地下勘探表面地下穿透雷达法使用标准指南

详细信息   

• 标准号：ASTM D6432-2011
• 发布日期：2011
• 英文题名：Standard Guide for Using the Surface Ground Penetrating Radar Method for Subsurface Investigation
• 英文主题词：Civil engineering ; Engineering criteria/design--soil/rock/related materials ; Environmental site assessment (ESA)--soil/rock ; Geological investigations ; Ground-penetrating radar ; Ground water ; Radar ; Subsurface investigation--soil/rock ; Surface analysis--soil/rock/related materials ; Surface ground penetrating radar method
• 标准状态：现行
• 发布单位：US-ASTM
• 载体形态：18P.;A4
• 中国标准分类号：P10
• 国别：美国材料与试验协会

文摘

Concepts8212;This guide summarizes the equipment, field procedures, and data processing methods used to interpret geologic conditions, and to identify and provide locations of geologic anomalies and man-made objects with the GPR method. The GPR uses high-frequency-pulsed EM waves (from 10 to 3000 MHz) to acquire subsurface information. Energy is propagated downward into the ground from a transmitting antenna and is reflected back to a receiving antenna from subsurface boundaries between media possessing different EM properties. The reflected signals are recorded to produce a scan or trace of radar data. Typically, scans obtained as the antenna(s) are moved over the ground surface are placed side by side to produce a radar profile.

The vertical scale of the radar profile is in units of two-way travel time, the time it takes for an EM wave to travel down to a reflector and back to the surface. The travel time may be converted to depth by relating it to on-site measurements or assumptions about the velocity of the radar waves in the subsurface materials.

1.1 Purpose and Application:

1.1.1 This guide covers the equipment, field procedures, and interpretation methods for the assessment of subsurface materials using the impulse Ground Penetrating Radar (GPR) Method. GPR is most often employed as a technique that uses high-frequency electromagnetic (EM) waves (from 10 to 3000 MHz) to acquire subsurface information. GPR detects changes in EM properties (dielectric permittivity, conductivity, and magnetic permeability), that in a geologic setting, are a function of soil and rock material, water content, and bulk density. Data are normally acquired using antennas placed on the ground surface or in boreholes. The transmitting antenna radiates EM waves that propagate in the subsurface and reflect from boundaries at which there are EM property contrasts. The receiving GPR antenna records the reflected waves over a selectable time range. The depths to the reflecting interfaces are calculated from the arrival times in the GPR data if the EM propagation velocity in the subsurface can be estimated or measured.