A Compatible Swarm Intelligence Model and Construction Method to Satisfy Bridge Design and Load Rating Requirements and Considering Geotechnical Variability
Presented at: Transportation Research Board (TRB) 101st Annual Meeting
Standing Committee on Foundations of Bridges and Other Structures (AKG70)
Chad Harden, PE, SE, Michael Baker International
January 11, 2022
Purpose & Need
Constraints complicate bridge construction:
Imagine a bridge construction method uncoupled from these constraints
2
1/7/2022
Purpose & Need
“The Proposal”
This paper proposes a basic population-based swarm intelligence algorithm, combined with current and developing technological capabilities, and following a specific construction staging methodology, which can construct a bridge over a complicated and previously unknown crossing geometry while satisfying conventional design code requirements.
3
1/7/2022
What is Swarm Intelligence?
Hydrophilic action of fire ants
“Emergence” and Collective Animal Behavior
4
1/7/2022
Video: Christian Jost (CRCA, Toulouse, FR) "Collective construction in social insects: coordination of the individual construction behavior & characterization of the emerging architectures". https://youtu.be/c9N56FkpfGQ
https://www.livescience.com/13867-raft-fire-ants-buoyancy-flood-water-repellant-floatation.html
Others: National Geographic Documentaries: Wild City of Ants
BBC Documentary: Natural World – Ant Attack
Simple Aggregation of Prey Fish
Termite Mounds
Combination of Fields
5
1/7/2022
Briseghella, B. et al. (2016)
Stuart-Smith, R. (2015)
http://statescoop.com/ohio-testing-drones-for-bridge-inspections
https://www.wired.de/collection/design/eine-brucke-aus-dem-3d-drucker-konstruiert-von-robotern
Design Algorithm
6
1/7/2022
Design Algorithm
The algorithm is not based on a current, living system, but rather is formulated from the basic needs in a logical order
7
1/7/2022
“…algorithms do not have to be designed after accurate or even true models of biological systems: efficiency, robustness, and flexibility are the driving criteria, not bio-logical accuracy.”
Bonabeau, Dorigo and Theraulaz (1999)
Comparison Structure
8
1/7/2022
Completed Bridge (Sketchup)
9
1/7/2022
Bridge Growth
10
1/7/2022
Completed Bridge (LumenRT Visualization)
11
1/7/2022
Effect of Geotechnical Variability
Diagram of Equivalent Column Quadrilateral Element
Representative Foundations
12
Spring Stiffness (kip / ft) | Comparable Pile Type (2 Pile Row) | Pile Capacity at 1/2-inch Displacement (kip) | Comparable subgrade modulus for 2’ x 10’ Spread Footing (pci) |
4,000 | 16” CIDH | 90 | 115 |
6,000 | -- | -- | 175 |
9,000 | 24” CIDH | 200 | 260 |
Effect of Geotechnical Variability
13
(a) Stiffness of 58,400 kN/m (4,000 kip/ft)
(b) Stiffness of 87,500 kN/m (6,000 kip/ft)
(c) Stiffness of 131,300 kN/m (9,000 kip/ft)
Applications
14
1/7/2022
http://contourcrafting.com/space-applications/
Thank you