Analyze bridge loading with clear structural output insights. Review axle, uniform, and impact effects confidently. Generate reports, graphs, and decisions for safer design checks.
Enter bridge geometry, line loads, axle load position, section properties, and allowable limits.
| Parameter | Example Value | Unit |
|---|---|---|
| Span length | 30 | m |
| Bridge width | 10 | m |
| Number of girders | 4 | - |
| Distribution per girder | 30 | % |
| Dead load, self weight | 18 | kN/m |
| Dead load, superimposed | 12 | kN/m |
| Live load, lane UDL | 9 | kN/m |
| Axle load | 180 | kN |
| Axle position | 12 | m |
| Impact factor | 25 | % |
| Typical maximum moment | 2703.864 | kN·m |
| Typical left reaction | 328.219 | kN |
This tool uses a simplified girder line method for fast preliminary assessment. Final bridge design should follow project codes, load models, combinations, and detailing checks.
This page uses a simply supported girder line model. It distributes bridge loads to one selected girder using a user-entered percentage. That makes it useful for quick checks, screening studies, and teaching examples.
No. It is meant for preliminary engineering checks. Final approval should use project-specific load models, distribution rules, fatigue checks, combinations, detailing requirements, and the governing bridge design code.
Not every girder carries the whole bridge load. The distribution factor assigns a realistic share to the checked girder. Changing it directly affects reaction forces, moments, stresses, and serviceability predictions.
The impact factor represents dynamic amplification from moving vehicles. It increases the live load effects before the live load factor is applied. Higher impact factors raise reactions, moment, shear, and deflection results.
Bending stress is calculated from the maximum design bending moment divided by the section modulus. This gives a quick flexural demand estimate for the checked girder section.
Shear stress is approximated using maximum design shear divided by the effective web area. It is a simplified average shear check. Detailed web buckling and stiffener behavior are outside this tool’s scope.
Yes. The Plotly graph shows the shear force diagram and bending moment diagram together across the span. This helps you see where peak demand occurs and how the axle position changes the shape.
A utilization above one means the calculated demand exceeds the selected allowable limit. You should review loads, section properties, load distribution, and design assumptions before moving ahead.
Important Note: All the Calculators listed in this site are for educational purpose only and we do not guarentee the accuracy of results. Please do consult with other sources as well.