CN119322366A - Sector type slope crack monitoring system and monitoring method thereof - Google Patents

Abstract

The invention provides a sector-shaped slope crack monitoring system and a monitoring method thereof, which relate to the technical field of crack monitoring, wherein the sector-shaped slope crack monitoring system comprises an ultrasonic detector, a sensor and a sensor, wherein the ultrasonic detector is used for generating and receiving required sound wave frequency; the system comprises a sensing network, a data acquisition unit, a communication module, a central processing platform and a central processing platform, wherein the sensing network is used for acquiring crack data in a sector area, the data acquisition unit is used for acquiring data of the sensing network and sonic frequency data of an ultrasonic detector and preprocessing the data, the communication module is used for transmitting the data acquired by the data acquisition unit to the central processing platform, the central processing platform is used for analyzing and processing the collected data to generate a report, and sending an alarm notification according to a preset threshold value, the underground crack monitoring and the earth surface crack monitoring are combined, so that the omnibearing coverage of a slope crack can be realized, continuous innovation and perfection of a related monitoring technology and an early warning system can be promoted based on the analysis of the monitoring data, and the automation and intelligent level of geological disaster monitoring and early warning can be improved.

Description

Sector type slope crack monitoring system and monitoring method thereof

Technical Field

The invention relates to the technical field of crack monitoring, in particular to a sector type slope crack monitoring system and a monitoring method thereof.

Background

The ground cracks are geological phenomena that the ground mantlerock and the soil body are cracked under the action of natural or artificial factors, and cracks with certain length and width are formed. The ground crack is slowly developed progressive disaster geology, is influenced by geological environment and human factors, the development of the ground crack is progressive and periodic, the damage of the ground crack causes deformation and stress field to be generated in the geological body in a certain range around the ground crack along with the change of time, for slope disasters, the ground crack develops into the most common deformation representation, the development change trend has strong correlation with the overall stability of the slope, and therefore, the monitoring of the development of the deformation characteristic of the ground crack is also an important technical means for disaster prevention and disaster reduction of the slope disasters.

At present, for the detection of slope cracks, a professional adopts a crack depth finder and a crack width finder to periodically go to the slope for detection, and then the professional judges the dangerous grade of the crack according to experience, but the slope is generally inclined, so that the manual detection is dangerous, time and labor are wasted, the real-time detection is difficult, and the phenomena of missed judgment and misjudgment are easy to occur in the manual detection.

Therefore, it is necessary to provide a new sector type slope crack monitoring system and a monitoring method thereof to solve the above technical problems.

Disclosure of Invention

The invention provides a sector type slope crack monitoring system and a monitoring method thereof, which aim to solve the technical problems that slopes generally have inclination, manual detection is dangerous, time-consuming and labor-consuming, real-time detection is difficult, and the phenomena of missed judgment and misjudgment occur easily in manual detection.

The sector slope crack monitoring system provided by the invention comprises an ultrasonic detector, a sensor and a sensor, wherein the ultrasonic detector is used for generating and receiving required sound wave frequency and comprises a transducer transmitting end and a transducer receiving end, the transducer transmitting end is perpendicular to a sector area of a slope, the transducer receiving end is positioned above the transducer transmitting end, and the transducer transmitting end and the transducer receiving end are positioned at the same vertical line;

The sensor network comprises a plurality of sensors arranged on the position of the slope sector area and used for collecting crack data in the sector area, wherein the crack data comprise crack opening width, local inclination degree of the slope and stress change in the crack;

the data acquisition unit is used for acquiring data of the sensing network and sonic frequency data of the ultrasonic detector and preprocessing the data;

The communication module is used for transmitting the data acquired by the data acquisition unit to the central processing platform;

and the central processing platform is used for analyzing and processing the collected data, generating a report and sending out an alarm according to a preset threshold value.

Further, the sensor network comprises a displacement sensor, a sensor module and a control module, wherein the displacement sensor is used for monitoring the change of the width of the crack opening;

the inclination sensor is used for monitoring the inclination degree of a local slope;

And the stress sensor is used for monitoring the stress change in the crack.

