The Ballpark Village Development Deep Foundation System

Video Transcription

Video Summary

The presentation describes the deep-foundation design and construction for Ballpark Village’s Block 400 and Block 100 projects in St. Louis. Initially planned with driven piles, both projects ultimately used auger-cast piles after a competitive evaluation of foundation options. Block 400 used 383 piles, 24 inches in diameter and about 94 feet deep; Block 100 used 30-inch piles, 50–88 feet deep.<br /><br />Subsurface conditions included soft clay and silt over limestone, with urban debris and historic stone foundations creating construction challenges. Additional rock coring and Osterberg-cell load tests helped verify pile capacity and refine the design. Test results showed substantially greater end-bearing and side-shear capacity than initially assumed. However, a clay seam in part of Block 100 led the team to use a more conservative design capacity in that area.<br /><br />Construction required pre-drilling in places, careful grout management, and pile testing. When one pile produced an anomalous integrity-test result, the team performed a static load test to twice its design load; the pile performed satisfactorily and was accepted. The buildings have reportedly performed well since completion.

Keywords

deep-foundation

auger-cast piles

Ballpark Village

St. Louis

Osterberg-cell load test

pile capacity

subsurface conditions