Is Damage Possible?
Anyone searching the Internet for information on construction vibration effects and damage will find numerous sites of vibration monitoring firms and consultants. Many of these say, in essence, that "construction can't cause damage". Unfortunately, these views may not be entirely unbiased and free of conflict-of-interest, since such vibration monitoring firms and consultants do virtually all their work for construction contractors. The goal of this chapter of the CVDG is to place construction damage, and representations about it, in a more complete scientific context. I'll try to give you some sense of whether these claims can be taken literally or cum magno grano salis (with a very large grain of salt).
Many of the topics here are discussed with greater detail in later pages of the CVDG, but this page provides an introduction to many of the issues which surround the question of construction vibration damage possibility. There are other forms of misconceptions or misinformation which are often heard when damage claims are made. These are discussed in more aspects in the CVDG's Misconceptions chapter.
People and Vibration
The vibration scientific literature recognizes repeatedly that people are more sensitive to vibration perception than structures are to vibration damage. Another way of saying this is that felt vibrations in a home may not cause damage to it. Scientific studies of human vibration perception show that the longer a vibration of a given peak velocity lasts, the more disturbing people will find it.13 For more on vibration perception and damage, see Vibration and Damage.
Vibration Damage and its Causes
Although structural damage associated with construction can, and does, occur, often the apparent construction damage is seen as "cosmetic" cracking in drywall or plaster and exterior surfaces such as stucco. This may, or may not, be an indicator of underlying structural damage. Since such cosmetic damage can also be caused, at least in principle, by settling, thermal cycling (i.e. temperature changes) and normal aging, a few hairline cracks (e.g. under 10) in a house after construction in the neighborhood is not necessarily indicative of construction vibration causation.
Once people find cracking, they may begin to look more carefully for hairline cracking and other forms of damage that they might otherwise have failed to notice. Thus, simply becoming more aware of such cracks or other damage during construction is not necessarily proof of construction as the source of the damage (see Damage Causation in the CVDG Pro), per se. Indeed, all these arguments are often offered as damage rationalizations (CVDG Pro) by contractors and their paid "experts".
That said, the experience of watching cracks form as a construction crew used a large excavator bucket to break asphalt pavement by pounding on it (see video frame capture at right) in front of my home convinced me that construction vibration damage is real.9,16 I found damage of similar sorts to that in my home in every home on my street which I examined. Other residents all along the street reported similar use of pounding with an excavator to demolish pavement17 and extensive damage they attributed to it.18 These facts, and many others, strengthened my views both that the construction was responsible and that construction damage is more common than some might think - or have you believe.
The Construction Position
Like many others all over the world, I was told by the construction firm management, its employees, its attorneys, its "experts", the employees of the municipality sponsoring the work and the project insurer that "construction can't cause damage". Several of those who made these statements refused outright multiple invitations to view either the damage or video of the damage being done, indicating a position entirely based on bias. Even the many construction or construction-allied workers in a pre-trial jury pool repeatedly made prejudicial statements, some angrily so, in front of the other prospective jurors to the effect that "construction can't cause damage". Still others in that jury pool, whose livelihood depended upon construction in some way, made these same unsupported claims. None of these people offered any scientific evidence whatsoever supporting that opinion. Nor did any of those advocating that view have any significant scientific background, which might have helped and qualified them to champion such a clear-cut, and scientifically questionable, position.
Worse yet, these views among those who are involved in the construction field are so widespread and strong on this subject that it could reasonably be asked if such unsupported opinions might be contributory to the kind of reckless behavior that I saw and videotaped on multiple occasions. This behavior directly violated the operator's manual instructions in multiple places for the types of heavy equipment used.14 It also violated the internal policies of the contractor, per sworn testimony of one of the contractor's executives. In addition, the use itself of some of the types of equipment employed in that job violated specific Federal Transportation Administration advice against such use in "sensitive areas".3,4
That reckless behavior, which occurred both before and after notification to the contractor of the damage and its cause, also seriously damaged large numbers of homes. When we consider that construction heavy equipment is used often to demolish homes intentionally, it confirms that such equipment has the power to cause damage to homes unintentionally, especially if used inappropriately. Because I'm a scientist by training and inclination, I decided to look into "construction can't cause damage" assertions on a broader scale than my own experience, in the hope of finding some valid scientific basis for them, or, at least, understanding their source.