The invention provides a monitoring method of a sector-shaped slope crack monitoring system, which comprises the following steps:

s1, dividing a slope into a plurality of sectors according to geological characteristics and crack trend of the slope, and uniformly distributing a sensing network and an ultrasonic detector in each sector;

S2, enabling a transducer transmitting end in the ultrasonic detector to be perpendicular to the slope sector area, enabling a transducer receiving end to be located above the transducer transmitting end, and enabling the transducer transmitting end and the transducer receiving end to be located on the same perpendicular line for placement;

s3, collecting crack width, displacement and inclination angle data according to preset frequency by each sensor in the sensor network;

s4, transmitting the data of the sensing network and the ultrasonic detector to a data acquisition unit in a wireless or wired mode;

S5, preprocessing the data received by the data acquisition unit by the central processing platform, analyzing the width of the crack, the internal stress change of the slope crack, the local inclination degree of the slope and the sound wave frequency, and generating an analysis report;

s6, continuously monitoring the development trend of cracks;

And S7, when the crack development exceeds a preset threshold, triggering an alarm by the system.

Further, the crack width analysis includes the steps of:

s1, calculating a crack width change rate, namely calculating a crack width difference value between two adjacent time points, and calculating an average change rate;

S2, analyzing the crack expansion trend, namely analyzing the trend of crack width expansion by using a linear regression model;

S3, comparing the trend of crack width expansion with a preset safety threshold value;

And S4, early warning judgment, namely judging that potential risks exist when the crack width expansion trend exceeds a safety threshold value, and triggering early warning.

Further, the slope local inclination degree analysis comprises the following steps:

S1, according to inclination angle data acquired by an inclination angle sensor, a time sequence set is established, and inclination angles of a slope at different times are represented;

s2, predicting the inclination degree of the local crack of the slope by adopting time sequence analysis;

And S3, triggering an early warning mechanism when the inclination degree of the predicted slope local crack exceeds an early warning threshold value.

Further, the slope crack internal stress variation analysis comprises the following steps:

S1, establishing a stress state equation;

s2, establishing a stress observation equation;

s3, predicting the stress state at the current moment, namely predicting the state at the current moment based on the state estimation and control input of the last moment;

s4, predicting covariance:

S5, calculating Kalman gain according to the prediction covariance and the observation matrix;

s6, updating state estimation according to the observed stress value and the Kalman gain;

S7, updating a covariance matrix of the state estimation;

And S8, early warning judgment, namely triggering an early warning mechanism when the predicted stress value exceeds an early warning threshold value.

Further, the acoustic frequency analysis includes the steps of:

s1, decomposing signals, namely decomposing sound wave frequency signals to different scales by utilizing a wavelet basis function;

S2, extracting features, namely extracting the energy distribution and frequency component features of the signals on each scale;

S3, crack identification, namely judging whether cracks exist or not according to the change of the characteristics;

s4, quantifying the crack degree, namely quantifying the crack degree through the amplitude change of the features;

and S5, early warning judgment, namely triggering an early warning mechanism when the detected crack change degree exceeds an early warning threshold value.

Compared with the related art, the sector type slope crack monitoring system and the sector type slope crack monitoring method provided by the invention have the following beneficial effects:

1. According to the invention, the transducer transmitting end is perpendicular to the slope sector area, the transducer receiving end is positioned above the transducer transmitting end, and the transducer transmitting end and the transducer receiving end are positioned at the same vertical line, so that the ultrasonic energy is ensured to be transmitted along a specific direction (namely perpendicular to the slope sector area), so that the concentration degree and the propagation efficiency of the ultrasonic energy are improved, and meanwhile, the receiving end is positioned above the transmitting end and on the same vertical line, thus being beneficial to accurately receiving the reflected acoustic wave signals, reducing the acoustic wave interference from other directions and improving the accuracy and the reliability of measurement by keeping the vertical relation between the transmitting end and the receiving end.

