ANCHOR CHANNEL FASTENING Design guide with examples Version 1, September 2021
DISCLAIMER 1. The technical data presented in this design guide are based on numerous tests and evaluation criteria according to the current state-of-the-art and the relevant European regulations. 2. For anchor channels holding a European Technical Assessment (ETA), noted in the cover with the respective icon, the technical data in this design guide are based on and in accordance with the current European Technical Assessment (ETA).
Interactive PDF! Table of contents Click on tab or content topic to view chapter.
DESIGN BASICS The design of anchor channels is based on the following documents: • For static and quasi-static 2D loading in tension and shear loads acting transverse to the channel axis as well as fire exposure the anchor channels are designed in accordance with EN 1992-4 or EOTA TR 047 • For 3D static and quasi-static loading the anchor channels are designed additionally with CEN TR 17080 or EOTA TR 047-Annex B • For fatigue loads, the anchor channels are designed in accordance with EOTA TR 050 TECHNICA
General Design of anchor channels EN 1992-4 or EOTA TR 047 based design currently covers anchor channels located in cracked or uncracked normal-weight concrete which are subjected to transfer the static and quasi-static tensile loads NEd and shear loads perpendicular to channel VEd,y or any combination of these loads. Additionally, CEN-TR 17080 or EOTA-TR 047 Annex B covers design of anchor channels under static 3D loading (NEd, VEd,y , VEd,x) as shown in figure 1 and 2.
PARTIAL SAFETY FACTOR CONCEPT According to the safety concept of the European Codes, the basic verification of fastening in the Ultimate Limit State (ULS) is based on a comparison of action and resistance under consideration of the respective safety factors. The design value of the action must not exceed the design value of the resistance.
Table of contents Partial safety factors for resistance Partial factors for fastening under static and quasi-static loading shall be applied to characteristic resistances. Note: In the absence of national regulations the recommended values of partial safety factors are given in the following table: Failure Mode Symbol Factor Failure of anchor γMs 1.8 Connection b/w anchor and channel γMs,ca 1.8 Local failure by flexure of channel lips γMs,l 1.8 Bending of channel γMs,flex 1.
STATIC AND QUASI STATIC LOADS IN EN-1992-4, EOTA-TR 047 OR CEN-TR 17080 Determination of anchor forces under tension and shear loads acting transverse to the channel axis (NEd, VEd,y) as per EN 1992-4 or EOTA TR 047 The path of the load transfer is from channel bolts to the channel lips, then to anchors and from there directly into concrete. That’s why besides the calculation of bolt forces the next step in the design of anchor channels is the calculation of anchor forces NaEd,i.
Table of contents Determination of anchor forces under shear loads acting in the direction of channel axis VEd,x as per CEN-TR 17080 or EOTA TR 047-Annex B The anchor forces calculations and verifications for shear in the longitudinal axis of the channel are based on EOTA TR 047 Annex B or CEN-TR 17080.
Anchor channel installed transverse to the edge In case of steel failure and concrete pry-out failure the load distribution according to figure 7 applies. In case of concrete edge failure or verification of supplementary reinforcement, only the anchor closest to the edge is assumed to be effective. Therefore, the sum of all the bolt forces VcbEd,x acting along the longitudinal axis of the channel are considered to act on the single anchor closest to the edge figure 8.
The path to transfer the load is shown in figure 10. From the fixture, loads are transferred to the channel bolts, from the channel bolts the load goes to the channel lips and from there to anchors and finally into the concrete. Based on the load path the verifications of each part of the channel and concrete are performed from the applied loads in different directions and their combined effects. The basic equation Ed ≤ Rd must be fulfilled for all types of verifications.
VERIFICATIONS UNDER TENSION LOADS Steel failure modes If tension loads act on the anchor channel, the steel verifications have to be performed as shown in the table below. The characteristic strength values given in this table should be taken from the current European Technical Assessment (ETA) or technology manual. Material safety factors are taken from table on page 7.
Design of anchor channels Note: Anchors should always be designed for use in cracked concrete, unless a sound justification is given to the selection of uncracked concrete HAC Design Examples With: k 2 = 7.5 for cracked = 10.5 for uncracked concrete Ah = load bearing area of the anchor head given in the current European Technical Assessment (ETA) or technology manual fck = nominal characteristic compressive cylinder strength Concrete cone failure For anchor channels, hch/hef ≤ 0.4 and bch/hef ≤ 0.
