定向钻孔雷达(Orientated Borehole Ground Penetrating Radar，OBGPR)有效解决了矿井或油井钻孔、工程检测探孔等周边地质情况的定向精细化探测问题。针对深孔中介质多变，雷达天线配重不合理，导致天线下沉时状态难以控制、探测效果不理想的情况，开展定向钻孔雷达探测过程中的天线平衡分析和配重优化设计研究。首先对深孔/井探测中的定向钻孔雷达天线进行平衡状态下的受力分析，在明确不同密度介质条件天线所受重力、浮力的前提下,通过构建钻孔泥浆黏度系数随密度变化模型，数值模拟与试验验证相结合确定雷诺数与阻力系数关系，重点研究雷达天线匀速下沉检测的运动阻力情况。接着开展定向钻孔雷达天线的配重优化设计，形成了配重大小可调节的配重块结构以及不同探测条件下(钻孔直径0.1~0.2 m、介质密度1 000~1 700 kg/m³、检测速度0.03~0.06 m/s)的配重方案。在此基础上，开展定向钻孔雷达的电塔桩基和大坝坝基质量现场探测试验，以验证天线的配重优化设计结果。对试验过程中的线缆拉力变化情况和雷达探测结果进行分析，结果表明：优化设计出的钻孔雷达天线配重结构和方案满足不同工况条件下天线平稳下沉探测的需求，探测结果能有效得到钻孔周边地质异常区域的方位和尺寸。研究结果可为钻孔雷达实现复杂孔/井中环境下的超深、定向和精细化探测提供技术支撑和指导价值。

Orientated borehole ground penetrating radar (OBGPR) can effectively solve the problem of orientated and detailed detection of geological conditions around the mine or oil well boreholes and engineering probe hole, etc. In view of difficult state control and unsatisfactory detection effect during antenna sagging due to the changeable medium in deep hole and the unreasonable counterweight of OBGPR antenna, the balance analysis and counterweight optimization design of orientated borehole ground penetrating radar antenna during detection was implemented in this paper. Firstly, analysis was conducted on the force of OBGPR antenna under the balance condition during the deep hole and well detection. Definitely, the model of viscosity coefficient of drilling mud changing with density was built under the condition of the known gravity and buoyancy of antenna in medium with different densities. On this basis, the relationship between Reynolds number and drag coefficient was obtained through numerical simulation and experimental verification. In particular, the movement resistance of OBGPR’s antenna for detection at uniform velocity was studied. Then, the counterweight optimization design was operated for OBGPR antenna, forming the adjustable counterweight structure and the counterweight schemes under different detection conditions (with borehole diameter of 0.1‒0.2 m, medium density of 1 000‒1 700 kg/m³ and detection speed 0.3‒0.6 m/s). Besides, the field detection tests were carried out for the quality of pylons and dam foundation of OBGPR, to verify the counterweight optimization design result of antenna. Moreover, analysis was performed for the change of cable tension and the detection results of radar. The results show that the optimized counterweight structure and scheme of OBGPR antenna could meet the detection requirements of antenna under different conditions, and according to the detection results, the orientation and size of the geological anomaly area around the borehole could be obtained accurately. Generally, the research results could provide technical support and guidance value for the borehole ground penetrating radar to realize the ultra-deep, orientated and detailed detection in complex borehole/well environment.