MULTI-PLATE PRODUCT GUIDE - Armtec

MULTI-PLATESPECIAL CONSIDERATIONSCompaction efforts exceeding and/or not meeting specified densities, unbalancedbackfill levels on opposing sides of the pipe or self weight of the plates may causesagging, peaking, swaying or rolling of the structure. Contact an Armtec Salesrepresentative for additional information should these conditions be encountered.Under HaunchesSpecial attention must be paid to thearea beneath the haunches of a fullperiphery pipe in order to provide fullsupport. Hand tamping using rods maybe required at these points.Water jetting of material under thehaunches is also an option where siteconditions provide proper drainage.Pipe ArchesSpecial attention must be paid toensure the site foundation bearingcapacity exceeds the pressuresgenerated at the corner (haunch) ofthe pipe arch. The height of coverlimits for pipe arches may be governedby the foundation bearing capacity inthis area. Pipe arches generate radialcorner pressures that are greater thanthe applied pressure at the top of thestructure. A minimum corner bearingcapacity of 200 kPa is required.HIGHWAY 99, BC - MULTI-PLATE PIPE-ARCHCompetent Native MaterialEngineered Backfill ZoneArea for Special AttentionGranular Cushion Below PipeMONITORINGDue to the flexible nature of Multi-Plate structures, monitoring of some sizes andshapes will be required. A sample monitoring method is accomplished bysuspending plumb-bobs at key locations along the structure’s length andrecording periodic movements of the vertical and horizontal displacement of theplumb-bob relative to a fixed point of reference.