Product Technical Guides : US-EN Cast-In Anchor Channel Fastening Technical Guide | Page 198

1. Anchor Channel Systems 2. HAC Portfolio 3. HAC Applications Seismic tension Seismic Loading (SDC C, D, E and F) 5. Base material 6. Loading 8. Reinforcing Bar Anchorage 9. Special Anchor Channel Design 10. Design Software 11. Best Practices ϕ M s,flex,seis ≥ M u,flex The reduced anchor nominal tensile strengths associated with concrete failure modes is to account for increased cracking and spalling in the concrete resulting from seismic actions. Because seismic design generally assumes that all or portions of the structure are loaded beyond yield, it is likely that the concrete is cracked throughout for the purpose of determining the anchor strength. In locations where it can be demonstrated that the concrete does not crack, uncracked concrete may be assumed for determining the anchor strength as governed by concrete failure modes. Nominal tensile strength of a channel bolt for seismic design ϕ N ss,seis ≥ N bua N ss,seis and ϕ are tabulated in Table ESR-3520 Table 8-10 Nominal tensile steel strength for local failure of channel lips for seismic design 13. Field Fixes 14. Design Example Figure 7.5.4.2 — Required load history for simulated seismic shear test (Figure taken from AC232, Figure 7.7). Apply a seismic reduction factor (ø seismic ) of 0.75 to non-steel tension design strengths per ACI 318-14 Section 17.2.3.4.4. 12. Instructions for Use ϕ N sl,seis ≥ N bua N sl,seis and ϕ are tabulated in Table ESR-3520 Table 8-3 Nominal tensile steel strength of a single anchor for seismic design Load level N eq N l N m Number of cycles 10 30 100 taken from AC232, Figure 7.8). ϕ N sc,seis ≥ N aua Nominal shear steel strength for local failure of the channel lips for seismic design N sc,seis and ϕ are tabulated in Table ESR-3520 Table 8-3 ϕ V sl,y,seis and ϕ are tabulated in ESR-3520 Table 8-5 ϕ V sl,y,seis ≥ V bua Anchors in structures assigned to Seismic Design Category (SDC) C, D, E, or F shall satisfy the additional requirements ∆w Minimum No. of tests Channel Anchor Material [-] Secion in Annex A [-] psi [N/mm 2 ] inch (mm) [-] [-] [-] [-] Channel bolt d s strength inch (mm) [-] Seismic Tests 7.12 Seismic tension Low 0.020 (0.5) 5 see Section 7.12.2 1 13 7.13 Seismic shear perpendicular to the channel profile Low 0 5 see Section 7.13.2 1 14 7.14 Seismic shear in longtitudinal channel axis Low 0.020 (0.5) 5 see Section 7.15.2 1 Table 7.1-b — R  equired load history for simulated seismic shear test Load level ∓V eq ∓V l ∓V m Number of cycles 10 30 100 V sc,y,seis and ϕ are tabulated in ESR-3520 Table 8-5 ϕ V sc,y,seis ≥ V aua Nominal shear steel strength of a single anchor for seismic design V sa,y,seis , and ϕ are tabulated in ESR-3520 Table 8-5 ϕ V sa,y,seis ≥ N aua Nominal shear strength of a channel bolt for seismic design and Nominal flexural strength of the channel bolt for seismic design V ss,seis , M ss,seis and ϕ are tabulated in ESR-3520 Table 8-11 ϕ V ss,y,seis ≥ V bua Cast-In Anchor Channel Product Guide, Edition 1 • 02/2019 199 12 Perform the tests on anchor channels with two anchors embedded in concrete. The frequency of loading shall be between 0.1 and 2 Hz. To reduce the potential for uncontrolled slip during reversal, the alternating shear loading shall be permitted to be approximated by the application of two half- sinusoidal load cycles at the desired frequency connected by a reduced-speed, ramped load as shown in figure 7.8. The edge distance shall be large enough to avoid an edge influenced failure. Nominal shear steel strength of connection between anchor and channel for seismic design f c V sa,y,seis and ϕ are tabulated in ESR-3520 Table 8-5 ϕ V sa,y,seis ≥ V aua Test description Seismic shear perpendicular to the channel profile Seismic Loading (SDC C, D, E and F) Test Ref Nominal shear steel strength of a single anchor for seismic design All anchor channels systems in a test series shall complete the simulated seismic-shear loads. Test No. 13 is performed to extract seismic strength values for the various failures listed below. AC232 Table 4.2 — Optional test program for anchor channels for use in uncracked and cracked concete for shear loading in longitudinal channel axis and for siesmic loading (SDS C, D, E and F) Test no. f . f seismic N cb ³ N aua According to section ACI 318-14 section17.2.3.4.4 0.75ϕN pn for a single anchor, or for the most highly stressed individual anchor in a group of anchors. ϕ seis is 0.75. 198 Figure 7.5.4.3— Permitted approximation of seismic shear cycle (Figure Table 7.1-a — Required load history for simulated seismic tension test f . f seismic N sb ³ N aua Figure 7.6.4.1 — Required load history for simulated seismic tension test Nominal tensile steel strength of connection between anchor and channel for seismic design f . f seismic N pn ³ N aua ϕ N sa,seis ≥ N aua N sa,seis , and ϕ are tabulated in Table ESR-3520 Table 8-3 Nominal bending strength of the anchor channel for seismic design HBC-C-N and HBC-T M s,flex,seis and ϕ are tabulated in Table ESR-3520 Table 8-3 All anchor channels systems in a test series shall complete the simulated seismic-tension load history. Subject the anchor channel to the sinusoidal tension loads with a cycling frequency between 0.1 and 2 Hz. All anchor channels systems in a test series shall complete the simulated seismic-tension load history specified. Failure of an anchor channel system to develop the required tension resistance in any cycle before completing the loading history shall be recorded as a failure of an anchor channel system to develop the required tension resistance in any cycle before completing the loading history. Test No. 12 is performed to extract seismic strength values for various failure listed above. 7. Anchor Channel Design Code 7.6.5 A  NALYSIS IN SCD A OR AND SDC C, D, E OR F 4. Design Introduction