While the "construction can't cause damage" assertion is, by far, the most common one offered in response to damage claims by those associated with the construction industry, there are other types of misconceptions and misinformation that are often heard in response to damage claims. A description of some of these, along with some suggested ways of ascertaining the real facts in the face of such assertions, is found in Misconceptions.
Much of the scientific and technical literature on vibration damage, and many of the vibration standards, are based on studies of damage due to vibrations from surface mine and quarry blasting. One commonly cited vibration standard in the U.S., the Office of Surface Mining (OSM) standard is founded largely on the recommendations of the highly respected U.S. Bureau of Mines Report of Investigations 8507 (USBM RI 8507) study of these kinds of blasting-caused ground vibrations. While the OSM standard doesn't conform to all the recommendations of USBM RI 8507 (see Vibration Standards for a discussion of this point), the OSM standard is widely cited not only in mining, but construction settings, perhaps because it sets very high limits on allowable vibration velocities. Thus, claims in the literature, in state and municipality regulations, and on the Internet about the "impossibility" of construction damage are often largely or entirely based on the OSM blasting standard, not construction vibration standards. Neither the OSM standard nor the underlying USBM RI 8507 study make any assertions to the effect that damage is impossible from blasting vibration. Many of those other studies which cite "construction vibration" mostly describe blasting in construction settings, not heavy equipment use and misuse.
There is relatively little direct, let alone thorough, study of heavy equipment work and similar activities unique to construction and different in vibration characteristics from blasting (see below). I have not been able to find a single statement anywhere in the scientific literature of vibration effects on structures to the effect that "construction can't cause damage", although there are certainly indications that doing construction properly, with attention to the vibrations caused, can dramatically reduce the risk of damage.
As discussed in USBM RI 8507, there has been a steady downward trend in blasting vibration intensities adjudged as "non-damaging" and "allowable", as more research has been done.1 You can find links to download free copies of these and other standards and studies on our More Information page.
Mine Blasting vs. Construction Vibration
Surface mine blasting vibrations occur infrequently (perhaps as much as once a day at most mines) and produce vibrations which last, at most, only a few seconds. Construction vibration, on the other hand, can persist for minutes, hours, days or even months in some instances. To give some sense of these differences in a real-life situation, I have expanded a small part of the construction vibration monitoring record at one location in the diagram at right, so that one can see the detailed time history of the vibrations. These paving vibrations (largely from vibratory compactors), from a real-life road reconstruction project in a suburban neighborhood, remain over Federal Transit Administration road construction standards for about a minute at a time in this example. There are four such episodes in just the 6 minute period shown in the diagram, of more than an hour of such vibrations in this one pass, of nine such scattered over several days of paving operations, in addition to still more compaction passes involving compaction of the underlying soil.8 Some vibrations recorded on the project lasted as long, were twice the intensity shown here and were repeated some 20 times in front of one home on one day, again, of at least nine such episodes involving the paving operations.
This difference in duration and number of occurrences between mine blasting and construction vibrations is critical, since long-lasting vibrations can enhance both fatigue and resonance effects, which are of far less importance in short-lived, infrequently repeated blasting vibrations. Indeed, USBM RI 8507 indicates this limitation of blasting studies explicitly:
There are other significant differences between blasting and construction vibrations which also serve to make construction even more concerning from a vibration standpoint than blasting. These are discussed later in the CVDG.
Thus, use of blasting standards in construction settings, especially in the absence of supporting data justifying it in a specific set of circumstances, is scientifically and technically questionable at best. Use of the OSM vibration standard, on which so many of the "damage can't happen" assertions are based, is clearly unsupportable in construction vibration damage evaluations.15 Its basis is the recommendations of USBM RI 8507, which specifies applicability only in blasting settings with vibrations of short duration. There are other, far more stringent, standards for construction vibration, which recognize this fundamental difference, perhaps most notably in the U.S. the one in the Federal Transit Administration's Noise and Vibration Manual (at right). The fact that construction vibration standards set far lower limits for "allowable" vibrations than those imposed for blasting settings is, by itself, strongly indicative that "construction can't cause damage" contentions are unsupportable, scientifically and, perhaps, legally.