Key 1 = anchor under consideration Figure 13 Critical spacing for concrete cone verifications If the concrete cones under tension load overlap with each other due to neighboring anchors, then we should consider the reduction in the concrete cone strength. In figure 14, the concrete cones which are developed at angle are intersecting and reduction in strength due to this overlapped area Aoverlap has to be taken into account through a factor ch,s,N.
ch,e,N < 1 ch,e,N = 1 c1 ccr,N Design of anchor channels ccr,N c1 Ae Figure 17 Due to close edge distance concrete cones, intersecting edge with reduction in strength Figure 18 Due to larger edge distance, concrete cones not intersecting edge with no reduction in strength With: c2 = edge distance of the considered anchor ccr,N = 0.
c2 < ccr,N c2 1 c2 < ccr,N 1 c2.1 < ccr,N 1 1 2 2 3 3 2 2 3 3 c2.2 < ccr,N c1.1 (a) Figure 21 Definition of corner edge distance (b) a) Anchor 1 under consideration b) Anchor 2 under consideration (c) c1.
c) I f the conditions b) 1) and b) 2) are not fulfilled, the characteristic resistance of an anchor channel in case of concrete splitting failure shall be calculated according to Formula: Table of contents N0Rk,c, ch,s,N, ch,c,N, ch,e,N, re,N as per page 13 however the values ccr,N and scr,N shall be replaced by ccr,sp and scr,sp, respectively, which correspond to the minimum member thickness hmin d) I f in the current European Technical Assessment (ETA) or technology manual ccr,sp is given for more
Supplementary reinforcement for tension loads When the design relies on supplementary reinforcement, concrete cone failure does not need to be verified, but the supplementary reinforcement shall be designed to resist the total anchor load. It shall be anchored adequately on both sides of the potential failure planes, as shown in the figure 23.
Design of anchor channels HAC Design Examples 3. This additional supplementary reinforcement is placed as close to the channel profile as possible to avoid any eccentricity associated with an angle of failure cone 5. Enough anchorage length and splice length as per EC-2 must be provided HAC-C(-P) Design Examples 2. Where supplementary reinforcement has been designed for the most loaded anchor, the same reinforcement shall be provided around all other anchors 4.
VERIFICATION UNDER SHEAR LOADS ACTING PERPENDICULAR TO THE LONGITUDINAL AXIS OF THE CHANNEL Steel failure modes If shear loads act transverse to the channel axis of the channel, the steel verifications have to be performed as shown in the table below. The characteristic strength values given in this table should be taken from the current European Technical Assessment (ETA) or tables from technology manual and material safety factors are taken from the table on page 7.
Full constraint of fixture: M=2.0 VEd,y HAC Design Examples The value M can be chosen with any value between 1 and 2 depending on the constraint conditions. In case conditions are not clear M should be chosen with M=1.0. Design of anchor channels VEd,y The characteristic resistance of a channel bolt VRk,s,M with stand-off installation is calculated: with la = stand-off distance i.e.
Concrete failure modes Concrete capacities are calculated according to the formulas given in this section. The table below lists the required concrete verifications under shear loading.
ccr,V C2 v ch,c,V < 1 Table of contents The reduction - factors are explained in the following. The influence of neighboring anchors on the concrete edge resistance is taken into account by the factor ch,s,V : v C2 ch,c,V < 1 ccr,V Figure 29 Due to corner edge distance concrete cones, not intersecting edge with no reduction in strength The component member thickness also plays a vital role in the calculation of concrete edge strength.
c1 c1 VEd,y VEd,y 2hch 2hch h h hcr,V hcr,V 2c1 2c1 Figure 30 Influence of member thickness on the concrete edge strength The factor re,V takes into account the effect of reinforcement in the concrete member.
Required reinforcement Design of the reinforcement Table of contents VRd.c 1.2 ∙ VRd.c 1.4 ∙ VRd.c ~ 5 VRd.c - Straight edge rebar Straight edge rebar + stirrups - Not required Verification of the rebar of the HAC-EDGE product is considered in the PROFIS software analysis. - Not required Recommendations regarding the reinforcement detailing in the concrete member (Hilti method) Edge reinforcement (re.V=1.
Edge reinforcement and stirrups (re.V=1.4): The diameter of the edge rebars must be ≥ 12 mm and stirrup diameter ≥ 8 mm with maximum stirrup spacing of 200 mm. 2*c1 b.ch Stirrups must be placed on both sides of the channel up to spacing of 2c1 as shown in the figure 34. (n-1)*s b.
