BHATE Geosciences Corporation SUE Investigation: ALDOT Central - PowerPoint PPT Presentation

BHATE Geosciences Corporation SUE Investigation: ALDOT Central Business District Bridge Replacement on I-59/I-20 from I-65 to 31 st St Project Number: IM-1059 October 29, 2014

ALDOT - Central Business District I-59/I-20 from I-65 to 31 st Street Birmingham, Alabama

CBD Project Summary ALDOT is planning bridges along Interstate 59/20  through the City of Birmingham’s Central Business District (CBD). As part of the restructuring and rerouting and proposed  new construction, detailed information on subsurface utilities was required for the planning and design. The work includes approximately 1.5 miles of roadway  and bridge widening on I-59/I-20 and I-65 Approximately 32 new bridges/ramps/bridge widening  Additionally, improvements to the I-59/20/31st Street  North interchange, and the I-59/20.US 31(Red Mountain Expressway) interchange are planned.

Utility Verification Prior to Borings Geotechnical drilling included nearly 500 boring  locations performed by multiple consultants CBD is a highly urbanized and developed area  (since late 1800 ’s) with multitude of utilities. It was necessary to verify that the proposed boring locations were free of subsurface high value utilities This area consisted of gas, telephone, fiber-optic  cables and other sensitive targets that could be significantly disrupted and impacted in case of damage during field exploration.

CBD Boring Locations BHATE provided pre-drilling SUE services to locate the  utilities and clear boring locations to manage subsurface conflicts and reduce risk of potential damage. Approximately 500 boring locations scanned  Nearly 20% of the borings were impacted by subsurface  utilities and had to be shifted. O O R O R R

CBD Boring Locations  Used geophysical methods to clear safe boring locations Ground penetrating radar (GPR)  Cable and pipe locators  Note: Differences noted at numerous locations  between actual and One Call marked utilities.  After scanning and relocation of the borings where conflicts were indicated, 100% of scanned borings were safely drilled.  Considerable potential cost savings in regards to interruptions in service and/or utility repair had this scanning not been done prior to commencing drilling. Information from available records and One-Call could not be completely relied upon.

ALDOT Phase Prioritization  Phase I: 31 st Street North and 12 th Avenue North  Phase 2: I-59/I-20 and I-65 Interchange  Phase 3: 12 th Court North  Phase 4: CBD Interchange Ramps  Phase 5: CBD Bridge Demo and Replacement

Why SUE???  Preconstruction Planning  Utility-related problems are a leading cause of delays that occur during the construction phase of highway projects (FHWA-IF-02-048)  Cost Management  For small fraction of total construction costs, initial SUE investigation can save significant costs caused by delays, repairs, change orders etc.  Utilities management  Accurately determine existing utilities and as-built conditions and depths  Address conflicts during design stage  Replace/relocate discussions with utility companies prior to final design completion  Avoid risks  Damage to utilities  Repairs  Disruptions in service  Safety

ALDOT SUE Objectives  “ALDOT realizes utility identification, relocation and management is critical information for project design and to give to the contractor”  Want nothing to slow or disrupt progress  Can’t stand any surprises!  “That is why ALDOT is going through this effort and have seen significant value in the SUE process for the CBD project” Mr. Steve Walker, P.E. ROW- Engineer

Procedure for Accomplishing Field Work General Outline  Four (4) main utility data quality levels established by American Society of Civil Engineers' Standard Guideline for the Collection and Depiction of Existing Subsurface Utility Data – ASCE 38-02  Provides a means of obtaining a professional opinion of the quality and reliability of utility information  Utility Quality Levels  QL-D  QL-C  QL-B  QL-A

Procedure for Accomplishing CBD Field Work  Records Research- QL-D – First Step  Gather and review available drawings and records. Included historical archives going back to late 1800’s.  Obtain available as-built information from Utilities, Alabama Gas, Alabama Power, Birmingham Waterworks etc.  Preliminary assessment of the types of utilities present in the area and their likely location and depth.  ATT will not provide information – only confirm if there is a conflict with a proposed construction activity  Field Observation- QL-C – Second Step  Visually inspect available surface indicators  Verify approximate depth and alignment of utilities present based on surface features

SUE Level B Field Work This included in-situ verification of utilities using GPR and other NDT methods  Geophysical Investigation- QL-B  Application of surface geophysical methods to determine the existence and position of utilities.  Ground penetrating radar (GPR)  Ferromagnetic Locators  RD 7000 cable and pipe locators  One Call locating services are also used. However, we often find discrepancies in lines located by these agencies and actual field conditions.

SUE ‘Level B’ Field Equipment Ground-Penetrating Radar – multiple SIR 3000 utility  carts by GSSI. Multiple antenna frequencies available. Multi-channel GPR system - a 14-channel - cart-based  ground penetrating radar unit that is typically towed behind a vehicle during survey operations. Optical Equipment- using visible light as an  electromagnetic method. For example, using a laser through a pipe from one vault to another. FLIR ThermaCAM EX320 infrared cameras RD7000 cable and pipe locators and Tx transmitter -  induces a frequency into a buried pipe or cable and allows the user trace out the alignment of the utility on the ground surface Ferro magnetic locators- locating and pinpointing buried  metal objects such as manholes and metallic pipes

Level ‘A’ Field Work  Actual Exposure- QL-A  This level was implemented in limited areas where Level B information was limited and high risk underground utilities required in-place exposure and verification of type and depths.  Highest level of accuracy available  Nondestructive exposure of underground utilities  Employed minimally intrusive excavation equipment (vacuum extraction) to minimize the potential for utility damage  Type, size, depth, and location of utilities were recorded and used to verify provided information  Depth of exposure ranged from 3 ’ to 5 ’

SUE Process Workflow

CBD Bridge Demolition and Replacement  I-59/I-20 and I-65 Interchange - Findings

Site Specific Findings I-59/I-20 and I-65 Interchange  Records Review QL-D - Sanborn Maps and other sources revealed:  Oil Refinery  Dry Cleaners  Birmingham Electric Co.  Foundry, Machine Shop, Storage Yard  10-15 Tanks were identified  Multitude of old utilities – it was unknown which utilities were abandoned.

Site Specific Findings I-59/I-20 and I-65 Interchange QL-D and QL-C investigation uncovered numerous  inconsistencies. Utility records from Alabama Power, Jefferson County  Environmental Services and Water Works did not match in- field conditions. Manhole covers not found in the field but present on the utility records. Information on abandoned and active utilities was not  clearly documented and would require further verification. Utilities marked in the field by One-Call were not consistent  with the records provided by utilities. Level B SUE work is pending and will be implemented in this  area and supplemented by Level A, as necessary.

CBD Bridge Demolition and Replacement  23 rd Street to 31 st Street North Section - Findings

Site Specific Findings 23 rd Street to 31 st Street North  QL-D and QL-C also uncovered discrepancies  Historical records as well as Sanborn maps indicated old gas stations, a railroad yard with multiple tracks etc.  Utility records and surface features indicated that the drawings provided by utility companies did not accurately reflect in-ground conditions.

Site Specific Findings 23 rd Street to 31 st Street North  QL-B investigation was performed to verify the location of buried utilities beneath proposed CBD bridge alignment  Identified locations of buried railroad tracks. These were covered up by existing pavement with no visible signs on the surface.  The entire area was mapped in detail at each intersection. Numerous undocumented underground utilities were found.  Discrepancies between utility drawings and actual locations were resolved. Conflicts between actually existing utilities and proposed construction were identified.

CBD Bridge Demolition and Replacement  9 th Ave from 15th St to 23 rd St – Findings