January/February 2023 - 82

BC40 hydro cutter mounted on MC96 crane
The 41.5 ft (13 m) deep excavation is
supported by a 3 ft (1 m) thick, rebarreinforced
diaphragm wall (D-Wall),
which is typically restrained by three
levels of tiebacks.
Two hydro cutters and one hydraulic grab
Tiebacks were typically installed
at 5 ft (1.5 m) on center and were installed
at 30-degree angles with sufficient
unbonded length such that
bond zone reached the competent
upper layer sediments that are below
the young Bay mud. The tiebacks were
installed through pipe block-outs that
were pre-tied in with the diaphragm
wall rebar cages.
Drilling the level two and level
three tiebacks below the groundwater
table and risking excessive water and
soil inflow to the excavation was a
challenging part of the construction.
However, the team used a wal l
mounted preventer system and developed
cased drilling and grouting
techniques to minimize the amount of
soils and water that entered the
excavation during the tieback install.
Ultimately, hydroactive grout was
pumped into the locked-off tieback
wedge plate to stop the leaking water.
All tiebacks were either performance
or proof tested prior to lock-off.
To allow for future site build out all tiebacks
were required to be detensioned.
It was very important that the
drilled shaft foundation piles were
installed first to avoid the risk of
drilling through tensioned tiebacks.
The diaphragm wall and the 100 ft
(30 m) long tiebacks had to be drilled
straight in order to miss the already
existing pile foundations.
82 * DEEP FOUNDATIONS * JAN/FEB 2023

January/February 2023

Table of Contents for the Digital Edition of January/February 2023

TOC
January/February 2023 - Intro
January/February 2023 - 1
January/February 2023 - 2
January/February 2023 - TOC
January/February 2023 - 4
January/February 2023 - 5
January/February 2023 - 6
January/February 2023 - 7
January/February 2023 - 8
January/February 2023 - 9
January/February 2023 - 10
January/February 2023 - 11
January/February 2023 - 12
January/February 2023 - 13
January/February 2023 - 14
January/February 2023 - 15
January/February 2023 - 16
January/February 2023 - 17
January/February 2023 - 18
January/February 2023 - 19
January/February 2023 - 20
January/February 2023 - 21
January/February 2023 - 22
January/February 2023 - 23
January/February 2023 - 24
January/February 2023 - 25
January/February 2023 - 26
January/February 2023 - 27
January/February 2023 - 28
January/February 2023 - 29
January/February 2023 - 30
January/February 2023 - 31
January/February 2023 - 32
January/February 2023 - 33
January/February 2023 - 34
January/February 2023 - 35
January/February 2023 - 36
January/February 2023 - 37
January/February 2023 - 38
January/February 2023 - 39
January/February 2023 - 40
January/February 2023 - 41
January/February 2023 - 42
January/February 2023 - 43
January/February 2023 - 44
January/February 2023 - 45
January/February 2023 - 46
January/February 2023 - 47
January/February 2023 - 48
January/February 2023 - 49
January/February 2023 - 50
January/February 2023 - 51
January/February 2023 - 52
January/February 2023 - 53
January/February 2023 - 54
January/February 2023 - 55
January/February 2023 - 56
January/February 2023 - 57
January/February 2023 - 58
January/February 2023 - 59
January/February 2023 - 60
January/February 2023 - 61
January/February 2023 - 62
January/February 2023 - 63
January/February 2023 - 64
January/February 2023 - 65
January/February 2023 - 66
January/February 2023 - 67
January/February 2023 - 68
January/February 2023 - 69
January/February 2023 - 70
January/February 2023 - 71
January/February 2023 - 72
January/February 2023 - 73
January/February 2023 - 74
January/February 2023 - 75
January/February 2023 - 76
January/February 2023 - 77
January/February 2023 - 78
January/February 2023 - 79
January/February 2023 - 80
January/February 2023 - 81
January/February 2023 - 82
January/February 2023 - 83
January/February 2023 - 84
January/February 2023 - 85
January/February 2023 - 86
January/February 2023 - 87
January/February 2023 - 88
January/February 2023 - 89
January/February 2023 - 90
January/February 2023 - 91
January/February 2023 - 92
January/February 2023 - 93
January/February 2023 - 94
January/February 2023 - 95
January/February 2023 - 96
January/February 2023 - 97
January/February 2023 - 98
January/February 2023 - 99
January/February 2023 - 100
January/February 2023 - 101
January/February 2023 - 102
January/February 2023 - 103
January/February 2023 - 104
January/February 2023 - 105
January/February 2023 - 106
January/February 2023 - 107
January/February 2023 - 108
January/February 2023 - 109
January/February 2023 - 110
January/February 2023 - 111
January/February 2023 - 112
January/February 2023 - 113
January/February 2023 - 114
January/February 2023 - 115
January/February 2023 - 116
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