摘要
耕地资源紧是中国面临的现实问题,土地复垦作为补充耕地的重要手段之一,复垦后耕地的表土层厚度直接影响工程质量,特别是薄表土地区覆土厚度检查是关键。传统的检验方法费时费力。针对上述问题,选择微波遥测仪器——探地雷达为工具进行了土层结构无损探测的室外模型实验。构建模型自下而上依次为原状土(40cm)、粗砂(25cm)、土(15cm)和细砂(30cm),中心天线频率为500MHz,测量方法为共剖面法。通过对雷达图像分析,各层介质探测差值小于5cm,表明探地雷达能够有效探测土层结构,可以用于土地复垦工程土层厚度的验收工作;同时,尝试对实验的时间-振幅和频率-振幅进行分析,通过时间-振幅图可以看出,振幅在0.95、7.15、9.93、15.7和17.50ns附近发生了5次明显变化,能够更加直观地解译雷达信号;通过频率-振幅图可以看出,在频率达到470.10MHz时,振幅最大为1821,电磁波最有效,可为探地雷达设备选择提供理论支持。
In a land reclamation project, the surface soil level thickness, especially in the thin surface soil area, directly influences the project quality. The traditional inspection procedure is both time-consuming and very difficult to implement. In this paper, the microwave remote-sensing instrument （Ground Penetrating Radar） is used to carry out the soil layer structure nondestructive survey in outdoor model experiments. The model consists of undisturbed soil （40 cm）, coarse sand （25 cm）, soil （15 cm）, and fine sand （30 cm）, from bottom to top, with central antenna frequency of 500 MHz. The radar image analysis shows that the soil layer structure can be effectively distinguished within 5 cm. The analysis on the time-oscillation amplitude shows that amplitude sees a significant change near 0.95, 7.15, 9.93, 15.7 and 17.50 ns, as a direct interpretation of the radar signal. From the frequency - bscillation amplitude chart one can see that at the frequency of 470.10 MHz, the amplitude reaches up to 1 821, as the most effective electromagnetic waves, which can be used as a reference in design of radar equipment.
出处
《科技导报》
CAS
CSCD
北大核心
2009年第17期35-37,共3页
Science & Technology Review
基金
国家科技支撑计划项目(2008BAB38B03-02)
中国矿业大学(北京)大学生创新性实验计划项目(0814)
关键词
探地雷达
土壤层次
无损探测
振幅
频率
Ground Penetrating Radar
soil layer
nondestructivedetection
oscillation amplitude
frequency
