3400 RIVERFRONT BLVD Geotech Report 2022-10-25

• • • level; therefore, we anticipate that settlement due to the decomposition of organic material will • be negligible. Our goal for this project is to limit the total post-construction settlement to less than 2 inches. • • During earthwork in the drainage swale, we observed that soft organic soil was present at the • bottom of the swale. In order to minimize the settlement risk to the new roadway that will be built above the drainage swale, we recommended that the soft organic soil be over-excavated• and replaced with coarse granular material such as stabilization rock, quarry spalls, or recycled • concrete. We also recommended that a geotextile fabric be placed between the bottom of the • excavation and the granular material. We also recommended that the bottom 18 inches of • granular material be placed in a single lift and compacted with the excavator bucket or the tracks of the excavator. Polygon's earthwork contractor followed these recommendations when • working in the drainage swale and filled the remainder of the swale with structural fill. We • documented the earthwork in the drainage swale in our construction observation field reports. •• 6.2 TN There areSETTLEMENT currently 16 MONI settlementORI plates at the site to monitor settlement. These settlement • plates were installed along existing utilities, new building, and new pavement areas. In our • opinion, the 16 settlement plates installed will be adequate to monitor settlement across the site. • We were unable to install settlement plates at the southwest portion of the site because of the • presence of a large soil stockpile, but we anticipate that minimal settlement will occur beneath the stockpile area. Figure 5 shows the approximate locations of the 16 settlement plates. A • typical settlement plate detail is shown on Figure 6. • • For ease in handling, the casing and rod portions of the settlement plate are usually installed in 5-foot sections. As surcharge placement progresses, couplings are used to install additional • sections. Continuity in the monitoring data is maintained by reading and recording the top of • the measurement rod immediately prior to and following the addition of new sections. Care • must be taken during fill construction not to bend or break the rods. • The settlement plates should be installed prior to site filling and immediately surveyed. Survey • measurements should be taken at each settlement plate at least twice per week during fill • construction and for at least one month after fill construction, followed by once weekly • thereafter. In addition to recording the elevation of the settlement plates during each survey • event, a complete record of the surcharge history requires reading and recording the fill height at each settlement plate. The settlement plates should be monitored using survey equipment with • accuracy of 1/100`h of a foot and referenced to a stationary datum established at least • 500 feet from the edge of the surcharge area. The survey data should be provided to GeoDesign • within three days of the survey. We will provide a Microsoft Excel spreadsheet to the surveyors that can be used to transfer data via email. • 6.3 SITE PREPARATION • 6.3.1 Grubbing and Stripping Stripping and grubbing may be required at this site to remove any vegetation that is at the • ground surface. If present, the existing root zone material should be stripped and removed from • all proposed building and pavement areas. We anticipate a stripping depth of approximately 1 to • • • G EO DESIGN= 13 Polygon-128-01:091615