Examples of Good Practices For Excavation and Trenching

Transcription

1 Examples of Good Practices For Excavation and Trenching Prepared by the Construction Practices Subcommittee Of APWA s UPROW Committee Presented to the 2000 APWA International Public Works Congress Louisville, Kentucky September 12, 2000 Introduction The Construction Practices Subcommittee was asked by the UPROW Committee to research available documents related to excavation and trenching standards and to identify good examples. The request initiated from the report Recommendation to Establish a New Professional / Educational / Technical Committee for Utility and Public Right-of-Way Issues, prepared by the Utility and Right-of-Way Task Force, and dated April 13, This report documents the process the subcommittee followed to gather the information, assess and evaluate the data and the results of our findings. Data Collection Requests were made to local governments, utility companies and other agencies around the United States and Canada for samples of excavation and trenching standards. The subcommittee members also contacted associates and colleagues for similar information. A total of 39 documents were received and reviewed. Some of the submittals included drawings, ordinances, codes and specifications. The submittals ranged from one page to hundreds of pages, from standard drawing sheets to research reports. Each was reviewed and evaluated pertaining to the topic Trenching and Excavation Standards by the members of the subcommittee. It should be pointed out that the committee reviewed information supplied by the agencies listed in Table 1. It is likely other agencies have very good examples of standards but they did not respond to the request of this committee. Analysis and Evaluation Prior to receiving all the samples, the committee members developed a table of criteria to use to evaluate the information and data. These criteria included the following factors: CSI format Ideal for consistency sake among agencies and professions. Reference Standards ANSI, OSHA, AWWA, AASHTO, DOT, etc. Measurement and Payment description, quantities, etc. Length of specification namely, too short or too long may be hard to deal with. Reference Drawings also called Standard Drawings or Details Construction Methods The process the contractor goes through to complete the work Compaction Requirements For various classes of trenches.

2 Material Requirements For example, bedding material, backfill material, flowable fill, etc. Testing - For example, AASHTO T-99 Standard Method of Test for Moisture - Density Relationship for Soils Inspection Specific requirements. Related Specifications For example, Section 3300 Concrete. Utility Coordination Requirements to assure utility coordination The members of the subcommittee analyzed the data and scored each of the criteria on a basis of 5 being the best, 1 being poor, and 0 for being not at all. Findings The committee agreed early on in the review process that our objective was not to write the perfect specification for Trenching and Excavation. The committee recognized that different regions required different techniques due to unique environmental conditions. For example, materials for backfill in warm climates may not always be suitable in cold climates. While flowable fill may work rather well in the south, it may create problems when used in some trench repairs in the north, which is subjected to deep frost penetration. The committee received information from cites, counties, utilities and agencies located in the United States and Canada. An analysis of the documents revealed (as expected) that some documents were better than others and different than others. The committee used the criteria discussed above as a guideline for the type of items that should be included in an effective set of standards. Conclusion Of the 39 documents reviewed, five were selected, based on the evaluation scores, to represent Good Examples of Trenching and Excavation Standards. Narrowing the list down to these five documents does not mean the others are not worthy of attention that depends on the type of information one is trying to locate. It simply means if you are focused on locating good specs and drawings for trenching and excavation, these documents are a good place to start your search. The five good examples are: No. 10 Cincinnati. This document is produced in a book format that includes information on permits, design requirements, traffic control, fees, as well as specifications and drawings. The web address is: or No. 12 Denver. Denver s specifications were obtained from the Internet and were good but maybe a little general. No drawings were attached which would make the specifications better. (The latest revisions include drawings). The web address is: Their Rules and Regulations can be found at: The drawings are not on the web site but can be acquired by contacting their office. No. 25 Nashville. This submittal included very good specifications along with standard details. The specs were in English/Metric units, CSI format, and referenced standards and other regulations are available. The web address is:

3 No. 29 San Francisco. This submittal was also in a book format which included regulations, excavation code, barricade order, dust control order, standard specifications and standard drawings. The specifications may be too brief or general. However, the drawings did not include a trenching detail. The web address is: No. 33 Corps of Engineers. The Corps specifications are actually guide specifications and require editing and finishing by the user. Units are in English/Metric. The specifications include good reference specifications and a broad range of construction methods. No drawings were included. The web address is: Attachments Table 1 List of Submittals / Publications Table 2 Evaluation Matrix Scores Table 3 Evaluation Matrix Comments Table 4 Committee Members List

