VILLAGE OF OCEAN BEACH – BULKHEAD AND FERRY TERMINAL REHABILITATION
Vibration
Limits for Buildings
Vibration
Limits for Buildings
Scope
of Report
The purpose of this report is
to identify potential issues with the buildings surrounding the boat basin and
establishing recommended vibration limits at the property lines to ensure
damage does not occur to the adjacent properties located in Ocean Beach, Fire
Island.
Introduction
Construction activities have
the potential to produce vibration levels that may be annoying or disturbing to
humans and may cause damage to structures. Architectural and/or structural
damage may occur if appropriate precautions are not taken.
Effects of ground-borne
vibration include discernable movement of building floors, rattling of windows,
shaking of items on shelves or hanging on walls, and rumbling sounds.
Construction related activity can create vibration waves that propagate through
the various soil and rock strata to the foundations of nearby structure,
certain resonant, or natural, frequencies of various components of the building
may be “excited”. In extreme cases vibration can cause damage to buildings.
Types
of Vibration Impacts
Measurements of vibrations used
in the evaluation are expressed in terms of peak particle velocity (PPV) in
inches per second (ips or in/sec). The PPV, a quantity commonly used for
vibration measurements, is the maximum velocity experienced by any point in a
structure during a vibration event. It is an indication of the magnitude of
energy transmitted through vibration. PPV is an indicator often used in
determining potential damage to buildings from stress associated with blasting
and other construction activities.
One of the more frequently used
thresholds for vibration, established by the United States Bureau of Mines, is
a PPV of 2.0 ips at the closest structure to prevent structural damage. This
level is a typical nominal structural damage criterion employed by construction
projects. When most stringent criteria is required, PPV limit of 0.5 ips is
used. 0.5 ips is 10 times more restrictive than 2.0 on the logarithmic scale
and is associated with protection of surrounding historic structures that are
susceptible to cosmetic cracks in fragile plaster. This limit could be lowered
to protect fragile and/or historic structures based on a detailed vibration
assessment conducted by the construction contractor prior to construction. A
quantitative assessment of potential vibration impacts from blasting is not
provided as none is anticipated at this time.
Another type of vibration
impact is human annoyance which is highly dependent on frequency of occurrence
and generally occurs when inside buildings. Ground borne vibration impacts may
be somewhat perceptible to people who are outdoors. It is almost never
annoying. This is because without shaking of a building or items within a
building or the rumble noise that can only occur indoors, vibration does not
cause a strong adverse human reaction
Construction
Activities
To determine potential impacts
of the project’s construction activities, estimates of vibration levels induced
by construction equipment at 25 feet are based on the Federal Transit
Administration (FTA), “Transit Noise and Vibration Assessment”, April 1995 as
up dated in 2006.
For the equipment anticipated
to be used on this project we find:
Table A
Typical
Levels of Vibration for Construction Equipment
Similar
for that Proposed for Sheet Pile Construction
Construction
Activity PPV at 25 feet
(ips)
Pile Driver
(impact)
upper range 1.518
typical 0.644
Pile Driver (sonic)
upper range 0.734
typical 0.170
The values provided in the tables are based on the FTA literature.
Actual vibration levels are dependent on construction procedures, soil and
geological conditions, and the structural characteristics of the receptor
(e.g., foundation and construction type).
PPV at other distances can be calculated. PPV at Distance D = PPV
(at 25 feet) * (25/D) raised to the 1.5 power.
The anticipated typical vibration levels for this project using
continuous sheet pile driving with PPV at 25 ft = 0.170 in/sec implies:
10 feet 0.67
in/sec
15 feet 0.37
in/sec
25 feet 0.17
in/sec
40 feet 0.11
in/sec
And 50 feet 0.06
in/sec
The further away a building is
from sheet pile installation using continuous vibration the smaller the PPV is.
The closer the building is to the source of vibration the higher the PPV value
becomes.
Table B
Construction Vibration Damage
Criteria
Building Category PPV
(in/sec)
Reinforced-concrete, steel or
timber (no plaster) 0.5
Engineered concrete and masonry
(no plaster) 0.3
Non-engineered timber and
masonry buildings 0.2
Buildings extremely susceptible
to vibration damage 0.12
Establishing
Vibration Limits to Protect Buildings
One of the most commonly
referenced studies is the USBM RI 8507.
