About the research
Shrinkage and temperature forces are known to have short- and long-term effects on both super and substructure of bridges. In the substructure, such effects are more pronounced if frame piers are used as their volumetric change is often restrained. Considering the construction cost advantages of frame piers compared to hammerhead piers, it is essential to develop design strategies that ensure the satisfactory performance of this category of piers, particularly with taking into consideration the fact that they can be subjected to relatively large shrinkage and temperature forces during their service life.
The main objective of this research is to investigate the forces developed in frame piers and their supporting foundations due to volumetric changes caused by thermal and shrinkage effects. To properly evaluate such forces, a set of existing bridges that have frame piers will be inspected. A special effort will be made to identify the frame piers that are susceptible to produce large forces. Such piers primarily include the ones with long pier caps and/or short columns. This is an important step to understand the vulnerability of this category of piers to thermal and shrinkage effects. Upon obtaining a qualitative assessment of the performance of existing frame piers designed with the current practices, a one-year monitoring plan will be established to record the changes of strain, stress, and force at critical points of the frame piers from the time of construction to capture both short- and long-term effects.