求翻译：针对内蒙古四座钢筋混凝土跨河梁桥施工过程中一批13m钢筋混凝土预制空心板构件出现早期裂缝的工程实例，为探索早期裂缝产生的原因，本文结合实际工程情况，从力学角度上分析了导致13m钢筋混凝土预制空心板构件早期裂缝出现的原因是由于板在自重作用下梁底混凝土拉应力超过混凝土的极限抗拉强度。是什么意思？

Engineering examples of the early cracks in the Inner Mongolia, four reinforced concrete crossing beam bridge construction process, a number of 13m precast reinforced concrete hollow slab members, the actual project to explore the causes of early cracks, from the mechanical point of view, lead to 13

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Four reinforced concrete beam bridge construction across the River in Inner Mongolia in the process a number of 13m engineering of reinforced concrete precast hollow slab members appear early instances, to explore the causes of crack in early, this actual situation, from a mechanical point of view a