基于DTS的地下连续墙接头处渗漏预测

地下连续墙作为深基坑的支护墙体,具有良好的强度和安全稳定性。但墙体的不完整性会引起渗漏问题的发生,严重影响墙体的功能。针对地下连续墙的渗漏问题,设计模型试验探索了不同加压功率、不同加压时长下不同含泥量混凝土的温升稳定情况,通过温升曲线中的异常点,可分析墙体的完整性及发生墙体渗漏情况,提出了基于分布式光纤温度感测(Distributed Temperature Sensing,DTS)技术的地下连续墙混凝土浇筑完整性检测方法及对地下连续墙接头处渗漏的预测方法。以昆明地铁四号线的深基坑地下连续墙项目为例,介绍了利用DTS监测地下连续墙渗漏的感测光缆及其布设方法,对比检测结果及现场实际渗漏情况,验证了这一方法的可行性和有效性。

Leakage Prediction of Underground Continuous Wall Joints Based on DTS

As the supporting wall of deep foundation pit,diaphragm wall has good strength and safety stability.But the incompleteness of the wall will cause the leakage problem and seriously affect the function of the wall.Aiming at the leakage problem of diaphragm wall,a model experiment is designed to explore the temperature rise stability of concrete with different mud content under different pressure power and time.Through the abnormal points in the temperature rise curve,the integrity of the wall and the leakage of the wall can be analyzed.Distributed temperature sensing(DTS)based on distributed optical fiber is proposed.The detection method of concrete pouring integrity of diaphragm wall and the prediction method of leakage at the joint of diaphragm wall are proposed.Taking the deep foundation pit diaphragm wall project of Kunming Metro Line 4 as an example,the sensing optical cable and its layout method for monitoring the leakage of diaphragm wall are introduced by using DTS.The feasibility and effectiveness of this method are verified by comparing the detection results with the actual leakage situation.