4 Table 1 List of Submittals / Publications 1. Accommodation of Utility Plants Within the Rights-Of-Way of Urban Streets and Highways Manual of Improved Practice, by American Public Works Association, and American Society of Civil Engineers, dated July 1974, 102 pages. 2. City of Anaheim, California, Standard Drawings (4 sheets) plus Trench Review Report, dated October 1995, 21 pages. 3. Utility Cuts Restoration Practices, State of the Art Report, by American Public Works Association, dated January 1999, 25 pages plus appendices. 4. Arizona Public Service Company, General Trench and Backfill Requirements, dated 1996, 28 pages. 5. City of Arlington, Texas, Standard Drawings, 2 pages. 6. City Of Austin, Audit Report Public Works and Transportation Streets Cuts Management, dated Nov. 1998, 31 pages. 7. Bellcore Blue Book Manual of Construction Procedures, dated December 1996, 264 pages. 8. California Inter-Utility Site Restoration Committee, Site Restoration Standard, dated April 1998, 10 pages. 9. Charlotte, North Carolina, Utility Patch Regulations and Fee Schedule, dated May 18, City Of Cincinnati, Street Restoration Book, dated January 1, 1994, 63 pages. 11. City Of Columbus, Ohio, Chapter 903, Excavation / Occupancy Regulations and Standard Drawings, dated January 1996, 15 pages. 12. City And County of Denver, Rules and Regulations Governing Street Cuts, dated August 1, 1998, 23 pages. 13. City Of Detroit, Standard Specifications related to Excavation, Trench Restoration and Quality Control, 63 pages. 14. Manufacturer of Ditch Witch Products, Section 2600 Standard Specifications for Trench Excavation and Backfill / Surface Restoration, dated 1999, 19 pages. 15. Halifax Regional Municipality, By-Law Number S-300 Respecting Streets, and Supplementary Specifications, dated July 1999, 30 pages. 16. City Of Indianapolis, Regulations for Cuts within the Public Right of Way, dated Sep. 1996, 30 pp. 17. Town of Jackson Wyoming, Title 12 Streets and Other Public Places, Ordinance 571, City of Little Rock, Arkansas, Ordinance to establish standards, July 1, City Of Louisville, Utility Policy, 18 pages plus attachments, Mid-America Regional Council, Public Right of Way Cost Recovery Plan, dated May 1998, 24 pp. plus 12 exhibits (Includes Detail Drawing of Pipe Trenches For Future Roadways) 21. Minnesota Public Utilities Commission Rules, Restoration Standards, dated April 19, 1999, 17 pp plus 13 plates. 22. Misc., Document No. 1, Related to airports, Item P-152 Excavation and Embankment, 10 pages. 23. Misc., Document No. 2, Accommodation of Utilities on County Road Right of Way, by County Road Administration Board, dated May 5, 1992, 10 pages. 24. Restoration Standards, by H. A. Todres, draft outline, 4 pages.

5 Table 1 Continued 25. Metropolitan Government Of Nashville and Davidson County, Standard Specifications for Earthwork for Structures and Pipelines, Pavement Repair and Drawings, 28 pages. 26. City Of Norfolk, Utility Cuts Policy Manual, 20 pages plus attachments, dated July 23, Region Of Ottawa Carleton, Management of Regional Rights-of Ways for Utility, Construction and Maintenance Activities, Draft No. 2, dated August City of Redwood Falls, Standard Drawings, 13 plates. 29. City And County Of San Francisco, Regulations for Excavating and Restoring Streets in San Francisco, dated January 1999, 41 pp regulations, 64 pp specifications plus drawings. 30. St. Louis County, Missouri, Special Use Permit Application Requirements and Conditions, dated February 1, 1979, 29 pp plus exhibits. 31. City Of Tampa, Permit Requirements for New Construction in Public Right of Way, dated 1997, and Transportation Technical Manual, 1994 Edition, 47 pages. 32. City of Tucson, Development Standard No , and Standard Drawings, dated January US Army Corps of Engineers, Guide Specification for Construction, Section Excavation, Trenching, and Backfilling for Utilities Systems, revised Oct. 1999, 15 pages. 34. Vancouver B.C., Specification For Cutting Through Pavements, and Excavation Trenches and Holes on City of Vancouver Streets, Appendix A, dated August 17, 1990, 7 pages. 35. Vancouver, Washington, Procedures for backfilling, 1 page. 36. Ventura County, Standard Specifications and Drawings, dated 1996, 8 pages. 37. City Of Wichita, Supplemental Specifications for Utility Cut Repairs, 5 pages. 38. City Of Worcester, Massachusetts, Permit Manual, dated July 1, 1992, 28 pages plus attachments. 39. City of Richmond, Virginia, Standard Drawings Trench Cut Restoration, dated November 1999, 3 pages. 40. Utility Cuts in Asphalt Pavements: Best Engineering Practices, by H. A. Todres, P. E., 14 pages, published by APWA International Public Works Congress, NRCC/CPWA Seminar Series, Innovations in Urban Infrastructure, (Not scored by committee.)

