Huaneng Coal Technology Research Co., Ltd.
General Prospecting Institute of China National Administration of Coal Geology
Guangdong Coal Geology Bureau of China National Administration of Coal Geology
Xinzhuang Coal Mine, Qingyang Xinzhuang Coal Industry Co., Ltd.

沿海沿江地区地下工程建设中钻遇富水砂层地段，极易产生突发性透水涌泥涌砂，导致地面塌陷、隧道掩埋、基坑坍塌等事故发生。以某市轨道交通盾构区间透水事故为例，在收集工程事故资料的基础上，结合区域地质背景、大量钻孔数据、野外勘查、现场试验及室内测试结果综合分析，研究此事故背景中各重要地质因素的作用方式，明确引发事故的主控地质因素。结果表明：研究区地质背景复杂，第四纪沉积广泛发育，分布不均，沉积产物复杂多样，地下水位高，水量丰富，上覆淤泥、淤泥质土等不透水层而多具承压性，高水头压力下复合地层稳定性差，持续的渗流侵蚀易产生涌水通道，引发地层结构失稳。基底钻遇的华涌组火山岩节理裂隙发育，透水性弱～强，富水性中等～好，富水性和渗透性变化较大，基岩水发育具有非均一性，不同岩性及风化程度对施工的影响具有差异性。地下揭露的古河道与现今河网发育具有重叠性，东平水道主干河道表现出较高的稳定性和继承性，沿古河道分布有中等～强透水性的砂砾石、卵石层，赋存的深层承压水与基岩水之间大部分区域不存在隔水层，局部与地表水体连通，各种类型水水量交换顺畅，地下水补给方式多样，水文地质条件复杂。上述均为易引发富水砂层涌水涌砂的不良地质条件，尤其是古河道分布发育和复合地层沉积组合2个主控因素，在后续类似地质条件的地下工程建设中需进行重点防控。

When encountering water rich sand layers during underground engineering construction in coastal and riverside areas, it is very easy to cause sudden water permeability, mud gushing and sand gushing,causing accidents such as ground collapse, tunnel burial, foundation pit collapse. Taking the water leakage accident in a shield tunnel section of a certain urban rail transit as an example, based on the collection of engineering accident data, combined with the comprehensive analysis of regional geological background, a large number of drilling data, field exploration, field testing and indoor testing results, study the action mode of various important geological factors under the background of the accident,and identify the main control geological factors causing the accident. The geological background of study area is complex, the Quaternary sediments are widely developed and unevenly distributed, with complex and diverse sedimentary products. The groundwater level is high and the groundwater quantity is rich. The groundwater covering with impermeable layers such as silt and muddy soil are mostly under pressure. The stability of composite formation under high water pressure is poor, and the continuous seepage erosion is prone to generating water inrush channels leading to instability of the geological structure. The volcanic rock joints and fissures of the Huachong Formation drilled in the basement are developed, with weak to strong water permeability, medium to good water abundance, and large changes in water abundance and permeability. The development of bedrock water is heterogeneous, and the impact of different lithology and weathering degree on construction varies. The ancient river channels exposed underground are overlapped with the current river network development. The main river channel of Dongping Waterway shows high stability and inheritance. There are medium-strong permeable sand gravel and pebble layers distributed along the ancient river channel. Most areas between the deep confined water and bedrock water do not have an water-resisting layer, and the part of deep confined water is connected with surface water. The exchange of various types of water is smooth. There are various ways of groundwater recharge, and the hydrogeological conditions are complex. The above are the unfavorable geological background factors that are easy to cause water gushing and sand gushing in the water-rich sand layer, especially the formation and distribution of ancient river channels and the development of composite strata sedimentation, which need to be focused on prevention and control in the subsequent underground engineering construction with similar geological conditions.

华能集团总部科技项目资助（HNKJ20-H49）

顾雷雨，杨晶晶，赵新杰，等. 富水砂层地下工程涌水涌砂主控地质因素研究[J]. 煤炭科学技术，2023，51（S1）：275−283.

GU Leiyu，YANG Jingjing，ZHAO Xinjie，et al. Research on main geological factors controlling water gushing and sand gushing of underground engineering in water-rich sand layer[J]. Coal Science and Technology，2023，51（S1）：275−283.