calcnote ACI 318-19
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Continuous beam result

L-beam: bf=36.0, bw=14.0, hf=5.0 14.0 × 24.0 in 3-#8 f′c 4000 psi fy 60.0 ksi d 21.62 in 2 spans
FAIL

Span 1 midspan, Span 1 right support, Span 2 midspan, Span 2 left support failed. Review the details below.

Stirrup spacing exceeds torsion limit of 7.8 in (min of ph/8=7.8 and 12 in, Section 9.7.6.3).

Longitudinal torsion reinforcement Al = 1.406 in^2 required, distributed around stirrup perimeter (at least one bar in each corner, min size #3).

Torsion requires closed stirrups (one-piece or spliced U-stirrups with 135-degree hooks) per Section 9.7.6.3.1.

Stirrup spacing exceeds torsion limit of 7.8 in (min of ph/8=7.8 and 12 in, Section 9.7.6.3).

Longitudinal torsion reinforcement Al = 1.406 in^2 required, distributed around stirrup perimeter (at least one bar in each corner, min size #3).

Torsion requires closed stirrups (one-piece or spliced U-stirrups with 135-degree hooks) per Section 9.7.6.3.1.

Stirrup spacing exceeds torsion limit of 7.8 in (min of ph/8=7.8 and 12 in, Section 9.7.6.3).

Longitudinal torsion reinforcement Al = 1.406 in^2 required, distributed around stirrup perimeter (at least one bar in each corner, min size #3).

Torsion requires closed stirrups (one-piece or spliced U-stirrups with 135-degree hooks) per Section 9.7.6.3.1.

Stirrup spacing exceeds torsion limit of 7.8 in (min of ph/8=7.8 and 12 in, Section 9.7.6.3).

Longitudinal torsion reinforcement Al = 1.406 in^2 required, distributed around stirrup perimeter (at least one bar in each corner, min size #3).

Torsion requires closed stirrups (one-piece or spliced U-stirrups with 135-degree hooks) per Section 9.7.6.3.1.

Input summary

Span L (ft) wD (klf) wL (klf)
Span 1 24.0 1.8 1.2
Span 2 24.0 1.8 1.2
Supports: pin (left), pin (right); interior: continuous (pinned)

Moment and shear envelopes

Moment Envelope (kip-ft) 237.5 -342.1 Shear Envelope (kip) 73.4 -73.4

Pattern loading skipped (L/D ≤ 0.75 per ACI 6.4.3): single full-load case analyzed.

Critical sections

Location Mu (kip-ft) Vu (kip) Type Status
Span 1 midspan 189.2 2.4 L FAIL
Span 1 right support 293.8 53.8 rectangular FAIL
Span 2 midspan 189.2 2.4 L FAIL
Span 2 left support 293.8 53.8 rectangular FAIL
Span 1 midspan FAIL

Section type: L (positive moment, flange in compression)

D/C moment 0.84
φMn (kip-ft)
224.4
Mu (kip-ft)
189.2
D/C shear 0.04
φVn (kip)
55.5
Vu (kip)
2.4
Crack control: PASS
Torsion: FAIL
D/C development 0.27
ld,adj (in)
25.8
lavail (in)
94.8
ψt
1.00
Bar dia. limit (9.7.3.8.3): PASS
Span 1 right support FAIL

Section type: rectangular (negative moment, rectangular)

D/C moment 1.37
φMn (kip-ft)
214.7
Mu (kip-ft)
293.8
D/C shear 0.97
φVn (kip)
55.5
Vu (kip)
53.8
Crack control: PASS
Torsion: FAIL
D/C development 0.86
ld,adj (in)
56.5
lavail (in)
66.0
ψt
1.30
Span 2 midspan FAIL

Section type: L (positive moment, flange in compression)

D/C moment 0.84
φMn (kip-ft)
224.4
Mu (kip-ft)
189.2
D/C shear 0.04
φVn (kip)
55.5
Vu (kip)
2.4
Crack control: PASS
Torsion: FAIL
D/C development 0.27
ld,adj (in)
25.8
lavail (in)
94.8
ψt
1.00
Bar dia. limit (9.7.3.8.3): PASS
Span 2 left support FAIL

Section type: rectangular (negative moment, rectangular)

D/C moment 1.37
φMn (kip-ft)
214.7
Mu (kip-ft)
293.8
D/C shear 0.97
φVn (kip)
55.5
Vu (kip)
53.8
Crack control: PASS
Torsion: FAIL
D/C development 0.86
ld,adj (in)
56.5
lavail (in)
66.0
ψt
1.30

Deflection

PASS
Span Ie,avg (in4) δD (in) δL (in) δLT (in) L/δ Status
span_1 8582 0.180 0.120 0.481 599 PASS
span_2 8582 0.180 0.120 0.481 599 PASS
Weighted-average Ie per ACI 435.3R-68 (0.70·Ie,mid + 0.15·(Ie,left + Ie,right)); Bischoff Ie per ACI 24.2.3.5.
Run another analysis
2-span sample 3-span sample
Calculated 2026-10-26 · ACI 318-19