针对灌浆技术参数测量精度不高、稳定性较差,灌浆压力控制严重依赖人工操作等问题,基于传感器技术、微机技术和自动控制技术,将硬件和软件相结合,研制自适应灌浆测控系统。该系统采用压阻式压力传感器、电磁流量计、自主设计的自循环差压密度计和容栅传感器分别对灌浆压力、流量、密度和地层抬动值这4个关键技术参数进行高精度、动态检测,并利用PLC模块根据灌浆工况自动控制压力波动、保持其稳定性,继而实现智能化的自适应灌浆。研究结果证明:自适应灌浆测控系统对压力、流量、密度和地层抬动值的检测相对误差分别为2.5%,0.8%,0.5%和4.5%,压力自动控制精度保持在设定值的5%以内,控制响应时间为5-6S,系统精度高,响应快,稳定性好,能够在高灰尘、潮湿及强磁电干扰的现场施工条件下正常工作。
In view of the shortcomings existing in grouting construction such as low precision, poor stability of technical parameters detection and grouting pressure being relied heavily on manual operation, the adaptive grouting detection and control system was developed with hardware/software co-design based on sensor technology, microcomputer technology and automatic control technology. Piezoresistive pressure transducer, electromagnetic flowmeter, self-circulation differential-pressure densimeter with independent design and capacitive transducer were used to dynamically and precisely detect the four key technical parameters including grouting pressure, flow, grout density and ground lifting values respectively in the system. Meanwhile, according to the actual grouting situation, pressure fluctuation could be automatically controlled and kept stable on PLC, then intelligent adaptive grouting could be achieved. Curtain grouting test results show that the relative errors of detection on grouting pressure, flow, grout density and ground lifting values by the system are 2.5%, 0.8%, 0.5% and 4.5%, respectively, whilst grouting pressure fluctuation can be controlled to less than 5% of the set value in 5-6 s. The system with capabilities of high precision, quick response and good stability can be operated normally under dust, damp and strong magnetoelectric interference condition of grouting construction.