深部软岩地应力测量的FBG六向压力传感器研制及性能测试

Development and Performance Test of FBG Six-direction Pressure Sensor for Deep Soft Rock Stress Measurement

流变应力恢复法是针对煤矿深部软岩而提出的一种地应力测量新方法,该方法采用埋设压力传感器的方法来实现岩体原岩应力和扰动应力的长期监测。设计制造了一种新型光纤光栅式(FBG)六向压力传感器,该传感器外形为球体,球体内部包含6个独立的压力传感单元,每个传感单元呈不同的角度布置。传感单元由压头、螺旋扣环以及拱形梁式光纤光栅应变计组成。采用分级加载方法对传感单元的性能进行了标定测试,结果表明:各误差指标均符合准确度等级在2%以内的传感器研发要求。表明该传感器满足实际使用要求。

Rheological stress recovery method is an innovative in-situ stress measuring method for deep soft rock mass. This method is able to monitor the original rock stress and long term disturbance stress by embedding pressure sensors. A new FBG six-direction pressure sensor is designed and manufactured. The exterior shape of the sensor is sphere. The sphere contains six independent pressure sensing elements. Each sensing element is arranged at a different angle. The sensing element consists of a ram, spiral buckle and an arch-beam fiber grating strain gauge. The performance of the sensing element is calibrated by the method of multi-stage loading. The results show that all error indexes meet the requirements of the sensor with the accuracy level within 2%. This indicates that the sensor meets the actual use requirements.