If shear loads act on the longitudinal axis of the channel, steel verifications must be performed. The characteristic resistance values in the table below should be taken from the current European Technical Assessment (ETA) or technology manual. Steel verification of the bolt with lever arm for shear loads acting in the direction of the channel axis is currently not permitted by the code. Please contact your local team for an engineering solution.
Pry-out failure In pry-out failure mode, concrete break-out occurs at the back of the channel when loaded in shear.
The factor ratio s,V takes into account the disturbance of stresses in the concrete due to further edges of the concrete member on the shear resistance. For anchor channels with two edges parallel to the direction of loading e.g.
SUPPLEMENTARY REINFORCEMENT FOR SHEAR LOADS Shear loads acting transverse to the channel axis In case the concrete edge resistance is not sufficient, reinforcement can be added. The entire shear load must be taken up by the reinforcement and the concrete edge verification is not needed. Verifications for supplementary reinforcement include the proof of the rebar steel resistance and sufficient rebar anchorage length as per Eurocode 2.
Table of contents Detailing of supplementary reinforcement for shear loads acting transverse to channel axis based on EOTA TR047/EN-1992-4 The supplementary reinforcement shall be in the form of a surface reinforcement as shown in figure 41.
cb cb cb VEd,x,3 + VEd,x,2 + VEd,x,1 cb VEd,x,3 3 s cb VEd,x,2 2 s cb VEd,x,1 1 c1 c1 ≤ 0,75 c1 ≤ 0,75 c1 Figure 42 Anchor channel loaded longitudinal to shear axis Anchor channel arranged parallel to the edge When the design shear force acts parallel to the edge as per figure 43, the supplementary reinforcement may conservatively be designed by assuming that the component of the design shear force parallel to the edge is acting perpendicular and towards the edge.
In the first step, all single verifications for steel and concrete failure modes are carried out separately as explained in the above sections for the most unfavorable anchor or position of the bolt in the anchor channel. In this section, the combined effects of tension, shear perpendicular and shear longitudinal must be considered.
Steel failure of anchor and connection between anchor and channel The verification shall be satisfied: With k14 = 2.0 if max (VRd,s,a;VRd,s,c) ≤ min (NRd,s,a, NRd,s,c) = to be taken from the current European Technical Assessment (ETA) if max (VRd,s,a;VRd,s,c) > min (NRd,s,a, NRd,s,c) = 1.0 as a conservative assumption In this verification, the exponent k14 can be chosen according to the ratio of the shear and tensile resistance of the anchor or anchor-channel connection.
Table of contents Anchor channels with supplementary reinforcement The verifications for steel failure of the channel bolt and the anchor channel shall be done according to the above equations. The verification of concrete failure modes is explained in the following.
FATIGUE LOADS The design of anchor channels under fatigue loads is depicted in EOTA Technical report TR050. This technical report provides a design method for anchor channels only under tensile fatigue loading in combination with or without static and quasi-static loads. The qualification of anchor channels under fatigue loads is based on European Assessment Document EAD. No static or quasi-static shear or fatigue shear load may be applied in combination with a fatigue tensile load.
The range of influence of a single static tension load shall be taken into account according to the figure 49: The range of influence of a cyclic tension load is assumed to be different and is shown in the figure 50: Figure 50 Load distribution from bolt to anchor with fatigue load applied on channel bolt HAC-C(-P) Design Examples Figure 49 Load distribution from bolt to anchor with static load applied on channel bolt Design of anchor channels As shown in figure 51 the equivalent static action NEd,eq
DESIGN OF ANCHOR CHANNELS UNDER FATIGUE LOADS The partial safety concept is used for the design of anchor channels under fatigue loads. Fatigue loads are marked with ∆. e) Resistance: For the determination of design value of the fatigue resistance the characteristic values obtained from the tests shall be divided with a partial safety factor M,fat i.e.
Result Comment Table of contents Step 1 NRd S-N curves for design fatigue resistances developed with zero or low minimum cyclic load S-N curves can be determined for each failure mode. At a minimum, the value of the fatigue limit resistance, DNRd,0,oo shall be determined ∆NRd,0,∞ Design of anchor channels n number of cycles (log) 1 2 NRd Goodman-diagram developed for selected nr.
DESIGN METHOD I (COMPLETE/EXACT METHOD) The exact design methodology usually delivers better results but requires more detailed knowledge of the applied loads. The following three cases are distinguished: Case-1: The design value of the lower cyclic load NEud is known.
Table of contents Case-2: The maximum number of loading cycles n during the entire life is known.
