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This appendix contains detailed summary tables for the laboratory testing program for each pier scour countermeasure type. Tests were conducted for baseline conditions and to optimize the extent of coverage, termination details, and filter recommendations for the following: ⢠Riprap ⢠Partially grouted riprap and geotextile containers ⢠Articulating concrete block systems ⢠Gabion mattresses ⢠Grout-filled mattresses These tests were conducted in the 8-foot wide, 200-foot long, and 4-foot deep recirculating flume at Colorado State University (CSU). Additional testing of partially grouted riprap was con- ducted at a prototype scale in the CSU outdoor flume (20 feet wide, 108 feet long, and 8 feet deep) to evaluate constructability and environmental issues related to placing this countermeasure type. For each test series, the tables provide information on layout, filter, and design intent for each test, as well as a brief commentary on observations and/or results. Identification of a specific test run and pier is also provided for cross-reference to the more detailed description of testing results in the Reference Document (available on the TRB website: http://www.trb.org/news/blurb_ detail.asp?id=7998). H-1 A P P E N D I X H Summary of Laboratory Testing Program
H-2 aFLOW 2a 2a = Riprap placement = 2(a) from pier (all around) Pier width = âaâ (normal to flow) t 3d50 Riprap thickness = 3d50 (minimum) Filter placement = 4/3(a) from pier (all around) Filter Figure H.1. Baseline riprap design. Layout Filter Design Intent Observations Test Pier Stable, minimal particle launching after 8 hours at 2.5Vcrit, catastrophic loss after exposure to 8 more hours of testing at 3.0Vcrit 4a B BStable, minimal particle launching after 2 hours at 2.0Vcrit. Stable, minimal particle launching after 2 more hours at 2.5Vcrit. Stable, minimal particle launching after 2 hours at 2.0Vcrit. Loss/damage moderate after 2 more hours at 3.0Vcrit 5 Stable, minimal particle launching after 2 hours at 2.0Vcrit. Stable, minimal particle launching after 5 more hours of testing at 2.0Vcrit 7 Stable, minimal particle launching on downstream corner after 5 hours at 1.9Vcrit 11-3 C C HEC-23 guidelines with recommended geotextile, no skew Stable, minimal particle launching after 2 hours at 2.0Vcrit C12 B Loss/damage significant after 2 hours at 2.0Vcrit, pier skewed to flow 15° C12 A 5a areal extent, 3d50 thickness Geotextile filter, 2/3 coverage HEC-23 guide- lines with recom- mended geo- textile, pier skewed to flow Loss/damage significant after 2 hours at 2.0Vcrit, pier skewed to flow 30° C12 C Table H.1. Baseline Riprap Tests. Riprap
H-3 Lay out Filter Design Intent Comments Test Pier 4a lateral, 2a upstream, 1a downstream, 3d 50 thickness at pier for 1/3 extent, then 2:1 slope at bottom to thickness of 6d 50 at perimeter Stable after 2 hours at 2.0V cri t , some particle launching into side troughs 8 3a areal extent, 3d 50 thickness at pier, then 2:1 slope at bottom to thickness of 6d 50 at perimeter Loss/damage severe after 2 hours at 2.0V cri t , particle displacement in troughs and downstream of pier 8 4a decreased areal extent, 3d 50 thickness at pier for 1/3 extent, then 2:1 slope at bottom to thickness of 6d 50 at perimeter Areal riprap coverage and edge treatment with recommended geotextile Stable after 2 hours at 2.0V cri t 8 3a decreased areal extent, 3d 50 thickness Loss/damage moderate after 2 hours at 2.0V cri t , particle launching on all sides 7 Loss/damage after 2 hours at 2.0V cri t , particle displacement in side troughs 7 Loss/damage severe launching and particle displacement after 8 hours at 2.5V cri t . Catastrophic loss/damage after exposure to 8 more hours of testing at 3.0V cri t 4a C C 4a decreased areal extent, 3d 50 thickness Areal riprap coverage variation from HEC-23 with recommended geotextile Loss/damage minimal after 2 hours at 2.0V cri t C16 C 4a decreased areal extent, 4.5d 50 thickness Areal riprap coverage and thickness variation from HEC-23 with recommended geotextile Loss/damage severe, scour at nose after 8 hours at 2.5V cri t 4c B B B Stable, minimal particle launching after 2 hours at 2.0V cri t C14 B Stable, minimal particle launching after 2 hours at 2.0V cri t pier skewed to flow 15° C14 A A A Geotextile filter, 2/3 coverage Scour hole extent with recommended geotextile Stable, minimal particle