2. The invention monitors the underground crack through the sound wave frequency which is generated and received by the ultrasonic detector, combines a plurality of sensors which are arranged on the position of the slope sector area and are used for collecting the crack opening width in the sector area, the local inclination degree of the slope and the stress change in the crack, can realize the omnibearing coverage of the slope crack by combining the underground crack monitoring and the earth surface crack monitoring, reduces the monitoring blind area, solves the problem that the underground crack is difficult to directly observe and easily neglect the influence of the underground crack on the slope stability, and can promote the continuous innovation and perfection of related monitoring technology and early warning systems based on the analysis of monitoring data, thereby improving the automation and intelligent level of geological disaster monitoring and early warning.

3. According to the invention, the slope is divided into a plurality of sectors according to the geological characteristics and the crack trend of the slope, the sensing network and the ultrasonic detector are distributed in each sector, and the specific geological characteristics and the crack trend of each sector are subjected to fine monitoring, so that the local fine change can be captured in a partition monitoring mode compared with the whole monitoring.

Drawings

FIG. 1 is a block diagram of a sector-shaped slope crack monitoring system provided by the invention;

FIG. 2 is a block flow diagram of a method for monitoring a sector-shaped slope crack monitoring system provided by the invention;

FIG. 3 is a block flow diagram of crack width analysis provided by the present invention;

FIG. 4 is a block flow diagram of a ramp local inclination analysis provided by the present invention;

FIG. 5 is a flow chart of the analysis of the internal stress variation of the slope crack provided by the invention;

FIG. 6 is a block flow diagram of acoustic frequency analysis provided by the present invention.

Detailed Description

The invention will be further described with reference to the drawings and embodiments.

Referring to fig. 1, fig. 2, fig. 3, fig. 4, fig. 5 and fig. 6 in combination, fig. 1 is a block diagram of a fan-shaped slope crack monitoring system according to the present invention, fig. 2 is a block diagram of a monitoring method of the fan-shaped slope crack monitoring system according to the present invention, fig. 3 is a block diagram of crack width analysis according to the present invention, fig. 4 is a block diagram of slope local inclination analysis according to the present invention, fig. 5 is a block diagram of slope crack internal stress variation analysis according to the present invention, and fig. 6 is a block diagram of sound wave frequency analysis according to the present invention.

Example 1

In a specific implementation process, as shown in fig. 1, the invention provides a sector-shaped slope crack monitoring system and a monitoring method thereof.

The sector slope crack monitoring system provided by the invention comprises an ultrasonic detector, a sensor and a sensor, wherein the ultrasonic detector is used for generating and receiving required sound wave frequency, the ultrasonic detector comprises a transducer transmitting end and a transducer receiving end, the transducer transmitting end is perpendicular to a slope sector area, the transducer receiving end is positioned above the transducer transmitting end, and the transducer transmitting end and the transducer receiving end are positioned at the same vertical line, so that the reflected sound wave signals can be accurately received, and the sound wave interference from other directions can be reduced by keeping the vertical relation between the transmitting end and the receiving end;

The sensor network comprises a plurality of sensors arranged on the position of the slope sector area and used for collecting crack data in the sector area, wherein the crack data comprise crack opening width, local inclination degree of the slope and stress change in the crack;

The data acquisition unit is used for acquiring data of the sensing network and sonic frequency data of the ultrasonic detector, preprocessing the data, integrating various sensor interfaces, and taking charge of acquiring and storing the data, wherein the data preprocessing comprises the steps of cleaning the acquired data and removing noise and abnormal values;

the communication module is used for transmitting the data acquired by the data acquisition unit to the central processing platform, and can select wireless communication (such as LoRa, bluetooth, wi-Fi and the like) or wired communication (such as RS485, ethernet and the like), wherein the wireless communication is suitable for occasions with long distance and difficult wiring depending on the monitoring range and environmental conditions, and the wired communication is suitable for situations with short distance and convenient wiring;

The central processing platform is used for analyzing and processing the collected data, generating a report, and sending an alarm according to a preset threshold, wherein the alarm notification comprises sending the alarm notification to related personnel through a short message, a mail or an APP.

