No two bridge projects are ever alike. Even a small bridge can present unforeseen obstacles that can create added costs. But by answering a few questions at the beginning of a bridge project, you can help ensure the project gets off to the best possible start, ultimately preventing delays, boosting public satisfaction, and increasing the lifespan of the bridge.
- Do We Really Need Soil Information?
The answer is “yes” if you want the most economical design and a design that is most compatible with the actual soil conditions at the site. Many people may think they are saving money by skipping a geotechnical investigation, but it forces the structural engineers to guess about the load capacity of the soils and other soil properties that are central to the design. Without a geotechnical investigation, the structural engineer is forced to be conservative in the design, likely driving up the cost of the bridge. The added costs due to a conservative design are likely to be more than the cost of the geotechnical investigation.
- Does Traffic Need to Be Maintained Throughout the Project?
Before beginning a project, municipal or county officials will need to decide how important it is to maintain traffic during construction. While maintaining traffic is often more costly and can lengthen construction time, depending on the route, a detour may cause undue inconvenience to the public.
- Will the Roadway and Stream Alignment Cause Any Special Design Considerations?
The alignment of the roadway will likely play a big part in what type of bridge is best suited to the site. For instance, if a medium-span bridge is needed and it is on a horizontal curve, a cast-in-place concrete slab will likely be the best deck type because of the ability to form the edges of the deck. Stream alignment relative to the bridge foundations should be closely evaluated because it can have a major effect on scour potential. Poor stream alignment causes scour to occur more easily, adding maintenance costs and likely reducing the lifespan of the bridge.
- Is the Project in A FEMA Special Flood Hazard Zone?
If a bridge is in a flood zone, there are special design considerations. For instance, a bridge that crosses a stream in a flood zone has to be high enough and long enough to avoid causing an increase in the flood elevation. This often results in a bridge that is larger than what would otherwise be required for non-flood zone stream crossings. Coordination with the local floodplain administrator is also required when the site is in a flood zone.
- Where Are the Utilities?
Design should not begin without accurately identifying the precise location of utilities and including that information in the survey of existing conditions. Accidentally hitting a utility during construction is extremely dangerous and will cause costly delays. The design of the bridge should be such that as few utilities as possible will have to be moved to accommodate the construction.
- Will Environmental Permits Be Needed? What About an Environmental Assessment?
The design of the bridge can drive whether an individual permit (a long, drawn-out process) is needed, or if the design can qualify under a nationwide permit. But other issues, such as if there are wetlands in the area, will also affect the permitting process. Nearly every bridge project should begin with an environmental review to identify those potential issues.
Ultimately the right project manager can help you make choices that are both cost-effective and will have a positive long-term impact on your community.
At the Kleingers Group, our team of structural engineers and bridge inspectors are focused on innovative ideas to build and restore bridges, cost-effectively and quickly. Our licensed structural engineers work closely with our transportation engineers to ensure coordination is seamless and meets your project’s needs.
Contact Mike Brunner at email@example.com to learn more about how Kleingers can help with your next bridge project.
For more than 13 years, Engineers Without Borders has been building engineering projects that empower communities to meet their basic needs.
With 300 chapters across the United States, more than 15,900 volunteers work together to provide engineering services and have impacted more than 2.5 million lives.
Mike Brunner, Water Resources Group Leader at The Kleingers Group, is currently acting as a mentor for the group, helping to train Miami University students who plan to travel to Ecuador, South America or Rwanda, Africa. Under the guidance of a mentor, the students will provide engineering services to build water systems that ensure the communities have access to water.
In late September, Brunner helped the students learn a variety of hands-on skills and the practice of engineering and surveying theory, including how to run an elevation level circuit, mix and place concrete, construct water piping systems, and test concrete beams.
Particularly popular was the process of breaking beams, which was done by having increasing numbers of students stand on the beams, which were positioned 3 inches off the ground until they broke. This was preceded by reviewing the design calculations and making predictions of how many students it would take to break them and how much they would deflect before breaking.
At an upcoming meeting this weekend, Brunner will help teach the student volunteers about building masonry walls.
Each training session prepares students for civil engineering, surveying, and other experience they may need on their upcoming trip.
“I had been looking for an organization like this, with an opportunity to give back and work with students for a long time,” Brunner said. “This really is a wonderful organization.”
Engineers Without Borders is organized by local chapters that partner directly with communities, mostly international, on projects to meet the community’s self-identified needs. The vast network of dedicated volunteers ranges from first-year engineering students and engineering professionals to public health professionals.
The over-arching philosophy of EWB-USA is to partner with communities in a sustainable way, and through the use of appropriate technology, so that they have ownership in the project(s) and will be able to maintain the project facilities long-term.
Along with two or three other local professional engineers, Brunner meets weekly with the student volunteers to provide advice and direction on the engineering/technical aspects of the project, as well as to guide them through the development of the project documents and EWB-USA paperwork.
Two different teams of Miami students from the chapter, along with a mentor, traveled to Ecuador and Rwanda last year to gather survey data that is being used to design the projects and to meet the local community leaders and citizens. Trips for the construction phase are being planned for this year.