May/June 2021 - 85

Inland (upslope) side of Tram Building
recorded every hour. A seismograph
geophone was also deployed adjacent to
the crack to record floor vibrations along
with a Supco DVTH temperature and
humidity data logger. The crack gauge
data logger was programmed to cotrigger
with the seismograph during
dynamic events, capturing data over 3 or
6 sec at 1,000 samples/sec. Data were
collected for 216 days, which covered
5,188 hours at the start and at the end of
the South Berth pile driving (which was
carried out from September 26, 2015 to
April 16, 2016).
T r a n s i e n t
Ground strains at the memorial
Juneau Harbor are primarily peaty " muck, "
literature citations suggested a risk of
settlement should have existed during
the several days of vibratory pile removal
and driving that was up to 42 ft (12.8 m)
away. However, this was not the case.
A simpler, more direct means of
estimating ground strains at the
memorial's foundation is to use the
relation d /L, where d
max
max
is the
maximum differential ground displacement
over the memorial's horizontal
distance, L, between the seaward
foundation measurement location and
the upland foundation edge based on
actual site measurements. Assuming a
worst-case upland ground displacement
of zero across the 23 ft (7 m)
concrete foundation, the ground strain
and hence foundation strain becomes
(0.003 in-0)/ 23 ft (12 in/ft) or 10.9 micro
strains (0.00109%). Thus, the estimated
transient ground strains during
construction were far too low to cause
additional settlement.
Vibratory time histories for the highest event there
Building Crack Monitoring
The Tram Building slab-on-grade
concrete crack demarked a boundary
between the upslope slab on fill and
downslope (ocean side) on pile supports.
Vertical and lateral offsets suggested the
ocean-side slab has settled over time
and displaced toward the ocean. An
instrument system was employed to
measure changes in the vertical and
lateral dimensions of the crack
separation as a result of pile driving and
general construction. In addition, the
impacts of other potential influences on
cracking were studied for comparison:
human activities in the building, and the
typical expansion and contraction that
concrete undergoes due to daily and
seasonal weather changes. Kaman
eddy-current displacement gauges were
installed over the floor crack; the gauges
were oriented vertically and horizontally,
and had a resolution of 3.9 micro-in
(0.1 microns). Output voltages correlating
to dimensional changes were
p i l e d r i v i n g
events typically
produced peak
vert ical crack
displacements of
up to 259 microin
(0.0066 mm),
which were negligible
compared
to the effects of
the other factors
studied.
Geophone and gauges monitoring building's slab
crack, and side view of vertical crack gauge
(upslope side of crack at left)
DEEP FOUNDATIONS * MAY/JUNE 2021 * 85

