Some of the biggest considerations in long-span bridge construction

As a civil engineer, Reddy Kancharla is involved on a regular basis in long-span bridge construction. Today, he shares some of the biggest considerations in this type of project.

1. Rafts and Pilecaps

Raft type foundations are always concerned with the pilecaps they use, specifically the thickness of the pilecaps. In construction, the pilecaps need to be cast into a series of lifts so as to avoid the formation of large temperature gradients within the concrete. If not done properly, this can lead to excessive cracking and tensile stress, making the structure less stable and unsafe to do its purpose.

2. Caisson Foundations

Long-span bridges are lengthy because these connect lands that are separated by huge bodies of water. In this case, there is a need to set foundations multiple times along the full length of the bridge. Caisson foundations serve this purpose very well because they are suited to marine environments. As these are constructed in controlled dry-dock conditions, the seabed is prepared to receive the caisson. This is done by means of rock excavation or the implanting of steel inclusions and laying down of gravel layers.

3. Precast and in situ concrete members

As a material, concrete naturally requires time to set so that it can attain its useful strength. This can otherwise be thought of as similar to pre-fabrication, or the creation of precision parts to be plugged in to the whole assembly later on. This type of preparation factors in elements that make it stable, like high-strength concrete mixes that have the right thermal gradient for the application.

Reddy Kancharla has a master's degree in civil engineering, with a professional career spanning 25 years. He has a broad comprehension of engineering theories and is well-versed in the complexities involved in the design and construction of commercial and residential buildings, bridge and roadway structures, earth retaining structures, and shallow and deep foundations. For more on this industry, visit this page.