Exhibit II Wall Foundation

Revised 7/17/2019

The geotechnical engineer in charge of the project is the professional geotechnical engineer who will sign the WFI report

5.2

DEPARTMENT OF TRANSPORTATION

STATE OF GEORGIA

GEOTECHNICAL E N G I N E E R I N G BUREAU

FOUNDATION DRILLING AND SAMPLING GUIDELINES

Retaining Wall Foundation Investigations - Drilling and Sampling

A. Drilling Criteria

1. Borings for retaining walls should generally be made at 200-foot intervals for long walls (walls longer than about 300 feet) unless erratic foundation conditions are found. In this case, enough borings should be made to sufficiently define the subsurface conditions. Shorter walls and walls used in bridge abutments should have at least 2 borings per wall. If the borings made for the bridge are relatively close to the proposed wall, these may be used in lieu of new boring(s). For mechanically stabilized earth walls (MSE walls), borings should be made along the proposed leveling pad line in front of the wall (passive side) and behind the wall facing within the special backfill area (active side).

2. Borings should be drilled as closely as possible to the location of the proposed footing or special backfill area. Borings should be offset only when site or traffic conditions prevent this. If a lane or shoulder closure is required to perform borings, prior approval must be obtained from the District Engineer’s office. All lane or shoulder closures must be set up in accordance with MUTCD standards, and within the hours set by the District Engineer’s office.

3. Borings should be drilled to a depth of 1½ times the wall height as measured from the bottom of the wall footing. At longer walls, one boring every 600 feet (with at least one boring per wall) should be drilled slightly deeper, to 2 to 2½ times the wall height to check for groundwater or varying foundation conditions. If voids or other erratic subsurface conditions are encountered, notify the geotechnical engineer in charge of the project as soon as possible.

4. For load and resistance factor design (LRFD) wall foundation investigations, borings should be performed at both the active (beneath and behind wall) and passive (in front of wall) sides of the proposed wall. The boring depth and frequency along the wall should follow item number 1 and 3 above. In addition, any critical sections of the wall should be identified and borings should be taken at these locations. These will facilitate more accurate global stability analyses.

If the borings have not encountered 15-blow count or better material within a boring depth of 1½ times the height of the wall as measured from the bottom of the wall footing, then use the following Standard Penetration Test (SPT) criteria as a guideline to terminate the borings:

Thickness of Strata SPT Greater Than

5 feet 31 blows

10 feet 21 blows

15 feet 11 blows

Note that these guidelines are minimum requirements and the geotechnical engineer in charge of the project is responsible for performing adequate borings to depths sufficient to aid the design of a deep foundation system should very loose/soft soils be encountered before the criteria above is met. If any of the SPT sampling criteria have not been met after approximately 50 feet, contact the geotechnical engineer in charge of the project.

B. Sampling Guidelines

1. If the proposed footing is more than 5 feet below the existing ground, perform

SPT tests at 5-foot intervals from the ground line to the proposed wall footing, beginning at a depth of 5 feet. At the footing elevation, perform SPT tests at 2½-foot intervals for the next 10 feet and at 5-foot intervals thereafter. Save all samples in a clean sample jar, and mark all jar boxes with the project number and county, boring number, bridge location and date. Sample jars must be a minimum of 16 oz (500 ml) in size. Fill up the jar so the lab has sufficient material for testing. CPT (Cone Penetration Test) and DMT (Flat Dilatometer Test) tests are acceptable however they must be accompanied by SPT tests so samples are collected and tested in the lab. SPTs should comprise of no less than 40% of the drilling plan when CPT and/or DMT are being considered.

2. Note the type of bit(s) used throughout the boring. When drilling hard rock layers or boulders, also note the time to drill through these materials.

3. Obtain 24-hour groundwater elevations on at least one of the borings at each wall site. If the borings are dry, indicate this on the boring logs.

4. If soft layers of clay or plastic silt are found at the borings, push at least two

3 inch diameter Shelby tubes at or near the center of the soft layer(s) (N<10) so that consolidation tests can be performed on the samples. The total number of

Shelby tubes obtained should depend on the extent of the soft layers encountered. Mark the tube with the project number and county, the boring number, the depth of the sample, and the date.

C. Special Notes

1. Obtain the ground elevations at each boring by using a benchmark from the survey control package for that project. This can be obtained from the GDOT Statewide

Location Bureau in the Office of Design Policy and Support. If it is not available, have a Georgia registered land surveyor create a benchmark from which ground elevations at each boring can be determined.

2. In addition to all drilling and sampling data, each boring log should contain the project number and county, the date, the wall location, the driller’s name, the type of drill used (truck-mounted Failing 250, CME 550 on ATV, etc.), the drilling method used (auger, rotary, etc.), the groundwater elevation and all other notes relevant to the subsurface conditions. The driller should also include energy rating data for the hammer. Note: SPT hammers must be calibrated once every 2 years and calibration data must be submitted as part of the deliverables on every project.

3. After groundwater checks are made, all boring holes should be filled in (and patched if made in a travel lane or paved shoulder) and the site left in good condition. Drill cuttings and all other spoils should be cleaned off any paved areas.

D. Laboratory Testing

1 . Laboratory testing for most soil samples for WFI’s normally consists of a Unified classification test, which includes an Atterberg limits test, moisture content test, and sieve analysis.

2. The sieve sizes used for the sieve analysis are Nos. 4, 10, 40, 60 and 200, which is one more than the minimum required by AASHTO or ASTM standards.

3. Laboratory testing for rock samples normally consists of unconfined compressive strength tests, and on occasion, split tensile tests.

4. Undisturbed tests such as Triaxial - Consolidated Undrained (CU) (other types of triaxial tests (CD or UU) may be run in addition to the CU test based on the discretion of the geotechnical engineer in charge of the project) and Consolidation should be run if Shelby tube samples are collected.

5. The latest editions of the following ASTMs should be followed for any lab tests performed:

Test ASTM Designation

Unified Soil Classification System (USCS) D2487

Moisture Content D2216

Atterberg Limits D4318

Unconfined Compressive Strength of Rock D7012

Split Tensile Strength of Rock D3967

Triaxial - Consolidated Undrained (CU) D4767

Triaxial – Consolidated Drained (CD) D7181

Triaxial – Unconsolidated Undrained (UU) D2850

Consolidation D2435