launching after 2 hours at 2.0V cri t , pier skewed to flow 30° C14 C C C Based on scour hole dimension, 3d 50 thickness None Scour hole extent Stable, minimal particle displacement after 2 hours at 2.0V c 3 5.5a areal extent, 3d 50 thickness for 3a, bottom or riprap sloped upwar d 1.5H:1V to thickness of 1d 50 at perimeter Geotextile filter, full coverage Examine HEC-18 guidelines Stable after 2 hours at 2.0V c 3 None Loss/damage moderate, scour at nose after 8 hours at 2.5V cri t . Loss/damage severe scour at nose after 8 more hours at 2.5V cri t 6 5a areal extent, 4.5d 50 thickness Granular filter, 4d 50 thickness, 2/3 coverage Thickness and filter variation from HEC-23 guidelines Loss/damage moderate, scour at nose after 8 hours at 2.5 V c . Loss/damage severe scour at nose after more 8 hours at 2.5 V c 6 5a areal extent, 4d 50 thickness at pier, slope to height of 1d 50 at perimeter, mounded Loss/damage after 2 hours at 2.0V cri t , particle displacement in trough and sand filling in riprap matrix after 3 hours at 2.0V cri t C16 A 5a areal extent, 2.5d 50 thickness, mounded Loss/damage after 2 hours at 2.0V cri t , particle displacement in trough and sand filling in riprap matrix after 4 hours at 2.0V cri t C16 B B B 5a areal extent, 3d 50 thickness all around, mounded None Examine mounded riprap Loss/damage moderate after 2 hours at 2.0V cri t , particle launching on all sides 13 C Table H.2. Riprap Coverage Tests.
Layout Filter Design Intent Comments Test Pier 4a lateral, 2a upstream, 1a downstream. 3d50 thickness at pier for 1/3 extent, then 2:1 slope at bottom to thickness of 6d50 at perimeter Stable after 2 hours at 2.0Vcrit, some particle launching into side troughs 8 3a areal extent, 3d50 thickness at pier, then 2:1 slope at bottom to thickness of 6d50 at perimeter Loss/damage severe after 2 hours at 2.0Vcrit, particle displacement in troughs and downstream of pier 8 4a decreased areal extent, 3d50 thickness at pier for 1/3 extent, then 2:1 slope at bottom to thickness of 6d50 at perimeter Geotextile filter, 2/3 coverage Areal coverage and edge treatment with recommended geotextile Stable after 2 hours at 2.0Vcrit 8 5.5a areal extent, 3d50 thickness for 3a, bottom or riprap sloped upward 1.5H:1V on perimeter Geotextile filter, full coverage Examine HEC-18 (3rd edition) guidelines Stable after 2 hours at 2.0Vcrit 3 B C A B Layout Filter Design Intent Comments Test Pier 5a areal extent, 4.5d 50 thickness Thickness and filter variation from HEC-23 guidelines Loss/damage moderate, scour at nose after 8 hours at 2.5 V crit . Loss/damage severe scour at nose after 8 more hours at 2.5V crit 6 2/ 3 granular filter 4d 50 thickness Loss/damage severe, scour at nose after 8 hours at 2.5 V crit 4c C Full granular filter, 4d 50 thickness Loss/damage moderate after 2 hours at 2.0V crit . Loss/damage moderate after 2 more hours at 2.5V crit . Loss/damage catastrophic after 2 more hours at 3.0V crit 5 5a areal extent, 3d 50 thickness HEC-23 guidelines, filter type Stable, minimal particle loss after 2 hours at 2.0V c 5 5.5a areal extent, 3d 50 thickness for 3a, bottom of riprap sloped upward 1.5H:1V on perimeter Full geotextile Examine HEC- 18 (3 rd edition) guidelines Stable after 2 hours at 2.0V crit 3 Based on scour hole dimension, 3d 50 thickness Examine current practice Stable, minimal particle launching after 2 hours at 2.0V crit 3 Stable after 2 hours at 2.0V crit 3 5a areal extent, 3d 50 thickness Examine current guidelines Stable, minimal particle launching after 2 hours at 2.0V crit 12 C 5a areal extent, 4.5d 50 thickness Thickness and filter variation from HEC-23 guidelines Loss/damage moderate, scour at nose after 8 hours at 2.5V crit . Loss/damage severe, scour at nose after 8 more hours at 2.5V crit 6 5a areal extent, 4d 50 thickness at pier, slope to height of 1d 50 at perimeter Loss/damage after 2 hours at 2.0V crit , particle displacement in trough and sand filling in riprap matrix after 3 hours at 2.0V crit C16 A A A 5a areal extent, 2.5d 50 thickness Loss/damage after 2 hours at 2.0V crit . Particle displacement in trough and sand filling in riprap matrix after 2 more hours at 2.0V crit C16 B B B 5a areal extent, 3d 50 thickness all around, mounded None Examine mounded riprap Loss/damage moderate after 2 hours at 2.0V crit , particle launching on all sides 13 C C C C Table H.3. Riprap Termination Tests. Table H.4. Riprap Filter Tests.
