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Is Damage Possible?
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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 vibration damage, and representations about it, in a more complete scientific context. I'll try to give you some sense of whether these assertions can be taken literally or cum magno grano salis (with a very large grain of salt). Many of the topics covered here are discussed with much greater detail in later chapters of the CVDG, but this one provides an introduction to many of the issues which surround the question of construction vibration damage possibility and probability. Other forms of misconceptions or misinformation, which are often offered when damage claims are made, are discussed in the CVDG Pro'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 vibration ("shaking") 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 particle velocity (PPV) lasts, the more disturbing people will find it.[13] For more on vibration perception and damage, see Vibration and Damage in the CVDG. Damage Causes Although structural damage associated with construction can, and does, occur, apparent construction vibration damage is more often observed 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) found in a house during or after construction in the neighborhood does not necessarily indicate a construction vibration cause. 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. 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 pavement[17] and extensive damage they attributed to it.[18] These facts, and many others, strengthened my view that the construction was responsible for all that damage. Later, well over 1600 reports of apparent construction-linked damage from all over the world demonstrated for me that construction damage is more common than some might think - or have you believe. The Construction Position Like many others worldwide, 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 statements like these refused outright multiple invitations to view either the damage or video of the damage being done, indicating a position entirely based on bias. None of these people ever offered any scientific evidence whatsoever supporting their claim. 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. They also asserted that the vibrations were "within standards" or "within limits", but these statements proved to be literally false, when even partial vibration monitoring data became available. Worse yet, such views among people who are involved in, or associated with, the construction field are so widespread and strong that it could reasonably be asked if these and similar unsupported opinions might be contributory to the kinds 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 disregarded the internal policies of the contractor, per sworn testimony of one of the contractor's executives. In addition, the very use itself of some of the types of equipment employed in that job gave no heed to specific Federal Transportation Administration advice against such use in "sensitive areas".[3],[4] That reckless behavior occurred both before and after the immediate notification to the contractor of the damage and its cause. Construction heavy equipment is used regularly to demolish homes intentionally. That fact alone 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. The Vibration Damage Scientific Literature 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), it is widely cited not only in mining, but construction settings, perhaps because it sets very high limits on allowable ground 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 or USBM blasting standards, not construction vibration standards.
There is relatively little direct, let alone thorough, study of the vibration effects of heavy equipment work and related 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 whose thrust is that "construction can't cause damage". However, there are certainly indications that doing construction properly, with attention to minimizing the vibrations caused, can dramatically reduce the probability of damage. Mine Blasting vs. Construction Vibration Surface mine blasting vibrations occur infrequently, perhaps as much as once a day at the most active mines. They 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.
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 compaction episodes scattered over several days of paving operations, in addition to still more similar periods involving compaction of the underlying soil.[8] Some individual 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. 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 in the structure, which are of far less importance in short-lived, infrequently-repeated blasting vibrations. Indeed, USBM RI 8507 indicates this limitation of blasting studies explicitly:
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 the very best. Use of the OSM blasting 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 explicitly 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
Another concern, with limited investigation in the vibration damage literature, is the vibration caused by driving tracked heavy equipment for longer than 10 seconds or so 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.[6] 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. Construction Vibration Damage Prevalence A little over half of those downloading the extended PDF e-book 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 (over 1500 damage examples to date) and worldwide distribution[10] (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.
Science and Opinion Not every construction job causes vibration damage, even if vibration is felt and makes nearby residents uncomfortable and concerned. 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 likely to cause 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, used the right equipment, without taking vibration mitigation steps, too close to homes and other structures, didn't understand or didn't care about applying relevant vibration standards, was given poor quality vibration data, 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, if present, 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,[19] which, in some documented cases, ignore extensive contradicting data entirely, do not meet scientific or legal standards for reliability.[21] The CVDG Pro chapter, Damage Assessment, details how damage cause can be determined scientifically and to what degree of confidence. While people are entitled to their personal opinions, unsupported or questionably 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. Get the Real Facts When you read on the web or hear statements from "experts" about vibration damage, give most weight to those sites, documents and statements which provide scientific references in support of their conclusions, whereby you can examine the literature to verify them. Ask for title, authors and page numbers for supporting scientific papers, when they are not provided. Give little weight to unsupported assertions, written or verbal, even if based on claimed "experience". These are the standards by which scientists judge reliability of statements about known science. In part, they are also those adopted for evaluating reliability of statements by "experts" in U.S. courts (the "Daubert" standard).[21] Such verifiable, fact-based criteria are entirely appropriate for statements about vibration damage. The over 70 scientific papers referenced in the over 500 footnotes of the CVDG are a good start in understanding and evaluating the many unsupported claims you will hear and read as you investigate vibration damage. The CVDG chapter, Damage Inspections, has further discussion of the kinds of claims that you might hear in the context of a vibration damage report and some suggestions as to how you might find out about their relative reliability. Cum Magno Grano Salis In the end, there is little or no 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 cause damage than blasting, at any 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 many documented examples, literally false.[22] 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.
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E-mail to drzeigler@vibrationdamage.com or send online questions or comments about Vibrationdamage.com.
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Thus, simply becoming
more aware of such cracks or other damage during
construction is not necessarily proof that construction is the source of the damage, per se (see Damage Causation in the CVDG Pro). Indeed, all these arguments are often offered as damage rationalizations (see
Counterarguments in the CVDG Pro) by contractors and
their paid "experts". 
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 
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. 
Although blasting vibration standards are inappropriately employed for evaluating 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 