Further, the sensor network comprises a displacement sensor, a sensor module and a control module, wherein the displacement sensor is used for monitoring the change of the width of a crack opening, and the displacement sensor adopts a laser displacement sensor;

The inclination sensor is used for monitoring the local inclination degree of the slope, is an electronic inclinometer and measures the angle change of the slope through a built-in gyroscope or accelerometer;

the stress sensor is used for monitoring stress changes inside the crack, and the stress sensor can be a resistance strain gauge or a Fiber Bragg Grating (FBG) sensor.

Example two

In another aspect of the present invention, a method for monitoring a fan-shaped slope crack monitoring system is provided, and referring to fig. 2 to 6, the method includes the following steps:

S1, dividing the slope into a plurality of sectors according to geological features and crack trend of the slope, and uniformly distributing a sensing network and an ultrasonic detector in each sector, and carrying out fine monitoring on the specific geological features and crack trend of each sector, wherein the partition monitoring mode can capture local fine changes more than the whole monitoring mode;

S2, enabling a transducer transmitting end in the ultrasonic detector to be perpendicular to a slope sector area, enabling a transducer receiving end to be located above the transducer transmitting end, enabling the transducer transmitting end and the transducer receiving end to be located on the same vertical line, and enabling the sensing network and the ultrasonic detector to be comprehensively arranged in the sector, so that no dead angle is formed in monitoring of each area of the slope, and potential risks caused by the monitoring dead angle are avoided;

s3, collecting crack width, displacement and inclination angle data according to preset frequency by each sensor in the sensor network;

s4, transmitting the data of the sensing network and the ultrasonic detector to a data acquisition unit in a wireless or wired mode;

S5, preprocessing the data received by the data acquisition unit by the central processing platform, analyzing the width of the crack, the internal stress change of the slope crack, the local inclination degree of the slope and the sound wave frequency, and generating an analysis report;

s6, continuously monitoring the development trend of cracks;

And S7, when the crack development exceeds a preset threshold, triggering an alarm by the system.

Further, the crack width analysis includes the steps of:

s1, calculating a crack width change rate, namely calculating a crack width difference value between two adjacent time points, and calculating an average change rate;

S2, analyzing the crack expansion trend, namely analyzing the trend of crack width expansion by using a linear regression model;

S3, comparing the trend of crack width expansion with a preset safety threshold value;

And S4, early warning judgment, namely judging that potential risks exist when the crack width expansion trend exceeds a safety threshold value, and triggering early warning.

It should be noted that, the linear regression model is used to predict the variation trend of the crack, and assuming that the width of the crack at the time t is w (t), the following model is established:

w(t)=a+bt

wherein a and b are intercept and slope respectively, represent the rate of change of the crack width along with time, and are obtained by fitting time data so as to predict the future crack width;

Further, the analysis of the inclination degree of the slope part comprises the following steps:

s1, according to inclination angle data acquired by an inclination angle sensor, establishing a time sequence set y _t, and representing inclination angles of a slope at different times t;

S2, predicting the inclination degree of the slope local crack by adopting time sequence analysis:

(1-φ₁B-…-φ_pB^p)(1-B)^dy_t＝c+(1+θ₁B+…+θ_qB_q)∈_t

Wherein B is a backward operator, and E _t is a white noise process;

And S3, triggering an early warning mechanism when the inclination degree of the predicted slope local crack exceeds an early warning threshold value.