Heavy Equipment Concerns
Although mining vibration standards are inappropriately employed for setting allowable construction vibrations, even those lenient standards can be violated by some construction operations. In particular, hammer-type pile drivers are known to produce vibrations in excess of the OSM blasting standard.3 Widely used vibratory compactors, like the one at left, often exceed some or all of the FTA construction standards and, in specific documented examples, the USBM RI 8507 blasting recommendations. Indeed, the FTA specifically advises against their use, "Avoid vibratory rollers and packers near sensitive areas."4 Thus, any use of these kinds of equipment in populated areas should be viewed with concern for the vibration it may produce.
Another concern, with limited investigation in the vibration damage literature, is the vibration caused by driving tracked heavy equipment over significant distances in populated areas. Vibrations produced by driving tracked equipment have a broad span of frequencies (see Vibration 101 and Vibration Frequencies for an explanation) in the sub-40 Hz range of most concern for damage effects. They produce accelerations, another measure of vibration intensity, higher than those produced by vibratory compactors and commonly last for a minute or more. This is more than long enough for the self-reinforcing effects of resonance to manifest themselves in home damage. For more on this topic, see the CVDG Pro page, Vibration Signatures and the CVDG page, Vibration Potential.
Science and Opinion
Not every construction job causes vibration damage, even if vibration is felt and makes nearby residents feel uncomfortable. Not all damage found in a home or building is necessarily a result of construction vibration, even if an owner becomes aware of it during, or shortly after, nearby construction work. Not all construction operations are equally prone to causing damage; not all contractors perform those operations in ways equally likely to result in damage.
However, some construction jobs do result in damage, in most cases, predictably so. Damage usually occurs because the contractor has violated equipment use instructions, used the wrong equipment in the wrong areas, didn't understand or didn't care about applying relevant vibration standards, was given poor quality vibration data or poor advice about it,19 or some combination thereof.
Careful scientific study of the damage and its patterns, in and around a structure, with thoughtful correlations to well-done vibration monitoring results and ongoing construction procedures and equipment, can often allow a scientific determination about which kinds of damage are likely caused by construction vibration or which are most fairly assigned to other causes. Scientifically valid conclusions must be based on reliable and full data, thoughtfully, properly and fully interpreted. Unspecified "experience" alone, highly selective choices of which data to credit and which to ignore, selective "losses" of critical vibration monitoring data, and pre-conceived or pre-ordained opinions, which, in some documented cases, ignore extensive contradicting data entirely, do not meet scientific or legal standards for reliability.21
While people are entitled to their personal opinions, unsupported or incompletely supported opinions cannot, and should not, be taken or presented as scientific or practical fact. Even representations of large amounts of "experience" with construction vibration damage "evaluation" do not, by themselves, prove that "construction can't cause damage" in a given set of circumstances. If anything, such all-encompassing, poorly supported, unscientific, pre-conceived notions establish more about the mindset of the speaker than about construction vibration damage potential or causation.
In the end, there is little or no direct scientific support for statements to the effect that "construction can't cause damage" to homes and other structures. Indeed, the much lower maximum allowable velocities set in construction vibration standards vs. those set for blasting indicate that construction using heavy equipment is more prone to causing damage than blasting at a given vibration peak particle velocity (intensity), not less. In the absence of reliable, complete and well-documented scientific data, along with properly-applied vibration standards supporting such statements in the specific example at hand, "construction can't cause damage" statements, and ones like them, should be treated as unscientific, inherently questionable and, in some documented examples at least, literally false.
The decision on whether to pursue a construction vibration damage claim should be based on a careful analysis of the facts which you can prove, not on the unscientific, uncritical, unsupported assertions of those who may not understand (or want to understand) the science of vibration damage, as applied in your situation, or those who may have a conflict-of-interest in rendering an unbiased opinion about construction vibration damage.
Construction Vibration Damage Prevalence
About half of those downloading the extended PDF version of the CVDG from Vibrationdamage.com cite "Damage to home" or "Damage to building" as the reason for their interest in it. Their sheer numbers and worldwide distribution10 (see map graphic below) suggest that construction vibration damage is a problem deserving of acknowledgement, concern, and better, more directly relevant, scientific study.11 There is ample reason to suspect that these greatly under-represent the amount of construction vibration damage done. More about vibration damage prevalence and causes can be found on our page, Damage Prevalence, in the CVDG Pro version. The CVDG Pro page, Damage Occurrence, has statistical information about the breakdown of CVDG downloads by reason for download, technical background of damage reporters, building type, construction project type, damage-causing operations, and more.
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