Required verifications for design: Design case 1: Design case 2: Design case 3: Steel failure Steel failure Steel failure Pullout Pullout Pullout Concrete cone failure Concrete cone failure Concrete cone failure 42
Table of contents DESIGN METHOD II (SIMPLIFIED METHOD) Precise allocation of the design value of the lower cyclic load NEud is not possible and an upper limit to the number of load cycles n over the working life of the anchor channel cannot be predicted.
FIRE LOADS The verification of anchor channels under fire exposure shall include all the failure modes i.e. steel and concrete. The relevant requirements of EN 1992-1-2 e.g. partial factors and load combinations shall be observed. The characteristic resistances under fire exposure should be taken from the current European Technical Assessment (ETA) or from this document in the respective sections The fire resistance is classified according to EN 13501-2 using the standard ISO time-temperature curve (STC).
Table of contents CONCRETE FAILURE MODES UNDER FIRE LOADS Pull-out failure The characteristic resistance of anchor channels installed in concrete classes C20/25 to C50/60 may be obtained from equations: Hence final equations are: for fire exposure up to 90 minutes where NRk,p is the characteristic resistance for pull-out failure given in the current European Technical Assessment (ETA) in cracked concrete C20/25 under ambient temperature for fire exposure between 90 and 120 minutes k 2 and Ah values fro
Concrete splitting failure Concrete blow-out failure The assessment of concrete splitting failure due to fire exposure is not required because the splitting forces are assumed to be taken up by the reinforcement. The assessment of concrete blow-out failure is not required because of the required edge distance.
Table of contents CONCRETE FAILURE MODES Pry-out failure The characteristic resistance in case of anchor channels installed in concrete classes C20/25 to C50/60 should be obtained using equations: Hence the final equations are: for fire exposure up to 90 minutes Design of anchor channels for fire exposure up to 90 minutes VRk,cp,fi k 8 NRk,c,fi for fire exposure between 90 minutes and 120 minutes for fire exposure between 90 minutes and 120 minutes VRk,cp,fi k 8 NRk,c,fi HAC Design Examples
HAC ANCHOR CHANNELS Design examples 48
Table of contents DESIGN EXAMPLE 1 Design of standard HAC anchor channel with 3D loading Design basics: Concrete C30/37, Normal weight concrete Concrete condition: cracked Member thickness h = 250 mm Edge distance c1 = 160 mm, c2 =150 mm Existing reinforcement widely spaced Standard: Hilti design method based on EN 1992-4.
2. Calculation of anchor forces 150 hef= 91 a2 a1 25 a3 150 150 Influence length: li = 13 x Iy0.05 x s0.5 li = 13 x 214630.05 x 150 0.5 li = 262 mm 25 Critical load position on anchor channel 1.0 A‘1 li hef= 91 A‘3 li 150 a2 a1 a3 150 25 25 Anchor load due to bolt 1 1.
Table of contents 3. Verifications Type of failure mode Applied Load [kN] Resistance [kN] Utilization [%] Status Anchor 2.33 18.39 13 Ok Connection anchor-channel 2.33 13.89 17 Ok Channel lip 2.5 13.89 18 Ok Channel bolt 2.5 83.73 3 Ok Flexure channel N/A N/A N/A N/A Pull-out 2.33 31.33 8 Ok Concrete cone 2.33 14.74 16 Ok Design of anchor channels Tension loading summary 3.1 Steel failure (EN 1992-4 section 7.4.1.3) NRk,s,a = 33.1 kN gMs= 1.8 NRd,s,a= 18.
3.1.3 Local flexure of channel lip (bolt 1) (EN 1992-4 section 7.4.1.5) scbo = 150 mm (given bolt spacing) yl,N = 82 mm NcbEd = 2.50 kN N0Rk,s,l =25 kN NRk,s,l =25 kN Ms,l = 1.8 NRd,s,l=13.89 kN 3.1.4 Channel bolt (bolt 1) ccr,N = critical edge distance i.e. 0.5 scr,N ≥ 1.5hef ccr,N = 0.5 x 390 = 195 mm ≥ 136.5 mm NcbEd = 2.50 kN NRk,s,=125.6 kN gMs = 1.5 NRd,s,=83.73 kN 3.2 Concrete failure (No c2,2 given) 3.2.1 Pull-out failure (Anchor a3) (EN 1992-4 section 7.4.1.4) k1 = 8.
