Orlando's subsurface profile creates specific challenges that the IBC and ASCE 7 address through strict ground improvement standards. Many sites across the city sit on loose to medium-dense sands with occasional silty lenses, and the water table is often just a few feet below grade. We design vibrocompaction layouts that densify these granular deposits and reduce the risk of differential settlement under structural loads. Our approach integrates field data from spt-drilling to calibrate target relative density, and we verify particle distribution with grain-size analysis before finalizing the probe grid. Each design accounts for the city's humid subtropical climate, where seasonal rainfall can temporarily raise the groundwater and alter compaction efficiency during construction.
Targeting 70 percent relative density after vibrocompaction transforms loose Orlando sands into a reliable bearing stratum without importing fill.
Top questions
What does vibrocompaction design typically cost for an Orlando site?
Design fees for vibrocompaction in the Orlando area range from US$1,320 to US$5,660 depending on the size of the treatment area, the number of pre-treatment borings required, and the complexity of the subsurface conditions. A small commercial lot with straightforward sand profiles falls toward the lower end, while a multi-acre site with variable stratigraphy and karst investigation requirements moves toward the upper range.
How deep can vibrocompaction effectively treat the loose sands found in Orlando?
In the sandy deposits common across Orlando, vibrocompaction can typically reach depths of 15 to 35 feet below grade. The practical limit depends on the water table position, the presence of cohesive interbeds, and the proximity to the limestone rockhead that underlies much of Orange County.
Why is a pre-treatment SPT program necessary before designing the vibrocompaction grid?
The SPT borings provide the baseline blow count profile that the design uses to calculate the required energy input and probe spacing. Without this data, we cannot quantify the initial relative density or identify thin layers that might block the vibratory energy from propagating through the full treatment depth.
How do you verify that the ground improvement actually worked?
We specify post-compaction CPT soundings at locations offset from the probe points. Comparing the tip resistance and sleeve friction before and after treatment confirms whether the target relative density has been reached. We also review the ammeter records from the vibro rig itself, which show the power draw at each probe location as the sand densifies.
