b'Determining Pier SpacingWhen locating piers on a structure, two factors Pier Spacing Based Uponmust be considered that can limit the center-to- Footing Strengthcenterdistancebetweenpiers.Thespacing The strength of the footing is of great importancebetween piers cannot be so large such that: in lighter structures.These structures generally The spacing between piers exceeds the havesmallfootingswithlittle orno rigid stempier capacity. (Pier Strength Spacing) wallforstrength.IfEquation1wereusedtoestimate the spacing for a single story with slab The spacing between piers overloads the ongrade, theresultwould suggest ahuge pierfooting. (Footing Strength Spacing) spacing distancethatthefootingcannotspan.This issue is explained in Design Examples 3-3Ain Chapter 7, a typical light structure is shown.Pier Spacing Based Upon Using Equation 1 to estimate the pier spacing forPier Strength the light structure in Design Example 3, the pierThestrengthofthepiersystemisusuallyof capacityis34,000lb.andthefoundationloadconcern when supporting and restoring a heavy was only 1,141 lb/lin.ft.Using Equation wouldstructuresuchasacommercialbuildingora suggest 29-10pierspacing.Thesmallheavy, two-story residence with a full basement. monolithic concretefoundationsimplycannotSafeDesigndictatesthatthedesigner supportsuchalongspanbetweenpiers.appliesasuitablefactorofsafety.Table1 Therefore, inthis Example3 Chapter7, theprovidesa quickreferencetoselectinga foundation strength determines the maximumRecommended Design / Service Load.In other pier spacing.cases the Factor of Safety may be dictated by the Graph 2 is provided to assist with estimating pierproject.Equation 1 is used to determine the pier spacing when dealing with:spacing relative to pier capacity. 1. Monolithic (turned down) footings and/or,Equation 1: Pier Spacing 2. Steel reinforcedspreadfootings,no stemwallX = P DSL/ P Lor P DSL= X x P L or,3. When hollow masonry stem walls are present.Where: Graph 3 is provided to help estimate pier spacingX =Pier Spacing (ft.)P DSL = Recommended Design/Service Load (Table 1) when estimatingfootings withsteelreinforcedP L = Estimated Lifting Load footings with integral short concrete stem walls.Thesegraphs assume generallyaccepted goodconstructiontechniques,adequatesteelreinforcement that is properly embedded into theconcrete,andconcrete witha compressiveEARTH CONTACT PRODUCTS strength of 2,500 psi or more. (28 day strength)Designed and Engineered to PerformTechnical Design AssistanceEarth Contact Products, LLC, has a knowledgeable staff that stands ready to help you with understanding howtodesignusingECPSteelPiers,installationprocedures,loadtesting,anddocumentationofeachpierplacement.If you have questions about structural weights, product selection or require engineering assistancein evaluating, designing, and/or specifying Earth Contact Products, please call 913 393-0007, Fax at 913 393-0008.ECP Steel Piers - Technical Design Manual2021 Earth Contact Products, L.L.C.2021-09 Chapter 6 - Page 122 All rights reserved'