May 2, Mr. Tim Kurmaskie, AIA ARCHITECT KURMASKIE ASSOCIATES, INC Washington Street Raleigh, NC

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1 Mr. Tim Kurmaskie, AIA ARCHITECT KURMASKIE ASSOCIATES, INC Washington Street Raleigh, NC May 2, 2017 Re: Report of Subsurface Investigation Westfield Rehabilitation & Health Care Additions 3100 Tramway Road Sanford, North Carolina GeoTechnologies Project No EA Gentlemen: GeoTechnologies, Inc. has completed the authorized investigation to evaluate subsurface soil conditions for additions proposed to the Westfield Rehabilitation & Health Care facility at 3100 Tramway Road in Sanford, North Carolina. Our investigation consisted of performing a total of seven soil test borings at the approximate locations shown on the attached Figure 1. The borings were located in the field with a hand held Trimble GPS unit using State Plane coordinates obtained from a provided CAD plan. Elevations were estimates from a provided one-foot contour interval topographic map. The attached Table 1 summarizes the boring coordinates and elevations. The borings were advanced with an ATV drill rig turning hollow stem augers with standard penetration sampling at select intervals to a depth of about 5 to 15 feet. This report presents the findings of our investigation and our recommendations concerning site grading and foundation support for the proposed additions. SITE AND PROJECT INFORMATION The project site is located at 3100 Tramway Road in Sanford, North Carolina. The area of the proposed addition is comprised primarily of a lawn area with the exception of some paved parking area. Topography on the site generally slopes to the north with elevations of about 486 to 489 feet in the area of the proposed addition. The proposed project will involve construction of a new one story addition to the northwest side of the Westfield Rehabilitation & Health Care facility. No detailed structural information was provided; however, we anticipate that the building will be supported on load bearing walls and isolated columns and will include a slab on grade. Based on experience with similar structures we expect wall loads of 3 to 5 klf with column loads of 50 to 75 kips. In addition to the proposed building, a new parking lot will be constructed just west of the proposed building addition. Based on the provided site grading plan, it appears that the building pad will required placement of 1 to 4 feet of fill. SUBSURFACE CONDITIONS A generalized subsurface profile prepared from the test boring data is attached to this report as Figure 2 to graphically illustrate subsurface conditions encountered at this site. More detailed descriptions of the conditions encountered at the individual test boring locations are then presented on the attached test boring records.

2 Architects Kurmaskie Associates, Inc. Re: Westfield Rehabilitation & Health Care Additions May 2, 2017 Page: 2 The borings encountered near surface topsoil that typically extended to depths of 2 to 3 inches, except at boring B-2 where the topsoil had been placed as fill to a depth of about 2.5 feet. Underlying the topsoil, borings B-1, B-3 and B-4 encountered fill material comprised of firm to stiff sandy clay and loose silty sand that extended to depths of 2.5 to 5.5 feet and had penetration resistances of 8 to 11 blows per foot (bpf). Underlying the fill and topsoil the borings encountered firm to stiff clays and firm silt that became sandy in several of the borings below 12 feet. Penetration resistances in these soils ranged from 5 to 14 bpf. Groundwater was encountered in borings B-3 and B-4 ant 14 feet at the time of boring completion. However, it should be noted that the near surface soils at the site are conducive to the temporary development of perched groundwater conditions during periods of wet weather, and that groundwater levels will fluctuate during different periods of the year. RECOMMENDATIONS The following recommendations are made based upon a review of the attached test data, our understanding of the proposed construction, and past experience with similar projects and subsurface conditions. As development details become available, they should be provided to GeoTechnologies so that they can be incorporated into our recommendations. Site Grading Considerations. Following the removal of pavements, vegetation and topsoil, GeoTechnologies recommends that all areas at grade or designated to receive fill be proofrolled with a loaded dump truck in the presence of a geotechnical engineer. At the time of the proofroll, we also advise that hand auger borings be performed to further evaluate soil conditions, particularly in those areas where fill has been placed in the past. Although our test borings indicate that the existing fill is relatively compact in the building area, conditions can be less favorable intermediate of the boring locations. The most significant findings from our borings in that regard are the presence of topsoil to a depth of 2.5 feet in boring B-2 that will need to be undercut and replaced with compacted structural fill. Additionally, the material in the upper 3 feet at boring B-4 may represent topsoil strippings from earlier construction and could therefore contain organics and/or softer zones intermediate of the boring location. The clays in the upper 3 feet at boring B-7 were also somewhat soft and will likely require some repair. Where topsoil or soft soils (less than 6 bpf) are encountered, it is expected that undercut type repairs will be necessary as directed by the geotechnical engineer. We recommend that the site be graded during a period of relatively warm and dry weather when any near surface repairs (less than about 12 inches) associated with suitable but wet soils can generally consist of discing, drying, and recompacting. If the site is graded during a period of wet weather, or if the contractor is not prepared to disc and dry any wet near surface soils we anticipate that instability will be observed and that undercut repairs will be greater. Borrow Sources/Fill Placement. The on-site materials, excluding asphalt, topsoil, and any unsuitable old fill that is encountered, will be suitable for reuse as structural fill provided they are within an acceptable range of the optimum moisture content. If the soils are wet at the time of construction, some drying will be needed to achieve density and stability. Additionally, the on-site soils are moisture sensitive and in some cases are micaceous. These soils will require good technique on the part of the contractor to achieve compaction. If off-site borrow is needed we recommend this material consist of silty and clayey sands or low plasticity silts and clays having Unified Soil Classifications of SM, SC, ML, or. All fill materials in structural and

