CONNstruction - Winter 2018 - 13

* Estimate the potential for ground vibration to impact nearby structures or be
perceived by occupants
* Develop measures to help mitigate damage caused by vibration generating work

Pre-Construction Surveys
Pre-construction surveys should be completed for the following operations: pile driving, excavation and trenching, use of heavy
equipment close to structures, underpinning,
and demolition of a structure. By implementing a valid pre-construction survey program,
it is possible to avoid substantial claims.
Pre-construction survey reports could
record the physical condition of structures
and utilities near a construction area. The
need for and extent of the survey should be
based on the planned construction activities
and the degree of exposure to the surrounding structures and utilities. Surveys should
identify potential risks to the surrounding
areas so that contractors can consider them
when pre-planning a project.
In several cases, pre-construction surveys are often not done, or not consistently.
When they are completed, they may not be
as thorough as they should be. ZoneCheck
simplifies this process by providing a
visual reference of the areas that should be
included within pre-construction surveys.

Survey Guidelines
Pre-construction surveys of structures
and utilities may include any or all of the
following suggested practices:
Written building condition reports
A professional survey consultant should
inspect and document the condition of a
structure's foundation, exterior and interior
walls, floors, ceilings, roof, chimney and
other structural components, if possible. The
report also should cover pipe systems, heating and cooling systems, hot water tanks
and other delicate machinery or equipment.
The use of an independent commercial
photographer is suggested. The photographer should work under the direction
of the professional survey consultant.
Photographs should be properly labeled,
dated and notarized, if necessary, to certify
that the photographs are accurate and true

copies of the conditions on the day taken.
Noticeable cracks and existing deterioration
should be described in detail, measured and
Benchmarks and survey points
An independent, licensed land surveyor
should complete benchmarks and/or survey
points. Vertical and horizontal references will
provide evidence of settlement and movement of the building, roadway and any shoring systems used. Revised work procedures
should be considered immediately if unanticipated movement occurs.
Videotapes may help document conditions. They should be properly labeled and
the date verified for future reference.
An independent qualified consultant
should complete seismographic monitoring of surrounding vibration-producing
operations. Results should be recorded
and retained. If blasting is performed, blast
logs and shot pattern records should be
retained. Blast records and shot pattern
records should clearly indicate the type
and amount of explosives used for each
delay period.

Assessing Potential
Areas of Impact
ZoneCheck develops two radii from the
source; the "alert zone" and the "human
perception zone". The "alert zone" is closer
to the vibration source. Structures within
this zone should receive a higher degree of
analysis/review and include photos documenting exterior building conditions and,
where appropriate, interior photos. In certain
situations, seismographs may need to be
positioned in key areas to document the
levels of ground vibrations, and construction
methods may need to be altered to protect
more sensitive structures.
In the outer radius, the "human perception
zone," vibrations are likely to be perceived
by occupants but less likely to result in
structural building damage. Understanding
the human perception zone and following
appropriate measures can prepare you in
the event occupants perceive vibrations
and allege damages. Communicating with
those inside the human perception zone

can help alleviate any concern when and if
vibrations are felt.

Implement Mitigation
While using ZoneCheck during the
pre-planning process has a number of
advantages, if that data isn't applied to further develop mitigation efforts, the benefits
are severely restricted. ZoneCheck provides
supporting information in effort to help proactively identify risk enabling the user to plan
and act accordingly.
ZoneCheck can also produce documentation that can be shared with other stakeholders at a project with the tap of a button.
These reports streamline communication
with various decision makers to help facilitate collaboration around risk prevention.
Contractors need to be prepared for
claims even if no damage occurs, according
to Mike Koppang, a Travelers Risk Control
Professional. "Even when the probability
of damage is really low, residents can still
perceive vibration, allege damage and file
a claim," explained Koppang, who is part of
the Construction team at the Travelers Risk
Control Lab.
That insight was the spark for Travelers
ZoneCheckSM. "It can help customers identify potentially impacted areas that are farther away from the proposed site, where they
are less likely to expect damages or perceived damages to occur," said Koppang.
"It helps them take into account the human
perception zone."
If construction related activity is transmitting energy that can be perceived by occupants within the area, does that mean it can
also impact nearby structures? The answer
depends on a variety of factors, including
the location and nature of the work. Yet,
despite these variables, there is one certainty: fully understanding a risk is the first
step to addressing it.
Excerpts from the following resources were
included with permission from Travelers:
- ZoneCheck
- Pre-Construction Survey
- Awareness of Risks Can Help Avoid
Construction Vibration Damage
CONNstruction / WINTER 2018 / 13


CONNstruction - Winter 2018

Table of Contents for the Digital Edition of CONNstruction - Winter 2018

Fleet Tracking with Telematics
Don’t Let Vibration Damages Shake You
Trenching and Excavation Safety
Preventing Runovers and Backovers in Work Zones and Construction Sites
If OSHA Knocks, How Do You Respond?
Diggers Mixers Fixers Golf Outing
2018 AGC/CT Industry Recognition Dinner
Connecticut Road Builder Association Dinner
YCF Yard Goat Baseball/BBQ & Fall Membership Meeting
OSHA-CCIA-ConnOSHA Annual Safety Alliance Conference & Press Conference
A Blue Light for Safety
“If You See Something, Say Something” Applies to More Than Homeland Security
CONNstruction - Winter 2018 - Intro
CONNstruction - Winter 2018 - cover1
CONNstruction - Winter 2018 - cover2
CONNstruction - Winter 2018 - 3
CONNstruction - Winter 2018 - 4
CONNstruction - Winter 2018 - 5
CONNstruction - Winter 2018 - A Blue Light for Safety
CONNstruction - Winter 2018 - “If You See Something, Say Something” Applies to More Than Homeland Security
CONNstruction - Winter 2018 - Fleet Tracking with Telematics
CONNstruction - Winter 2018 - 9
CONNstruction - Winter 2018 - 10
CONNstruction - Winter 2018 - 11
CONNstruction - Winter 2018 - Don’t Let Vibration Damages Shake You
CONNstruction - Winter 2018 - 13
CONNstruction - Winter 2018 - Trenching and Excavation Safety
CONNstruction - Winter 2018 - 15
CONNstruction - Winter 2018 - 16
CONNstruction - Winter 2018 - 17
CONNstruction - Winter 2018 - Preventing Runovers and Backovers in Work Zones and Construction Sites
CONNstruction - Winter 2018 - 19
CONNstruction - Winter 2018 - 20
CONNstruction - Winter 2018 - 21
CONNstruction - Winter 2018 - If OSHA Knocks, How Do You Respond?
CONNstruction - Winter 2018 - 23
CONNstruction - Winter 2018 - 24
CONNstruction - Winter 2018 - 25
CONNstruction - Winter 2018 - Diggers Mixers Fixers Golf Outing
CONNstruction - Winter 2018 - 2018 AGC/CT Industry Recognition Dinner
CONNstruction - Winter 2018 - Connecticut Road Builder Association Dinner
CONNstruction - Winter 2018 - OSHA-CCIA-ConnOSHA Annual Safety Alliance Conference & Press Conference
CONNstruction - Winter 2018 - 30
CONNstruction - Winter 2018 - cover3
CONNstruction - Winter 2018 - cover4
CONNstruction - Winter 2018 - outsert1
CONNstruction - Winter 2018 - outsert2
CONNstruction - Winter 2018 - outsert3
CONNstruction - Winter 2018 - outsert4