地铁深基坑连续墙渗漏风险的量化控制

Quantitative Control of Diaphragm Wall Leakage Risk in Metro Deep Foundation Pit

深基坑连续墙止水帷幕发生渗漏,会严重威胁工程建设安全。提出了一套基于声纳渗流测量原理的地下连续墙渗漏风险测量方法。以某地铁站基坑连续墙渗漏检测及堵漏效果为案例,通过对该站24幅地下连续墙进行渗漏声纳检测,并对测量结果进行分析计算,获得了原位测量孔内渗透流速、渗流方向、渗漏流量及渗透系数等参数的空间分布。计算结果与施工现场基本一致。基于可视化成像智能分析方法,反演得到了复杂环境下地下水的三维空间可视化渗流场,准确地确定了渗漏通道的位置,用以指导局部封堵灌浆。灌浆前后渗漏流速对比分析表明,基坑渗漏得到有效控制。

The frequent diaphragm wall seepage flow in deep foundation pit during excavation will seriously threaten the safety of metro construction. Based on the principle of sonar seepage flow detection method,a diaphragm wall seepage risk measurement method is proposed. According to a practical project of diaphragm wall leakage measurement during deep foundation pit excavation,the sonar seepage flow detection method is applied to detect the seepage field of 24 diaphragm walls,the measurement results are calculated and analyzed. Using the calculated data,the spatial distribution of parameters is obtained, including seepage velocity per meter,seepage direction,seepage flow and permeability coefficient,and the calculation results are consistent with the construction site. On the basis of intelligent visualization analysis method,a three-dimensional visualization chart of seepage filed is achieved after deduction,and the channel water curtain leakage is accurately detected,this chart is used to guide the local plugging grouting. A comparative analysis shows that the seepage velocity after the anti-seepage plugging measure is significantly reduced,and the potential risk of pipeline leaking is effectively controlled.