Bolted beam splice with flange and web cover plates to SIA 263

Checks a rolled beam spliced with bolted flange and web cover plates under a bending moment and a shear force, to SIA 263:2013: the split of the moment, then the flange joint and the web joint. Every step shows its formula and the clause it comes from.

Pro SIA 263:2013

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This module is included in the Pro plan and above, with its calculation note.

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About this check

clauses, worked example and questions

What it checks

The bolts: one shear plane resists F_v,Rd = 0.6 · f_ub,k · A/γ_M2, equation (75), with the hole d₀ of table 17.
Split of the moment, M_Ed = M_w + M_f: the flange plates alone, an elastic split by the inertias I_w = n_w · t_p · h_p³/12 and I_f = 2 · A_f · (a/2)², or a plastic split by W_pl,w = n_w · t_p · h_p²/4 and W_pl,f = A_f · a, with a = h − t_f.
Flange joint: N_f = M_f/a, shared by n_f = n_1,f · n_2,f bolts with two shear planes. Bearing, equation (76): 0.85 · (e/d₀) · f_u,k · d · t/γ_M2 ≤ 2.4 · f_u,k · d · t/γ_M2, on the beam flange under the whole bolt force and on the outer and inner plates under half of it each.
Flange plates and beam flange: the gross section f_y,k · A_f/γ_M1, equation (38), and the net sections 0.9 · f_u,k · A_net/γ_M2, clause 5.1.2.2 and equation (39), on the tension side.
Web joint: the shear acts with the eccentricity e = g/2 + e_x,b + (n_c − 1) · p_2,w/2 from the hinge at mid-gap. The group carries V_Ed/n and M_e + M_w elastically; the most loaded bolt takes F_Ed = √(F_x² + F_z²).
Web plates and beam web: bearing, equation (76); the gross shear A_v · f_y,k/(√3 · γ_M1), equation (41); the net shear 0.9 · f_u,k · A_v,net/(√3 · γ_M2), equation (82), the beam web taking A_v from equation (42a) less the holes (clause 5.1.4.3).
Placing of the holes, flanges and web: e₁, e₂, p₁ and p₂ against the minimum of table 17, with e₂ ≥ d₀ and p₂ ≥ 2 · d₀ for the bearing resistance.

What you enter and what you get

You enter f_y,k and f_u,k from table 1, the five dimensions of the rolled profile, the bolt grade (table 2) and size, whether the shear planes cross the shank or the thread, γ_M1 and γ_M2 (clause 4.1.3), M_Ed, V_Ed and the gap g. For the flanges: the cover plates (outer and two inner plates, outer plate only, or none), the split of the moment, the plate sizes and the bolt rows, lines, gauge and end distances. For the web: one or two plates, t_p, h_p and the bolt columns and rows.

You get every force and resistance and the utilisation of each check with a pass or fail. With the Pro plan, it prints as an A4 calculation note.

Assumptions and limits

A normal force is not included.
Without flange plates the flanges are not spliced and the web plates carry the whole moment.
The two shear planes of a flange bolt are taken as equally loaded.
In compression the holes are filled and the gross section governs.
The inner plates fit beside the web, at most (b − t_w)/2 − r wide; the web plates fit between the root fillets.

Worked example

A rolled beam with h = 390 mm, b = 300 mm, t_w = 11 mm, t_f = 19 mm and r = 27 mm in f_y,k = 235 N/mm², under M_Ed = 250 kN·m and V_Ed = 200 kN, spliced with M20 bolts of grade 4.6 sheared in the shank: an outer plate of 300 × 8 mm and two inner plates of 90 × 10 mm carrying the whole moment with three rows at 70 mm and two lines on each side, and two web plates of 4 × 280 mm with two columns and two rows. These are the module's own results for its worked example, computed when this page was built.

