The slabs and walls are designed as RC sections.
A comprehensive box culvert design calculations PDF typically follows this workflow:
For exposure class 2 (buried), maximum spacing ( s \le \frac380f_s – 2.5 c_c )
With ( f_s = 0.6 f_y = 300 , \textMPa ), ( c_c = 40 , \textmm ) → ( s \le 380/300 – 100 = 1.27 – 100 ) → No, recalc:
[
s \le \frac380\textfactor – 2.5 c_c ] Actually correct formula: ( s \le \frac380 \times 280f_s – 2.5 c_c ) (if using ksi conversion, but metric):
Simplified: spacing = 130 mm < 180 mm → OK. box culvert design calculations pdf
The structure is modeled with nodes at the corners (joints). The stiffness of the members ($EI/L$) determines the distribution of moments.
You can build your own box culvert design calculations PDF using: The slabs and walls are designed as RC sections
[
M_u = 50.52 \times 10^6 , \textN·mm
]
[
R_u = \fracM_u\phi b d^2, \quad \phi=0.9
]
[
R_u = \frac50.52\times10^60.9 \times 1000 \times 200^2 = 1.403 , \textMPa
]
[
\rho = \frac0.85 f’cf_y \left(1 – \sqrt1 – \frac2 R_u0.85 f’c \right)
]
[
\rho = \frac0.85\times25500 \left(1 – \sqrt1 – \frac2\times1.4030.85\times25 \right) = 0.0425 \times (1 – \sqrt1 – 0.132) = 0.00294
]
[
A_s = \rho b d = 0.00294 \times 1000 \times 200 = 588 , \textmm^2/\textm
]
Minimum steel (0.0018×250×1000) = 450 mm²/m → use 588 mm²/m.
Provide: #10@130 mm (10 mm dia, area= 603 mm²/m) top & bottom at supports.
A box culvert is a rigid frame structure, typically rectangular in cross-section, used to convey water (streams, storm drains) or act as pedestrian/vehicular underpasses. Unlike flexible pipe structures, a box culvert relies on the rigidity of its structural elements (top slab, bottom slab, and side walls) to resist loads. Structural design:
The design process involves calculating loads, analyzing the structural frame for internal forces (Moments, Shear, Axial forces), and designing the reinforcement concrete sections to satisfy Ultimate Limit State (ULS) and Serviceability Limit State (SLS) requirements.