6 Table 2 Evaluation Matrix Scores Weighting Scale 5 = Best 1 = Poor 0 = Not at all Title of Publication CSI Format Reference Standards Measurement & Payment Length of Spec Reference Drawings 1. Acc., Utility Plants w/in R.O.W City of Anaheim, CA A.P.W.A Az Public Service Co City of Arlington City of Austin Bellcore CA I.U.S.R.C Charlotte Cincinnati Colombus Denver Detroit Manufacturer Ditch Witch Halifax Indianapolis Jackson Little Rock Louisville Mid America Regional Minn. P.U.C.R Misc. Doc Misc. Doc Misc. Doc Metro Gov. Nashville Norfolk Ottawa Redwood Falls San Francisco St. Louis Tampa Tucson US Army C.O.E Vancouver, B.C Vancouver, WA Ventura Wichita Worcester City of Richmond, Vir Construction Methods Compaction Requirements Material Requirements Testing Inspection Related Specifications Utility Coordination Guarantee Readability Totals

7 Table 3 Evaluation Matrix Comments Title of Publication Comments 1. Acc., Utility Plants w/in R.O.W Concise guideline of Public Works practices, Good guide specs. 2. City of Anaheim, CA Good pavement repair details 3. A.P.W.A. Light review of 30 studies - not a good trench spec..but good resource 4. AZ Public Service Co. Main emphasis is Electrical Utility guideline 5. City of Arlington Two pages of repair detail 6. City of Austin Dept. Audit Report, not applicable for specs. 7. Bellcore Primarily for overhead cables and guys, some underground info 8. CA I.U.S.R.C General specs for backfill and pavement restoration 9. Charlotte Regulations and fee schedule 10. Cincinnati Very good specs and drawings 11. Columbus 6 pages of drawings and specs 12. Denver Good specs, no drawings 13. Detroit 14. Manufacturer Ditch Witch 15. Halifax 16. Indianapolis 17. Jackson 18. Little Rock ordinance 19. Louisville Policy and drawings 20. Mid America Regional R/W Cost recovery study 21. Minn. P.U.C.R Standard drawings 22. Misc. Doc 1 Military Guide Spec. (Air Force?) 23. Misc. Doc 2 Policy Material only Todre's paper is a good introduction to the issues at hand. However, it is 24. Misc. Doc 3 not a specification. 25. Metro Gov. Nashville Overall, a very good spec w/ details 26. Norfolk Policy w/ drawings 27. Ottawa Report of Life cycle cost of roadways; Good 28. Redwood Falls Same as 21*; 29. San Francisco Regulations, code, good specs 30. St. Louis 31. Tampa 32. Tucson 33. US Army C.O.E Good guide spec, no drawings 34. Vancouver, B.C. 35. Vancouver, WA 36. Ventura 37. Wichita 38. Worcester 39. City of Richmond, Vir.

8 Table 4 Committee Members List Mark Macy, P. E. - Chairman 720 South 5th Street Nashville, TN Bus: (615) Bus Fax: (615) mark_macy@metro.nashville.org Norm Bowers 1800 W. Highway 56 Olathe, KS Bus: (913) Bus Fax: (913) norman.bowers@jocoks.com Kevin Gangaware 1935 Twenty First Avenue South Nashville, TN Bus: (615) Bus Fax: (615) kgangaware@leainc.com Steve Goodman Mail Station: 3162 P. O. Box Phoenix, Arizona Bus: (602) Mobile: (602) Bus Fax: (602) sgoodm01@apsc.com Dr. Mohamed Hussein Institute for Research in Construction Building M Montreal Road Ottawa, Canada K1AOR6 Bus: (613) Bus Fax: (631) mohamed.hussein@nrc.ca Diane Linderman - Committee Liaison Department of Public Works 900 E. Broad Street, Room 701 Richmond, VA Bus: (804) Bus Fax: (804) dlinderman@ci.richmond.va.us Ron Mannz P. O. Box S. Washington Street Redwood Falls, MN Bus: (507) Bus Fax: (507) rmannz@ci.redwood-falls.mn.us Shawn O Keefe Northern States Power Co. 825 Rice Street, MS 16 St. Paul, MN Bus: (651) Bus Fax: (651) shawn.m.okeefe@nspco.com James Snyder, P. E. 720 South Fifth Street Nashville, TN Bus: (615) Bus Fax: (615) james_snyder@metro.nashville.org H. A. (Alan) Todres 8920 Tamaroa Terrace Skokie, IL Bus: (847) Bus Fax: (847) HATODRES@aol.com