December 2011

The Wisconsin Department of Transportation (WisDOT) is looking into further use of the Cone Penetrometer Test (CPT): a fast means of determining how deep bearings and piles must be driven into soil to provide a suitable foundation. Although useful, WisDOT officials need to learn more about the device and how to read its output before investing further in its use. The Cone Penetrometer Comparison Testing (CFIRE 04-21) project compares CPT results to conventional readings in several locations around the state, discusses advantages and disadvantages of the technology and provides suggestions for applications.

Currently, soil profile data is obtained using a standard penetration test (SPT). The SPT measures the number of standard hammer blows to drive a sampling rod a certain distance into the ground, and uses this number to estimate the mechanical properties of the soil. Although it is the most common penetration test, the SPT is inexact and subject to human error.

In a cone penetrometer test, a cone-shaped probe equipped with electronic sensors is hydraulically jacked into the soil by a mobile rig. This test moves at a constant rate providing a continuous stream of data which can be interpreted to obtain the soil profile of a site, as well as additional data such as clay and sand stresses or water flow characteristics.

0421

Example CPT rig from UW-Madison

The primary research effort, led by CFIRE affiliate researcher James Scheider, showed that CPT could be used in regions that had undergone glaciation (a concern given the high variability in soil components and risk of damaging the cones), and could be jacked down to 75 feet deep in the tests; this information was corroborated with the Minnesota Department of Transportation, which has already been using the CPT in seventy-five percent of its foundation work. Despite the small sample size, it was found that CPT correlated well for determining soil type, as well as the coefficient of consolidation.

This project reaffirmed existing views on the CPT: the test provides large amounts of accurate data at a faster speed than SPT methods. Unfortunately, the presence of gravel or cobble can prohibit the use of CPT due to risk to the cones, and this project failed to achieve depths beyond 100 feet. This project recommended continued and expanded use of CPTs on foundation projects along with close boreholes to verify test results and increase future accuracy.

To learn more about this project and to read the final report, visit the CFIRE 04-21 project page.

The CFIRE staff
wishes you
a joyful holiday season
and a Happy New Year!

This year’s holiday card was designed by Lisa Beneker.

Talking Freight: FRATIS

December 22, 2011

Talking Freight Seminar January 18, 2012 The January edition of the FHWA Talking Freight seminar will focus on the Freight Advanced Traveler Information System (FRATIS). Improving the efficiency of goods movement in and through an urban core is a high-priority for the U.S. DOT. The Freight Advanced Traveler Information System (FRATIS) is a bundle of […]

Read the full article →

Freight Transportation Leadership Academy

December 21, 2011

The University of Memphis will be hosting the Freight Transportation Leadership Academy starting in February 2012.  This 4-part certification program is targeted for mid-upper level executive positions. This program offers a unique collaboration between academic and industry experts that will insure participants receive the most up-to-date information on critical issues facing the freight transportation industry. By […]

Read the full article →

CFIRE Geoeconomist

December 15, 2011

Geoeconomist National Center for Freight & Infrastructure Research & Education University of Wisconsin-Madison Madison, WI CFIRE is currently looking to hire a Geoeconomist to support the freight-focused policy, planning, and engineering research for the ten states of the Mid-America Freight Coalition and other CFIRE initiatives. Applications are due on January 9, 2012. For the complete […]

Read the full article →

Shifting Freight to Rail to Improve Air Quality

December 12, 2011

Erica Bickford’s work on truck-rail modal shifts and air quality was recently featured by Science Daily: Shifting from road to rail 500 million tons of the freight passing through or to the Midwest would make a large dent in the carbon dioxide spilled into the air by the movement of goods. For more information, read […]

Read the full article →

2012 Wisconsin Transportation Reception

December 8, 2011

January 22, 2012 5:30pm-7:30pm Marriott Wardman Park Hotel Thurgood Marshall Ballroom West Washington, DC Are you attending the 2012 TRB Annual Meeting? If so, please join us at the Wisconsin Transportation Reception on Sunday, January 22, 2012. You can also download the invitation flyer as a PDF for printing and distribution.

Read the full article →