H-5 FLOW a 1.5a 1.5a grout Pier width = âaâ (normal to flow) Extend partially grouted riprap a distance of 1.5(a) from pier (minimum, all around) Filter placement = 1.0(a) from pier (all around) t = 4â Filter Pier grout Figure H.2. Partially grouted riprap baseline design layout. Layout d50 Filter Design Intent Comments Test Pier 4a areal extent, 6.67d50 full extent of thickness, 100 mL grout per spot 0.6 in Stable, minimal particle launching at sides after 2 hours at 2.0Vcrit 15 A 4a areal extent, 4d50 full extent of thickness, 65 mL grout per spot Loss/damage severe after 8 hours at 2.5Vcrit breakup into numerous conglomerates 14 C 4a areal extent, 4d50 full extent of thickness, 100 mL grout per spot 1.0 in Stable after 2 hours at 2.0Vcrit, some undermining at downstream sides, excess grout created rigid mass 15 B 4a areal extent, 3d50 full extent of thickness, 100 mL grout per spot 1.3 in 2/3 geotextile filter Rock size performance Undermining on all sides, after 2 hours at 2.0Vcrit, excess grout created rigid mass 15 C Table H.5. Partially Grouted Riprap Baseline Tests. Partially Grouted Riprap
H-6 Layout d50 Filter Design Intent Comments Test Pier 4a lateral extent, turndown 4:1, 3.3d50 thickness, 65 mL grout per spot Stable after 2 hours at 2.0Vcrit 16 A 4a lateral extent, 3.3d50 thickness, 65 mL grout per spot Stable after 2 hours at 2.0Vcrit 16 B 4a lateral extent, turndown 4:1, 3.3d50 thickness, 65 mL grout per spot Layer thickness and termination detail Stable after 2 hours at 2.0Vcrit 17 C 4a lateral extent, 5d50 thickness, 100 mL grout per spot Layer thickness Loss/damage minimal, undermining on sides after 2 hours at 2.0Vcrit 16 C 3a lateral extent, 3.3d50 thickness, 65 mL grout per spot Areal coverage and thickness Stable, minimal particle launching at sides after 2 hours at 2.0Vcrit 17 A 3a lateral extent, turndown 4:1, 3.3d50 thickness, 65 mL grout per spot 0.6 in Stable, minimal particle launching at sides after 2 hours at 2.0Vcrit 17 B 5a lateral extent, turndown 2:1, 3d50 thickness, 65 mL grout per spot 1.0 in 2/3 geotextile filter Areal coverage, layer thickness, and termination detail Stable after 8 hours at 2.5Vcrit 18 B Layout d50 Filter DesignIntent Comments Test Pier 4a lateral extent, 3.3d50 thickness, turndown 4:1, 65 mL grout per spot Stable after 2 hours at 2.0Vcrit 16 A 4a lateral extent, sloped down 4:1, 3.3d50 thickness, 65 mL grout per spot Layer thickness and termination detail Stable after 2 hours at 2.0Vcrit 17 C 3a lateral extent, sloped down 4:1, 3.3d50 thickness, 65 mL grout per spot 0.6 in Stable, minimal particle launching at sides after 2 hours at 2.0Vcrit 17 B 5a lateral extent, sloped down 2:1, 3d50 thickness, 65 mL grout per spot 1.0 in 2/3 geotextile filter Areal coverage, layer thickness, and termination detail Stable after 8 hours at 2.5Vcrit 18 B Table H.6. Partially Grouted Riprap Coverage Tests. Table H.7. Partially Grouted Riprap Termination Tests. Layout Filter Design Intent Comment Test Constructability Installation of geocontainers, riprap, and grout in slow-moving water (1.5 ft/s) was accomplished Environmental issues Water quality parameters during underwater grout application remained below maximum allowable 3.5 pier widths from pier face High-velocity performance test Partially grouted riprap remained stable after exposure to 5.6 ft/s flow conditions C1 3.5 pier widths from pier face, half of installation composed of loose riprap Sand-filled geocontainers High-velocity, comparison to loose riprap Partially grouted riprap remained stable, loose riprap was displaced after exposure to 6.4 ft/s flow conditions C20 Table H.8. Partially Grouted Riprap Prototype Scale Tests.
