A Theoretical Model to Predict Both Horizontal Displacement and Vertical Displacement for Electromagnetic Induction-Based Deep Displacement Sensors

Abstract

Deep displacement observation is one basic means of landslide dynamic study and early warning monitoring and a key part of engineering geological investigation. In our previous work, we proposed a novel electromagnetic induction-based deep displacement sensor (I-type) to predict deep horizontal displacement and a theoretical model called equation-based equivalent loop approach (EELA) to describe its sensing characters. However in many landslide and related geological engineering cases, both horizontal displacement and vertical displacement vary apparently and dynamically so both may require monitoring. In this study, a II-type deep displacement sensor is designed by revising our I-type sensor to simultaneously monitor the deep horizontal displacement and vertical displacement variations at different depths within a sliding mass. Meanwhile, a new theoretical modeling called the numerical integration-based equivalent loop approach (NIELA) has been proposed to quantitatively depict II-type sensors’ mutual inductance properties with respect to predicted horizontal displacements and vertical displacements. After detailed examinations and comparative studies between measured mutual inductance voltage, NIELA-based mutual inductance and EELA-based mutual inductance, NIELA has verified to be an effective and quite accurate analytic model for characterization of II-type sensors. The NIELA model is widely applicable for II-type sensors’ monitoring on all kinds of landslides and other related geohazards with satisfactory estimation accuracy and calculation efficiency.

Research on Structure Optimization and Measurement Method of a Large-Range Deep Displacement 3D Measuring Sensor

“…By measuring the displacement of each layer of rock and soil from N-1 measuring units in turn, the distributed flexible measurement of three-dimensional displacement from the surface to the depth of rock and soil mass can be realized. Figure 2 shows the prototype of the magneto-electric deep displacement 3D measuring sensor, which we designed before [32][33][34][35][36]. Each sensing unit has the same structure.…”

“…Here we only outline its working principle. More detailed description can refer our published works [32][33][34][35].…”

“…(4) Easy to realize remote, real-time and networked automatic monitoring. For these sensors, we have carried out in-depth research on sensor theory, measurement modeling, performance analysis and testing [32][33][34][35][36].For our proposed deep displacement 3D measuring sensor, the measurement ranges of horizontal and vertical displacement between two adjacent sensing units (height of the sensing unit is 70 mm) is 0-30 mm, which can meet the monitoring requirements of most landslides, but not necessarily able to meet the monitoring requirements of some large-scale landslides in the fast-changing or near-sliding stage, thus limiting the sensor's overall effectiveness on landslide early warning monitoring. At the same time, in order to adapt to the harsh and complex deep environment of rock and soil mass, the measuring device needs to have strong water-proof, anti-corrosion and compression resistance performance.…”

“…(4) Easy to realize remote, real-time and networked automatic monitoring. For these sensors, we have carried out in-depth research on sensor theory, measurement modeling, performance analysis and testing [32][33][34][35][36].…”

An adaptive distributed dipole model for enhanced dynamic inversion in magnetic field and induction sensor

“…An ultrasound and radar can be utilized to monitor wide area with high accuracy but is bulky and cannot be used with obstacle along the optical path [27]. Magnetic sensors have been utilized in numerous applications such as motion, orientation sensing and path tracking [28][29][30][31]. It is compact in size, easy at operation and capable of providing high sensitivity without mechanical contact.…”