Utilization [%] Status Channel bolt w/o lever arm 7.28 50.24 15 Ok Flexure channel lip w/o lever arm perpendicular 7.00 13.89 51 Ok Flexure channel lip w/o lever arm longitudinal 2.00 7.82 26 Ok Anchor perpendicular 6.52 13.89 47 Ok Anchor longitudinal 1.33 12.27 11 Ok Connection anchor-channel perp. 6.52 13.89 47 N/A Connection anchor-channel long. 1.33 6.94 20 Ok Concrete pry out perpendicular 6.52 29.50 22 Ok Concrete pry out longitudinal 1.33 23.
3.3.4 Anchor-shear perpendicular (Anchor a3) 3.4 Concrete failure (EN 1992-4 section 7.4.2.3) 3.4.1 Concrete pry-out failure – shear perpendicular (Anchor a3) (EN 1992-4 section 7.4.2.4) VaEd,y = 6.52 kN VRk,s,a,y = 33.1 kN gMs= 1.5 VRd,s,a,y =13.89 kN (same as tension capacity for quadratic interaction) NRk,c taken from section 3.2.2 NRk,c = 22.35 kN 3.3.5 Anchor-shear longitudinal (Anchor a3) (Longitudinal shear as per EOTA TR 047 Annex B, section B 6.2.2.2.2) VaEd,x = 1.33 kN VRk,s,a,x = 18.
= 0.5 x 390 = 195 mm ≥ 136.5 mm scr, V = 4 c1 + 2 bch Table of contents ccr,N scr, V = 4 x160 + 2 x 41 =722 mm ccr,v = 0.5 scr,V ccr,v = 0.5 x 722 =361 mm Design of anchor channels (as now c2,1 given) (no c2,2 given) hef = 91 mm N0Rk,c= 38.04 kN s= 150 mm scr,N = 390 mm ych,s,N = 0.51 c1 = 325 mm ccr,N = 195 mm ych,e,N = 1.0 c2 = 160 mm ych,e,N,1 = 1.0 ych,e,N,2 = 0.90 yre,N = 1.0 a V = 1.33 kN Ed,x k8 = 2.0 NRk,c = 17.46 kN gMc= 1.5 VRk,cp,x = 34.92 kN VRd,cp,x = 23.28 kN 3.4.
Ac,V = h(1.5c1 + 1.5c1), if c2 is less than 1.5c1 then take c2 h = 1.5c1 if h < 1.5c1 then take h h=1.5 x 175 = 262.5 mm > 250 mm (slab thickness) = 250 mm 1992-4 section 8.3.3, longitudinal shear as per EOTA TR047 Annex B Section B.6.3) 3.5.1 Channel bolt (bolt 1) Ac,V = 250(1.5 x 175 + 160) = 105625 mm2 A0c,V = 4.5 x 1752 =137813 mm2 Utilization = 3% 3.5.2 Point of load application – channel lip (bolt 1) k13 = 2.0 if VRd,s,l ≤ NRd,s,l Utilization= 53% 3.5.
Table of contents DESIGN EXAMPLE 2 Design of standard HAC anchor channel with tension fatigue loading INPUT DATA Design of anchor channels Base Material: Side view Design basics: Applied loads per bolts: Standard: Hilti design method based on EOTA TR047/EN 1992-4 & EOTA TR050 Tension: Static permanent characteristic load NEk,g = 1 kN per bolt Static variable characteristic load NEk,q = 1 kN per bolt Fatigue characteristic load ∆NEk = 1 kN per bolt European Technical Assessment: ETA 11/0006 HAC-C(-
2. Calculation of anchor forces under static loads (permanent & variable) 150 hef= 148 a2 a1 25 a3 150 150 Influence length: li = 13 x Iy0.05 x s0.5 li = 13 x 579300.05 x150 0.5 li = 276 mm 25 Critical load position on anchor channel 2.85 2.
Table of contents 3. Equivalent static and fatigue design action calculation Permanent static load: Equivalent static design action calculation: A‘1 li li 25 150 li li a2 a1 1.35 A‘2 a3 150 a2 a1 25 25 Applied static load bolt 1 Design of anchor channels 1.35 a3 150 150 25 Applied static load bolt 2 0.62 1.97 1.35 0.62 1.97 li=276 HAC Design Examples 1.35 li=276 150 150 Load 1 Load 2 1.35 1.35 (1.35/276) x (276-150) = 0.62 (1.35/276) x (276-150) = 0.62 0.62 + 1.