H-7 Layout Filter Design Intent Comments Test Pier Standard ACB layout Minor loss after 2 hours at 1.9Vcrit 12 B Stable after 2 hours at 1.9Vcrit 13 B 2:1 turndown for 5a lateral Geotextile filter, full coverage Standard ACB layout with grouted interface Loss/damage after 8 hours at 2.5Vcrit on right side 14 B Table H.9. ACB Baseline Tests. FLOW 2a a 2a ACB placement = 2(a) from pier (all around) Pier width = âaâ (normal to flow) Filter Filter extended to the edge of the block around the entire perimeter ACB Blocks sloped 1V:2H (50%) Figure H.3. Baseline ACB design. Articulating Concrete Block Systems
H-8 Layout Filter Design Intent Comments Test Pier 3:1 turndown on down- stream and sides for 1.5a to a depth of 0.5a, upstream extends horizontal for 1.5a then 4:1 turndown ending at 0.5a depth Stable after 2 hours at 1.9Vcrit, loss from upstream after 5 hours at 1.9Vcrit 11-2 B 3:1 turndown from pier all sides from 0.25a below bed for 2a lateral ending at a depth of 1.5a Geotextile filter, full coverage Areal coverage and termination detail Stable after 2 hours at 1.9Vcrit, stable after 5 hours at 1.9Vcrit 11-3 B 2:1 turndown for 1a, riprap key installed to 5a at a depth of 0.5a Stable after 2 hours at 1.9Vcrit 12 A 2:1 turndown for 1a, riprap installed to 5a with inverted 2:1 slope at bottom edge Geotextile filter extended beyond perimeter of the blocks into the riprap ACBs in conjunction with riprap Stable after 2 hours at 1.9Vcrit 13 A Table H.10. ACB Extent of Coverage Tests. Layout Filter Design Intent Comments Test Pier 5a horizontal with 10-inch radius of curvature ending at 0.5a depth Termination detail Loss/damage downstream after 2 hours at 1.9Vcrit, undamaged at leading edge 11-1 B 3:1 turndown on downstream and sides for 1.5a to a depth of 0.5a, downstream extends horizontal for 1.5a then 4:1 turndown ending at 0.5a depth Stable after 2 hours at 1.9Vcrit, loss from upstream after 5 hours at 1.9Vcrit 11-2 B 3:1 turndown from pier all sides from 0.25a below bed for 2a lateral ending at a depth of 1.5a Geotextile filter, full coverage Areal coverage and termination detail Stable after 2 hours at 1.9Vcrit, stable after 5 hours at 1.9Vcrit 11-3 B 2:1 turndown for 1a, riprap key installed to 5a at a depth of 0.5a Stable after 2 hours at 1.9Vcrit 12 A 2:1 turndown for 1a, riprap installed to 5a with inverted 2:1 slope at bottom edge Geotextile filter extended beyond perimeter of the blocks into the riprap ACB used in conjunction with riprap Stable after 2 hours at 1.9Vcrit 13 A Table H.11. ACB Termination Tests. Layout Filter Design Intent Comments Test Pier 2:1 turndown for 5a lateral beginning 0.5a below bed with interface grouted Geotextile filter, 2/3 coverage Standard ACB layout with grouted interface below the bed surface Loss/damage nearly complete after 8 hours at 2.5Vcrit and deformation of subgrade beneath geotextile 18 C 2:1 turndown for 1a, riprap key installed to 5a at a depth of 0.5a Stable after 2 hours at 1.9Vcrit 12 A 2:1 turndown for 1a, riprap installed to 5a with inverted 2:1 slope at bottom edge Geotextile filter extended beyond perimeter of the blocks into the riprap ACB used in conjunction with riprap Stable after 2 hours at 1.9Vcrit 13 A Table H.12. ACB Filter Tests.