3 Architects Kurmaskie Associates, Inc. Re: Westfield Rehabilitation & Health Care Additions May 2, 2017 Page: 3 pavement areas should be compacted to not less than 95% of the standard Proctor maximum dry density except in the final foot where this requirement should be increased to 98%. to achieve density and stability, the soils should be compacted within about 2% of optimum moisture content unless otherwise directed by the geotechnical engineer. Foundation Support Considerations. Assumed loading data was used in conjunction with the boring results and past experience to estimate settlements for shallow spread foundations. For an allowable soil bearing pressure of 3,000 psf, those analyses estimate settlements of 1 inch or less for 90 kip columns and 7.5 klf walls (see Figures 3 and 4). Differential settlements are expected to be about half of the total except where new footings tie into the existing building. It is noted that our estimates are for individual footings and do not account for stress superposition which can occur where foundations are closely spaced. Once civil drawings and a foundation plan are available, more specific settlement analyses can be performed to verify our estimates. Given the relatively light loads expected for the addition, it is unlikely that settlements will be significant. We recommend that an allowable bearing pressure of 3,000 psf be used for design. Bearing conditions should be inspected by a geotechnical engineer to verify that adequate bearing and suitable materials have been encountered. Should foundations need to be extended to provide adequate bearing, we recommend that overexcavated footings be backfilled to design bearing elevation utilizing uniformly graded #57 or #67 washed stone. Foundations should bear at least 12 inches below grade for frost protection. Slab-on-Grades. Slab subgrades should be prepared in accordance with our previous site grading recommendations. We recommend that slab-on-grades be designed for an assumed subgrade modulus of 100 pci. We recommend placing 4 inches of CABC below the slab to protect the subgrade prior to concrete placement, and to provide more uniform support. Below Grade Walls and Retaining Walls. Rigid below grade walls and retaining walls, with level backfill should be designed assuming the adjacent soils will behave as an equivalent fluid having a unit weight of 60 pcf for the at-rest condition and 45 pcf for the active earth pressure condition. These values do not account for any loading associated with slopes or other surcharging. A design friction factor of 0.35 may be utilized to calculate sliding resistance. Specific passive earth pressure diagrams can be provided if requested. Any fill material placed adjacent to below grade walls should be compacted to a minimum of 95% of the standard Proctor maximum dry density, except where 98% is required at subgrade. Additionally, any soils placed within 3 to 4 feet of below grade walls should be compacted with light hand held equipment to prevent overstressing of the walls. This will necessitate that backfill be placed in 4 to 6 inch lifts. We recommend that all below grade walls be properly waterproofed and that a drainage medium be placed against those walls to intercept seepage and prevent a build-up of hydrostatic pressure behind the walls. The medium should be connected to a foundation drain that daylights to a down gradient area unless a sump pump is used. For flexible segmental retaining walls, we recommend that the on-site soils be excluded from the reinforced zone. Local materials which are readily available and will be suitable for use within the reinforced zone would include CABC base course stone or quarry screenings which are all available from area quarries. Pavement Design. If any new pavements will be constructed, we recommend using a design CBR of 5% for the design of flexible pavements and a subgrade modulus of 100 pci for rigid pavements. Any new pavement subgrades should be moisture conditioned and recompacted to not less than 98% of the standard Proctor maximum

