Retaining Walls that Fail Civil Engineering Logic
In engineering there are certain things that scare me.
Civil engineering normally deals with buildings or the way land works with a building. This type of engineering can go very wrong. One of the biggest problems is people just building something just to build. What ends up happening? Big problems that are more than just scary, they can be life threatening. Take for instance a recent job site walk that I took. The owner bought a foreclosed property to do a beautiful a remodel and landscape the backyard for his family. The first concern of the homeowner was a retaining wall that was failing. I had taken a look at the survey and couldn’t understand what was happening, as the survey drew a wall on a backyard. Immediately when I took in the backyard I saw the problem. A retaining wall that was buckling. The odd part of the wall that was failing was that the wall was failing at the bottom causing the top of the wall to fall on itself. I am more used to seeing retaining walls fall over from the top like a domino.
So why does this wall stick out? First the wall appears to be a newer Keystone type wall. Newer retaining walls that are failing mean that either the wall was engineered wrong or the wall was installed improperly. The next thing that sticks out to me regarding this retaining wall is that there is no proper drainage on the top, a civil engineering norm. Normally a swale is used to control rainwater, unless the wall was built a long time ago, this is a civil engineering standard. The buckling of the wall from the middle to bottom, shows that water has permeated down through the soil and applying pressure to the bottom causing the failure. These clues lead me to believe that this was another non permitted wall being built by someone who does not know what they are doing. Let me stress that building a retaining wall is not something you just eyeball and start building.
What is this wall holding up? The wall is not only holding up the backyard of two properties. But this wall is also retaining an 8′ easement with a sewer line. Just imagine not only part of a property having a landslide, but also a sewer pipe breaking open, with at least two houses pouring into your beautiful backyard. For every one of these problem walls, a civil engineer should be hired.
I have seen plenty of plans where a hillside house is being remodeled and we are asked to draw up the grading plans. I take a look at the survey and notice that someone has already built the retaining walls. Without structural plans and soil report, I have no idea how a retaining wall can be built. As a civil engineering firm, we will take these projects on and call for the removal of the now existing walls. But this is very expensive to build nice looking walls and then remove and replace these non permitted walls.
This homeowner is facing the same issue. Except he bought the house in this state. We are going to engineer a good fix, that is cost effective as well. The waste of money involved on the part of the homeowner to fix a bad retaining wall makes me upset to see this stuff in the first place. Please hire the proper consultants when deciding to build or renovate as the repercussions can be life threatening.