Inputs
Input	Value	Ref.
Characteristic yield strength f_y,k	235 N/mm²	§ t.1
Characteristic tensile strength f_u,k	360 N/mm²	§ t.1
Overall depth h	390 mm
Flange width b	300 mm
Web thickness t_w	11 mm
Flange thickness t_f	19 mm
Root radius r	27 mm
Bolt grade	4.6	§ t.2
Bolt size	M20	§ t.17
The shear planes cross the	Shank — the unthreaded part
Resistance factor, gross sections γ_M1	1.05	§ 4.1.3
Resistance factor, bolts, welds and net sections γ_M2	1.25	§ 4.1.3
Design bending moment at the splice M_Ed	250 kN·m
Design shear force at the splice V_Ed	200 kN
Gap between the two beam ends g	10 mm
Flange cover plates	Outer plate and two inner plates — two shear planes
Split of the bending moment	Flanges alone carry the moment
Outer plate, width b_o	300 mm
Outer plate, thickness t_o	8 mm
Inner plates, width of one b_i	90 mm
Inner plates, thickness t_i	10 mm
Rows along the beam n_1,f	3
Pitch along the beam p_1,f	70 mm
Lines across the flange n_2,f	2
Gauge between the two lines nearest the web w	160 mm
End distance in the beam flange e_1,b	40 mm
End distance in the flange plates e_1,p	40 mm
Web cover plates	Two plates, one on each face — two shear planes
Thickness of one plate t_p	4 mm
Depth of the plates h_p	280 mm
Columns n_c	2
Horizontal pitch p_2,w	60 mm
Rows n_r	2
Vertical pitch p_1,w	200 mm
Beam end to the first column e_x,b	40 mm
Outer column to the plate end e_x,p	40 mm

Calculation: Common values
Step	Value	Ref.
Bolt	– = M20, grade 4.6, hole d₀ = 22 mm	§ t.17
Shear resistance of one plane0,6·f_ub,k·A/γ_M2, f_ub,k = 400 N/mm², A = 314.2 mm².	F_v,Rd = 60.32 kN	§ (75)
Lever of the flange forcesa = h − t_f, between the flange centroids.	a = 371.0 mm
Inertia of the web platesn_w·t_p·h_p³/12.	I_w = 14.635 10⁶ mm⁴
Inertia of the flange plates2·A_f·(a/2)², their own inertia neglected.	I_f = 289.046 10⁶ mm⁴
Plastic modulus of the web platesn_w·t_p·h_p²/4.	W_pl,w = 156,800 mm³
Plastic modulus of the flange platesA_f·a.	W_pl,f = 1,558,200 mm³
Share of the moment on the web platesThe flange plates carry the whole moment; the web plates the shear alone.	M_w/M_Ed = 0.0000
Moment on the flange platesM_f = M_Ed − M_w.	M_f = 250.00 kN·m
Flange forceN_f = M_f/a: tension in one flange, compression in the other.	N_f = 673.9 kN
Area of the flange plates at one flangeb_o·t_o + 2·b_i·t_i = 2,400 + 1,800.	A_f = 4,200 mm²
Flange bolts on each siden_1,f·n_2,f = 3·2.	n_f = 6
Force on one shear planeN_f/(n_f·2): the outer plate and the inner plates each take one plane, equally loaded when A_o = A_i.	F_v,Ed = 56.15 kN

Calculation: Check 1 — flange bolts in shear
Step	Value	Ref.
Flange bolts in shearF_v,Ed ≤ F_v,Rd	η = 0.931 · Pass93 % of the capacity used	§ (75)

Calculation: Check 2 — bearing on the beam flange
Step	Value	Ref.
End distance usede_1,b, from the beam end.	e = 40.0 mm	§ (76)
Bearing resistance per bolt0,85·(e/d₀)·f_u,k·d·t/γ_M2 ≤ 2,4·f_u,k·d·t/γ_M2, t = 19.0 mm.	F_b,Rd = 169.13 kN	§ (76)
Bearing on the beam flangeF_b,Ed ≤ F_b,Rd	η = 0.664 · Pass66 % of the capacity used	§ (76)

Calculation: Check 3 — bearing on the outer plate
Step	Value	Ref.
End distance usede_1,p, from the plate end.	e = 40.0 mm	§ (76)
Bearing resistance per bolt0,85·(e/d₀)·f_u,k·d·t/γ_M2 ≤ 2,4·f_u,k·d·t/γ_M2, t = 8.0 mm.	F_b,Rd = 71.21 kN	§ (76)
Bearing on the outer plateF_b,Ed ≤ F_b,Rd	η = 0.789 · Pass79 % of the capacity used	§ (76)