Fatigue load: Equivalent design fatigue cyclic load 1.2 li-0.5s 1.2 1.2 s li-0.5s 150 1.2 li-0.5s a2 a1 25 1.2 a3 150 a1 25 25 Applied fatigue load bolt 1 1.2 s a2 150 li-0.5s a3 150 25 Applied fatigue load bolt 1 1.20 2.40 1.20 li=276 150 li=276 150 Calculation of equivalent design fatigue cyclic load Load 1 Load 2 Applied load [kN] 1.2 1.2 A’I, A’2 1.2 1.2 Equivalent design fatigue force ΔNEd,eq [kN] 2.4 2.
Applied bolt loads (static + variable) Applied bolt loads (static + fatigue) 1.2 KN 1.2 KN 2.85 KN Design of anchor channels 1.35 KN Resulting anchor forces (static + fatigue) a1 a2 a2 a1 a2 a2 1.59 KN 2.54 KN 1.59 KN 0.87 KN 0.87 KN 0.22 KN 1.07 KN 1.07 KN 0.26 KN HAC-C(-P) Design Examples Resulting anchor forces (static + variable) 150 HAC Design Examples 1.35 KN 150 HAC EDGE Design Examples 2.85 KN Table of contents Summary of applied loads ansd anchor forces 4.
4.1 Steel failure (EN 1992-4 section 7.4.1.3) 4.1.1 Anchor (Anchor a2) NaEd = 2.54 kN NRk,s,a = 52.5 kN gMs = 1.8 NRd,s,a = 29.17 kN 4.1.2 Connection between anchor and channel (Anchor a2) NaEd = 2.54 kN NRk,s,c = 50.1 kN gMs,ca= 1.8 NRd,s,c= 27.83 kN 4.1.5 Flexure of channel (assume a beam with two loads to calculate the bending moment) MchEd = 0.11 kNm MRk,s,flex = 2.19 kNm gMs,flex = 1.15 MRd,s,flex = 1.90 kNm 4.2 Concrete failure 4.2.1 Pull-out failure (Anchor a2) (EN 1992-4 section 7.4.
Table of contents NaEd,eq = 1.97 kN gM,fat = 1.35 gM = 1.8 NRk= 50.1 kN gM,fat,n = M,fat + (M - M,fat) x (NRk,n - NRk,)/(NRk - NRk,) = critical edge distance i.e. 0.5 scr,N ≥ 1.5hef ccr,N = 0.5 x 512 = 256 mm ≥ 222 mm gM,fat,n = 1.35 + (1.8 – 1.35) x (3.5 – 3.5)/(50.1 – 3.5) Design of anchor channels ccr,N gM,fat,n = 1.35 (No c2,1 given) k1 = 8.6 fck = 35 MPa hef = 148 mm N0Rk,c= 91.60 kN s = 150 mm scr,N = 512 mm ych,s,N = 0.57 c1 = 200 mm 5.2 Concrete failure (EOTA TR 50 section 5.
15G S ( Q 5.2.2 Concrete cone failure-fatigue NaEd,eq = 0.87 kN gM,fat = 1.35 gM,c = 1.5 ηc,fat,n = 0.571 NRk,c = 45.95 kN NRkc0n = 0.571x45.95=26.24 kN ηc,fat,∞= 0.50 NRkc0∞ = 0.5x45.95=22.98 kN gM,fat,n = gM,fat + (gM - gM,fat)(NRk,c,n - NRk,c,)/(NRk,c - NRk,c,) gM,fat,n = 1.35 + (1.5 – 1.35) x (26.24 – 22.98)/(45.95 – 22.98) gM,fat,n = 1.
HAC EDGE Design Examples HAC-C(-P) Design Examples HAC Design Examples Design of anchor channels Table of contents
HAC-C HOT-ROLLED ANCHOR CHANNELS Design example 66
Table of contents DESIGN EXAMPLE Design of HAC-C hot rolled anchor channel with 2D loading Design basics: Concrete C30/37, Normal weight concrete Concrete condition: cracked Member thickness h = 200 mm Edge distance c1 = 150 mm, no corner influence Existing reinforcement widely spaced Standard: EOAT TR 047 / EN 1992-4 European Technical Assessment: ETA-17/0336 Side view Applied loads: Solution Tension load NEd = 10 kN Shear load VEd = 16 kN Selected product: HAC EDGE Design Examples Top view HAC
2. Calculation of anchor forces 125 Influence length: li = 13 x Iy0.05 x s0.5 li = 13 x 536520.05 x 2500.5 li = 354 mm hef= 94 a2 a1 25 250 25 Critical load position on anchor channel 1.0 i hef= 94 25 l 250 A‘2 li hef= 94 a2 a1 1.
