Shoring and excavation are under way at 4230 Raleigh Street.

Prior to actually getting the foundation for 4230 Raleigh Streetbuilt, we are installing shoring piers along the edges of the adjacent property boundaries. Below I will run you through some photos of the work but it might be worth a little explanation on what exactly shoring is and why it is necessary.

Shoring is used to provide lateral support. In our case, we are providing lateral support to the earth adjacent to 4230 Raleigh Street. While it may not be obvious, digging a large hole for our foundation and basement will actually pose a risk to the stability of the adjacent structures. The adjacent homes are approximately 100 years old and most of the soil around their foundations has been untouched since the original structures were built. If we dig a hole the soil around it loses lateral support and often times the soil collapses into the hole. Scale this up and you can see why there is a need for lateral support for our neighbors. Without shoring, there is a very real potential for movement of the neighboring soils and ultimately settlement and damage to the neighboring foundations.

We are using similar methods for both the shoring installation that you will see below and the actual drilled pier foundation that the home will rest on in the near future. The shoring piers are made of concrete and contain steel rebar reinforcement cages to provide bending strength for the lateral and shear forces they will incur as a result of the earth they will be retaining. Our piers are 10″ in diameter and 20′ deep. spaced at approximately 4′ on center. They are placed 6″ inside the property line so that they are out of the way of the future foundation and provide maximum benefit to the adjacent structures. There will be a line of shoring piers along both the north and south property boundaries. The front and back of the house (the house faces west) will be graded as necessary to prevent collapse of soils into the hole.

The pier installation procedure is pretty simple. A drilling rig is brought onto the site and the pier holes are drilled in sequence.

Next the contractor slides the reinforcing cages into the pier hole.

Then a concrete pump truck is used to fill each pier hole with concrete.

The procedure is repeated until the entire line of shoring piers is in place.

Once the piers are in place, the contractor backfills and levels soil on top of them. They will be left in place as the piers cause no harm once they are no longer needed and they would be prohibitively expensive to remove.  If required, the piers may be cut down so that they do not interfere with the final landscaping and it’s associated irrigation system as well as the future privacy fence encompassing the back yard.

While not quite as fun to watch as the demolition, the installation of the shoring piers means we can move on to the foundation excavation and form setting in about a week. From there things will start to take shape.