Most construction procedures create vibrations which can be felt, if
you are sufficiently close. However, not all vibrations are of equal concern from the standpoint of damage.
Felt vibrations will not always cause damage. On this page, I
summarize some typical construction operations, with comments, based both on my
road construction damage experience and the literature of vibration damage, on their potential for causing vibration damage. Since other kinds of construction
involve many similar uses of the same types of construction heavy equipment, one can apply this information in other
types of construction using the same types of heavy equipment in similar ways.
Construction Operations and Vibration Potential
Those operations of the most concern are
bolded in the list below. I separate those operations which may produce felt
vibrations from those which produce vibrations which may be damaging. Note that this list may not include absolutely every kind of
operation involved in road demolition and construction, or construction
generally. Some items of lesser
concern could produce damage if inappropriately performed or if your house is
particularly close to the work. Indeed, some such operations are known to have produced many
vibrations in excess of the FTA standard
This list is provided for those who may want to plan for documenting certain
activities around their home during construction operations.
- This operation, if done correctly with the correct equipment at sufficient distance, is usually
not a cause for worry. Most commonly, pavement can be "rolled up" by getting
under it with a loader or excavator bucket and raising it (e.g. photo at
This operation generally produces
relatively little and short-lived vibration. Other types of
pulverization/cutting equipment (e.g. Wirtgen pulverizer) can also
be properly used without much concern for excessive vibration. Even a
specially-designed excavator attachment can be used to roll up or
break pavement without significant risk. However, there are
other, generally non-approved, methods which can cause very large
vibrations and damage. I have personally observed and repeatedly documented on video the
use of a large excavator standard bucket
to pound on asphalt pavement to break it on multiple occasions.4 The effect of this was similar to being in a large
number of moderate size earthquakes and caused widespread damage, to my home
and many others on the street.10 The types of damage resulting from this pounding
(e.g. multiple breaks in monolithic concrete 180 feet from the work site) was such
that it implied vibration
intensities far in excess of any vibration standard worldwide. Such a use of the excavator violates the
Operator's Manual for the excavator in several places.6 I have also
documented pavement being broken by
large chunks of it up and dropping them on the ground to break them.
also created felt vibration, exceeded construction vibration standards and
created documented damage.
- General demolition - Demolition has the potential to cause
damage, because many of the vibrations it produces are of the ground impact
variety. Impacts produce
vibrations with a broad spectrum of frequencies that overlap the
resonance frequencies of homes. The damage potential of demolition depends
on the procedures and equipment used, the type of structure demolished, and
the skill and concern with which it is done.
Pile driving - There are several different methods for pile driving.
Impact pile drivers are known to cause large and potentially damaging
vibrations. Vibrational or sonic pile drivers, despite the names, generally produce
less ground vibration than impact pile drivers2, although even they can be a
problem if your home is sufficiently close.
- There are two basic kinds of compactors, static and vibratory. Static
compactors (i.e. those which merely roll the asphalt or ground) have less damage
potential than vibratory compactors. Vibratory compactors (at right) are designed
to produce substantial vibrations, which can cause damage in our experience
(vibration record of a small portion of one day's compaction operations at left). The amplitude (intensity) of the vibration can be varied over a wide range by the compactor operator. Vibratory compactors also can be operated as static compactors merely by turning off vibration of the compactor drums.
Vibratory compactors are of sufficient concern that the Federal
Transit Administration has advised against their use in "sensitive"
locations, including residential areas.1 As the diagram at left shows, the contractor violated
some or all FTA construction vibration standards (starting at 0.12 in/sec
for structures sensitive to vibration and going up to 0.5 in/sec for reinforced,
engineered structures) numerous times during
vibratory compaction at this and other locations.7,8
In this example and others, the contractor also repeatedly exceeded the far
less demanding USBM RI 8507 blasting vibration recommendations for homes
with plastered walls of 0.5 in/sec.
If you can feel vibrations occurring as a compactor approaches, chances are that the vibratory compactor is responsible.9 You will need to observe and document carefully the use of the compactor and any damage that may occur during its
Blasting - It is well-known that blasting vibration can damage structures
to varying degrees. Indeed, much of the scientific literature about
vibration damage deals with damage caused by blasting. Although blasting is
usually done in mines and quarries and, to a lesser extent, in new road
construction, it must be done properly and at sufficient distance from
structures to avoid damage.