3.1 Steel failure (EN 1992-4 section 7.4.1.3) 3.1.5 Flexure of channel (assume a beam with two loads to calculate the bending moment) Table of contents Tension loading 3.1.1 Anchor (Anchor a1) 5kN NRk,s,a = 31 kN NRd,s,a= 17.22 kN 3.1.2 Connection between anchor and channel (Anchor a1) 2.5kN MchEd =0.313 kNm 2.5kN Design of anchor channels NaEd = 6.35 kN gMs= 1.8 MchEd = 0.31 kNm MRk,s,flex = 2.084 kNm gMs,flex = 1.15 MRd,s,flex = 1.81 kNm Spacing between supports s=250 mm 3.
ccr,N ccr,N = critical edge distance i.e. 0.5 scr,N ≥ 1.5hef = 0.5 x 399 = 199 mm ≥ 141 mm k1 = 8.1 hef = 94 mm s = 250 mm ych,s,N = 0.88 ccr,N = 199 mm ych,e,N,1 = 1.0 yre,N = 1.0 NRk,c = 30.95 kN NRd,p =20.63 kN fck = 30 MPa N0Rk,c= 40.43 kN scr,N = 399 mm c1 = 150 mm ych,e,N = 0.87 ych,e,N,2 = 1.0 NaEd = 6.35 kN gMc= 1.5 (No c212 given) (No c2,2 given) Shear loading Type of failure mode Applied Load [kN] Resistance [kN] Utilization [%] Status Channel bolt w/o lever arm 8.00 26.
3.4.2 Concrete edge failure – shear perpendicular y- (Anchor a1) (EN 1992-4 section 7.4.2.5) Table of contents 3.3.3 Anchor-shear perpendicular (Anchor a1) (EN 1992-4 section 7.4.2.3) Design of anchor channels VaEd,y = 10.35 kN VRk,s,a,y = 40.3 kN gMs = 1.5 VRd,s,a,y = 17.22 kN (same as tension capacity NRd,s,a for quadratic interaction) VaEd,y = 10.35 kN VRk,s,c,y = 40.3 kN gMs,ca = 1.8 VRd,s,c,y =17.22 kN (same as tension capacity NRd,s,c for quadratic interaction) scr, V = 4 c1 + 2 bch ccr,v = 0.
3.5 Combined tension and shear loads (EN 1992-4 section 8.3.3) 3.5.1 Channel bolt (bolt 1) Utilization: 14% 3.5.2 Point of load application – channel lip (bolt 1) k13 = 2.0 if VRd,s,l ≤ NRd,s,l Utilization: 23% 3.5.3 Anchor and connection between anchor and channel (anchor a1) k14 = 2.0 if max (VRd,s,a;VRd,s,c) ≤ min (NRd,s,a, NRd,s,c) Utilization: 50 % 3.5.
HAC EDGE Design Examples HAC-C(-P) Design Examples HAC Design Examples Design of anchor channels Table of contents
HAC EDGE ANCHOR CHANNELS 74
Table of contents DESIGN EXAMPLE HAC EDGE - static 2D loads Design basics: Concrete C30/37, Normal weight concrete Concrete condition: cracked Member thickness h = 150 mm Edge distance c1 = 100 mm, no corner influence Existing reinforcement widely spaced Standard: Hilti design method based on EOAT TR 047 or EN 1992-4 European Technical Assessment: Internal tests for concrete edge as the product is not covered in European framework Top view HAC-C(-P) Design Examples HAC Design Examples Base Material:
A suitable solution for the given situation is with Hilti HAC EDGE: Selected product: Anchor channel: Rebar HAC-50 106/300 F EDGE 100 mm Channel bolt: HBC-C 8.8F, M12 x 50 mm HAC EGDE: Boundary conditions Max. anchor load on HAC-50 Max. concrete edge resistance special anchor channel HAC EDGE Utilization VaEd = 15.64 kN VRd,c,y = 40.05 kN βv = 15.64/40.
Table of contents DESIGN STEPS NcbEd [kN] VcbEd [kN] 1 4 12.75 2 4 12.75 Bolt Design of anchor channels 1.Calculation of bolt forces 150 hef= 106 a2 25 250 Influence length: li = 13 x Iy0.05 x s0.5 li = 13 x 331250.05 x 2500.5 li = 345.87 mm 25 HAC Design Examples a1 Critical load position on anchor channel A‘2 i hef= 106 l 25 250 li hef= 106 a2 a1 1.0 A‘1 A‘2 li a2 a1 25 Anchor load due to bolt 1 HAC-C(-P) Design Examples 1.
