Geological and Topographical Research

Central High School in Springfield, Missouri is located in a karst area.  Southwest Missouri's subteranean surface is a mixture of granite, marble and limestone.  When rain water mixes with limestone it creates carbonic acid.  Carbonic acid corrodes limestone and creates caves.  Some caves are far enough below the surface that they don't create structural problems for buildings.  Other caves are so close to the surface, they can create sink holes.  According the the Greene County web site, no known sink holes exist in the area surrounding Central High School.  http://www.springfieldmo.gov/stormwater/pdfs/sinkhole.pdf

The topography of Central High School is relatively flat.  However, from Central avenue to the Jordan Valley is a fifty foot drop.  Water drains southward toward the Jordan Valley and then westward toward the James River Basin.

There is little overburden in Springfield.  That is, you don't have to dig very deep to hit rocks.  Usually excavating less than a foot will reveal some rock.  Construction cost increases when excavating through rock. 

Building foundations need footings below the frost line.  The frost line in Springfield is 24" below the surface.  Larger buildings require deeper footings.  Buildings with basements require footings that are even deeper.  It is likely that rock will be encountered when excavating and preparing foundations for an addition at Central High School.