In one embodiment, the slope crack internal stress variation analysis comprises the steps of:

S1, establishing a stress state equation, wherein x _t-1＝αx_t+w_t, x _t is a stress value, alpha is a state transfer coefficient, and w _t is process noise;

S2, establishing a stress observation equation z _t＝x_t+v_t, wherein z _t is an observed stress value, and v _t is observation noise;

S3, predicting the stress state at the current moment:

Predicting a state of the current time based on the state estimate and the control input of the previous time;

s4, predicting covariance:

wherein Q _t is a process noise covariance matrix;

s5, calculating Kalman gain according to the prediction covariance and the observation matrix:

wherein R _t is an observed noise covariance matrix;

S6, updating state estimation according to the observed stress value and the Kalman gain:

S7, updating a covariance matrix of the state estimation:

P_t|t＝(I-K_tH_t)P_t|t-1＝(1-K_t)P_t|t-1

And S8, early warning judgment, namely triggering an early warning mechanism when the predicted stress value exceeds an early warning threshold value.

Further, at each time step, the state transition coefficient α, the process noise covariance matrix Q _t, and the observed noise covariance matrix R _t parameters are adjusted according to the prediction error.

Experiment one:

A stress sensor was placed inside a specific ramp crack, which collected stress data every 10 minutes, and collected one week as a historical dataset for subsequent analysis:

The stress data collected were as follows:

initializing parameters:

a state vector x _t＝[s_t, where s _t is the stress value at time t;

Initializing state estimation: i.e. the first observation;

An initial state covariance matrix, P _0|0 = 100;

A state transition matrix, F _t =1, representing that the change in stress values can be approximated as a first order autoregressive process;

Control input matrix B _t = 0, since there is no external control input;

A process noise covariance matrix, Q _t =0.01, representing the variance of the process noise;

an observation matrix H _t = 1, representing that the observation directly corresponds to the state;

An observation noise covariance matrix, wherein R _t = 1, represents the variance of the observation noise;

the prediction and update process is as follows:

Initial state

Taking the first data point as an example, assume t=1

Prediction state:

the expected covariance: P _1|0＝P_0|0+Q₀ = 100+0.01 = 100.01

Calculating Kalman gain:

updating the state estimation:

Update covariance matrix, P _1|1 = (1-0.9901) ×100.01≡0.9999

The updated state estimate and covariance matrix continue to be used to predict the state at the next point in time, and so on.

In one embodiment, the acoustic frequency analysis includes the steps of:

s1, decomposing signals, namely decomposing sound wave frequency signals to different scales by utilizing a wavelet basis function;

S2, extracting features, namely extracting the energy distribution and frequency component features of the signals on each scale;

S3, crack identification, namely judging whether cracks exist or not according to the change of the characteristics;

s4, quantifying the crack degree, namely quantifying the crack degree through the amplitude change of the features;

and S5, early warning judgment, namely triggering an early warning mechanism when the detected crack change degree exceeds an early warning threshold value.

Application:

Let sound wave signal x (t), multi-scale wavelet transform it using wavelet basis function ψ (t)

1. Wavelet transform-decomposing a signal into detail coefficients on different scales

Wherein a is a scale factor and b is a translation factor;

2. The wavelet transform is repeated over multiple scales:

W_x(a_i,b_i)for i=1,2,...,N and j=1,2,...,M

3. Extracting the energy distribution on each scale:

4. by comparing the energy distribution on different scales, the presence of cracks is identified:

ΔE=E_i+1-E_i

If delta E is greater than zero, a gap exists;

5. the extent of cracking is quantified by the extent of change in energy distribution:

A crack identification threshold deltae _th can be set based on the historical data;

setting different early warning levels according to the crack degree quantized value C;

And continuously monitoring the change of cracks in the pavement, and triggering early warning when delta E > delta E _th.

According to the comprehensive monitoring method, false alarm and missing alarm conditions possibly caused by a single monitoring means can be reduced. Through multi-source data fusion analysis, the actual condition and potential risk of the slope crack can be accurately judged.

From the above description of embodiments, it will be apparent to those skilled in the art that the embodiments may be implemented by means of software plus a general purpose hardware platform, or may be implemented by hardware. Based on such understanding, the foregoing technical solution may be embodied essentially or in a part contributing to the related art in the form of a software product, which may be stored in a computer readable storage medium, such as ROM/RAM, a magnetic disk, an optical disk, etc., including several instructions for causing a computer device (which may be a personal computer, a server, or a network device, etc.) to perform the method described in the respective embodiments or some parts of the embodiments.

