Next month, schools across the country will enter a two-month summer vacation. At the same time, school security building reinforcement projects have been carried out successively throughout the summer. Why is the school security building reinforcement project indispensable once every winter and summer vacation?

According to statistics, most of the school buildings in the country are brick-concrete teaching buildings built in the seventies or eighties. The earthquake resistance of the brick-concrete structure building is obviously insufficient. Once an earthquake shock occurs, it will cause damage to the school teaching building and other places, posing a serious threat to the safety of teachers and students. Especially after the Wenchuan and Yushu earthquakes, the safety of school security construction has aroused widespread concern in the community. Especially in areas where earthquakes and debris flows are common, all school buildings are required to conduct seismic and safety assessments. Buildings that do not meet the assessment results will be reinforced and reinforced to achieve seismic safety levels. Moreover, due to the difficulty of practical operation of the school security building reinforcement project, it can only be operated during the winter and summer vacations.

Let's follow Horse to see the main problems in the current school buildings:

1. Most teaching and dormitory buildings have a long service life, and some components have different degrees of damage and diseases. And the building is a brick-concrete structure, which is not conducive to shock and vibration.

2. Some schools have only two vertical walls in the single-sided corridor masonry teaching building, and there are many doors and windows in the vertical wall, which greatly weakens the vertical wall. And the height and width of the single-sided corridor masonry teaching building are relatively large. When the bending stress caused by the overturning moment generated by the high-intensity earthquake action exceeds the tensile strength of the brick masonry, the brick wall will crack. It is a structural form with slightly poor seismic performance.

3. The seismic level of the school building does not meet the requirements of the existing codes. The requirements for earthquake resistance are different from those for buildings decades ago, so schools should be reinforced and reinforced according to the existing seismic requirements.

4. The load bearing phenomenon of longitudinal walls of masonry structure still exists. The load-bearing destructiveness of the vertical wall is greater than that of the horizontal wall. The Tangshan earthquake is the best example.

5. No anti-seismic structural measures are taken, and the masonry structure has no ring beams and structural columns;

6. The overall structure of the single-span frame lacks redundancy, and there are no multiple seismic lines of defense.