摘要
电力排管由PVC管和其外包混凝土构成,目前上海中心城区的绝大多数供电线路采用电力排管形式敷设,其结构健康对电力传输有着非常重要的意义。由于结构老化或周边环境影响,电力排管混凝土极易破坏开裂会造成电力运营故障。对于电力排管这种小直径的复合形式的管道毫米级的裂缝检测非常困难。本文针对电力排管管道直径大小和裂缝损伤情况及内部环境复杂的情况,运用探地雷达对其进行检测。选取了Bow-tie天线作为探测的天线类型,并通过对天线的尺寸、形状进行优化使得天线的S11和S21参数达到了理想的结果,并满足电力排管裂缝检测的分辨力及管道小直径的检测要求。根据不同的天线与传输线阻抗匹配原则,设计制作了微带馈线组、巴伦组的3.5 GHz左右的两组Bow-tie雷达天线。同时为验证此探地雷达天线对裂缝的可见性和对电力排管结构裂缝检测的可行性,进行了二维和三维的数值模拟和模型试验以验证其检测效果。通过数值模拟和试验,使用3.5 GHz左右的Bow-tie天线能够实现电力排管3 mm及以上裂缝的有效检测。
Cable ducts which consist of PVC pipes and concrete covering around the pipes to protect interior power lines are mainly used for urban power line installation. So the health of cable ducts is key to electric energy transmission. Due to the aging of buildings and urban construction,the concrete of cable ducts are very easy to get cracked and damaged and then lose the ability of power cable protection. the crack width is just a few millimetres,so the detection in the small-diameter hole with complex conditions is of great difficulty. This thesis focuses on the use of Pipe Ground Penetrating Radar( GPR) for detection in cable ducts. Bow-tie antenna as the detection antenna,after the optimization of its size and shape,was utilized to get the best result of S11 parameter and S21 parameter and make it meet the requirements of the resolution and the detection in small-diameter holes. According to the principle of impedance matches between different antennas and cables,two groups of 3.5 GHz Bow-tie antennas named Microstrip group and Balun group were manufactured. Also,in order to verify the visibility of crack and practicability of cable duct detection with Pipe GPR,several two dimensional and three dimensional simulation and modeling detection of cable duct cracks with 3. 5 GHz Bow-tie antennas were designed. From the result of the simulation and modeling detection,a conclusion was made that 3.5 GHz Bow-tie antenna can detect 3mm width of cracks in cable ducts.
出处
《地下空间与工程学报》
CSCD
北大核心
2015年第S2期756-763,共8页
Chinese Journal of Underground Space and Engineering
基金
上海市电力公司科技项目
关键词
电力排管
探地雷达
裂缝检测
天线设计
模型试验
cable ducts
ground penetrating radar
crack detection
antenna design
modeling test
