Circular Secant Pile Access Shafts for the Ohio River Tunnel Project-PPT Presentation

PPT Presentation

Pdf Summary

The presentation describes the design and construction of secant pile shafts for the Ohio River Tunnel, part of a project addressing combined sewer overflows (CSOs) in Louisville.<br /><br />The shafts are designed as rigid walls with minimal deflection, accounting for ground and water conditions, construction tolerances, and varying loads. Key tolerances include pile verticality of 0.5% and out-of-roundness of 0.25%. The wall is thicker near the top, while loads are greater at the bottom. Primary piles must be installed carefully and plumb; they guide secondary piles, which are less likely to deviate into adjacent piles and tend to remain vertical.<br /><br />Design methods range from simplified calculations of hoop stresses to finite element analysis for complex, unbalanced loads, including those from cranes and conveyor-belt footings. Because the completed underground work cannot be observed directly, quality control relies on indirect measures: monitoring verticality, testing concrete and rock strength, checking concrete volume, and observing drill spoils and equipment behavior.<br /><br />Construction involves templates, large drill rigs, casing, and support equipment, with drilling through both overburden and rock. Work must also accommodate extreme weather, from winter temperatures near 0°F to summer conditions around 100°F. The presentation concludes with the finished face of the secant piles.

Keywords

secant pile shafts

Ohio River Tunnel

combined sewer overflows

Louisville

rigid wall design

finite element analysis

construction tolerances

pile verticality

quality control

drilling in rock