This week we set out to rescue the South Path wall – The first wall we built.
After suffering damage from multiple torrential storms and downpours it has started to fail in a serious way.
We started the South Path wall way back in December 2015, and since that time numerous weather events have taken their toll on the wall and it’s supporting hill. This was topped off in March 2017 with the arrival of Ex-tropical Cyclone Debbie and the 400mm of rain we received in one day.
As you can see in the picture above, the wall is leaning downhill at a stark angle.
It should be leaning the other way… into the hill.
So to fix this we are adding some more supporting structures on the downside. We have previously done this on the uphill end of the South Path Wall where it first started failing.
The wall is failing in part due to the weather events we have suffered, but also because we ‘under-engineered’ it. We had assumed that the ground we were putting post holes in was natural ground, but this turned out to be not the case.
As we have found with other areas around the house, some of our ‘hill’ is pushed off earth from the time of building. This means that the ground is weaker and softer and requires a bit more engineering when constructing on it.
If we had known what we know now we would have made our post holes for this wall much bigger, deeper and we would have sloped the wall back on a greater angle to stop the slip and subsidence.
So we have now added 4 new below-wall supports.
Like the previous ones(visible in the picture above), these supports consist of a new post dug into the ground below the wall with a significant slope back towards the wall(approx 100), a supporting cross beam, and two additions to support the cross beam.
The hardest part was digging the post holes on our the steeply loped ground, but we got them done and got down around 1000-1200mm for each post. These posts only protrude from the ground for around 400-600mm.
Each was leveled and straightened as close as possible to the original wall angle, and then concreted in place.
Each post will have a piece of treated pine sleeper(200mm x 200mm) attached to it’s top to support the cross beam.
We will finish them off tomorrow when the concrete has hardend.