4 Architects Kurmaskie Associates, Inc. Re: Westfield Rehabilitation & Health Care Additions May 2, 2017 Page: 4 dry density within 2% of the optimum moisture content immediately prior to placement of base course stone. The subgrades should also be proofrolled for stability. Site grades should be detailed to promote drainage away from the pavement areas, and underdrains or ditches should be provided along the high side of all pavements. If we can be provided with anticipated traffic volumes and loadings, detailed pavement sections can be provided; however, typical sections include 2 inches of asphalt in car only parking stalls and 3 inches of asphalt in drive areas, or small bus parking areas. A minimum of 8 inches of CABC stone should be used in both areas. Seismic Design Considerations. Based on the test borings, the North Carolina Building Code, and past experience, we recommend a site class D be utilized relative to soil seismic design considerations. GeoTechnologies, Inc. appreciates the opportunity to be of service on this phase of the project. Please contact us if you have any questions concerning this letter or if we may be of additional service on this or other projects. Very Truly Yours, GeoTechnologies, Inc. DLI/pr-els Attachments David L. Israel, P.E. NC Registration No

5 Architects Kurmaskie Associates, Inc. Re: Westfield Rehabilitation & Health Care Additions May 2, 2017 Page: 5 TABLE 1 Summary of Test Boring Coordinates Boring # State Plane Coordinates (ft) Elevation (ft) Northing Easting B B B B B B B

6 B-3 B-1 B-4 B-5 B-6 B-2 B-7 FIGURE 1

7 Elevation (Feet) GENERALIZED SUBSURFACE PROFILE LEGEND Topsoil B- 1 B B B B B B Low Plasticity Clay Low Plasticity Silt Clayey Sand Silty Sand Moderate Plasticity Clay Fill 8 Standard Penetration Resistance Groundwater at Time of Boring PROJECT: Westfield Rehab & Health Care Center Sanford, North Carolina SCALE: As Shown JOB No: EA FIGURE No:2

8 SETTLEMENT vs LOAD Estimated Settlement (Inches) Load (Kips) Estimated settlement for a spread footing foundation designed for a contact pressure of 3,000 psf, bearing at 1.5 feet Figure 3

9 ESTIMATED SETTLEMENT OF A WALL FOOTING DESIGNED FOR A CONTACT PRESSURE OF 3,000 PSF Est. Sett.(in) Footing Width (ft) Assumes footing bearing 1.5 ft below grade. FIGURE 4

10 TEST BORING RECORD DEPTH (FT.) 0.0 DESCRIPTION Topsoil Fill - Firm Orange Brown & Red Sandy Silty AY ELEVATION PENETRATION (FT.) (BLOWS/FT.) BLOWS PER SIX INCHES Stiff Brown & Orange Fine to Medium Sandy AY Boring terminated at 5' Groundwater not encountered at time of boring. GTI_MAIN GPJ GTI.GDT 5/2/17 JOB NUMBER BORING NUMBER DATE EA B PAGE 1 OF Wellington Court, Ste 108 Raleigh, NC 27615