Pavement milling - This is a process by which pavement is ground off (see at
right above for a photo of a pavement miller in use) with rotating blades, rather than
broken apart by impact. It usually produces a small amount of non-damaging
vibration. That said, because pavement millers are tracked vehicles removing
pavement by impact and moving at a slow rate in front of any given location,
their use should probably not be completely disregarded as a vibration source in
at least some circumstances.
- Excavation - Excavation can be done with backhoes or excavators. In our
experience, excavation usually causes little vibration.
- Dirt moving - This can be done with a wide variety of heavy equipment.
It usually produces little or no vibration or damage, if properly done.
- Pavement forming - This is the process of laying down the pavement. It
involves a pavement former and trucks which provide a continuous supply of
asphalt to the pavement former. In our experience, pavement forming produces only minor vibrations, which do not generate damage.
- Jack-hammering - This procedure is often used in road projects, as well
as many others. Perhaps surprisingly, the vibrations created are so localized that
they can't normally be felt if you are more than 50 feet away.
- Other operations - Grading, sweeping, concreting, curb installation,
manual operations and a host of other activities can take place during road
building or other construction activities. Although there could be
exceptions in specific cases, all of these are usually of little worry, if
carried out properly and in accordance with accepted procedures for use of
the equipment. Similarly, construction operations done by people using only
hand tools pose little risk of damage in most circumstances.
Heavy Tracked Equipment Movement
not a construction operation, per se, movement of heavy equipment is a
part of any construction project. Indeed, tracked excavators and dozers must move
small distances (usually well under 100 feet in any one movement) to perform their work at a given
location. These short distance moves in the normal
and approved performance of heavy equipment use represent small risk to
Tracked heavy equipment is supposed to be transported
any significant distance on trailers. However, we've observed and documented
on video several instances
(e.g. the video frame capture at right) where tracked heavy
equipment was being driven on a city street for a mile or more. That movement caused
so much vibration in homes that it could be felt more than a half block away and
continued for more than a minute in each such case. I
documented damage specifically caused by those movements.
The size (velocity) of ground vibration associated
with movement of tracked equipment is often relatively small and even within
vibration standard limits. For this reason, it is generally discounted
as a damage source. However, as described in detail in the CVDG Pro pages,
Vibration Signatures, and in abbreviated form on the CVDG page,
Is Damage Possible?, because the vibration frequency distribution is skewed toward
frequencies close to the
resonant frequency of the home and because the vibration created in the house can last for a minute or more, such passages can be particularly ill-advised.
tracked equipment movement is rarely a subject of vibration damage studies, a study from the U.K.3
shows that driving large tracked vehicles of the sort used in road construction
(large bulldozers, excavators)
can produce vertical axis ground vibration accelerations in excess of those
caused by vibratory compactors. Higher accelerations mean higher final ground
vibration velocities (higher peak particle velocities, PPV's) over any given time period. Vibratory compactors, themselves, are known to violate some U.S.
and international construction
vibration standards. Vibrations produced by driving tracked equipment have
peak frequencies in the sub-40 Hz range of most concern for damage effects. The U.K. study demonstrates that such vibrations
from driving tracked equipment
are of special concern, especially when repeated or lasting a significant period of time
(more than a few seconds),
even though they were not suspected to be capable of causing "architectural" (cosmetic) damage at the time of the study cited
(1977), when vibration standards set far higher limits than are acceptable today.
Vibration levels are known to vary with the weight of the tracked equipment, the
speed at which it is driven, the underlayment (soil and type or pavement) and
the type of track (standard or low-vibration track patterns, metal or rubber
tracks) on the equipment. The U.K. study also shows that rubber-tired vehicles
usually produce little vibration above background levels. My own observations of movement of a wide variety of tired construction equipment, and other vehicles, in a road reconstruction project are consistent
with that finding. Thus, it is tracked
equipment whose movement over distances should be monitored for vibration, not
only with respect to the largest vibration produced, but with careful
consideration of both its duration and frequency distribution.
Vibration and Damage
Structures respond differently to vibration and have different damage thresholds, as well as different responses to
vibrations having different characteristics. The materials of construction, the building design, its age and its
level of maintenance are some of the important determinants of vibration damage resistance. The CVDG page, Vibration and Damage, discusses building design and construction type effects on the
potential for damage by vibration.
|1. Federal Transit Administration
Noise and Vibration Manual,
|2. Federal Transit Administration
Noise and Vibration Manual,
3. GROUND VIBRATIONS CAUSED BY ROAD
CONSTRUCTION OPERATIONS, D J Martin, Department of the Environment,
Department of Transport TRRL
Supplementary Report 328: Crowthorne, 1977
4. Even properly done pavement breaking can be dangerous to homes: "With
the exception of a few instances involving pavement breaking, pile
driving, all Caltrans construction vibration measurements have been
below the 5 mm/s (0.2 in/sec) architectural damage risk amplitude for
continuous vibrations. The highest measured vibration amplitude was 73.1
mm/s (2.88 in/sec) at 3 m (10 ft) from a pavement breaker." (Transportation-
and construction-induced vibration guidance manual. June 2004.