H-9 Gabion Mattresses Pier a Geotextile extends full length of the gabions for baseline tests Top of gabion mattress flush with ambient bed elev. FLOW Figure H.4. Baseline unconnected gabion mattress coverage test layout. Layout Filter DesignIntent Comments Test Pier 4a areal extent parallel to flow, 4a normal to flow Minimal gabion displacement on front and sides C3 B 4a areal extent parallel to flow, 3a normal to flow Loss/damage severe, gabions displaced downstream, deformation of subgrade and scour at nose C3 C 5.5a areal extent parallel to flow, 5a normal to flow Full geotextile Areal coverage Stable, gabion displacement on periphery C3 A Table H.13. Unconnected Gabion Mattress Coverage Tests. Layout Filter Design Intent Comments Test Pier 4a horizontal extent adjacent to the pier, 3:1 turndown at periphery to depth of 0.25a, total areal extent 5.5a Loss of gabions from front of pier; gabion displacement on sides and in back C4 CFull geotextile Termination detail Loss of gabions from periphery downstream of pier C4 B4:1 turndown to a depth of 0.38a, 4a areal extent Loss displacement of gabions on periphery C5 B 2:1 turndown to a depth of 0.75a, 4a lateral extent Filter extent and termination detail Loss/damage catastrophic, gabions completely displaced downstream, deformation of subgrade and significant scour at nose C5 C 0.75a horizontal extent from pier face, 2:1 turndown at periphery to depth of 0.38a, 4a total areal extent 2/3 geotextile filter Termination detail Loss/damage severe, deformation of subgrade below geotextile, significant scour at nose C5 A Table H.14. Unconnected Gabion Mattress Termination Tests.
H-10 Layout Filter DesignIntent Comments Test Pier 2:1 turndown to a depth of 0.75a, 4a lateral extent Loss/damage catastrophic, gabions completely displaced downstream, deformation of subgrade and significant scour at nose C5 C 4:1 turndown to a depth of 0.38a, 4a areal extent Loss displacement of gabions on periphery C5 B 0.75a horizontal extent from pier face, 2:1 turndown at periphery to depth of 0.38a, 4a total areal extent 2/3 geotextile filter Filter extent and termination detail Loss/damage severe, deformation of subgrade and scour at nose C5 A 5.5a areal extent parallel to flow, 5a normal to flow None Filter extent Displacement of gabions into trough on sides of installation C4 A Layout Filter Design Intent Comments Test Pier 0.75a horizontal extent from pier face, 2:1 turndown at periphery to depth of 0.38a, 4a total areal extent Undermining of gabions behind pier C19 A 2:1 turndown to a depth of 0.75a, 4a lateral extent Loss of material under gabion mattress at pier nose C19 C 4:1 turndown to a depth of 0.38a, 4a areal extent 2/3 geotextile filter Gabions connected at top edge Stable C19 B Table H.15. Unconnected Gabion Mattress Filter Tests. Table H.16. Connected Gabion Mattresses Tests. Grout-Filled Mattresses Top of grout filled mattress flush with ambient bed elev. Geotextile extends full length of the mattresses Pier a FLOW Figure H.5. Typical grout-filled mattress coverage test layout.
H-11 Layout Filter Design Intent Comments Test Pier 4a areal extent parallel to flow, 3a normal to flow Minor undercutting after 2 hours at 1.0Vcrit. After 2 hours at 2.0Vcrit undercutting was severe; pier exposed under mattress C7 C 4a areal extent parallel to flow, 5a normal to flow Undercutting around entire perimeter after 2 hours at 2.0Vcrit C7 B 5.5a areal extent parallel to flow, 5a normal to flow Full geotextile Areal coverage Undercutting on sides and behind pier after 2 hours at 2.0Vcrit C7 A Table H.17. Rigid Grout-Filled Mattress Coverage Tests. Layout Filter Design Intent Comments Test Pier 2:1 turndown to a depth of 0.75a, 4a parallel to flow, 5a normal to flow Undercutting on sides after 2 hours at 2.0Vcrit C8 C 4:1 turndown to a depth of 0.38a, 4a areal extent parallel to flow, 5a normal to flow Undercutting on sides after 2 hours at 2.0Vcrit C8 B 0.75a horizontal extent from pier face, 3:1 turndown at periphery to depth of 0.25a, 4a total areal extent Full geotextile Termination detail Undercutting around entire perimeter; pier exposed under mattress after 2 hours at 2.0Vcrit C8 A Layout Filter Design Intent Comments Test Pier 2:1 turndown to a depth of 0.75a, 4a parallel to flow, 5a normal to flow Undercutting severe; pier exposed under mattress after 2 hours at 2.0Vcrit C18 C 4:1 turndown to a depth of 0.38a, 4a areal extent parallel to flow, 5a normal to flow Undercutting on sides and behind pier after 2 hours at 2.0Vcrit C18 B 0.75a horizontal extent from pier face, 2:1 turndown at periphery to depth of 0.25a, 4a total areal extent Full geotextile Articulating grout mattress Undercutting behind pier, mats had begun to gap after 2 hours at 2.0Vcrit C18 A Table H.18. Rigid Grout-Filled Mattress Termination Tests. Table H.19. Flexible Grout Mattress Tests.
