Pittsburgh Geologist

The Importance of a Professional Geologist in Pittsburgh

The Greater Pittsburgh Area is notorious for soil instability because of the difficult combination of steep slopes, a clay based soil, lots of human alteration of the landscape, and a wet climate. With the wrong combination of factors, slope failures and cracking foundations on new and old structures occur. Since the type and strength of the soil is a key component in this equation an experienced geologist is needed to determine these parameters through soil testing. Hiring a Professional Geologist (a geologist who holds a certification license from the state of Pennsylvania) lets you know that your are hiring a competent professional who will provide the right information to determine the stability of your planned construction in the Pittsburgh Area.

To learn more about Professional licensure for Professional Geologists, click the link here:

https://www.pa.gov/agencies/dos/department-and-offices/bpoa/boards-commissions/engineers-land-surveyors-geologists/professional-geologist-licensure-snapshot.html

Causes of Landslides in the Greater Pittsburgh Area

Identifying the cause of a landslide is an important part of mitigating or preventing any damage it may cause. They can be caused by any combination of several contributing factors including:

Slope steepness.
Relatively weak soil and/or underlying rock.
Soil Saturation
Human alteration of a site.

Changing water content and weathered rock are the most frequent triggers for landslides:

Water content changes over time. The clay-rich soils and weathered rocks common in the greater Pittsburgh area readily absorb moisture and soften.
Landslides may move as a solid block of soil sliding on a weak layer or as a very thick fluid, flowing like wet concrete or oatmeal, deforming as it flows. Increased soil moisture can soften the key material and has been shown to either initiate or accelerate movement.
The Pittsburgh Red Beds (as well as other red bed layers) are a layer of claystone rock that deteriorate when exposed to water. When deteriorated, this layer can act like a lubricated plane for all material above to slide.

Soil Saturation

Excess water causes soil to become buoyant, reducing its ability to support material above it. Soil also becomes heavier when wet, meaning a saturated slope will have more weight supported by weaker material. The result is a landslide which typically reaches equilibrium at the bottom of the slope.

Identifying sources of saturation on a given slope is the first step to designing a solution. Precipitation is just one possible source of soil saturation. The following sources may also be contributing to the saturation and weakening of a slope:

Broken or leaking utility lines (water, sanitary and/or stormwater).
- Research utility lines in the area for trouble spots. Televise stormwater lines to determine if they are contributing to the saturation of the slope
Mine drainage.
- Review mine maps for possible mines in the area.
- Check local streams for discoloration or odors.
Underground Springs.
- Check topographic and geological maps for the presence of shale layers and low permeable soil (clays).
Roof downspouts emptying over hillsides.
- Field view possible contributing factors from adjacent structures.
- Check for clogging of drain pipe from landscape debris.
Clogged stormwater inlets may direct excess water to slide prone areas.
- Inlets may clog from soil erosion washing into the basin and settling out.
- Foliage (heavier in the fall), and roadway debris.

Human Alterations

Residents and businesses may make changes to their properties which contribute to a landslide. Such changes can include:

Removal of Embankment toe areas to extend flat space or extend yards:
- Toe support is reduced making hillside or embankment less stable.
Use of Non-engineered fill to construct embankments:
- Material is sometimes dumped and spread out to extend property features (driveways, yard space, or parking areas).
- Material used is often unsuitable and placed without proper compaction.

Allegheny Land Slide Portal

The above information is taken from the Alleghany Land Slide Portal, which summarizes information from PennDOT and the Allegheny County DPW.

Why Choose Hickman Consulting Services

Hickman Consluting Services has been helping commercial construction and residential customers with their soil testing needs for over a decade. Our process is simple. We answer your call, identify your issue, ask how else we can help, and get an engagement for our services to you quickly.

When we say that HCS will answer your call, we mean it. During our working hours, a live HCS representative will be on hand to answer your call or return call promptly.

With years in the business, we will identify your needs with simple and respectful questions about your project needs. To avoid additional costs, if there is something we need to understand we will use the technology to help. This may involve referencing satellite imagery or having the client send us photographs or live video of the need.

If we are your first call, we will help you line up other professionals to solve your issue. This can include surveyers, professional engineers, and construction companies that will all see your project through to the end.

Our engagements are comprehensive, yet easily understood. You will get a fair estimate of the cost of our services so that you know up front what to include in your project budget.

PittsburgH Geologist

Your Key to Successful Building Projects