Investigation of Improved Utility Cut Repair Techniques to Reduce Settlement in Repaired Areas, Phase II, TR-566, 2010

Trench maintenance problems are caused by improper backfill placement and construction procedures. This report is part of a multiphase research project that aims to improve long-term performance of utility cut restoration trenches. The goal of this research is to improve pavement patch life and reduce maintenance of the repaired areas. The objectives were to use field-testing data, laboratory-testing data, and long-term monitoring (elevation survey and falling weight deflectometer testing) to suggest and modify recommendations from Phase I and to identify the principles of trench subsurface settlement and load distribution in utility cut restoration areas by using instrumented trenches. The objectives were accomplished by monitoring local agency utility construction from Phase I, constructing and monitoring the recommended trenches from Phase I, and instrumenting trenches to monitor changes in temperature, pressure, moisture content, and settlement as a function of time to determine the influences of seasonal changes on the utility cut performance.

Utility System Revenue Bond Funds, June 30, 2002

State University Audit Report

Utility System Revenue Bond Funds, Iowa State University of Science and Technology, Independent Auditor's Report Financial Statements and Supplemental Information, June 30, 2004

State University Audit Report

Utility System Revenue Bond Funds, Iowa State University of Science and Technology, Independent Auditor's Report, Financial Statements and Supplemental Information, June 30, 2005

State University Audit Report

Utility Cut Repair Techniques— Investigation of Improved Cut Repair Techniques to Reduce Settlement in Repaired Areas, December 2005

Pavement settlement occurring in and around utility cuts is a common problem, resulting in uneven pavement surfaces, annoyance to drivers, and ultimately, further maintenance. A survey of municipal authorities and field and laboratory investigations were conducted to identify the factors contributing to the settlement of utility cut restorations in pavement sections. Survey responses were received from seven cities across Iowa and indicate that utility cut restorations often last less than two years. Observations made during site inspections showed that backfill material varies from one city to another, backfill lift thickness often exceeds 12 inches, and the backfill material is often placed at bulking moisture contents with no Quality control/Quality Assurance. Laboratory investigation of the backfill materials indicate that at the field moisture contents encountered, the backfill materials have collapse potentials up to 35%. Falling Weight Deflectometer (FWD) deflection data and elevation shots indicate that the maximum deflection in the pavement occurs in the area around the utility cut restoration. The FWD data indicate a zone of influence around the perimeter of the restoration extending two to three feet beyond the trench perimeter. The research team proposes moisture control, the use of 65% relative density in a granular fill, and removing and compacting the native material near the ground surface around the trench. Test sections with geogrid reinforcement were also incorporated. The performance of inspected and proposed utility cuts needs to be monitored for at least two more years.

Utility System Revenue Bond Funds, Iowa State University of Science and Technology, Independent Auditor's Report, Basic Financial Statements and Supplementary Information, June 30, 2006

State University Audit Report

Audit of the Utility System Revenue Bond Funds of Iowa State University of Science and Technology (Iowa State University) as of and for the year ended June 30, 2007

Audit of the Utility System Revenue Bond Funds of Iowa State University of Science and Technology (Iowa State University) as of and for the year ended June 30, 2007

Consumer Advisory Bulletin, Storm Warning: Be Wary of Impostors Posing as Utility Workers, March 2007

The Attorney General’s Consumer Protection Division receives hundreds of calls and consumer complaints every year. Follow these tips to avoid unexpected expense and disappointments. This record is about: Storm Warning: Be Wary of Impostors Posing as Utility Workers

Consumer Advisory Bulletin, "Flood and Storm Warning: Be Wary of Impostors Posing as Utility Workers", June 12, 2008

The Attorney General’s Consumer Protection Division receives hundreds of calls and consumer complaints every year. Follow these tips to avoid unexpected expense and disappointments. This record is about: "Look Before You Lease!"

Report of the Utility System Revenue Bond Funds of Iowa State University of Science and Technology as of and for the year ended June 30, 2008

Report of the Utility System Revenue Bond Funds of Iowa State University of Science and Technology as of and for the year ended June 30, 2008

Audit report on the Regional Utility Service Systems Commission for the year ended June 30, 2011

Audit report on the Regional Utility Service Systems Commission for the year ended June 30, 2011

Audit report on the Regional Utility Service Systems Commission for the year ended June 30, 2012

Audit report on the Regional Utility Service Systems Commission for the year ended June 30, 2012