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Effects of Transient and Cyclic Loads on Structural Elements

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I am developing a protection and monitoring program for existing historic
unreinforced masonry buildings directly adjacent to a project that involves
paving demolition, excavation, fill and compaction, and construction
equipment traffic.

Has there been research into the effects of construction-related transient
and cyclic loads of various intensities, durations and frequencies (other
than earthquake shaking and wind) on building components, such as masonry
veneers, and unreinforced  masonry walls?

It is conventional that retrofit codes require that drilling of holes into
unreinforced masonry buildings be done with non-impact rotary equipment.
This is intended to prevent damage to the adjacent masonry.  I've assumed
that the basis of such a requirement is intuitive, and not based on
research?  Is anyone aware of research?

As an extension of the rotary drilling requirement, it is usual to require
that demolition on concrete slabs adjacent to unreinforced masonry buildings
may not be done by breaking with a jackhammer.  On my projects, I'm used to
requiring demolition of slabs in or adjacent to URM buildings to be done by
cutting them up with masonry saws into sizes that can be taken out without

On the other hand, I remember growing up near a part of town with old brick
buildings, and recall that jackhammers might be used to break paving and
excavate hard soil adjacent to old brick buildings with no apparent thought
of precautions to prevent impact-or-vibration-caused damage to adjacent
walls.    Has anyone been able to identify a part of a building that may
have been damaged in that way?

With the engineers' goal to maximize effectiveness while minimizing cost, I
want to develop a program that is restrictive enough, without being too
restrictive on the types of construction activities that can be allowed
adjacent to, or at various distances from the buildings.  Are there any
references out there?

Nels Roselund
Structural Engineer

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