| Cracking of massive concrete structures has been a concern for many years for the engineers who design these structures. Due to the size of structures such as locks and dams, temperature differentials can be created during construction which do not occur in conventional civil engineering structures. These temperature differentials can become severe enough to cause cracking in the structure which can lead to undesirable conditions.; The Corps of Engineers has developed tools for evaluating massive concrete structures which account for temperature changes, the incremental construction process used and aging material properties. In addition, part of the constitutive model used in the mechanical analysis is a smeared crack which predicts the generalized cracking that may occur in a structure.; To better understand the cracking which occurs in these massive concrete structures, a methodology has been developed for including a discrete crack model to be used in conjunction with the current Corps of Engineers analysis tool. The cracking mechanism used is based on a fracture mechanics approach. Implementation of this discrete crack model will now allow information about the exact path of the crack, the length of the crack, and the crack mouth opening displacement to be obtained. These details are not currently available in the tool used by the Corps of Engineers but are valuable parameters for assisting designers in the assessment of massive concrete structures.; The research has developed the necessary process and mechanisms for including a discrete crack into the analytical process currently used to analyze massive concrete structures. This has been accomplished partially by adapting the efforts and experiences of other researchers to accomplish this specific objective. As part of the research, the various components have been validated and verified to show that the methodology is in fact a viable means for assessing cracking in massive concrete structures. |
