ISSN 1003-8035 CN 11-2852/P

    广州市白云区夏茅村岩溶地面塌陷特征及致灾因素和风险分析

    Karst collapse characteristics, disaster factors and risk analysis in Xiamao Village, Baiyun District, Guangzhou City

    • 摘要: 广州市白云区夏茅村岩溶塌陷地质灾害严重,塌陷区内地质环境条件极其复杂,隐伏灰岩岩溶土洞发育强烈,溶洞、土洞规模较大,且发育多层溶洞,溶洞间相互连通,岩溶塌陷区基岩面起伏较大,高程变化剧烈,第四系覆盖层厚度较大,底部粉质黏土层土洞发育,土体中规模巨大的土洞是产生岩溶地面塌陷的基础条件。基岩断裂构造带及其影响带范围内,岩石破碎,形成导水断层,存在地下水迳流通道,沿断裂带地下水循环活跃,溶蚀强烈,形成岩溶强发育带,为岩溶塌陷的发生提供了良好的动力条件。区内楼房基础施工扰动了地下水和土洞间的平衡状态从而成为了地面塌陷发生的诱发因素。运用7项地质环境条件指标和5项经济人口指标分别定性评估岩溶地面塌陷的易发度和易损度,并将二者叠加进行地质灾害风险评估。研究结果表明,夏茅村潜在地质灾害风险大,只有严格控制地下水动力条件,才能避免再次发生岩溶地面塌陷。

       

      Abstract: Xiamao Village has been suffered from serious karst collapse geological disasters. The geological environment conditions in the collapse area are extremely complex. Karst soil caves of hidden limestone have strong development, and karst caves and soil caves are large in scale. Moreover, there are many karst caves with good connectivity among karst caves. The bedrock surface of karst collapse area fluctuates greatly, elevation changes sharply, the Quaternary overburden is thick, and the bottom silty clay layer soil is very large in saze. The cave development, the large-scale cave in the soil is the material foundation of karst ground collapse. In the bedrock fault structural zone and its influence zone, the rock is broken, and the water guide fault is formed. There is groundwater runoff channel. The groundwater circulation along the fault zone is active and the dissolution is strong, forming a strong karst development zone, which provides a good dynamic condition for the occurrence of karst collapse. The construction of the building foundation in the area disturbed the balance between groundwater and soil cave, which became the inducing factor of ground collapse. The risk assessment of karst ground subsidence is carried out by using seven geological environmental conditions and five economic and demographic indexes respectively. The results show that the potential geological disaster risk is large in Xiamao Village. Only by strictly controlling the dynamic conditions of groundwater can avoid karst ground collapse.

       

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