Structural Engineering — Plinth Level · Drg No. MHPB-03
Plinth Beam Layout & Reinforcement
Mayank's House · G+1 Residential · 300×450mm Tie Beams · 12 Spans · M20/Fe500
PB Size: 300×450mm
Grid: A–C × 1–4
M20 / Fe500
Plinth: +450mm NGL
Spans: 3500 / 3800 / 4000mm
2T16 Bot + 2T12 Top
Drg. No. MHPB-03
Date: 01.03.2026
Scale: NTS
Rev: 00
300
Beam Width mm
450
Beam Depth mm
12
Beam Spans
4m
Max Span
2T16
Bottom Steel
2T12
Top (Hanger)

Plinth Beam Layout Plan

Sheet 1 of 4
Top view showing all tie beams along grid lines A–C × 1–4 · Beam IDs labelled · All dims in mm

Plinth Beam Plan — Top View at +450mm NGL

BEAMS ALONG ALL GRID LINES · 300×450mm THROUGHOUT · 12 SPANS
PB-LA PB-LB PB-LC PB-T1 PB-T2 PB-T3 PB-T4 3800×3500 3800×3500 3800×3500 3800×3500 3800×4000 3800×4000 A1 B1 C1 A2 B2 C2 A3 B3 C3 A4 B4 C4 A B C 1 2 3 4 3800 mm 3800 mm 3500 3500 4000★ ← 7600 mm TOTAL WIDTH → ← 11000 mm TOTAL LENGTH → N X–X X–X
Plinth Beam 300×450mm
Column 300×300mm
Bay Zone
Section Cut X–X

Beam ID & Span Schedule

ALL 7 BEAM LINES · 12 SPANS
Beam IDDirectionSpanFrom→ToSize
PB-LALong.3×(3.5+3.5+4.0)mA1→A4300×450
PB-LBLong.3×(3.5+3.5+4.0)mB1→B4300×450
PB-LCLong.3×(3.5+3.5+4.0)mC1→C4300×450
PB-T1Trans.2×3800mmA1→C1300×450
PB-T2Trans.2×3800mmA2→C2300×450
PB-T3Trans.2×3800mmA3→C3300×450
PB-T4Trans.2×3800mmA4→C4300×450
Span TypeLengthBeam SteelStirrups
3.5m (Long.)3500mm2T16 bot + 2T12 topT8@150
3.8m (Trans.)3800mm2T16 bot + 2T12 topT8@150
4.0m (Long. ★)4000mm2T16 bot + 2T12 topT8@120

Beam Cross-Section

300×450 ALL BEAMS
T16 T16 T12 T12 300 mm 450 mm 30mm T8 STIRRUP

Section X–X — Longitudinal Section through PB-LB

Sheet 2 of 4
Section through central B-line beam · Showing 3 spans: 3500 + 3500 + 4000mm · Steel curtailment · Depth from NGL

PB-LB Longitudinal Section — B1 to B4 (11000mm total)

3 SPANS: 3500+3500+4000mm · 2T16 BOT · 2T12 TOP · T8 STIRRUPS · ALL DIM IN mm
NGL FFL +450 GF SLAB 125mm +2T12 (L/4 each) +2T12 (L/4 each) SPAN 1: 3500mm SPAN 2: 3500mm SPAN 3: 4000mm ★ 3500 mm 3500 mm 4000 mm 11000 mm TOTAL 450mm +450 2T16 (Bot) 2T12 (Hgr) T8 Stirrups B1 B2 B3 B4 Footing Footing Footing Footing @100 @100 @150
2T16 Bottom (Main)
2T12 Top (Hanger + Extra @ supports)
T8 Stirrups @150/120
Confinement Zone @100
Footing (schematic)

Beam End Detail, Section AA & Bar Bending Schedule

Sheet 3 of 4
End bearing · Section at mid-span · Full reinforcement schedule · All dims in mm

Beam End at Column — Detail

BEARING · L-ANCHOR BARS · COLUMN PASS-THROUGH
NGL FFL COLUMN 300×300 PLINTH BEAM 300×450 L-hooks (2T16) Hanger L-hooks (2T12) Beam span → 450mm Ld=600mm anchor BEAM END DETAIL

Section A–A (Mid Span)

SAGGING MOMENT ZONE · 2T16 BOT · 2T12 TOP
T16 T16 T12 T12 NA Tension Zone Compression Zone 300 mm 450 mm d=396mm 30mm SECTION A–A · MID SPAN

Bar Bending Schedule

PLINTH BEAM · ALL SPANS
MarkBarShapeL/BarNosTotal
B1T16Straight+hook3800mm2×753.2m
B2T16Straight+hook4300mm2×434.4m
H1T12Straight3800mm2×753.2m
H2T12Straight4300mm2×434.4m
E1T12Straight+hookL/2+6002×12~96m
S1T8Rect.220×3901340mm12×~18~290m
S2T8Rect.220×3901340mm4m×~22~118m
Steel Estimate
T16 total:87.6m → ~138 kg T12 total:183.6m → ~163 kg T8 stirrups:408m → ~161 kg Grand Total:~462 kg
Engineering Notes
· Beam sits at plinth level: top = FFL +450mm
· All beams are continuous over columns
· Extra 2T12 over supports for hogging
· Anchor all bars Ld=600mm into columns
· Stirrup hook: 135° with 10d extension
· Confinement zone: T8@100 for L/6=583mm
· Cover to stirrup: 30mm clear
· Anti-termite treatment before casting
· Curing: minimum 14 days