IS 13920:1993 is the Indian Standard (BIS) for ductile detailing of reinforced concrete structures subjected to seismic forces - code of practice. This code provides mandatory requirements for detailing reinforced concrete structures to ensure ductile behavior during earthquakes. It focuses on specific rules for reinforcement in beams, columns, and joints, such as special confinement steel, 135-degree hooks, and splice locations. The primary goal is to prevent brittle failure and allow the structure to safely deform and dissipate seismic energy.
Provides provisions for ductile detailing of reinforced concrete buildings to ensure satisfactory performance during earthquakes (older version).
Ductile detailing of RCC structures for seismic forces — older edition. Hoop spacing, beam-column, splice rules.
| Reference | Value | Clause |
|---|---|---|
| Applicability — seismic zones | III, IV, V (mandatory) | Cl. 1.1.2 |
| Concrete minimum grade — flexural members | M20 | Cl. 5.2 |
| Concrete minimum grade — vertical members > 4 storey | M25 | Cl. 5.2 |
| Steel grade — minimum— 2016 edition mandates Fe500D | Fe415 (HYSD) | Cl. 5.3 |
| Beam — width minimum | 200 mm | Cl. 6.1.2 |
| Beam — depth/width ratio | ≤ 4 (preferably 1.5–2.0) | Cl. 6.1.3 |
| Beam — clear span / depth | ≥ 4 | Cl. 6.1.4 |
| Beam tension steel — minimum | 0.24 √fck / fy (= 0.205 % typical) | Cl. 6.2.1b |
| Beam tension steel — maximum | 2.5 % | Cl. 6.2.2 |
| Beam compression steel — minimum (at face) | 0.5 × tension steel | Cl. 6.2.3 |
| Beam stirrups — confining length each end | 2 d from face of support | Cl. 6.3.5 (a) |
| Beam stirrup spacing — confining zone | ≤ d/4 or 8 × bar diameter, whichever less | Cl. 6.3.5 (b) |
| Beam stirrup spacing — middle of span | ≤ d/2 | Cl. 6.3.5 (c) |
| Beam stirrup hook angle— 2016 retained 135° | 135° required (≥ 6d extension) | Cl. 6.3.5 |
| Column — minimum dimension | 200 mm (when reinforcement laps occur) | Cl. 7.1.2 |
| Column — minimum aspect ratio | 0.4 (shorter side / longer) | Cl. 7.1.3 |
| Column longitudinal steel — minimum | 0.8 % | Cl. 7.2.1 (refers IS 456) |
| Column — maximum reinforcement | 6 % (4 % at lap) | Cl. 7.2.2 (refers IS 456) |
| Column — confining hoop spacing— tightened in 2016 | ≤ ¼ × least lateral dimension or 100 mm | Cl. 7.4.6 (b) |
| Column — confining length end zone | ≥ depth, L/6, or 450 mm (whichever max) | Cl. 7.4.1 |
| Beam-column joint — design shear— fully recodified in 2016 | from beam yielding (capacity design) | Cl. 8.2 |
BIM-relevant code. See the BIM Hub for ISO 19650, IFC, and LOD/LOIN frameworks used alongside it.