笔者基于对箱涵开裂的宏观力学分析 ,运用损伤力学的理论论证了箱涵开裂的原因 ,推得了箱涵顶板所能承爱的极限荷载为 31 17kN·m ,为实际荷载的 30 %左右 ,初步估计砼箱涵的损伤区 ,极限深度 1 5 6cm .换言之 ,从损伤力学的观点可见 ,箱涵开裂是必然的 Based on the macroscopic mechanics analysis of box culvert cracking, the author uses the theory of damage mechanics to prove the reason of cracking of box culvert, and deduces that the ultimate load of box culvert roof is 3117kN · m, which is about 30% of actual load, Preliminary assessment of concrete box culvert damage area, the ultimate depth of 156cm. In other words, from the damage mechanics point of view, cracking of the box culvert is inevitable