沉管接头突发渗漏水的红外监测模型试验

在沉管隧道的应用中,渗漏水已经成为威胁到沉管建设和运行过程中的重大问题。针对沉管隧道接头渗漏水的问题,通过建立等尺寸模型进行室内试验,模拟港珠澳大桥沉管隧道接头渗漏。采用红外技术建立无接触、无明水渗漏监测系统,收集沉管接头渗漏的红外辐射图像数据,并采用Matlab对图像数据进行分析。采用温度突变法,通过分析不同温度的水渗入接头OMEGA中导致构件红外辐射特征发生变化,从而对是否有渗漏水发生进行有效的判断,同时对影响判别的因素进行分析。试验结果表明:采用温度突变法的红外监测系统在沉管隧道中的监测,可以对突发渗漏水进行判别;当快速渗漏的水体与沉管接头处构件存在较大温差,则会造成构件表面温度突变;温差越大,造成的温度突变越明显,监测系统判定出渗漏所需时间越短。研究成果为红外监测在沉管隧道以及其他类似工程中的应用提供了一种思路,并验证了其可行性。

Model test of infrared monitoring sudden leakage of immersed tube joints

In the application of immersed tube tunnel, water leakage has become a vital problem both in the construction and in the period of operation. For this reason, laboratory experiment is carried out to simulate the seepage of immersed tube tunnel joints of Hongkong-Zhuhai-Macau Bridge by building a full-scale model. By applying infrared technique to the contactless detection of invisible leakage water, monitoring system can collect data of infrared radiation image which is then analyzed with Matlab. Temperature jump method is adopted by analyzing the change of infrared signature, to make the judgment whether leakage happens behind OMEGA or not. Influencing factors on the judgment are analysed at the same time. Results of the experiment show that infrared techniques can be used to monitor sudden leakage of immersed tube joints with the temperature jump method. Relatively large temperature difference between sudden leakage water and structure of joints will lead to temperature jump on the surface of structure. The larger the temperature difference is, the less time system needs to make a judgment. The experiment provides a possible method for application of infrared technique in immersed tunnel and other projects. Feasibility of application of infrared technique in immersed tube joints is researched.