APPLICATION OF NLFM MODELS TO PREDICT CRACKING IN CONCRETE GRAVITY DAMS

Smeared crack analysis models based on a nonlinear fracture mechanics (NLFM) crack propagation criterion are considered to study the two-dimensional static fracture behavior of plain concrete structures. A coaxial rotating crack model (CRCM) and a fixed crack model with a variable shear resistance factor (FCM-VSRF), both using a secant stiffness formulation, are considered in studying the behaviors of a notched shear beam, a model concrete gravity dam, and a full-scale concrete gravity dam: all have been experimentally or numerically investigated in the past. The responses obtained from smeared crack analyses are compared with those reported in the literature by other investigators. The CRCM appears to perform better than the FCM-VSRF in alleviating the stress-locking phenomenon generally observed in smeared crack analyses. However, the crack profiles predicted by the rotating crack model are prone to the directional bias caused by finite element meshes of the elementary beam problem and the model concrete dam. The two smeared crack propagation models (CRCM and FCM-VSRF) provide reasonable responses when a full-scale concrete gravity dam is analyzed.