Beluga Slough Boardwalk Installation
Techno Metal Post Alaska was awarded the subcontract to supply and install 200 posts for a City of Homer project to replace about 1000’ of boardwalk over a wetlands area. The original boardwalk was a floating plastic design that had become dangerous.
Before the contracts went out for bid, we were able to do some test installations with the City of Homer and our representatives from Quebec. During these tests we learned that the specified length of post would not support the desired loads as determined by the engineering firm. From the information gained by our tests, our engineers were able to specify the proper sized helix.
The project commenced in September; which was one of the rainiest and stormiest on record. Installing posts in a wetlands was difficult enough; but our light weight equipment kept us on schedule and (literally) above water with minimal impact to the surrounding environment.
We ended up installing our P3 model with 16’’ & 18’’ helices. The installed posts were 10.6’ in length and each helical pier met the ultimate bearing capacities specified in the plans.
The existing trail was removed and the route was surveyed for us by another subcontractor. Working with the surveyor we decided that we only needed 2’ offsets and height benchmarks every 48’; except for turns and viewing platforms as seen below. With these locations marked we began the installation.
The plotted route and terrain did not always agree with each other; we ran into old stumps, driftwood and even a part of an old boat embedded in the mud. We were able to install all of the 200 posts, as surveyed with a little chainsaw work. This photo highlights the tolerances and ability of our installations. We started this particular post (with 16’’ helix) beside the stump and directed it under once we were below it to get it into it’s surveyed location.
After installing the 200 posts, we doubled back and began the process of marking the heights and cutting the posts to their final height. All of this work was done by Techno Metal Post Alaska; including the marking and cutting the grade changes throughout the boardwalk.
Techno Metal Post Alaska provided the final design and materials for the brackets that were to be welded on the posts. The original plans called for a solid plate to be welded from below. We quickly realized that would be nearly impossible to do due to the post heights off grade, so we proposed an alternative design with bored hole to allow the welding to be done from above. This design change cut the welders time in the field by at least 1 week. The General Contractor’s welder was able to weld the 200 brackets in less than a weeks time.
Before we began the installation, the General Contractor asked us if we were confident enough in our installation ability to allow them to order the lumber pre-cut. Since we had done several test installations previously; we were confident that we could install the posts within the stated tolerances and save them quite a bit of money by eliminating the additional labor costs of cutting material to length in the field.
The General Contractor pre-assembled each 12’ unit and staged them in the parking lot until they were set on our posts.The pre-assembled units were placed on every other group of posts. The infill framing was completed with pre-cut lumber. Once the framing was set, they placed the grating over the frame.