隧道穿越江堤段防渗体消险加固处理技术

Risk elimination and reinforcement technology of anti-seepage for river embankment in tunnel crossing section

鉴于大型隧道穿堤盾构施工引起的堤防变形会导致防渗体破坏,结合南京市纬三路过江通道N线三汊河段穿江大堤工程汛期出现的散浸渗漏险情,研究应用了隧洞穿越江堤消险防渗加固处理技术。基于现场试验检验,提出了先灌水泥黏土浆固结7~15 d,再采取引孔后高压旋喷桩的成墙方案及处理技术,建成了堤防有效新防渗体并成功消险。工程完工后,江堤经受住了2020年南京长江超历史洪水10.39 m的考验,江堤防渗性能满足功能要求。

Since the deformation of embankment caused by shield construction of large-scale tunnel passing through embankment would cause anti-seepage body destruction,the Yangtze River embankment should be reinforced for seepage prevention.Taking the actual crossing river embankment of Sanchahe River section in Nanjing as an example,in which the tunnel Line N of Weisan Road crosses the Yangtze River.For the situation of scattered seepage danger in flood season,the risk elimination and anti-seepage reinforcement technology was investigated and applied.Based on field tests,a wall forming scheme and corresponding treatment technology was proposed,in which cement clay slurry was firstly poured with a solidification period of 7 to 15 days,and then the high-pressure jet grouting pile with double pipe method after the leading hole was adopted.The danger risk of the embankment was successfully eliminated.After completion of the project,the embankment has stood up to the exceeding history flood with 10.39 m water level of the Yangtze River in 2020,and the anti-seepage performance of the embankment meets the functional requirements.