SUBSURFACE Marker Ball Installation and Information Retention at INL David Inskeep/Shawn Williams 2014 EFCOG/DOE Electrical Safety Workshop NREL- Golden, CO
SUBSURFACE INVESTIGATIONS A subsurface locate continues to prove the most effective means of preventing underground excavation damages. The Common Ground Alliance (CGA) has reported for 2011 and 2012 that when locates were performed that 99% were completed without any incidents. That’s less than 1% of underground excavations that are preceded by a locate resulted in damages. For 2012 of the more than 232,000 reported events that included facility damages, almost 60,000 were not preceded by a subsurface locate (26%). Assuming a greater than 99% effectiveness for performed locates, had locates been performed for the 60,000 hits there may have been 59,400 less hits. Keep in mind that these statistics only reflect reported hits.
SUBSURFACE INVESTIGATIONS 16,381 electrical hits, 86,727 telecomm. hitstotal average daily hits: 638if all hits were reported The number of hits would be significantly higher
Overview of Newer Technologies • Multi-Channel GPR Array • Wireless GPR for surface penetrations • Developing EM 61 Array
EM 61 ARRAY Photo: Courtesy of ZAPATA Inc.
MARKER BALLS • WHAT ARE THEY? • 4 inch plastic ball or 12 inch plate built with a programmable chip inside. • Liquid inside is reclaimed water and is used to ensure that chip is level and can be correctly read. • Each ball has a unique serial number provided by the factory. • Can be installed up to 7 feet deep for the plates and 4 feet with the ball.
Advantages of Marker Ball • Allows for safer excavations (knowing what’s below) • Aids in planning of maintenance/construction projects • Reduces uncertainties during design phase • Helps lower cost of excavations during maintenance/construction work • Overall better configuration management of what is buried.
MARKER BALLS • Recommended placement • • All ‘Items of Plant’ that are assigned unique reference numbers on facility maps and records. • • Handholes • • Buried splices of all types • • Buried transformers • • Repair points • • Buried service drops - Service stubs • • Slack loops • • Depth changes • • Laterals • • Bends - Changes of direction, arcs • • Conduit stubs .
MARKER BALLS • Encasement ends - Conduit ends of horizontally directional drilled (HDD) facilities • Path of deep facilities installed using trenchless (HDD) construction technology • Manhole covers • Water crossings • Utility crossings – locations where the cable crosses over or under other utilities. • Change in utility material or size • Using the GPS interface on the 3M™ Dynatel™ Locator model 1420 and 2200M-ID series will also provide positive verification of marker placement during construction and direct data import capability to leading industry standard GIS systems for electronic map updating
DATA MANAGEMENT • Establish a plan for saving data • Develop process to make data available • Develop an easy to use interface for customer • Design a process that requires consistent data collection techniques and questions • INL uses Trimble GEO XH 6000 with camera capabilities • Developed i-MAP application that combines subsurface data with other INL specific information
SUMMARY • Benefits • Safer Excavations • Better Design for Construction Projects • Used in Planning Process for Maintenance • Captures New and Historical Data