b'Design Example 3ABasement Wall Tieback AnchorQuick-Solve Design MethodMandatory Installation Requirements reachesmaximumtorquebeforeobtainingtheBefore beginning a complicated basement minimum lengthrequirement,theplateareaoftieback anchor design like Design Example 3A thetieback MUSTbereduced. The anchorusing the Quick -Solve design method with MUST be installed to minimum lengths statedonly general data from graphs and tables; the above, or there is the possibility that the anchorfollowing MANDATORY INSTALLATION will fail.REQUIREMENTS MUST ALWAYS BE CAUTION: If any conditions are encounteredDEFINED in the final design before the Quick - that are substantially different from what isSolve design method will be successful. normally expected for embedment intohomogenous soil, an analysis and design shallBefore performing a Quick-Solve Design be performed by a Registered Professionalfor a basement tieback system, the following Engineer, or the engineer needs to review anditems MUST be defined and specified to approve your Quick -Solve design.insure a Safe Use design: Structural Details: The only data available: Theanchor mustpenetratethewallatCast concrete basement wall is 8 feet tall and 10between 3 and 5 feet from the floor of an 8 inches thick.foot tall basement wall. (This is also valid for aBackfill against the wall is 7 feet9 foot basement wall with no more than eightSoilinformationgiven: Soilisbelievedtobefeet of soil overburden. inorganic clay (CL), stiff to very stiff115 There must be at least two feet of soil above pcf (approximate) in the areathe penetration point for the tiebacks. 1.Determine the Soil Class: Referring to the Ground water must be assumed present Soil Classification Table (Chapter 1 - Table 9) abehind the wall. soil class of 4 - 5 is selected based upon the soildescription being stiff to very stiff clay. The working soil load on the wall shall be 2. Ultimate Helical Pile Capacity: In thisassumedtobe2,900lb/lineal ft,unless design the largest spacing allowed is selected otherwise given. To obtain the ultimate load five feet on center.The Ultimate Design Loadon each tieback, multiply 2,900 lb/lineal ft. by for the project is estimated at:aFactorofSafety=2andbythe anchor T u= 2,900 lb/lin ft x FS x X = 2,900 x 2 x 5 ft =spacing on the wall (feet). T u= 29,000 lb per anchorP u= 2,900 lb x 2 x (X) = Ultimate Load - lb 3. Select the proper tieback anchor from the The maximum spacing of tiebacks shall be estimated capacity graphs: Referring to Graphnomorethan5feetoncenterwithadownward TORQUE ANCHOR HOLDING CAPACITYinstall angle15 0 unless Multiple Helical Plate Sizesspecified. 8-8" 8-10" 10-10" 10-12"70000 A minimuminstalledshaftEstimated Ultimate Capacitylengthof22feetfromthe 60000wall to the tip of the tieback 50000assemblyshallbeusedwhenthelargesthelical 40000plateontheshaftis12 30000inchesdiameter. Ifthelargestplatediameteris14 20000inches the minimum installed 10000 Earth Contact Productsshaftlengthata15 0downward is 25 feet. Graph3. 0 1 76 54 3 62 3 4 5IMPORTANT:Ifthetieback Soil ClassificationECP Technical Design ManualTorque Anchor Design Examples2021 Earth Contact Products, L.L.C.2021-09 Chapter 5Page 92 All rights reserved'