岩土中的热式渗流测量

Thermal Seepage Measurement in Rock and Soil

岩土中渗流的测量目前主要采用渗压计测量岩土内部的渗透(孔隙)水压力,从而进行渗流监测,这种测量方式测量的是标量,存在动态响应差、量程小、非直接测量等缺陷,难以满足岩土中渗流监测发展的需求;鉴于此,本文设计了一种基于热扩散原理的远程在线渗流计;主要由电源模块、温度检测模块、恒功率加热模块、显示模块四部分组成;由三线制铂电阻恒流源测温电路检测进水出水两端温度差,检测结果返回显示到stm32并经过RS-485总线传至主机进行数据分析;实验结果表明,该渗流计可实现在线监测岩土中的渗流情况,能有效的检测岩土中渗流的速度,分辨率达到0.05 mL/s,具有良好的灵敏度,准确性和重复性,适用于绝大多数种类岩土中的渗流测量。

At present,in the measurement of seepage in rock and soil,the osmotic pressure meter is mainly used to measure the infiltration( pore) water pressure inside rock and soil,and then the seepage monitoring is performed.The measurement is scalar,and there is a poor dynamic response,small range,non-Direct measurement and other defects are difficult to meet the needs of monitoring and development of seepage in rock and soil;in view of this,a remote online flow meter based on the principle of thermal diffusion is designed;it consists of power module,temperature detection module,constant power heating module,and display module.Three-wire platinum resistance constant current source temperature measurement circuit detects the temperature difference between the two ends of the influent water,the test results are returned to the display to the stm32 and passed through the RS-485 bus to the host for data analysis;experimental results show that the flow meter can be implemented on-line monitoring The seepage in rock and soil can effectively detect the velocity of seepage in rock and soil,with a resolution of 0.05 m L/s. It has good sensitivity,accuracy and repeatability,and is suitable for the seepage measurement of most types of rock and soil.