10/10/2018 PAS128 Indemnified Utility Surveys James Lewis PAS128 Consulting & John Robinson Malcolm Hughes Land Surveyors James Lewis 25 Years GPR & Mapping International GPR Support Manager 2 Yrs US Vacuum Excavation 13 Yrs UK Survey Manager Independent Consultant 1
10/10/2018 John Robinson – Director Malcolm Hughes Land Surveyors Ltd Co-Author PAS128 Today’s Overview ? Need for PAS128 What is PAS128 How Does PAS128 Work The Value of SUE / PAS128 ? Q & A’s ? ? 2
10/10/2018 Why Use PAS128? Existing records are often inaccurate/incomplete. UTILITY LOCATION ACCORDING TO STATS RECORD ACTUAL LOCATION OF UTILITY FOUND WITH DESIGNATION (SURVEYED) Risks become extremely difficult to manage . We don’t know where most utilities are ! 3
10/10/2018 Why a British Specification ? What type of Survey? Why such a price spread? What do we expect? ? What do we get? The formation of PAS 128 Specification for underground utility detection, verification and location Apr 2012 Apr 2012 Dec 2012 Dec 2012 Jun 2014 Jun 2014 • BSI • Second draft Elections • ICE • First draft complete Symposium Steering team complete appointed as • PAS 128 • Public Drafting team lead • Steering Launch Consultation Group review Jan 2012 Jan 2012 Jun 2012 Jun 2012 Jul 2013 Jul 2013 4
10/10/2018 PAS 128 process Defines Defines Provides Provides Defines Defines Quality Quality Sets out Sets out scope for scope for Detection Detection Levels for Levels for process for process for Project Project methods & methods & gathering gathering Deliverables Deliverables Planning Planning Effort Effort utility data utility data PAS 128 Quality Levels Desktop Desktop Utility Utility Site Site Detection Detection Verification Verification Record Record Reconnaissance Reconnaissance (QL-B) (QL-B) (QL-A) (QL-A) Search Search (QL-C) (QL-C) (QL-D) (QL-D) 5
10/10/2018 Quality Level “D” Records Research STATS Compilation As Built Drawings Quality Level “C” Visible Features Street Furniture Covers Valves Scars 6
10/10/2018 Quality Level “B” Quality Level “A” 7
10/10/2018 Table 1 – Quality levels of survey outputs (normative) Survey category Quality level designation Post- Positional accuracy Criteria used in the determination of quality level processing (Establish with client (Practitioner to Horizontal Vertical prior to survey) determine post survey) Desktop utility record search QL-D N/A Undefined Undefined Information provided by a utility record search. Site reconnaissance QL-C N/A Undefined Undefined A segment of utility whose positioned is confirmed by visual reference to street furniture, topographical features or evidence of previous road works (reinstatement scar). Detection QL–B4 No Undefined Undefined A utility segment which is suspected to exist but has not been detected and is therefore shown as an assumed route. QL–B4P Yes QL-B3 No ±500 mm Undefined Position of the utility detected by one of the geophysical techniques. (No reliable depth measurement possible) QL-B3P Yes QL-B2 No ±250 mm or ±40% of detected depth whichever is ±40% of detected Position and depth of the utility detected by one of the geophysical greater depth techniques. 1) QL–B2P Yes Position and depth of the utility detected by multiple 2) geophysical QL-B1 No ±150 mm or ±15% of detected depth whichever is ±15% of detected greater depth techniques. QL–B1P Yes Verification QL-A N/A ±25 mm ±35 mm Horizontal and vertical position of the top and/or bottom of the utility. Additional attribution is recorded as specified in 9.2.5 . NOTE Quality and confidence level: D = lowest, A = highest. 1) Electronic depth readings using EML equipment are not normally sufficient to achieve a B2 or higher. 2) Some utilities can only be detected by one of the existing detection techniques . As a consequence, such utilities can not be designated QL-B1. Electronic Depths ? 8
10/10/2018 Value of SUE FHWA Study (71 Projects) 4.62:1 Savings Biggest Savings: Reduced Construction Days Fewer Delay Claims SUBSURFACE UTILITY ENGINEERING Value of SUE IN ONTARIO: CHALLENGES & OPPORTUNITIES University of Toronto Study (10 Projects) 3.41:1 Savings Centre for Information Systems in Infrastructure & Construction (I2C) Biggest Savings: Department of Civil Engineering, University of Toronto Fewer Delay Claims October 2005 Relocations Avoided 9
10/10/2018 James Lewis PAS128 Consulting 07892 873559 PAS128.Consulting@GMail.com Contacts Us Quotation Request :Surveythis@mhls.co.uk General Enquiries: John.Robinson@mhls.co.uk Telephone: 0800 833 312 10
10/10/2018 Remember to look up!!! 11
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