Appleton Performing Arts Center

1. Wisconsin Section ASCE 2002 Annual Meeting September 20, 2002 Appleton Performing Arts Center Geotechnical Considerations River Valley Testing Corp Christopher Mallon, P.E.

2. Project Overview • Purchase of property from owners by the City of Appleton • Demolition of existing structures • An approximate 2,100 seat main theater and 450 seat second theater

3. The Performing Arts Center Rendering Courtesy of Zeidler Roberts Partnership Incorporated

4. Scope of Service Considerations • Abandoned parking ramp and several businesses in the plan area • Initial design • Finished floor a couple feet existing grade • Frost depth spread footings • Possible pile foundation • Orchestra pit 15’ below grade • 1,800 kip max column loads • Abandoned Ravines

5. Known Ravines in Appleton • Ancient ravines in downtown Appleton • Uncontrolled fill in the ravines • One ravine was suspected to cross the PAC • Variable soil support

6. Initial Scope of Services • Ten standard penetration test borings • Twenty-five geoprobe borings • Laboratory testing • Geotechnical analysis • Values for design considerations

7. Soil Borings and Ravine Fill • Several geoprobes were conducted through the decks of the parking ramp • Samples collected for classification

8. Field Results • About 12’ of rather stiff lean clay over a soft lean clay that extended to bedrock. • Hand penetrometer readings of 3.0 tsf to 4.5 tsf in the stiff layer and about 1.0 tsf in the soft layer. • Bedrock encountered from 59’ to 73’ below grade. • As much as 30’ of ravine fill encountered along the east property line.

9. Typical Boring Log • Stiff upper layer of soil • Soft deeper soils • Soft soils extended to bedrock

10. Consolidation Testing • Tests were performed in the stiff upper soils and in the soft, deeper soils • Consolidation tests confirmed that the settlements could exceed one inch

11. Geotechnical Analysis • Allowable soil bearing pressures varied from 1,500 to 4,000 psf to fill. The shallower the better. • Unsuitable soils in the ravines • Piling was an option • Spread footing option could have 1¼” settlements with 1,800 kip loads • Consideration was given to supporting part of the structure on piles and part on spread footings • Consideration should be given to additional borings with pressuremeter tests

12. Further Geotechnical Services • A mat foundation was attractive for structural and acoustic reasons • A basement was added and it extended as much as 35’ below grade • Borings at the location of the maximum loads • Pressuremeter testing • Correlation of Unconfined Compressive Strengths to Pressuremeter tests • Further laboratory testing

13. The Pressuremeter Test • A special borehole is prepared • The test module lowered to the test depth • The module pressurized and data recorded

14. Pressuremeter Testing • Placed at maximum column loads • Depth of test represented the zone of influence of the foundations

15. Geotechnical Recommendations • 4,500 psf in the deeper soft soils • Ok to allow up to 10,000 psf for localized maximum stresses in a mat foundation • Settlements of ½” total and ¼” differential • Correlation of Unconfined Strengths with Pressuremeter tests as a method to quickly and inexpensively verify the soil bearing during construction.

16. The PAC Today Sept 18, 2002 from the “PAC Cam” at www.foxcitiespac.com

17. Questions & Comments

18. The End