11 TEST BORING RECORD DEPTH (FT.) 0.0 Topsoil Fill - Topsoil DESCRIPTION ELEVATION PENETRATION (FT.) (BLOWS/FT.) BLOWS PER SIX INCHES Stiff Red, Orange & Brown Fine to Medium Sandy Silty AY Boring terminated at 5' Groundwater not encountered at time of boring. GTI_MAIN GPJ GTI.GDT 5/2/17 JOB NUMBER BORING NUMBER DATE EA B PAGE 1 OF Wellington Court, Ste 108 Raleigh, NC 27615

12 TEST BORING RECORD DEPTH (FT.) 0.0 DESCRIPTION Topsoil Fill - Stiff Brown, Orange & Red Sandy Silty AY ELEVATION PENETRATION (FT.) (BLOWS/FT.) BLOWS PER SIX INCHES Stiff Red, Tan, Orange & Brown Fine Sandy Silty AY Stiff Tan Fine Sandy Clayey SILT ML Loose Tan Clayey Fine to Medium SAND SC 15.0 Boring terminated at 15' Groundwater encountered at 14' at time of boring GTI_MAIN GPJ GTI.GDT 5/2/17 JOB NUMBER BORING NUMBER DATE EA B PAGE 1 OF Wellington Court, Ste 108 Raleigh, NC 27615

13 TEST BORING RECORD DEPTH (FT.) 0.0 DESCRIPTION Topsoil Fill - Loose Dark Brown Silty SAND w/organic Traces ELEVATION PENETRATION (FT.) (BLOWS/FT.) SM BLOWS PER SIX INCHES Stiff Red, Gray, Brown & Orange Fine Sandy Silty AY Stiff Orange, Red & Tan Fine Sandy Clayey SILT ML Loose Tan Clayey Fine to Medium SAND SC 15.0 Boring terminated at 15' Groundwater encountered at 14' at time of boring GTI_MAIN GPJ GTI.GDT 5/2/17 JOB NUMBER BORING NUMBER DATE EA B PAGE 1 OF Wellington Court, Ste 108 Raleigh, NC 27615

14 TEST BORING RECORD DEPTH (FT.) 0.0 DESCRIPTION Topsoil Stiff Light Brown to Red Fine to Medium Sandy AY ELEVATION PENETRATION (FT.) (BLOWS/FT.) BLOWS PER SIX INCHES Stiff Light Gray & Red Silty AY CH Firm Gray, Tan & Orange Fine Sandy Silty AY 15.0 Boring terminated at 15' Groundwater not encountered at time of boring GTI_MAIN GPJ GTI.GDT 5/2/17 JOB NUMBER BORING NUMBER DATE EA B PAGE 1 OF Wellington Court, Ste 108 Raleigh, NC 27615

15 TEST BORING RECORD DEPTH (FT.) 0.0 DESCRIPTION Topsoil Stiff Orange, Gray, Tan, Brown & Red Fine Sandy Silty AY ELEVATION PENETRATION (FT.) (BLOWS/FT.) BLOWS PER SIX INCHES Boring terminated at 15' Groundwater not encountered at time of boring GTI_MAIN GPJ GTI.GDT 5/2/17 JOB NUMBER BORING NUMBER DATE EA B PAGE 1 OF Wellington Court, Ste 108 Raleigh, NC 27615

16 TEST BORING RECORD DEPTH (FT.) 0.0 DESCRIPTION Topsoil Firm Brown, Orange, Red & Tan Fine to Medium Sandy Silty AY ELEVATION PENETRATION (FT.) (BLOWS/FT.) BLOWS PER SIX INCHES Stiff Orange, Gray, Tan, Brown & Red Fine Sandy Silty AY Loose Tan & Orange Clayey Silty Fine to Medium SAND SC 15.0 Boring terminated at 15' Groundwater not encountered at time of boring GTI_MAIN GPJ GTI.GDT 5/2/17 JOB NUMBER BORING NUMBER DATE EA B PAGE 1 OF Wellington Court, Ste 108 Raleigh, NC 27615