Contech A
Transcription
Contech A
S E Q U E N C E O F I N S TA L L AT I O N BRIDGE STREAMBANK A - J A C K S SCOUR 1 Contour the eroded bank and prepare for delivery of A-Jacks. Two halves of each A-Jacks arrive onsite in pallets of 36. A large lift truck or backhoe with forks is necessary to unload the pallets and transport them to the installation site. 2 Streambed material is excavated out of a shallow trench at the base of the eroding bank with a track hoe. The base elevation of the trench should be below the elevation of the streambed. 3 A-Jacks are assembled by sliding one half into another to form a complete unit. Rows of A-Jacks are assembled to interlock in horizontal as well as vertical directions. High embankments may require as many as three rows of A-Jacks at the toe. 1 Clear all debris if present and fill the existing scoured area with fill material by using a trackhoe. A bedding layer of rock and/or geotextile is recommended over the graded surface in preparation for the A-Jacks matrixes. 2 Pallets of A-Jacks arrive onsite and are offloaded by a large lift truck or backhoe with forks. Each pallet is lowered into the streambed (dry application) and A-Jacks are then assembled by sliding one half into the other. 3 A-Jacks are placed into a series of predetermined matrixes specially engineered to surround each pier on the lead edge and down both sides. Each A-Jacks is uniformly placed in contact with six adjacent units. 4 4 A small diameter cable made of high strength polyester or stainless steel is placed around each A-Jack matrix, crimped with an aluminum sleeve and the excess trimmed. Sediment from the toe trench is placed into rows of A-Jacks by the excavator. This fluid mix will enter the voids. The vertical streambank is sloped down over the A-Jacks and compacted with the face of the bucket. 5 Both rooted stock and cuttings are planted between A-Jacks and extended into the water table. Additional cuttings, rooted stock and grasses are placed behind the A-Jacks rows along the earth bank. O T H E R A R M O R T E C™ B R O C H U R E S ® RIVERINE, SCOUR AND STREAMBANK PROTECTION 5 This cabling serves two purposes. It stabilizes the matrix during the lift and place sequence on “wet” a p p l i c a t i o n s a n d also aids during the “ n e s t i n g ” sequence while turbulent flows begin to seat the A-Jacks into position. APPLICATIONS DROP STRUCTURES WIERS BRIDGE SCOUR PROTECTION ARMORTEC™ is a subsidiary of ENERGY DISSIPATION ARMORLOC · A-JACKS COASTAL · ARMORTEC MULTI-PRODUCT ARMORFLEX HAND PLACED · ARMORWEDGE · ARMORFLEX ARMORFLEX OS · DITCHLOK TOE STABILIZATION STREAMBANK PROTECTION AUTHORIZED AGENT 9025 Centre Pointe Drive Suite 400 West Chester, OH 45069 Toll Free (866) 551-8325 www.armortec.com www.armortecsoftware.com © 2006 ARMORTEC All Rights Reserved. AAJ06 E R O S I O N C O N T R O L S O L U T I O N S treambank erosion often produces steep banks with little or no vegetation. These unprotected banks are even more susceptible to erosion due to over steepening, loss of ground cover, groundwater discharge, and stream erosion at the base of the bank. The cost of stabilization may be quite high using conventional hard methods, particularly for high banks. A-Jacks concrete armor units provide an alternative which, when used with biostabilization techniques, develops a costeffective solution. S A - J A C K S A-JACKS® UNIT ® A-Jacks are high stability concrete armor units designed to interlock into a flexible, highly permeable matrix. A-Jacks can be installed either randomly or in a uniform pattern. The interstices formed within the A-Jacks matrix provide approximately 40% void space in the uniform placement pattern. The voids provide habitat for fish and other marine life when applied as a reef, revetment or as a soil support system in river applications. Whether or not A-Jacks are applied as a revetment on riverbanks or lakeshores, the voids may be backfilled with suitable soils and planted with a variety of vegetation including grasses, shrubs and trees above the normal base flow. ARM THICKNESS FILLET LENGTH L (INCHES) ® T (INCHES) H (INCHES) C (INCHES) UNIT VOLUME FT3 WEIGHT LBS (APPROX) AJ-24 24 3.68 1.84 0.56 78 AJ-48 48 7.36 3.68 4.49 629 AJ-72 72 11.04 5.52 15.14 2,120 AJ-96 96 14.72 7.36 35.87 5,022 AJ-120 120 18.40 9.20 70.69 9,699 Estimated Concrete Density - 140 PCF B R I D G E S C O U R A P P L I C A T I O N A P P L I C A T I O N A - J A C K S U N I T S P E C I F I C AT I O N S Licensed by Atkinson-McDougal Holdings, Inc. under one or more of U.S. Patent Nos. 5190403. Canadian patent applied for. Inspection of Scour Prone Bridge S T R E A M B A N K LENGTH ® A T W O R K F I E L D A N D L A B T E S T I N G Flow Associated with Storm Event The ability of the A-Jacks system to dissipate energy and resist the erosive forces of flowing water allows this system to protect channel boundaries from scour and erosion. Extensive laboratory research was performed on both model and full scale units in order to evaluate the hydraulic properties of the A-Jacks units. Field tests confirmed that the A-Jacks system provides a flexible, nonerodible barrier between the channel subgrade and the potentially damaging flow of water. An A-Jacks Design Manual for the hydraulic design of open-channel conveyanceways and pier scour countermeasures is available upon request. Localized Pier Scour In the hydraulic testing laboratory, vortices produced by flowing water removed bed material from around the base of the pier. Pier Scour Countermeasures A-Jacks effectively resisted the highvelocity flows and protected the pier from local scour by reducing the rate of sediment transport.