California Papers Presented at the NAT Conference
Various papers related to some of Jacobs Associates’ Californian projects were presented at the June North American Tunnel (NAT) conference that took place in Portland.
Glenn Boyce, Steve Klein, and Yiming Sun cowrote a paper titled “New Irvington Tunnel Design Challenges,” which discusses some of the issues faced during design of the new 3.5-mile-long tunnel, including potential risks associated with construction. This tunnel will run from the Sunol Valley to Fremont in Alameda County, CA. Other authors include Theodore Feldsher from URS Corporation and David Tsztoo from the San Francisco Public Utilities Commission (SFPUC).
A paper titled “Geotechnical and Design Challenges for TBM Selection on the ICE Tunnel” was cowritten by Steve Dubnewych and Steve Klein. Other authors include Paul Guptill from Kleinfelder. This paper considers the geotechnical challenges of the Irvine-Corona Expressway (ICE) tunnels that will extend between Riverside and Orange counties in Southern California. The purpose of these tunnels will be to relieve heavy traffic congestion.
Renée Fippin, Heather Stewart, and Rick Nolting cowrote a paper titled “The Sunnydale CSO Tunnel—Dealing with Urban Infrastructure.” The tunnel is designed to reduce flooding of residences during storm events near San Francisco Bay. The paper refers to the reasons for the multiple construction methods, including variable subsurface conditions and infrastructure crossings. Manfred Wong, from the SFPUC, also cowrote the paper.
“Show Me the Money: The Real Savings in Tunnel Contract Payment Provisions” was written by John Stolz, a principal in the San Francisco office. This paper guides the reader through contract payment provisions showing that when owners do not consider contractor cash flow in contract language, they are ultimately either subsidizing significant financing costs or receiving unbalanced bids.
John also authored another paper—“Overhead and Uncertainty in Cost Estimates: A Guide to Their Review.” This paper explains the categories of indirect costs typically used by contractors and their perhaps surprising contribution to overall cost. It then emphasizes the need for an integrated project schedule that quantifies the duration over which these indirect costs are incurred, and concludes with recommendations on the issue of estimating uncertainty.
Watch for upcoming news on East Coast papers that were presented at NAT!