May/June 2021

Table of Contents for the Digital Edition of May/June 2021

TOC
May/June 2021 - Intro
May/June 2021 - 1
May/June 2021 - 2
May/June 2021 - TOC
May/June 2021 - 4
May/June 2021 - 5
May/June 2021 - 6
May/June 2021 - 7
May/June 2021 - 8
May/June 2021 - 9
May/June 2021 - 10
May/June 2021 - 11
May/June 2021 - 12
May/June 2021 - 13
May/June 2021 - 14
May/June 2021 - 15
May/June 2021 - 16
May/June 2021 - 17
May/June 2021 - 18
May/June 2021 - 19
May/June 2021 - 20
May/June 2021 - 21
May/June 2021 - 22
May/June 2021 - 23
May/June 2021 - 24
May/June 2021 - 25
May/June 2021 - 26
May/June 2021 - 27
May/June 2021 - 28
May/June 2021 - 29
May/June 2021 - 30
May/June 2021 - 31
May/June 2021 - 32
May/June 2021 - 33
May/June 2021 - 34
May/June 2021 - 35
May/June 2021 - 36
May/June 2021 - 37
May/June 2021 - 38
May/June 2021 - 39
May/June 2021 - 40
May/June 2021 - 41
May/June 2021 - 42
May/June 2021 - 43
May/June 2021 - 44
May/June 2021 - 45
May/June 2021 - 46
May/June 2021 - 47
May/June 2021 - 48
May/June 2021 - 49
May/June 2021 - 50
May/June 2021 - 51
May/June 2021 - 52
May/June 2021 - 53
May/June 2021 - 54
May/June 2021 - 55
May/June 2021 - 56
May/June 2021 - 57
May/June 2021 - 58
May/June 2021 - 59
May/June 2021 - 60
May/June 2021 - 61
May/June 2021 - 62
May/June 2021 - 63
May/June 2021 - 64
May/June 2021 - 65
May/June 2021 - 66
May/June 2021 - 67
May/June 2021 - 68
May/June 2021 - 69
May/June 2021 - 70
May/June 2021 - 71
May/June 2021 - 72
May/June 2021 - 73
May/June 2021 - 74
May/June 2021 - 75
May/June 2021 - 76
May/June 2021 - 77
May/June 2021 - 78
May/June 2021 - 79
May/June 2021 - 80
May/June 2021 - 81
May/June 2021 - 82
May/June 2021 - 83
May/June 2021 - 84
May/June 2021 - 85
May/June 2021 - 86
May/June 2021 - 87
May/June 2021 - 88
May/June 2021 - 89
May/June 2021 - 90
May/June 2021 - 91
May/June 2021 - 92
May/June 2021 - 93
May/June 2021 - 94
May/June 2021 - 95
May/June 2021 - 96
May/June 2021 - 97
May/June 2021 - 98
May/June 2021 - 99
May/June 2021 - 100
May/June 2021 - 101
May/June 2021 - 102
May/June 2021 - 103
May/June 2021 - 104
May/June 2021 - 105
May/June 2021 - 106
May/June 2021 - 107
May/June 2021 - 108
May/June 2021 - 109
May/June 2021 - 110
May/June 2021 - 111
May/June 2021 - 112
May/June 2021 - 113
May/June 2021 - 114
May/June 2021 - 115
May/June 2021 - 116
https://www.nxtbook.com/dfi/DEEP-FOUNDATIONS/july-august-2024
https://www.nxtbook.com/dfi/DEEP-FOUNDATIONS/may-june-2024
https://www.nxtbook.com/dfi/DEEP-FOUNDATIONS/march-april-2024
https://www.nxtbook.com/dfi/DEEP-FOUNDATIONS/january-february-2024
https://www.nxtbook.com/dfi/DEEP-FOUNDATIONS/november-december-2023
https://www.nxtbook.com/dfi/DEEP-FOUNDATIONS/september-october-2023
https://www.nxtbook.com/dfi/DEEP-FOUNDATIONS/july-august-2023
https://www.nxtbook.com/dfi/DEEP-FOUNDATIONS/may-june-2023
https://www.nxtbook.com/dfi/DEEP-FOUNDATIONS/Jan-feb-2021_nxtbook
https://www.nxtbook.com/dfi/DEEP-FOUNDATIONS/july-august-2021
https://www.nxtbook.com/dfi/DEEP-FOUNDATIONS/march-april-2023
https://www.nxtbook.com/dfi/DEEP-FOUNDATIONS/january-february-2023
https://www.nxtbook.com/dfi/DEEP-FOUNDATIONS/november-december-2022
https://www.nxtbook.com/dfi/DEEP-FOUNDATIONS/september-october-2022
https://www.nxtbook.com/dfi/DEEP-FOUNDATIONS/july-august-2022
https://www.nxtbook.com/dfi/DEEP-FOUNDATIONS/may-june-2022
https://www.nxtbook.com/dfi/DEEP-FOUNDATIONS/march-april-2022
https://www.nxtbook.com/dfi/DEEP-FOUNDATIONS/january-february-2022
https://www.nxtbook.com/dfi/DEEP-FOUNDATIONS/november-december-2021
https://www.nxtbook.com/dfi/DEEP-FOUNDATIONS/sept-oct-2021
https://www.nxtbook.com/dfi/DEEP-FOUNDATIONS/july-aug-2021
https://www.nxtbook.com/dfi/DEEP-FOUNDATIONS/may-june-2021
https://www.nxtbook.com/dfi/DEEP-FOUNDATIONS/march-april-2021
https://www.nxtbook.com/dfi/DEEP-FOUNDATIONS/january-february-2021
https://www.nxtbook.com/dfi/DEEP-FOUNDATIONS/november-december-2020
https://www.nxtbook.com/dfi/DEEP-FOUNDATIONS/September-October-2020
https://www.nxtbook.com/dfi/DEEP-FOUNDATIONS/may-june-2020
https://www.nxtbook.com/dfi/DEEP-FOUNDATIONS/march-april-2020
https://www.nxtbook.com/dfi/DEEP-FOUNDATIONS/january-february-2020
https://www.nxtbook.com/dfi/DEEP-FOUNDATIONS/july-august-2020
https://www.nxtbookmedia.com