7-Structural Assessment Report - Hopewell MS Bridge.pdf

STRUCTURAL ASSESSMENT REPORT

LOCATION: Hopewell Middle School - Bridge

CLIENT: Fulton County Schools

INSPECTOR: Daniel Chiles, P.E., S.E.

DATE: December 15th, 2025

PURPOSE OF INSPECTION:

The purpose of our visit to Hopewell Middle School was to inspect large holes in the deck of the wooden pedestrian bridge which connects the main campus to the athletic fields to the west. Additionally, we surveyed the condition of the entire bridge structure so that we could make repair recommendations that may increase the lifespan of the structure.

DESCRIPTION OF STRUCTURE:

The wood framed pedestrian bridge spans a ravine with a small creek. The overall length of the bridge is roughly 85 feet, and the width of the bridge deck is roughly 9’-4”. Continuous steel guardrails line each side of the bridge – these guardrails are through bolted to the primary bridge posts. The bridge deck consists of 2x4s which have been oriented vertically.

The joints in the deck boards are staggered to create a continuous deck appearance. The main structure of the bridge consists of 8x8 posts spaced at roughly

10’-2” on center. The tops of the post extend past the top elevation of the guardrail and are cut at an angle with the hopes of allowing water to drain off the top of the posts. The bridge deck is then supported at each set of posts by a set of (2) 3 ½” x

11” beams. These beams sandwich the 8x8 posts and are through bolted with 3 galvanized bolts at each end. The 8x8 posts are supported by large cylindrical concrete piers. Galvanized steel baseplates have been provided to attach post to foundation.

Figure 1 - Wood Bridge Location

Figure 2 - Wood Bridge looking along top deck

For lateral stability, diagonal 2x8 “X” – Bracing has been provided between each set of posts in the bridge transverse dirction as a well as between each column in the longitudinal direction.

INVESTIGATION:

The primary reason for investigating the bridge structure was the condition of the bridge deck.

Generally, the bridge deck shows some signs of rot and deterioration. This could be because of the unique construction of the bridge deck – the vertical

2x4 members were fastened tightly together – which doesn’t allow water to easily drain off the bridge deck. This will eventually lead to soft spots which will then accelerate the decay of the bridge deck. Figure

3 shows how in the worst spot decay and rot have created a significant safety hazard as a 4-foot-long section of deck has fallen out. The hole shown in

Figure 3 was more easily created because of the way the deck boards were spliced. Figure 4 shows the staggered splice – here the rot occurred to the right of the splice. Once significantly weakened enough the deck failed and hinged on the splice location.

There were other areas which showed that there had been previous issues with the bridge deck – Figure 5 shows a previous repair at a different splice location.

Overall, the bridge deck has reached the end of its service life and is due to be replaced.

Figure 3 - Hole in bridge deck from above

Figure 4 - Hole in bridge deck from below

The superstructure, being defined as the main supports of the bridge – including the 3 ½” x 11” beams, the 8”x8” posts, and “X” bracing, were in generally good condition. There were a few issues noted. Figure 6 shows the split of a spacer block between a set of “X” bracing. Additionally, Figure 7 shows a split of one of the 2x8 “X” bracings. These damaged areas are considered minor in nature. The damaged items shown can be replaced with members matching the existing size.

Figure 6 - Split "X" Bracing Spacer

Figure 5 - Previous Repair to Bridge Deck

The 8”x8” posts did show some varying signs of decay which can be seen in Figure 8. The tops of the posts were sloped to encourage water to drain.

Despite this, over years water has saturated the tops of the post and rot and decay have occurred.

The connection of the posts to the foundations and the foundations themselves appeared to be in good condition – though care should be taken to remove dirt and leaves from the tops of the concrete piers.

This will help prevent the decay of the timber 8x8 posts at this location.

Figure 7 - Split diagonal brace

Figure 8 - Decay at top of wood post

The guardrail system appeared to be in fair condition. Figure 9 shows the typical through-bolted connection to the guardrail system. It appears that the connection is “cutting” into the hole of the 8x8 post – causing a downward deflection of the guardrail system. At another point it appears that a tree fell on the guardrail (Figure 10) which broke the connection to the 8x8 post. A repair was performed by installing a post and baseplate to the top surface of the deck. Repair to the guardrail – post connection should be performed.

RECOMMENDED REPAIRS

Starting with the bridge deck, replacement is recommended. Existing bridge deck should be removed. To avoid future problems with water pooling on the bridge deck surface it is recommended to replace it with a more traditional decking layout. This can be achieved by installing new floor joist connecting to the main 3 ½” x 11” beams. Then traditional 1” x decking can be installed spanning in the bridge transverse direction. Southern

A&E plans to provide Fulton County Schools with detailed drawings with these repairs included at a future date.

Issues relating to the “X” bracing system illustrated in

Figures 6 and 7 should be repaired by replacing the damaged items with the same sized item.

Rotting of the tops of the 8x8 posts can be repaired by removing any loose rot and filling the hole with an epoxy based filler material. The posts should then have a permanent metal cap installed to keep water from entering the post and causing further decay.

When it comes to the guardrail system, the guardrails themselves do not necessarily need to be replaced. Though, damage from falling limbs/trees have caused the railings to become bent – The owner may prefer this system be completely replaced for aesthetic reasons. From a safety perspective, at a minimum the connection between the railing and the

8x8 posts should be reworked. This can be done by welding a threaded rod to a square plate. Then the connection can be made between top and bottom guardrails to the square plate. On the reverse side of

Figure 9 - Damage to railing

Figure 10 - Previous damage to railing the 8x8 post the threaded rod will go through a plate washer and be tightened with a bolted connection.

As stated previously, these repairs will be highlighted and detailed on a set of future repair drawings provided by Southern A&E.

If you have any questions, please let me know.

Sincerely, Daniel Chiles, P.E., S.E.