What goes into building a pedestrian bridge guide, NZ building design tips, New Zealand construction

What goes into Building a Pedestrian Bridge construction

post updated 10 February 2024

A pedestrian bridge is a structure that provides people on foot with passage over a gap or obstacle. They are often used in urban environments to allow pedestrians access from one side of the street, across the other side, and back again, without having to cross at grade level. This article will discuss how such bridges are constructed and what materials go into them. Let’s get to the details.

10 December 2021

Determining the Purpose and Location

The first thing engineers and architects do when designing a new pedestrian bridge is determine where it will go. Before the bridge building and construction process begins, the professionals look at surrounding terrain, topography, and traffic patterns to find an appropriate location. Once that has been determined, they need to decide on what purpose the bridge will serve.

Will the bridge be used strictly for pedestrian purposes? Or will it also accommodate cyclists and allow them to pass underneath, or will motor vehicles also have access to use it? The designer must determine what kinds of traffic will occur regularly to design a structure suitable enough to handle all types of uses without breaking the bridge down.

Procurement and Set-Up

Once the location and purpose of a new bridge are determined, engineers must then design it. This process begins by creating an initial concept plan that provides artists with more detailed information about what they need to build. They can create a rendering of the bridge, which is later used for marketing purposes.

Next comes procurement and set-up. During this phase, engineers work on getting all necessary materials needed to build the structure, including steel reinforcing bars (rebar), concrete, cables, or other pieces required to assemble it. These are purchased from suppliers across the country or manufactured on-site.

Drilling, Anchoring, and Blasting

Now that all the materials have been delivered, it’s time to start construction. The first step is to drill holes into the ground and anchor the bridge’s foundation in place. This process can be quite dangerous as crews use many explosives to blast through mountainsides or solid rock formations.

Once the anchors are in place, work begins on the bridge’s substructure, which comprises columns and piers. The columns hold up the bridge deck while the piers transfer the loads from the deck to the ground anchors. Depending on the soil conditions, crews may need to install piles (wooden or steel) before pouring concrete for the foundation.

Building the Bridge Deck

The bridge deck is typically the last part of a pedestrian bridge. It’s made up of steel or concrete and can be either pre-cast off-site or cast in place on-site. The material used is based on the design requirements and how much traffic the bridge will see.

Once the deck is complete, it’s ready for installation. The final step is to lift the bridge using cranes and attach cables to secure it before opening it up to foot traffic.

Building a Pedestrian Bridge construction summary

Once everything has been installed, all that remains is testing which determines whether or not the structure can safely support the anticipated loads. If it passes, the bridge is ready for use. However, sometimes parts may be prefabricated in a factory and then transported to the construction site for assembly. This can happen when the terrain or other conditions don’t allow for traditional construction methods.

Comments on this Quick Guide: What Goes Into Building A Pedestrian Bridge article are welcome.