珠江三角洲东平水道的形成演变及工程意义
Formation and evolution of the Dongping Channel in the Pearl River Delta and its engineering significance
杨晶晶 1陈健 2刘伟明 3赵新杰 2吴晓东2
作者信息
- 1. 中国煤炭地质总局 勘查研究总院,北京 100039;矿山透明地质与数字孪生技术国家矿山安监局重点实验室,北京 100039
- 2. 中国煤炭地质总局 广东煤炭地质局,广东 广州 510000
- 3. 广东省重工建筑设计院有限公司,广东 广州 510000
- 折叠
摘要
珠江三角洲东平水道晚更新世以来古河道发育,施工遭遇古河道发育段易引发突水涌砂、地面塌陷、基坑失稳等事故,影响地下工程建设.通过大量钻孔数据、地形图判读、野外调绘、现场勘探和室内测试等手段,研究古河道的分布位置、沉积特征和水文地质条件,揭示晚更新世以来研究区河道的形成演变过程,探讨影响河道发育的关键地质要素.研究表明:珠江三角洲东平水道上-中段第四纪沉积广泛发育,沉积产物复杂多样,底部揭露有明显的砂砾石层.底砾层整体分布相对连续,沿北西-南东向呈带状延伸,平均厚度为 5.71 m,粒度向上逐渐变细,为低海平面时期古河道的冲积产物.河道前期严格受控于基底地形,依北西～南东方向优势发育,东平水道上段主干道表现出较高的稳定性和继承性,随着三角洲的沉积堆高,构造对河道的约束变小,中段则分流形成现今的潭州水道和顺德水道.古河道发育段水量丰富,透水性中等～强,有充足的地下水补给水源和顺畅的补给通道,具有承压性,水文地质条件复杂.当高水土压力击穿并形成涌水通道后,易导致地层失稳,具有重大施工风险,是工程建设中需重点防控的不利地质条件.研究成果可有效指导后期城市地下空间综合利用,为工程建设选址提供重要地质依据.
Abstract
The Dongping Channel in the Pearl River Delta has developed paleochannels since the Late Pleistocene.The construction encounters the development section of the paleochannel,which is prone to cause water inrush and sand inrush,ground collapse,foundation pit instability and other accidents,affecting the construction of underground project.Through a large number of borehole data,topographic map interpretation,field mapping,field exploration and laboratory testing,the distribution location,sedimentary characteristics and hydrogeological conditions of paleochannels were studied,the formation and evolution process of the river channels in the study area since the Late Pleistocene were revealed,and the key geological factors affecting the development of the river channels were discussed.The results show that the Quaternary sediments in the upper-middle part of the Dongping Channel in the Pearl River Delta are widely developed,and the sedimentary products are complex and diverse,and there are obvious gravel layers exposed at the bottom.The overall distribution of the bottom gravel layer is relatively continuous,extending in a belt along the NW-SE direction,with an average thickness of 5.71 m and a gradual taper particle size,which is the alluvial facies product of paleochannels during the low sea level period.In the early stage,the river channel was strictly controlled by the basement topography,and developed according to the advantages of the NW-SE direction,and the main channel in the upper section of the Dongping Channel showed high stability and inheritance,and with the sedimentary heap height of the delta,the structural constraints on the river channel became smaller,and the middle section was diverted to form the current Tanzhou Channel and Shunde Channel.The research results can effectively guide the comprehensive utilization of urban underground space in the later stage and provide an important geological basis for the site selection of engineering construction.
关键词
珠江三角洲/东平水道/古河道/晚更新世/河道演变Key words
Pearl River Delta/Dongping Channel/Paleochannels/late Pleistocene/river channel evolution引用本文复制引用
出版年
2024
NETL
NSTL
万方数据