泥石流作用下砌体房屋破坏机理与结构优化

Failure Mechanism and Structure Optimization of Masonry Building Due to Debris Flow Impact

针对提高砌体结构这一山区房屋的主要结构类型在泥石流作用下稳定性的问题,分析泥石流对房屋作用特点,提出砌体结构房屋中关键承重结构的破坏模式。以墙体弯曲应力破坏准则为基础,结合泥石流冲击力与流速流深的定量关系,建立基于泥石流流速流深的砌体墙结构破坏模型,找出不同砌体墙的破坏临界条件。结果表明:传统砌体结构抵抗泥石流冲击能力极低,以240 mm厚的墙体为例,当泥石流流速为4 m/s时,一旦泥石流深度超过0.4 m,受到正面冲击的墙体将会发生破坏。在考虑砌体墙结构特性的基础上,提出泥石流危险区砌体房屋优化方案;以七盘沟泥石流灾害调查中的房屋破坏实例,验证了方案的可行性,为提高房屋受泥石流作用影响的抗灾能力提供新思路。

Flood and debris flow are the main contributor of mountain hazards in China. Due to the space limitation, as the main elements at risk, buildings are commonly located at debris flow alluvial fan and become extremely vulnerable when mountain hazards occur. Based on the characteristic of debris flow impact and the behavior of masonry structure, the failure mechanism of masonry building was identified. The failure criteria of masonry wall were calculated using the debris-flow velocity and depth, The results showed that for wall of 240 mm thickness, when the debris flow velocity reached 4 m/s, the wall would fail if the flow depth past 0.4 m. Two structure improvement plan were proposed. The brick wall failure model and optimization plan were verified by a masonry building at Qipan Valley after a devastating debris flow event in 2013. At last,the advantages and limitations of two structure optimization plan were discussed.