Small Military Steel Bridges/various Span Steel Bridge

One notable example of a bridge that has been in use for a long time with galvanized steel is the **Stearns Bayou Bridge** in Ottawa County, Michigan. Constructed in 1966, this bridge was the first hot-dip galvanized steel bridge in the United States. The bridge has stood the test of time, demonstrating the durability and low maintenance requirements of galvanized steel.

Stearns Bayou Bridge
- **Construction Year**: 1966
- **Length**: 420 feet (128 meters)
- **Location**: Ottawa County, Michigan, USA
- **Design**: The bridge consists of eight spans, with two 60-foot and six 50-foot sections of 30-inch, 108-pound rolled steel beams.
- **Galvanizing**: All fasteners, handrails, diaphragms, shear connectors, and fittings were hot-dip galvanized.

Performance Over Time
- **Initial Inspection (1991)**: After 25 years, the bridge showed no signs of corrosion or staining. The galvanized coating was particularly effective at splice joints and bolted connections.
- **Coating Thickness**: In 1991, the main structural beams had an average zinc coating thickness of 6.2 mils, with a minimum of 4 mils and a maximum of 10.5 mils.
- **Long-term Projections**: Based on the 1991 inspection, estimates suggested that the bridge beams would not need maintenance for another 90 years.
- **Recent Inspection (2017)**: After 51 years, the bridge still showed no signs of corrosion on the superstructure beams or underside. The galvanized steel maintained a spangled appearance, indicating minimal wear.

Impact and Legacy
The Stearns Bayou Bridge has set a precedent for the use of galvanized steel in bridge construction. Its performance has influenced subsequent projects, such as the reconstruction of the nearby Fruitport Road Bridge in 2008, which also utilized hot-dip galvanizing. The bridge's longevity and maintenance-free service highlight the economic and environmental benefits of using galvanized steel in infrastructure projects.

The Stearns Bayou Bridge stands as a testament to the durability and sustainability of hot-dip galvanized steel, proving its effectiveness in providing long-term corrosion protection with minimal maintenance.

Specifications:

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CB200 Truss Press Limited Table
NO.	Internal Force	Structure Form
		Not Reinforced Model				Reinforced Model
		SS	DS	TS	QS	SSR	DSR	TSR	QSR
200	Standard Truss Moment(kN.m)	1034.3	2027.2	2978.8	3930.3	2165.4	4244.2	6236.4	8228.6
200	Standard Truss Shear (kN)	222.1	435.3	639.6	843.9	222.1	435.3	639.6	843.9
201	High Bending Truss Moment(kN.m)	1593.2	3122.8	4585.5	6054.3	3335.8	6538.2	9607.1	12676.1
202	High Bending Truss Shear(kN)	348	696	1044	1392	348	696	1044	1392
203	Shear Force of Super High Shear Truss(kN)	509.8	999.2	1468.2	1937.2	509.8	999.2	1468.2	1937.2

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CB200 Table of Geometric Characteristics of Truss Bridge(Half Bridge)
Structure	Geometric Characteristics
	Geometric Characteristics	Chord Area(cm2)	Section Properties(cm3)	Moment of Inertia(cm4)
ss	SS	25.48	5437	580174
	SSR	50.96	10875	1160348
DS	DS	50.96	10875	1160348
	DSR1	76.44	16312	1740522
	DSR2	101.92	21750	2320696
TS	TS	76.44	16312	1740522
	TSR2	127.4	27185	2900870
	TSR3	152.88	32625	3481044
QS	QS	101.92	21750	2320696
	QSR3	178.36	38059	4061218
	QSR4	203.84	43500	4641392

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CB321(100) Truss Press Limited Table
No.	Lnternal Force	Structure Form
		Not Reinforced Model				Reinforced Model
		SS	DS	TS	DDR	SSR	DSR	TSR	DDR
321(100)	Standard Truss Moment(kN.m)	788.2	1576.4	2246.4	3265.4	1687.5	3375	4809.4	6750
321(100)	Standard Truss Shear (kN)	245.2	490.5	698.9	490.5	245.2	490.5	698.9	490.5
321 (100) Table of geometric characteristics of truss bridge(Half bridge)
Type No.	Geometric Characteristics	Structure Form
		Not Reinforced Model				Reinforced Model
		SS	DS	TS	DDR	SSR	DSR	TSR	DDR
321(100)	Section properties(cm3)	3578.5	7157.1	10735.6	14817.9	7699.1	15398.3	23097.4	30641.7
321(100)	Moment of inertia(cm4)	250497.2	500994.4	751491.6	2148588.8	577434.4	1154868.8	1732303.2	4596255.2

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Advantage

Possessing the features of simple structure,
convenient transport, speedy erection
easy disassembling,
heavy loading capacity,
great stability and long fatigue life
being capable of an alternative span, loading capacity