b'Table 1. ECP Steel Pier System RatingsUltimate-Limit1 Ultimate-Limit1 Maximum Drive RecommendedPg Product Designation Pipe Size Bracket Only Mechanical System Force- Proof Design / ServiceCapacity Capacity Test2 Load5 PPB-300 Steel Pier2-7/8 dia. x 0.165 Wall 79,000 lb 68,000 lb 51,000 lb 34,000 lb5 PPB-350 Steel Pier3-1/2 dia. x 0.165 Wall 99,000 lb 86,000 lb 64,500 lb 43,000 lb5 PPB-400 Steel Pier4 dia. x 0.220 Wall 99,000 lb 99,000 lb 74,000 lb 49,500 lb6 PPB-350-EP2 3-1/2 dia. x 0.165Wall 68,000 lb 53,000 lb 39,750 lb 26,500 lb6 PPB-400-EP2 4 dia. x 0.220 Wall 68,000 lb 54,000 lb 40,500 lb 27,000 lb6 PPB-350-EP4 3-1/2 dia. x 0.165 Wall 55,000 lb 42,000 lb 31,500 lb 21,000 lb7 PPB-350-WM3-1/2 dia. x 0.165 Wall 107,000 lb 86,000 lb 64,500 lb 43,000 lb7 PPB-400-WM4 dia. x 0.220 Wall 107,000 lb 107,000 lb 80,000 lb 53,500 lb7 PPB-400- WMHD 4 dia. x 0.220 Wall 115,000 lb 115,000 lb 86,000 lb 57,500 lb8 PPB-166 Slab Jack 1-5/8 O.D.3(1-1/4 Sch. 40) 22,000 lb 22,000 lb 16,500 lb 11,000 lb8 PPB-250 Concentric Brkt 2-7/8 dia x 0.165 Wall 54,000 lb 54,000 lb 40,500 lb 27,000 lb9 PPB-350-MP2 Micro Pile Bracket 68,000 lb Note: Capacity depends upon drill dia, bar dia & grout strength1. Unfactored Failure Limit, use as nominal, P nvalue per design codes2.Maximum recommended load to confirm suitable end bearing capacity of pipe3. Alternate pier pipe 2-7/8 dia. x 0.165 WallSuitable Load Bearing StratumWhile field load testing of each resistance pier Fieldloadtestsovertheyearshaveconfirmedverifies that the pier has encountered suitable end thatresistancepierswillprovidelongtermbearing, several definitions can be found for the support in strata such as these.In many casesword Rock.Many times when a soil boring suitablebearingcanbeachievedinlessdenselogisavailableonemaywanttoestimatethe materialdependinguponthepileloadingapproximatedepthtoloadbearing.Presented requirements,thetypeofsoilandthesoilhere are guidelines to assist with the estimating density.depth to suitable bearing. Thousandsofcomparisonsbetween soilboringWhen material described in a soil boring reflects logsandfieldloadtestssuggestthat Suitablea Standard Penetration Test, N, greater than 50 LoadBearingisgenerallyachievedinsoilsblows per foot, the stratum is generally consider where N 35 blows per foot at the terminationbeingweathered rock oraveryhardsoil depth.stratum.Why Should You Determine Structural Loads?Beforeonecanbegintoprepareafoundation toomuchsuctionundertheslab.Otherunderpinning design, an accurate estimate of the indicationsofunderestimatedfoundationloadsfoundation loading is required.All loads that are arethe future appearanceofnewfoundationplaced upon a structure eventually transfer to the fracturesand/or the continuedsettlementsoil through the foundation.Many times all of (downward creep) of the underpinning piers afterthese loads are not considered during the design. project completion.This can lead to an underestimation of the total Thecosttothefoundationcontractorduetostructuralloadonthefoundation.Theresult improperlyestimatingstructuralloadscanbemaybea pier designthathasinsufficient high.First and foremost is the likelihood of astrengthtosupportandrestorethe structure. customercomplaintandlackofreferrals.InSeveralproblemssurfacewhenunderestimated addition,expensivecallbackscutintothestructuralloadsareused intheprojectdesign. companysprofits.Finally,thelongtermThefirstindicationofaproblemiswhenthe solutionusuallyinvolvesinstallingadditionalstructure cannot be lifted, whereby the contractor underpinning between the existing piers, whichusually tries to explain away the problem to the meansthattheprojectcouldeasilycosttheownerorengineerbysayingthatheisonly contractor twice as much as originally planned.trying to stabilize the structure or that there isECP Steel Piers - Technical Design Manual2021 Earth Contact Products, L.L.C.2021-09 Chapter 6 - Page 117 All rights reserved'