Calculation: Check 4 — bearing on an inner plate
Step	Value	Ref.
End distance usede_1,p, from the plate end.	e = 40.0 mm	§ (76)
Bearing resistance per bolt0,85·(e/d₀)·f_u,k·d·t/γ_M2 ≤ 2,4·f_u,k·d·t/γ_M2, t = 10.0 mm.	F_b,Rd = 89.02 kN	§ (76)
Bearing on an inner plateF_b,Ed ≤ F_b,Rd	η = 0.631 · Pass63 % of the capacity used	§ (76)

Calculation: Check 5 — flange plates, gross section
Step	Value	Ref.
Resistance of the gross sectionf_y,k·A_f/γ_M1.	N_Rd = 940.0 kN	§ (38)
Flange plates, gross sectionN_f ≤ N_Rd	η = 0.717 · Pass72 % of the capacity used	§ (38)

Calculation: Check 6 — flange plates, net section
Step	Value	Ref.
Net areaA_f less 2 holes in the outer plate and 1 in each inner plate.	A_net = 3,408 mm²	§ 5.1.2.2
Resistance of the net section0,9·f_u,k·A_net/γ_M2.	N_u,Rd = 883.4 kN	§ (39)
Flange plates, net sectionN_f ≤ N_u,Rd	η = 0.763 · Pass76 % of the capacity used	§ (39)

Calculation: Check 7 — beam flange, net section
Step	Value	Ref.
Net area of the beam flange(b − n_2,f·d₀)·t_f.	A_net = 4,864 mm²	§ 5.1.2.2
Resistance0,9·f_u,k·A_net/γ_M2.	N_u,Rd = 1,260.7 kN	§ (39)
Beam flange, net sectionN_f ≤ N_u,Rd	η = 0.534 · Pass53 % of the capacity used	§ (39)

Calculation: Check 8 — end distance
Step	Value	Ref.
End distancee₁ ≥ 30 mm	η = 0.750 · Pass75 % of the capacity used	§ t.17

Calculation: Check 9 — edge distance
Step	Value	Ref.
Edge distancee₂ ≥ 25 mm	η = 0.588 · Pass59 % of the capacity used	§ t.17

Calculation: Check 10 — pitch in the direction of the force
Step	Value	Ref.
Pitch in the direction of the forcep₁ ≥ 45 mm	η = 0.643 · Pass64 % of the capacity used	§ t.17

Calculation: Check 11 — spacing across the force
Step	Value	Ref.
Spacing across the forcep₂ ≥ 45 mm	η = 0.281 · Pass28 % of the capacity used	§ t.17

Calculation: Common values
Step	Value	Ref.
Bolt	– = M20, grade 4.6, hole d₀ = 22 mm	§ t.17
Shear resistance of one plane0,6·f_ub,k·A/γ_M2, f_ub,k = 400 N/mm², A = 314.2 mm².	F_v,Rd = 60.32 kN	§ (75)
Eccentricity of the sheare = g/2 + e_x,b + (n_c − 1)·p_2,w/2 = 5.0 + 40 + 30.0: from the hinge at mid-gap to the centroid of the bolts on one side.	e = 75.0 mm
Eccentricity momentM_e = V_Ed·e. It remains whatever the split of the moment.	M_e = 15.000 kN·m
Moment on the web platesFrom the split of the moment.	M_w = 0.00 kN·m	§ (9.8)
Bolts on each siden_c·n_r = 2·2.	n = 4
Polar second moment of the group	Σ(x² + z²) = 43,600 mm²
Horizontal force on the worst bolt(M_e + M_w)·z/Σ(x² + z²), at z = 100 mm.	F_x = 34.40 kN
Vertical force on the worst boltV_Ed/n + (M_e + M_w)·x/Σ(x² + z²), at x = 30 mm.	F_z = 60.32 kN
Force on the most loaded bolt√(F_x² + F_z²).	F_Ed = 69.44 kN
Force on one shear planeF_Ed/2: two web plates, two shear planes.	F_v,Ed = 34.72 kN

Calculation: Check 1 — web bolts in shear
Step	Value	Ref.
Web bolts in shearF_v,Ed ≤ F_v,Rd	η = 0.576 · Pass58 % of the capacity used	§ (75)

