本文把混凝土的动静力损伤本构模型通过应变等价性假设引入到线弹性断裂力学中，推出了混凝土Ⅲ型裂缝在动静力荷载作用下缝端附近的损伤场，给出了相应的判据，实现了损伤与断裂的耦合分析，为把损伤理论应用到混凝土断裂分析中提供了一条可行的途径。文末还给出了混凝土Ⅲ型裂缝允许损伤尺度的估计值。 In this paper, the constitutive model of dynamic and static damage of concrete is introduced into the linear elastic fracture mechanics through the assumption of strain equivalence, and the damage field near the end of the joint under the action of dynamic and static loads is introduced. The corresponding criterion is given. The coupling analysis of damage and fracture is realized, which provides a feasible way to apply the damage theory to fracture analysis of concrete. At the end of the paper, an estimate of the allowable damage scale for type III concrete cracks is also given.