North West Regional Group: The engineering geology of Florida - April 2020

A recording of the North West Regional Group online meeting which took place on Thursday 30 April 2020.
"The engineering geology of Florida: a guide to managing ground risk in the Sunshine State", by David Wilshaw.
Florida has an unusual geology, characterised by its paucity of exposed rock and its variety of geologically young soil deposits. Eogenetic karst processes dominate the landscape and influence most construction projects, either through the complex interrelationships between the surficial and Floridan aquifers or through the risks associated with developing in areas impacted by past or future sinkhole activity.
Geotechnically, Florida soils do not behave like soils found elsewhere in the United States. Many geotechnical engineers who move to Florida do not have an appreciation of the unconsolidated behaviour of deeper soil layers and the somewhat counter-intuitive reduction in soil stiffness with depth.
This presentation puts the depositional history of the shallow soil layers into context and explains their stress history from a geologic perspective. The exploitation of natural resources (such as economic minerals and groundwater) in certain areas of the State over the last 50 years has further changed the way the ground might behave during construction. The geologic history of sea level change and the challenges associated with coastal development are of direct relevance to the design process.
Finally, the limitations and challenges of applying standard geotechnical and geophysical exploration techniques to the geologic conditions unique to Florida must be appreciated by both geotechnical engineers and by clients ordering such services.
David Wilshaw is President of Integrity Drilling and Geophysical Services, LLC, based in Florida, and has spent 35 years in the engineering geology, geotechnics and geo-environmental industry in the UK, Europe, the USA and the Caribbean. He is a Chartered Geologist and has appeared on television programmes about sinkholes.
His specialities include neutral evaluation of disputed sinkhole claims and forensic engineering geological assessments.

[@ChestrCopprpot]

From a random Floridian: Thanks for posting this. I was already familiar with most of the geological history and hydrology of Florida, but it was very interesting to learn about some of the engineering, economics, and politics of sinkholes. Plus it’s always fun to hear our town names pronounced with an English accent. Cheers!

[@cg9612]

Really useful and interesting information. Thank you for posting this.

[@csh727]

Thank you for this lecture! I live in the Pacific NW but visit my cousin in Sebring almost every year. I loved learning more about Florida geology!

[@greendeane1]

I remember the winter park sink hole well, and drive by it often.

[@PaulPassarelli]

When I started home shopping in Florida (2019) there was a lot of mis-information on sinkholes. I tried to do my homework, but lots of the data I gathered turned out to be wrong. My parcel has ~ 70ft of vertical drop from the top of the driveway to the back corner, and the erosion is something I never even imagined possible, based on my Southern New England background.

[@joedonzi9552]

David Wishaw excellent video , many tens of thousands of Floridians now deeply concerned with the issue of "subsidence" since the tragic failure and collapse of Champlain Towers. I would be very interested if you can issue another video on the topic of soil subsidence and building supertall residential buildings on the waterfront areas in Florida. Thanks in advance. Warm regards from Miami Beach , jo donzi

[@oomphale]

Thank you! Very informative, and will add to my toolbox as I navigate a move from Homestead to regions farther north.

[@stevemillar9591]

Hi, didn't get chance to watch the lecture live, but great to catch up on You Tube (First subscription to Geological Society on YT to). Thanks for a thorough and comprehensive geology of Florida, very interesting and great to understand a different areas geology :-)

[@nativeamericanaffairs1031]

Respectfully yours Etowahchutke Tribe wado

[@nativeamericanaffairs1031]

I can see and hear

[@Gioxtream]

Please help get a a good place to buy a house in florida.