Calculation: Check 2 — bearing on one web plate
Step	Value	Ref.
End distance usedThe smaller of the vertical edge distance 40.0 mm and e_x,p: the bolt force is inclined, so both edges are taken.	e = 40.0 mm	§ (76)
Bearing resistance per bolt0,85·(e/d₀)·f_u,k·d·t/γ_M2 ≤ 2,4·f_u,k·d·t/γ_M2, t = 4.0 mm.	F_b,Rd = 35.61 kN	§ (76)
Bearing on one web plateF_b,Ed ≤ F_b,Rd	η = 0.975 · Pass98 % of the capacity used	§ (76)

Calculation: Check 3 — bearing on the beam web
Step	Value	Ref.
End distance usede_x,b, from the beam end.	e = 40.0 mm	§ (76)
Bearing resistance per bolt0,85·(e/d₀)·f_u,k·d·t/γ_M2 ≤ 2,4·f_u,k·d·t/γ_M2, t = 11.0 mm.	F_b,Rd = 97.92 kN	§ (76)
Bearing on the beam webF_b,Ed ≤ F_b,Rd	η = 0.709 · Pass71 % of the capacity used	§ (76)

Calculation: Check 4 — web plates, gross section in shear
Step	Value	Ref.
Gross shear arean_w·t_p·h_p.	A_v = 2,240 mm²
Shear resistanceA_v·f_y,k/(√3·γ_M1).	V_Rd = 289.4 kN	§ (41)
Web plates, gross section in shearV_Ed ≤ V_Rd	η = 0.691 · Pass69 % of the capacity used	§ (41)

Calculation: Check 5 — web plates, net section in shear
Step	Value	Ref.
Net shear arean_w·(h_p − n_r·d₀)·t_p, along a column of holes.	A_v,net = 1,888 mm²	§ (82)
Resistance0,9·f_u,k·A_v,net/(√3·γ_M2).	V_eff,Rd = 282.5 kN	§ (82)
Web plates, net section in shearV_Ed ≤ V_eff,Rd	η = 0.708 · Pass71 % of the capacity used	§ (82)

Calculation: Check 6 — beam web, net section in shear
Step	Value	Ref.
Shear area of the beamA − 2b·t_f + (t_w + 2r)·t_f.	A_v = 5,733 mm²	§ (42a)
Net shear areaA_v − n_r·d₀·t_w.	A_v,net = 5,249 mm²	§ 5.1.4.3
Resistance0,9·f_u,k·A_v,net/(√3·γ_M2).	V_eff,Rd = 785.5 kN	§ (82)
Beam web, net section in shearV_Ed ≤ V_eff,Rd	η = 0.255 · Pass25 % of the capacity used	§ (82)

Calculation: Check 7 — end distance
Step	Value	Ref.
End distancee₁ ≥ 30 mm	η = 0.750 · Pass75 % of the capacity used	§ t.17

Calculation: Check 8 — edge distance
Step	Value	Ref.
Edge distancee₂ ≥ 25 mm	η = 0.625 · Pass63 % of the capacity used	§ t.17

Calculation: Check 9 — pitch in the direction of the force
Step	Value	Ref.
Pitch in the direction of the forcep₁ ≥ 45 mm	η = 0.225 · Pass23 % of the capacity used	§ t.17

Calculation: Check 10 — spacing across the force
Step	Value	Ref.
Spacing across the forcep₂ ≥ 45 mm	η = 0.750 · Pass75 % of the capacity used	§ t.17

How this module is verified

Verified clause by clause against SIA 263:2013 and against independent calculations used on real projects, before release.

Questions

Why are the web bolts loaded by a moment when the flanges carry it all?

The shear reaches each bolt group from the hinge at mid-gap: in the worked example e = 75 mm and M_e = 15 kN·m, whatever the split. The most loaded web bolt takes 69.4 kN, 34.7 kN on each shear plane.

Are the two shear planes of a flange bolt really equal?

Only when the outer plate and the inner plates have the same area. In the worked example they have 2,400 and 1,800 mm², and the module warns that the equal split is an approximation.

Which plan includes this module?

The Pro plan, with its calculation note.

Norm: SIA 263:2013 · Page updated: 8 November 2026