摘要
为合理控制基坑第四系深层承压水带来系列施工难题,以粤东城际铁路车站基坑工程为背景,首先采用抽水试验预测分析基坑场地的水文状况和基坑涌水量,然后基于预测分析结果提出基坑周边设置水位观测井兼回灌井的悬挂式地连墙+坑内泄压井降水减压的方案,运用可视化三维地下水流动模拟软件Visual Modflow模拟分析对基坑降水工程,通过对比分析,采用墙底封底方案进行降水控制。研究结果表明:(1)该车站基坑场地内为海相、海陆交互相沉积地层,共有3层承压水,局部隔水层缺失存在越流天窗,抽取第3层承压水将造成各含水层的水位下降,存在越流补给;(2)经过结构分析及实际施工证明,利用墙底封底方案,可将水文状况复杂条件下的软土地区基坑施工过程中的基坑底抗突涌稳定性控制在规定安全范围;(3)在不同嵌固深度地连墙情况下坑外地下水的降深有显著有影响。
To reasonably control the groundwater during the construction of foundation pit,taking an intercity railway station foundation pit project as the engineering background,first the pumping test is conducted to make predictive analysis of the water hydrology and water inrush of the foundation pit site,and then based on the results,the scheme of hanging wall and the pit drainage well is proposed to serve as water level observation well and inverted well,then the visual 3D groundwater flow simulation software Visual Modflow is used to make simulation analysis of foundation pit precipitation works,through comparative analysis,the wall bottom sealing scheme is adopted for precipitation control.The results show that:(1)the foundation pit site of the station is a marine and marine-terrestrial transitional facies sedimentary formation,with three layers of confined water where the absence of aquiclude in local position forms a leaking hole and water extraction from the third layer will cause water level drop in each layer and leaking recharge exists.(2)the water level observation well and inverted well are set around the foundation pit.Timely recharging according to the monitoring results can reduce the influence of the external water level of the foundation pit on the surrounding environment;(3)the depth of the groundwater has significant influence under different embedded depth.
作者
马鹏远
岳岭
吕刚
陈慧
江辽
Ma Pengyuan;Yue Ling;Lv Gang;Chen Hui;Jiang Liao(Urban Rail Transit Design and Research Institute,China Railway Engineering Design and Consulting Group Co.,Ltd.,Ltd.,Beijing 100055,China)
出处
《铁道技术标准（中英文）》
2024年第7期37-44,共8页
Railway Technical Standard(Chinese & English)
关键词
基坑工程
深层承压水
降水控制
回灌井坑内泄压井
地下水流动模拟
foundation pit works
groundwater
precipitation control
inverted well
pressure relief well in pit and groundwater flow simulation
