Most people know that civil engineers design roads, bridges, dams, and subway tunnels. Indeed, this millennia-old profession has given us the public infrastructure that we so routinely use in our modern lives.
Whether you’re building a new house or your existing home has a leaky basement, a civil engineer’s input can help you keep the floods away. If you live in a rural area, civil engineers can design a safe, reliable sanitary system to last you for decades. If you’re living or building on a hillside, a civil engineer’s expertise can help reduce the risk of landslides and flooding.
Grading, septic tank design, erosion control, and retaining wall design are just some of the many ways civil engineers can help home and business owners and builders.
Are you building a new house? Does the home you live in have cracks in its concrete foundation? Does your basement leak? If you answered yes to any of these questions, you may need a civil engineer to analyze your site’s grading or draft a new grading design for your site.
Grading is the process of adding, removing, and compacting soil to alter a site’s topography. It may be used to prepare the site for a new structure, prevent the accumulation of rainwater, or shape your desired landscape features.
Buildings erected on soil that’s loose, expansive, or lacking in bearing capacity may settle over time. This settlement may cause serious structural damage to the building. A quality grading design will ensure that foundations are placed on firm, level, and stable soil.
Drainage is another key element of grading; poor drainage can pose a threat to your building’s structure and envelope. If rainwater is allowed to accumulate on the site, it may find its way to your building and eventually penetrate its exterior, while the hydrostatic pressure exerted by water-saturated soils may lead to cracks in the concrete foundation.
Good drainage entails that rainwater is channeled away from your building, and into an outfall location - ideally, a storm sewer.
Drainage may be designed around existing topography; for example, a home’s strategic placement at a high elevation will ensure that rainwater drains away. Likewise, a backyard pond can make a great natural outfall if channeling water to a storm sewer proves too difficult.
If existing conditions do not allow for adequate drainage, engineers will have to incorporate new features into the site’s grading design. Berms, swales, ridgelines, and valleys may all be used to direct rainwater runoff away from the building and into the storm system.
In the process of achieving adequate drainage and preparing the site for a building’s foundation, the grading design should also factor in your vision of the landscape that surrounds your home. Aesthetic features, such as ponds, waterfalls, and gardens may be incorporated as you see fit.
A septic tank is a rudimentary on-site sewage facility, primarily used in areas without a sewer system. It consists of two parts - a treatment tank, and a leach field.
The tank is usually a 1,000 or 2,000-gallon container, made of plastic, fiberglass, or concrete, into which household wastewater flows for treatment. Septic tanks typically have 2 chambers, separated by a wall with an opening halfway between the top and bottom of the tank.
Upon entering the first chamber, wastewater accumulates until its level reaches the opening in the dividing wall; this time allows the solids in the water to settle. In the second chamber, the remaining solids continue to settle while the water rises to an outlet and eventually drains into a leach field, where soil absorbs the leftover pollutants. The sludge that piles up in the tanks gets periodically pumped by a vacuum truck. A well-designed septic system can last for decades without producing an odor or contaminating the environment.
Not all jurisdictions allow septic systems and those that do require a permit for them. When considering a septic system permit application, building departments typically assess the system’s ability to process wastewater without polluting the surroundings. A test of the leach field soil’s absorption capacity, called a percolation test, is a common requirement.
If you want a septic tank system to work without flaws and serve you for a long time, consider hiring a civil engineer to design it. An engineer’s input will also help to secure your permit without delay and get your system installed as soon as possible.
Erosion is a process through which water washes away soil. If you’re building or living on a hillside, erosion poses a tangible threat to your building. Left uncontrolled, it can destabilize the soil around your structure and cause landslides. It can also affect local ecosystems and clog up storm-water systems with sediment deposits.
Civil engineers are experts in erosion control. These professionals can assess a site’s erosion risk and design measures to prevent it. These may include erosion mats, certain types of vegetation cover, and the appropriate channeling of rainwater.
If you’re building a home beneath a hill, the soil above you will always move; if it absorbs enough rainwater, or gets rattled by an earthquake, this movement may accelerate into a landslide. Even if your site is relatively flat, but the grading design involves excavating parts of a hill, chances are the soil that’s left standing will want to come down. In these scenarios, you will need to install a retaining wall - a barrier to hold the unsupported soil.
There are several types of retaining walls - gravity, cantilevered, anchored, and piling. All achieve a similar objective - holding back soil - with a slightly different mechanism. Gravity walls rely on their mass to support the soil’s pressure. Cantilevered walls convert the soil’s horizontal pressure into a vertical load and create a path for it to the ground. Anchored walls are strengthened by tension cables or other devices which are secured to the soil or rock behind them. Piling walls are built against piles that are driven into the ground.
Does your site have loose or unsupported soil? A licensed civil engineer can choose the right type of retaining wall to meet the unique needs of your site, and design them to add visual appeal.
Whether your project is residential or commercial, Design Everest’s civil engineers are ready to give you a hand with drainage, septic tanks, erosion control, retaining walls, and much more. Call us at (877) 704-5727 or email us at firstname.lastname@example.org for a FREE quote and consultation.