May 2021: Soil (Geotechnical) Engineering

 

 

 

Office: 843 846 2500
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May 2021
Number 87

Samuel Isaac Burdick, 4 months old

Kandy and I have spent the past few days having a very nice visit with our son and his family near Springfield, Missouri. We got to meet little Samuel, our 37th grandchild and our 24th grandson. He joined their family on December 20, 2020. As I finish this newsletter, we are on our way back home. 
 

From the Desk of Abbey

Am I a Wrecker or a Builder?
by Edgar Albert Guest

I watched them tearing a building down,
A gang of men in a busy town.
With a ho-heave-ho and lusty yell,
They swung a beam and a sidewall fell.
 
I asked the foreman, “Are these men skilled,
The men you’d hire if you had to build?”
 
He gave me a laugh and said, “No indeed!
Just common labor is all I need.
I can easily wreck in a day or two
What builders have taken a year to do.”
 
And I thought to myself as I went my way,
Which of these two roles have I tried to play?
 
Am I a builder who works with care,
Measuring life by the rule and square?
Am I shaping my deeds by a well-made plan,
Patiently doing the best I can?
 
Or am I a wrecker who walks the town,
Content with the labor of tearing down?
 
I recently heard this poem on the local Christian radio station while I was driving between jobs. I had never heard it before and it really started me thinking. I liked the reminder of how important it is to be the “builder” and not the “wrecker” – both in business and personal life. Every decision we make and every word we say affects someone, somewhere, either negatively or positively. We should be sure to stop sometimes and ask ourselves, “Am I being a wrecker or a builder?” I certainly hope the answer is, more often than not, “Builder”!
 
Now, on to matters of your home! It is that time of year when people are wrapping things up and getting ready to head to cooler climates before the heat and humidity arrive to stay! I have heard there are predictions of a busy hurricane season as well as promises of very hot weather, but be encouraged, I feel quite certain that we will survive this Summer just as we have so many in the past!
 
We have a full schedule over the Summer with new builds and remodels and additions! We have a lot going on and are very excited about what we will be able to accomplish by the time Fall arrives and everyone is returning! Mandy will still be doing house checks and sending out reports and we will still be taking care of your home maintenance as needed!
 
Please remember a couple of things that help keep your home from having issues with humidity:
 
  1. The “fan” setting on your thermostats should always be set to Auto during the higher humidity months. When temperatures are cold, running the fan can help distribute the warm air throughout the house. If the fan runs during the higher humidity months, it will actually pull more humidity into the house and create problems.
  2. If you have vaulted ceilings, remember to keep your ceiling fans on a higher speed to keep the air moving. Humidity rises and it is best to keep one fan pulling the humidity down from the peak and another fan (if you have two ceiling fans in the vaulted room) pushing the less humid air into the peak so it creates a cycle of air that is less likely to cause mildew in places that are hard to clean. If you only have one fan, we recommend setting it to blow down in the summer so that the hot, humid air at the top is forced down where it can be cooled.
  3. If you have cleaners coming in to pick up bugs, clean toilets, etc. every couple of weeks, ask them to run the bath fans while they are working. That helps with air exchange so the houses have a chance to ‘breathe’.
  4. If you are leaving any vehicles on Brays, it is a good idea to leave a hanging bag of DampRid in the vehicles to help absorb any extra moisture even if your garage is climate controlled.
Those are just a few items that may help with the high humidity we experience yearly! If you have any questions please feel free to contact us and we will help in any way we can.
 
Have a wonderful spring and safe travels to all of you in the months ahead!
 

Soil (Geotechnical) Engineering

Soil Engineering or more properly, Geotechnical Engineering, is a branch of Civil Engineering that is concerned with the behavior of earth materials. Basically, it deals with the density, moisture content and composition of soil. Clearly, a home cannot be built on loose soil, but how much should the soil be packed and what if it won’t pack enough because of moisture content or the composition of soil? What happens then? The soil engineer can determine if soil is suitable for construction and if it is not, what can be done to insure the ground will support a home (or other structure) properly?

Soil Engineering is a relatively new branch although its need was demonstrated about 850 years ago in the town of Pisa, Italy. 

The now famous Leaning Tower of Pisa  was built on soil that was not sufficiently compacted. As the tower was being built (starting in 1173), it began to lean because of the soft soil under it.
 
By the time it was completed in 1372, the 183 foot high tower was leaning noticeably. By 1990, the lean was 5.5 degrees. Work was done to stabilize the soil and the lean was reduced to about 4 degrees and (hopefully) stabilized so it should not lean more. (I suppose, it somehow seemed wrong to plumb the “leaning” tower so it was no longer leaning.)
 

In many areas of the country Soil Engineers don’t get involved with residential construction, but here in the Lowcountry, they are very important. The water table here is high and moisture content of the soil is frequently an issue. Organic matter in the soil composition can also cause density issues. 

One of the specific applications of soil engineering is to insure the soil in the footer of a home is compacted enough that it won’t sink over time and cause cracks in the foundation. If a slab is poured, several locations under the slab will also be tested to make sure the support is solid.

If the soil is not compacted enough, then the soil engineer will suggest a remedial action. These could include excavation and filling with a known dense material (gravel, for example), adding pilings or other actions. Once that is complete, the soil will be retested. Once the compaction tests are satisfied, construction can begin. 

There are several methods of testing soil compaction. Probably the simplest one is a probe that is pressed into the ground. Typically, there is a meter on the probe handle that indicates how much pressure is required to penetrate the soil. There are also nuclear and electrical test devices that can be used.
 
The technician in this photo is from a testing lab. He is checking the soil density using a probe, the most commonly used tool for testing soil compaction in our area. 
 

In addition to testing soil compaction, soil engineers deal with water soaked ground. If the water table is too high, the ground will be soft and not support the weight of a home. Often shallow post holes are dug to determine the water level.

If the water table is too high, then dewatering is needed to insure the ground below a (future) home will be dry. Once the weight from the home is in place, water will not be able to get under it and cause bearing problems.  

 Dewatering involves digging a trench, usually downhill from the home site, which then has about 6 inches of gravel placed in it. Water from the moisture laden soil can flow through the gravel to a pump which is also installed in the trench. The gravel is then covered with soil until the trench is completely filled (except for the pump well). The pump float enables the pump to run until sufficient water has drained from the soil. Once the home is constructed and weight is on the foundation, the pump is removed and the pump well filled.
 
Of course with dewatering, the footers and slab areas are checked for soil compaction before any concrete is poured just as they would be if dewatering was not required.
 
A well built home requires a good foundation and a good foundation requires solid support. Geotechnical Engineers play a critical role making sure the soil is solid.
 
If you have any questions about soil testing or any other construction related question, call or text us (843 846 2500). We can help. No charge or obligation on your part. 
 
 Next month, we will review hurricane preparation. Our hurricane season begins on June 1 and runs through the end of November.
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