The project consists of improvements to the Wood River Levee system. The improvements are along the Lower Wood River Levee system between the intersection of L-143 / Enviroway and IL-143 / Wood River Creek, in East Alton, Illinois. GFA International has performed quality control (QC) testing of the Deep Cut Off Wall’s Self-Hardening Slurry (SHS). The deep Cut Off Wall with permeability of not less than 1 x 10-6 extending to depths of upwards of 140 feet and 2,000 linear feet in length into the existing embankment with total thickness of 24 inches.

  • Provide soils and geotechnical engineering technicians to ensure compliance with geotechnical engineering details.
  • Mix design testing of proposed SHS for constant head permeability and unconfined compressive strength of controlled low strength material.
  • Pre-placement sampling and testing of the SHS for constant head permeability (permeability range of (1x10-6 to 9x10-9) and compressive strength. Over 6,000 pre-placement samples were cast.
  • Constructed on site testing laboratory and curing facilities and achieve US Army Corp of Engineers validation prior to start of seepage barrier.
  • To achieve the number of test samples an on-site testing laboratory was constructed with 20 constant head permeability test chambers and two 40-foot-long containers outfitted as curing room for samples.
  • Post placement testing of SBBM for permeability and compressive strength with samples collected from verification borings.
  • Verification HQ core borings with 95% recovery rate, over 600 lineal feet of verification core borings were performed on cut off wall material.
  • Post placement testing of SHS for hydraulic permeability and unconfined compressive strength from samples collected from verification borings.

Challenges encountered during verification borings included compressive strengths as low as 28 psi. To overcome these challenges, our highly experienced drillers utilized a triple barrel HQ wire line core barrel with low water pressure. Additional challenges included extremely high hydraulic permeability test results from pre-placement sample in the range of 8x10-9, resulting in delays in the reporting. We also coordinated with our client and the Corp to reduce duplicative testing requirements and added additional equipment to get reporting of samples on time to meet the project schedule.


Treviicos South


Madison County, Illinois

Services Provided