California Department of Transportation, p. 15)
5. USBM RI 8507, p. 58
6. Caterpillar Operation and Maintenance Manual, 320 B, 320 B L, and 320 B N Excavators, SEBU 6075-07, p. 31, p. 101, p. 106, among others. Obtainable in PDF format by online purchase from Caterpillar
7. Because these vibratory compaction data show such high peak particle velocities, some further information is in order. The vibration monitoring technician did not record, photographically or textually, the location of the
seismograph at the address he cited for these data, with respect either to the house, the work, or any other fixed landmark. However, photos taken that day by the vibration technician of the compaction operation show that the point of closest approach to the
seismograph was at least 17 feet away from the vibratory compactor (based on Google Earth measurements of the site and the photos taken) when the 0.66 in/sec PPV in this diagram was recorded. The point of closest compactor
approach to the home was, at most, 48 feet from the home, based on the same measurements. In the 33 minute period of monitoring at this date and location, there were 58 vibration events over FTA vibration standards, only a
portion of which are shown in the graphic record above. These data involved compaction of a first layer of asphalt over compacted soil (type classified as silty sand), using a vibratory compactor with a specified front drum static weight of
7,410 lb. (33 kiloNewtons, kN), a rear drum static weight of 7,485 lb. (33.4 kN) (from published specifications), and an unknown vibratory
amplitude (intensity) at a nominal vibration frequency of 66.7 Hz. The centrifugal force range for this compactor is 7,820 – 21,080 lb (35 – 94 kN).
The PPV's of all vibrations from compaction of a second layer of asphalt the next day in the same lane at the same address are not known, as the relevant
histogram data were among those "lost" by the vibration technician and the contractor. The seismograph monitor log for the second day at that site shows 6 events occurring in the first 2 minutes of a 20 minute
installation, before event
recording stopped when seismograph event memory filled. The largest of the recorded events, one minute into the installation period had a PPV of 0.320 in/sec, already in violation of the FTA standard for frame homes of 0.2
in/sec, with the FFT dominant vibration frequency at 40 Hz and
other component frequencies below 40 Hz. However,
compaction in the same lane at other locations on the same street that second day, for which histogram data were not "lost", resulted in maximum PPV's which were generally 0.15 to 0.2 in/sec
higher than those recorded the previous day for the same lane of paving over soil at or near the same locations. There were a correspondingly higher number of events recorded. Thus, it is a reasonable expectation that, if the data had not been "lost" by the technician and the contractor,
they would likely have shown a PPV of
at least 0.8 in/sec on this second day of vibratory compaction, in violation even of all current U.S. blasting vibration standards, as well as all U.S. construction vibration standards.
There were at least two later
paving days along the street in question, as shown by subcontractor documents produced in litigation, but the contractor did not do any vibration monitoring for this later paving. The contractor stopped all monitoring at
least a month before the completion of the job, as admitted in sworn testimony, in spite of the clear violations of vibration standards caused by its work.
8. "Starting and stopping of the vibratory compactor may temporarily increase the ground vibration... If there is any risk of damage to buildings, low amplitude or even static compaction should be used." Vibration Problems in Structures: Practical Guidelines, pp. 136-137. A manufacturer of vibratory compactors, Dynapac,
indicates that the minimum safe distance is 1 to 1.5 times the drum module weight in kN. (see
http://www.dynapac.co.uk/en/knowledge/End-user-Support/Soil-Applications/ (go to http://dynapac.co.uk, choose Knowledge, then End-user-Support,
then Soil Applications, if the direct link fails)
9. Vibratory compactors are the most commonly used equipment for pavement compaction. However, pneumatic rollers (rubber-tired rollers) and combination rollers (rollers with a steel drum on one axle and tires on the other)
are also employed. Such rubber-tired rollers are usually of less concern for vibration generation than vibratory compactors.
10. An excavator very similar to the one shown and referred to on this page has been used to simulate earthquakes by pounding on pavement: "Soon after, a PC750LC excavator shocked attendees by pounding its massive claw into the pavement and creating a "did you feel that?"
moment[.]", The Santa Clara Weekly, March 2011, Issue 10, Out With the Old: In With the New,