3. Calculation of tensile forces in rebars Rebar A'i 1 2 3 4 0.92 0.63 0.17 0 1 k ' A i 0.58 N1Ed,R,i = k x A'I x NcbEd,1 A'i 6.80 kN 4.66 kN 1.25 kN 0 0.19 0.65 0.89 0.43 1 k ' A i 0.46 N2Ed,R,i = k x A'I x NcbEd,2 N= Sum of bolt 1 and bolt 2 1.11 kN 3.82 kN 5.22 kN 2.52 kN 6.8 + 1.11 =7.91 4.66 + 3.82 =8.48 1.25 + 5.22 = 6.47 0 + 2.52 = 2.52 11.31 kN 12.12 kN 9.25 kN 3.60 kN NaEd,R = x.
Table of contents 4. Verifications Tension loading summary Applied Load [kN] Resistance [kN] Utilization [%] Status Anchor 4.93 29.17 17 Ok Connection anchorchannel 4.93 19.44 26 Ok Channel lip 4.00 19.44 21 Ok Channel bolt 4.00 44.93 9 Ok Flexure channel 0.24 1.39 18 Ok Pull-out 4.93 38.7 13 Ok Concrete cone 4.93 18.98 26 Ok 4.1 Steel failure (EN 1992-4 section 7.4.1.3) Design of anchor channels Type of failure mode 4.1.4 Channel bolt (bolt 1) NRk,s,a = 52.
4.2 Concrete failure 4.2.1 Pull-out failure (Anchor a1) (EN 1992-4 section 7.4.1.4) Ah = 258 mm2 fck = 30 MPa NRk,p = 58 kN NRd,p = 38.70 kN ccr,N = critical edge distance i.e. 0.5 scr,N ≥ 1.5hef ccr,N = 0.5 x 431 = 216 mm ≥ 159 mm k 2 = 7.5 NaEd = 4.93 kN gMp= 1.5 (No c2,1 given) (No c2,2 given) 4.2.2 Concrete cone failure (Anchor a1) (EN 1992-4 section 7.4.1.5) k1 = 8.2 hef = 106 mm s = 250 mm ych,s,N = 0.85 ccr,N = 216 mm ych,e,N,1 = 1.0 yre,N = 1.0 NRk,c = 28.33 kN NRd,p = 18.
4.3.4 Local flexure of channel lips (EN 1992-4 section 7.4.2.3) Table of contents 4.3 Steel failure (EN 1992-4 section 7.4.2.3) 4.3.1 Channel bolt 4.3.2 Local flexure of channel lips (EN 1992-4 section 7.4.2.3) VaEd,y = 15.75 kN gMs,ca = 1.8 (interaction) VRk,s,c,y = 53.6 kN VRd,s,c,y = 29.78 kN Design of anchor channels VRk,s,= 33.7 kN VRd,s,= 26.96 kN 4.3.5 Rebar – Perpendicular (rebar 2) NrEd,re = 12.12 kN gMs = 1.15 NRd,re = 49.17 kN HAC Design Examples VcbEd,y = 12.75 kN gMs = 1.
4.4 Concrete failure hcr,v = 2c1 4.4.1 Concrete pry-out failure – shear perpendicular (Anchor a1) (EN 1992-4 section 7.4.2.4) hcr,v = 2x100=200 mm NRk,c taken from section 4.2.2 NRk,c = 28.33 kN K8 = 2.0 VaEd,y = 15.75 kN NRk,c = 28.33 kN gMc = 1.5 VRd,cp,y = 37.77 kN VRk,cp,y = 56.66 kN 4.4.2 Concrete edge failure – shear perpendicular (Anchor a1) (Hilti design method) K(c)RTOS = 415 x3 = 0.25 c1 = 100 mm s = 250 mm ych,s,V,r = 0.97 ych,c,V,2,r = 1.0 ych,h,V = 0.93 VRk,c,y = 60.14 kN x1 = 0.
Table of contents 4.5.3 Anchor and connection between anchor and channel (anchor a1) Design of anchor channels k14 =1.0 Utilization = 79% 4.5.
Hilti Aktiengesellschaft 9494 Schaan, Liechtenstein P +423-234-2111 September, 1st 2021 www.facebook.com/hiltigroup www.hilti.com Hilti = registered trademark of Hilti Corp., Schaan W4347 0615 0-en 1 Printed in Germany © 2019 Right of technical and programme changes reserved S. E. & O Item no. 2095042.
