When designing a pedestrian bridge, what is the most important load we need to consider?
It can be said that the most critical load is the live load, specifically the pedestrian (crowd) load.
Let's explore the design criteria for live loads, focusing on pedestrian loads."
What is pedestrian load?
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The pedestrian load for pedestrian bridges includes bridges with sidewalks and bicycle paths, as well as bridges with pedestrian walkways on road bridges.
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It is a specified value representing the dynamic load of human movement (live load) applied to the design as a static load.
The magnitude of pedestrian load
The magnitude of pedestrian load on pedestrian bridges is well articulated in the 'AASHTO LRFD Guide Specifications for the Design of Pedestrian Bridges.'
LRFD Guide specifications for the design of pedestrian bridges, 2009
3.1 - PEDESTRIAN LOADING (PL)
→ Pedestrian bridges shall be designed for a uniform pedestrian loading of 90 psf. This loading shall be patterned to produce the maximum load effects. Consideration of dynamic load allowance is not required with this loading.
According to AASHTO, the pedestrian load on pedestrian bridges is considered as a maximum load of 90 psf (4.3kN/m2) without accounting for the reduction effect based on span length.
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C1 50psf (2.4kN/m2)  |
C2 100psf (4.8kN/m2)  |
C3 150psf (7.2kN/m2)  |
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The above figure cites experiments conducted by Professor Andrzej S. Nowak of the University of Michigan, as referenced by AASHTO. Measurements were taken by filling a space with a side length of 6ft with people, categorized into three levels: 50 psf, 100 psf, and 150 psf.
Considering the average adult weight as 160 lb (71.2 kg), the results can be summarized as follows.he results obtained from MIDAS CIVIL and manual calculation for anchorage slip loss are shown in the figure below.
You can check more of these details in the download file.
Reduction of load due to Span Length
Closing Remarks
References
[1] AASHTO LRFD Guide specifications for the design of pedestrian bridges, 2009
[2] ASCE 7-02 Minimum Design Loads for buildings and Other Structures, 2002
Topics
Pedestrian Load
KDS Pedestrian Load
AASHTO Pedestrian Loading
Eurocode Actions on Footways
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Structural Engineer with over 15 years of experience since 2005. Participated in the design of special structures including arch bridges, monorails, and sliding centers. Expert in BIM operations.
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