Research On Seepage Thermal Measurement Sensor Technology In Rock And Soil

Geotechnical monitoring and early warning of geological disasters has been occupying an important position in the prevention and control of geological disasters in the geotechnical work.Seepage in the surface and underground rock is one of the main causes of geological disasters,and the thermal seepage sensor is a sensor for measuring the seepage flow in the rock.In view of the fact that China's seepage monitoring in geotechnical soil can not get rid of large-scale instruments,the monitoring method can not get rid of indirect measurement,the monitoring accuracy is not high enough,and it can not be measured continuously for a long time.In this paper,the principle and simulation of heat transfer are analyzed,and the thermal seepage measurement system is designed.The theoretical simulation content is verified by experiments.The research contents are as follows:(1)Review a large number of relevant literatures,study the main technical methods of seepage measurement in rock and soil at home and abroad,and compare the advantages and disadvantages of various technical methods.(2)Explain the principle of seepage measurement in rock and soil based on heat conduction,clarify the characteristics of seepage in rock and soil,briefly introduce the mechanism of heat conduction in seepage and select the temperature sensor.(3)Derived the relationship between the flow rate and temperature of the fluid in the percolation sensor.The temperature field and velocity field were simulated by the ANSYS FLUENT software,and the velocity and temperature fields were analyzed in detail.(4)Design and manufacture the entire seepage measurement sensor.The overall design and planning of the seepage measurement section was carried out,mainly including measurement circuit design and sensor structure design.(5)The overall software design and planning of the system was carriedout.The software design of the instrument mainly includes the seepage measurement system and the display system,the most important of which is the seepage measurement system.(6)Design and manufacture an overall seepage measurement experimental platform.The flow and temperature change experiments in the percolation sensor,the calibration experiment of the percolation sensor and the rock and soil seepage measurement experiment were completed.At the same time,a portable geotechnical seepage measuring instrument was designed.(7)The output characteristics and error of the percolation sensor are analyzed.The concept of temperature characteristic value is used to represent the temperature difference between the two ends of the percolation sensor.The experimental results are in line with expectations,and the seepage flow as low as 0.025mL/s can be measured.The subject is closely related to the theoretical analysis and experiment based on the seepage measurement method in the geothermal soil.The feasibility of measuring the seepage in the rock by thermal conduction is confirmed by experiments,and the temperature characteristic value,ie the temperature difference and the seepage flow,are obtained.Correspondence relationship.It provides a strong theoretical basis and experimental support for the application of heat transfer-based seepage measurement sensors in practical engineering in the future.