Table C
Damage
Thresholds as reported by the US Bureau of Mines Report Investigations
8507, Structure Response and Damage Produced by Ground Vibration from Surface
Mining Blasting (USBM RI 8507),
Conditions
Observed Typical PPV (in/sec)
Threshold Damage (hairline
cracking in plaster, 2
- 3
Opening of old cracks, etc.) Never
at < 0.5
Minor damage (hairline cracking
in masonry, 4
- 5 breaking windows) Never at <
1.0
Major Structure Damage
(cracking or
Shifting of foundations or
bearing walls) >
5
There are limitations to these
findings, however, they are offered as a guideline.
Another study cited in the literature
is Swiss Standard SN 640 312 only available in French and German. A partial
translation indicates that for most light framed structures, and for continuous
vibrations anticipated on this project, the limit is 0.59 in/sec. For fragile
or historic buildings subjected to transient vibrations is a range from 0.12 to
0.24 in/sec. depending on professional judgement. Section 12 of the standard
provides useful commentary: “If the velocity values occur below the guide
values, then the probability of minor damage is extremely small. If the guide
values are only rarely exceeded up to about 30%, then the probability that
damage occurs is not increased significantly. If the values exceed twice the
guide values, then damage (i.e., cosmetic cracking) is likely to occur. Cracks
that penetrate through an entire wall or floor have to be expected if values
exceed the guide values by several times. If conditions are very special, an
expert would be allowed to define higher or lower guide values.
The limit for historical and/or
fragile buildings will likely be in the range of 0.12 to 0.5 in/sec depending
on evaluation of key factors for the individual case.
In the examples cited below,
vibrations typically originated outside the buildings, and the vibration
response (where the limits apply) was measured at the base of the building or
near a column or bearing wall within the building, such that dynamic
amplification effects were not included. This is consistent with the basis of
this paper which assumes that vibrations originate outside the building and are
measured at the base of the building.
Examples:
For cases of extreme fragility
or where a very high importance factor is desired, the lowest vibration limit
that should be set is the maximum ambient level of vibration in the building.
This level can be determined by monitoring vibrations in the building for a
period of time during normal, day to day activities before construction begins.
Per the literature these values are expressed as vibration amplitudes (in/sec) and
range between 0.02 – 0.05 for occupants walking or closing doors to 0.10 to
0.14 for moving furniture in an office building.
For the special case of using
vibratory sheet pile driving (i.e., potentially continuous vibrations) within
about 30 feet of a structure a lower vibration limit of 0.2 in/sec
(frequency-dependent) can be used for any continuous vibrations (defined as
cyclic vibrations with duration greater than 2 seconds) . Careful pre- and post
- construction surveys of the structure should be conducted by staff to ensure
no adverse effects are found.
It should be noted that in
2015, Mr. E. Hammarberg commented that he has been involved in the monitoring
of several hundred old (many historic) unreinforced-masonry buildings in New
York City and that he has never observed damaged caused by construction
vibrations at levels below 0.5 in/sec, which is the stipulated limit for New
York City landmark buildings (reference NYC TPPN-1088).
Summary
Using PPV = 0.5 in/sec is an acceptable limit for the
project where the distance from driving sheet piling to the base of a structure
is 25 feet or greater. The only structure at 10 feet to 15 feet away from the
piling is the police station. The allowable PPV should be limited to 0.3 in/sec
and could be lowered further in accordance with Table B above.
If at a future time it is
determined that a structure is an historic building, the limit for historic
buildings will be in the range of 0.12 to 0.5 in/sec depending on evaluations
of the key factors for the individual case. For cases of extreme fragility or
where a very importance factor is desired, the lowest vibration limit that
should be set is the maximum ambient level of vibration in the building.
Conclusion
PPV = 0.5 in/sec is the
recommended acceptable vibration limit for the project with a reduction down to
0.3 in/sec in the vicinity of the police station. The inspection staff
monitoring vibration can ask the Contractor to change his operations to reduce
the observed PPV if deemed desirable for the project.
References
and Notes
City Tunnel No. 3, Stage 2
Manhattan Leg Shaft 33B Final EIS
US Bureau of Mines Report of Investigations 8507, “Structure
Response and Damage Produced by Ground Vibration from Surface Mine Blasting”
(USBM RI 8507).
Federal Transit Administration
(FTA), “Transit Noise and Vibration Assessment”, April 1995 as up dated in
2006. Also see FTA Noise and Vibration
Manual.
Swiss SN 640 312, Swiss
Standard SN 640 312, notably J. Struder, translation found in APT Bulletin
published by Association of Preservation Technology, credit to: Arne P. Johnson
and W. Robert Hannen
“Protection of Historic Urban
Structures During Adjacent Construction,” E. Hammarberg et.al.
Sullivan Arch, Art Institute of
Chicago
