Architects have the greatest influence on changes to our landscape. They determine how the skyline will look, where we will live, and how we think about our living environment. The appearance of our landscape is also determined by the civil engineers who plan and build our roadways and bridges. These structures are built for posterity. Taking into account the size of the investment in millions, even billions, of dollars, a sturdy, solid structure is the first requirement. However, the earth that these structures sit on is anything but sturdy and solid. For this reason, the architect and civil engineer need to begin the design process with a relationship with a geotechnical consultant. Geotechnical consultants have a full understanding of the properties of the earth and how structures must take these properties into account.
When we think of properties of the earth that can destabilize a structure, earthquakes are usually the first to come to mind. In places such as California that are spider-webbed with geological faults, earthquake-proofing is the first consideration. These geological faults are caused by the slow, gradual movement of the earth’s tectonic plates. As these plates move, they gradually grind their way against the neighboring plates. When buildings are to be built in these areas, the geotechnical engineer studies the structure of the fault lines and history of the area to determine how the foundation of the new building, roadway, or bridge must be configured so that it will not collapse if an earthquake strikes. It must be remembered that California isn’t the only area that has experienced earthquakes. They also occur in such unexpected areas as Missouri, Ohio, and North Carolina.
Earthquakes aren’t the only event that can undermine the foundation of a structure. Another two consist of landslides and rock falls, which are very similar. When these events happen, problems can occur at both ends. If the building it at the top of the hill, it can slide down. If it is at the bottom of the hill, it is in danger of being buried in falling debris, and people below can be injured by falling rocks. Falling rock zones can occur where the hill structure consists of rock such as limestone that contains many cracks. If water seeps into the cracks as winter approaches, the water can freeze. As we all know, when water freezes, it expands. This expanding ice acts like a wedge, stressing the cracks and causing crumbling. This crumbling rock then crashes down the slope.
Another earthly source of instability is underground water. The first place we think of with this potential problem is the watery State of Florida. Geotechnical engineers have to make sure that structures can not be undermined by sinkholes or soil liquefaction. Careful testing is needed because it may not be easily determined that an area is prone to sinkholes unless they have been seen historically.
But land isn’t the only location where a geotechnical study is needed. Waterside areas also need to be tested when a pier is or wharf is to be built.
It should now be obvious that consulting a geotechnical engineer is a vital first step in developing a new structure, whether it is a skyscraper, road, bridge, or wharf is to be built.
Connor R. Sullivan recently met with a skilled geotechnical consultant for an engineering project he is working on. He hired several geotechnical consultants for a road construction project.