Site Update: Platform Recertified & Vibration Monitoring

Good morning! It’s just a quick site update.

We didn’t have much going on with the sheet piling team at first—then suddenly, everything ramped up.

What happened after the testing

Earlier, the platform was certified by the geotechnical engineer. That certification confirmed it could achieve 250 kPa bearing, and we confirmed that with nuclear density testing.

We received results of:

95% on one test site
97% on the other

The geotech report required results to be above 93%, so we met the threshold.

Heavy rain—and a new certification

Last week, we completed the testing. Then we had 4–5 days of serious rain, which flooded the site. The ground was still extremely hard, but because it was a rain event, we needed the engineer to reissue a certificate stating the platform was still certified.

We only received that recertification this morning. The sheet piling company needs it before they can set up on site.

Today’s work: recertification + drainage upgrades

This morning, the geotechnical engineer came back and re-certified the platform for water conditions.

We also brought in two truckloads of road base. The goal was to improve drainage by building a gentle hump in the middle so water flows toward the sides. We also installed sump points along the edges (you can’t fully see them yet).

To pump the water out, we used a:

bucket with a hole in the bottom
sump pump with layflat pipe and a few joiners
short pipe setup into the low point

We set up one pump on the side initially, then another where we had a low spot in the center.

After the gravel was laid, we brought in the 14-ton roller and recompacted the platform.

The trade-off (and why we had to move fast)

Because the ground underneath was still wet, we’re essentially creating a lamination layer—not an ideal setup but this was requested by the contractor so we complied and had the platform reinspected. The “perfect” way would be to wait about two weeks for everything to dry, but we don’t have that time luxury right now, nor do we want to pay re-mobilisation costs to the contractor to reschedule the allocated staff and machinery.

And once the 40-ton machine starts moving around, any loose layers can get damaged—so time matters.

Sheet piling setup is underway

The guys are currently rigging up the equipment. They’ve taken possession of the site, so we’re staying out of their way and letting them do what they do. The sheet piling work will be off-hired this afternoon, and they’ll complete their setup.

Vibration monitoring is installed

We also had the geotech team back today to install and run vibration monitoring.

We’ve installed three sensor points:

one on this side
one at the second location (and another point to complete the set)

We’re also marking everything clearly with grid lines and marking where the external walls will sit (the blue lines). I’ve also given the required height for the sheet piles so we don’t need to cut the tops later.

Monitoring tech (and big thanks)

This vibration monitoring system took about two days to configure.

Huge thanks to Bruno at Convergence Instruments (Canada)—I’m not sure if it’s Alberta or Calgary, but the instrument is fantastic and very affordable. The subscription is about $185/year, and data is streamed for monitoring.

We also set up a Ubiquiti router to broadcast and connect the devices. Right now, those devices are the only ones on the network.

We’re using PacGeo’s vibration monitor, and the fence area is equipped for monitoring so we have coverage at three points. The geotech team will receive alerts if anything looks off.

We also have our own real-time monitoring running on-site.