood. However, vibration attenuation is widely variable from locale to locale, depending on a number of factors. In addition, the simple propagation equations typically used do not take into account the changes in propagation in
different soil and basement rock types, nor do they account for vibration reflection and interference effects, which can cause significantly different velocities to be recorded at identical distances from the source.10
Even differences in landscaping from property to property can affect the vibration velocities observed at structures.12
Thus, such equations, while valuable, cannot be used with any assurance of accuracy in the absence of a careful study of the local ground vibration
environment, specific to the type of vibration source expected (e.g. construction vs. blasting vs. transport, etc). Vibration propagation calculations - and representations of "vibration safety" based on them - should only be viewed as
approximate, at best,
in the absence of proper validation. The limitations of vibration propagation calculations are discussed in more detail in the CVDG Pro's Calculating Vibration Amplitudes chapter.
Given the statistical nature of vibration damage, no regulation can prevent absolutely all damage. But, the scarcity of local and state vibration regulations is a major contributor to damage, especially in construction settings.5
It doesn't take a great deal of effort to institute some basic regulation of vibration sources which can be effective in preventing damage, lowering legal costs and maintaining citizen goodwill. By researching, choosing, applying and enforcing meaningful vibration standards,
regulators can reduce costs to all parties from unnecessary and largely predictable damage,
while providing a measure of litigation protection for contractors. Whether you're a heavy equipment-using contractor, a project sponsor, an insurer or a homeowner, having state or local vibration regulations in place will work in
your interest in both the short and long-term.
|1. Other chapters in the CVDG have many references to work about which those contemplating setting vibration regulations should know. These can be found in the footnotes to every chapter of the
CVDG, in both the free and Professional versions. The Pro version of the CVDG has a compilation of all cited documents in its Cited Literature section. The overwhelming majority of the documents cited in the CVDG can be downloaded for free, either by following the links to the most important studies on the CVDG's
Information chapter or by searching for the document titles in a search engine.
2. Blasting Standards: OSM Blasting Performance Standards, 30 Code of Federal Regulations, Sec. 816.61
Structure Response and Damage Produced by Ground Vibration From Surface Mine Blasting, D. E. Siskind, M. S. Stagg, J. W. Kopp, and C. H. Dowding, United States Bureau of Mines Report of Investigations 8507 (USBM RI
Construction standards: Transit Noise and Vibration Impact Assessment, Carl E. Hanson, David A. Towers, and Lance D. Meister, FTA-VA-90-1003-06, May 2006 (Federal Transit Administration's Noise and Vibration
High-Speed Ground Transportation Noise and Vibration Impact Assessment, Carl E. Hanson, P.E., Jason C. Ross, P.E., and David A. Towers, P.E., DOT/FRA/ORD-12/15, September 2012 (expanded, updated version of FTA Noise
and Vibration Manual)
Blasting and Construction Standards: Erschütterungen — Erschütterungseinwirkungen auf Bauwerke [Vibrations — Vibration effects in buildings], SN 640312a ("Swiss standard", available in German and French)
Standards for Historic Structures: Construction Practices to Address Construction Vibration and Potential Effects on Historic Buildings Adjacent to Transportation Projects, National Cooperative Highway
Research Program (NCHRP), Project 25-25 (Task 72), Richard A. Carman, September 2012
3. Many state Departments of Transportation have looked at construction vibration in some detail. A few state studies of value are: Transportation- and construction-induced vibration guidance manual, Jones & Stokes.
2004, (J&S 02-039), Sacramento, CA. Prepared for California Department of Transportation, Noise, Vibration, and Hazardous Waste Management Office, Sacramento, CA; Transportation and Construction Vibration Guidance
Manual, Jim Andrews, David Buehler, Harjodh Gill, Wesley L. Bender, California Department of Transportation,
Division of Environmental Analysis, Environmental Engineering, Hazardous Waste, Air, Noise, & Paleontology Office, Sacramento, CA, 2013 (While similarly titled to the previous document, this document is intended by CaDOT
to be "supplemental" to it and other CaDOT documents).
Ground Vibrations Emanating from Construction Equipment, R. M. Lane and K. Pelham, New Hampshire Department of Transportation, Report # FHWA-NH-RD-12323W, 2012
5. In the U.S. state of New Mexico, where I reside, there are no statewide construction vibration regulations whatsoever, aside from use of the OSM blasting standard, applicable only to construction blasting in
road-building. My home municipality has no vibration regulations at all, nor has the widespread damage described in the CVDG resulted in any impetus to put regulations in place. This lack of regulation meant that the FTA standard
became, by default, the only one applicable for construction statewide in New Mexico.
6. The map graphic depicts damage reports by state and territory for the U.S., Canada and Australia. Reports for other countries are indicated by country only. Most countries have multiple reports of damage; more damage
reports are indicated by increasingly warmer-colored markers.
7. See Structure Response and Damage Produced by Ground Vibration From Surface Mine Blasting, USBM RI 8507, p 59, for more on this half-amplitude criterion.
8. Vibration Limits for Historic Buildings and Art Collections, Arne P. Johnson and W. Robert Hannen, JOURNAL OF PRESERVATION TECHNOLOGY / 46:2-3 2015, pp 66-74; Baseline limits for allowable vibrations for
objects, Wei, W., L. Sauvage, and J. Wölk. 2014. In ICOM-CC 17th Triennial Conference Preprints,
Melbourne, 15–19 September 2014, ed. J. Bridgland, art. 1516, 7 pp. Paris: International Council of Museums.
9. Repairing historic homes damaged by construction can be more complicated and expensive because historic area designations may require that any changes/renovations be in accordance with the historic nature of the
home or district in which it resides. Any "grandfathered" non-historic elements of the home may have to be remedied when the repair is done. These complications provide even more reason for special care in historic
districts or with historic homes and structures.
10. During one road reconstruction job, one house experienced a maximum vibration velocity of 0.315 in/sec (cf. calculated FTA vibration equation minimum value of 0.374 in/sec at seismograph), in violation of the FTA Class III standard for timber-framed
homes. A few minutes later, a house one home further along on the same street had a measured vibration of 0.660 in/sec, measured with the same seismograph, essentially the same distance away from the paving operation,
using the same vibratory compactor at the same compaction vibration amplitude - over a factor of two higher and in violation of all FTA vibration standards and the USBM RI 8507 blasting recommendations for homes with
plastered walls. Since it is very unlikely that such large difference can be attributed to geology or equipment use variations under these conditions, it is likely that these differences were due to vibration wave
interference effects. Such effects simply aren't accounted for in most vibration propagation calculations.
11. These bans are suggested because they reflect procedure violations which have shown up repeatedly in reports from all over the world to http://vibrationdamage.com as causes of damage to structures. Many contractors
already ban some of these (e.g. pounding with excavator shovels to break pavement), usually because they are damaging to equipment, as well as buildings. Others are sufficiently dangerous to structures that their use is already
widely discouraged in certain construction circumstances, e.g. vibratory compaction of pavement on bridges, due to risk of damage to the bridge structure.
12. "It was found that anywhere from an appreciable reduction to an appreciable amplification of the vibrations produced can occur, depending upon the geometric parameters of the shaped landscape involved." Reduction in ground vibrations by using shaped landscapes, Persson, Peter, Persson, Kent, and Sandberg, Göran, Soil Dynamics and Earthquake Engineering, volume 60, May 2014, pp. 31 - 43
page is a chapter from the Construction
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