Long-term Foundation Monitoring �and the Internet of Things
Dr. Ronaldo Luna, PE
Professor, Saint Louis University
Presented to: TRB AKG70 Foundation Committee
January 11, 2022
Outline
2
A Team Effort
Foothills Parkway - The Missing Link
4
N
5
Bridge No. 2
Project Location
Subsurface Conditions
Subsurface Conditions
Piers 1 & 2
Subsurface Stratigraphy (Siegel et al., 2010)
Bridge No. 2
Pier 1
Pier 1
Pier 2
Pier 4
Pier 3
Pier 1 – Subsurface Conditions
Slate
Phyllite
Sand
Silt and Gravel
Metaconglomerate
Meta-Sandstone Fragments
Silt, Sand, Gravel
Micropile Installation
1.
Drilling Platform
Micropile Installation (Pier 1)- Step 1a
Micropile Sub-Footing
Micropile Installation (Pier 1)- Step 1b
Central Reinforcing Bar and Strain Gage Installation
Micropile Installation (Pier 1)- Step 1c
Grouting and Bar Cutting
5.
4.
Step 2 – Pile Cap and Terminal Box
13
2.
Pier 1 Pile Cap
Pier 2 Drilling Platform
Bridge Construction Process - Step 2a
Pier 1: Terminal Box Installation (pictured below)
Pier 2: Strain Gages, Central Reinforcing Bar, Framework, and Wiring Completed (not pictured)
Completed Bridge No. 2
Officially named in 2018 as the ”Dean Stone Bridge”
Data Collection During Construction
16
Data Collection
Geokon Model 4999 Terminal Box
Micropile 1, Pier 1
Uphill, Micropile #1
PLAN
16
4
11
Construction Monitoring Results
1
18
100% of Significant Loading
1.1%
5.8%
Construction Monitoring Results
Construction Monitoring Results
Micropile 1, Pier 1
47%
53%
Completed Bridge Load Transfer
Construction Sequence
Construction Monitoring Results
Pile Cap Poured
Column Segments Installed
Cantilever Segments Installed
Day 242: Abutment 1-Pier 1 closure joint poured
Day 280: Pier 1-Pier 2 closure joint poured
Long-term Monitoring and IIoT
Why Monitor Foundations?
23
What is IoT?
24
Internet of Things
IIoT vs IoT
25
What is IIoT?
26
What is IIoT?
27
Closing
28
Acknowledgements
The authors would like to acknowledge the contributions and financial support from Dan Brown & Associates, particularly Tim Siegel who participated as the foundation design engineer of for this project. Many other colleagues and engineers contributed in different parts of the project, such as Dr. Kyle Kershaw, Devin Dixon, and other individuals from the Bell & Associates Construction LP, Corven Engineering, and the owner FHWA Eastern Federal Lands Highway Division.
Cited References
�Thank You��Questions?�
All References
Completed Bridge Load Transfer and Live Load Test
33
Micropile 1, Pier 1
34
Completed Bridge Load Transfer
87.5%
12.5%
Micropile 11, Pier 1
35
Completed Bridge Load Transfer
94.1%
5.9%
36
Live Load Test
Loading Configuration #1
Loading Configuration #4
Loading Configuration #3
Loading Configuration #2
Truck Setup
37
Live Load Test
4 trucks
2 trucks
4 trucks
2 trucks
4 trucks
#1
#2
#3
#3
#4
Loading Position | Description |
1 | Four trucks directly on top of Pier 1 or Pier 2 |
2 | Four trucks on the down-station closure joint |
3 | Two trucks on each closure joint |
4 | Four trucks on the up-station closure joint |
38
Live Load Test
#4
#3
#2
#1
Loading Configuration
39
Live Load Test
#4
#3
#2
#1
Loading Configuration
Measured Live Load Compared to Measured Dead Load of Completed Bridge
40
Live Load Test
Objectives:
1. To compare the measured live loads to the measured dead load of the completed bridge
2. Compare the measured loads at the top of the cased lengths to the top of the bond zones of the instrumented micropiles
Measured Live Load Compared to Measured Dead Load of Completed Bridge
41
Live Load Test
Procedure:
1. For the loads monitored by gages B1/2 and D1 an average was taken to obtain one average load value for all the instrumented micropiles at either the top of the casing or the top of the bond zone for each truck loading configuration
Pier 1, Top of Casing (B1/2) Example:
average of 01B1/2, 06B1/2, 11B1/2 and 16B1/2 for all 4 loading configurations
Measured Live Load Compared to Measured Dead Load of Completed Bridge
42
Live Load Test
Procedure:
2. The load values recorded for gages B1/2 and D1 during the completed bridge stage for all for instrumented micropiles were averaged to obtain averages of the final dead load of the bridge for the top of the casing and top of the bond zone
Pier 1, Top of Casing (B1/2) Example:
P1P1 = 362k
P11P1 = 101k
P4P1 = 211k
P16P1 = 152k
Average = 206.5k
Measured Live Load Compared to Measured Dead Load of Completed Bridge
43
Live Load Test
PIER 1 | ||||
Loading Position | Top of Micropile Average (kips) | % Dead Load, Top of Micropile | Top of Bond Zone Average (kips) | % Dead Load, Top of Bond Zone |
1 | 11.0 | 5.4 | 0.5 | 1.8 |
2 | 5.5 | 2.7 | 0.3 | 1.1 |
3 | 6.8 | 3.3 | 0.4 | 1.3 |
4 | 9.3 | 4.5 | 0.5 | 1.6 |
% =
Measured Live Load Compared to the Applied Load of the Four Trucks
44
Live Load Test
Objectives:
1. Determine how much of the live load was monitored by the instrumented micropiles
2. Compare the top of the cased lengths to the top of the bond zones of the instrumented micropiles
Measured Live Load Compared to Measured Dead Load of Completed Bridge
45
Live Load Test
%=
PIER 1 | ||||
Loading Position | Top of Micropile Average (kips) | % Live Load (4 trucks), Top of Micropile | Top of Bond Zone Average (kips) | % Live Load (4 trucks), Top of Bone Zone |
1 | 11.0 | 3.8 | 1.2 | 0.4 |
2 | 5.5 | 1.9 | 0.8 | 0.3 |
3 | 6.8 | 2.3 | 0.9 | 0.3 |
4 | 9.3 | 3.2 | 1.1 | 0.4 |
percentage of load as compared to the gages located at the top of
the bond zone
294k