While the fundamental and principal features of the invention and advantages of the invention have been shown and described, it will be apparent to those skilled in the art that the invention is not limited to the details of the foregoing exemplary embodiments, but may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. The present embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.

Furthermore, it should be understood that although the present disclosure describes embodiments, not every embodiment is provided with a separate embodiment, and that this description is provided for clarity only, and that the disclosure is not limited to the embodiments described in detail below, and that the embodiments described in the examples may be combined as appropriate to form other embodiments that will be apparent to those skilled in the art.

Claims (8)

1. The sector slope crack monitoring system is characterized by comprising an ultrasonic detector, a sensor and a sensor, wherein the ultrasonic detector is used for generating and receiving required sound wave frequency and comprises a transducer transmitting end and a transducer receiving end, the transducer transmitting end is perpendicular to a sector area of a slope, the transducer receiving end is positioned above the transducer transmitting end, and the transducer transmitting end and the transducer receiving end are positioned on the same vertical line;

The sensor network comprises a plurality of sensors arranged on the position of the slope sector area and used for collecting crack data in the sector area, wherein the crack data comprise crack opening width, local inclination degree of the slope and stress change in the crack;

the data acquisition unit is used for acquiring data of the sensing network and sonic frequency data of the ultrasonic detector and preprocessing the data;

The communication module is used for transmitting the data acquired by the data acquisition unit to the central processing platform;

and the central processing platform is used for analyzing and processing the collected crack width, the change of the internal stress of the slope crack, the inclination degree of the slope part and the sound wave frequency, generating a report and sending an alarm notification according to a preset threshold value.

2. The fanning ramp crack monitoring system of claim 1 wherein the sensing network includes a displacement sensor for monitoring changes in crack opening width;

the inclination sensor is used for monitoring the inclination degree of a local slope;

And the stress sensor is used for monitoring the stress change in the crack.

3. The fanning ramp crack monitoring system of claim 1 wherein the alert notification includes sending an alert notification to an associated person via a short message, mail, or APP.

4. A monitoring method applied to the fan-type slope crack monitoring system of any one of claims 1 to 3, characterized in that the method comprises the steps of:

s1, dividing a slope into a plurality of sectors according to geological characteristics and crack trend of the slope, and uniformly distributing a sensing network and an ultrasonic detector in each sector;

S2, enabling a transducer transmitting end in the ultrasonic detector to be perpendicular to the slope sector area, enabling a transducer receiving end to be located above the transducer transmitting end, and enabling the transducer transmitting end and the transducer receiving end to be located on the same perpendicular line for placement;

s3, collecting crack width, displacement and inclination angle data according to preset frequency by each sensor in the sensor network;

s4, transmitting the data of the sensing network and the ultrasonic detector to a data acquisition unit in a wireless or wired mode;

S5, preprocessing the data received by the data acquisition unit by the central processing platform, analyzing the width of the crack, the internal stress change of the slope crack, the local inclination degree of the slope and the sound wave frequency, and generating an analysis report;

s6, continuously monitoring the development trend of cracks;

And S7, when the crack development exceeds a preset threshold, triggering an alarm by the system.

5. The method of monitoring a sector-shaped slope crack monitoring system of claim 4, wherein the crack width analysis comprises the steps of:

s1, calculating a crack width change rate, namely calculating a crack width difference value between two adjacent time points, and calculating an average change rate;

S2, analyzing the crack expansion trend, namely analyzing the trend of crack width expansion by using a linear regression model;

S3, comparing the trend of crack width expansion with a preset safety threshold value;

And S4, early warning judgment, namely judging that potential risks exist when the crack width expansion trend exceeds a safety threshold value, and triggering early warning.

6. The method of claim 5, wherein the slope local inclination analysis comprises the steps of:

S1, according to inclination angle data acquired by an inclination angle sensor, a time sequence set is established, and inclination angles of a slope at different times are represented;

s2, predicting the inclination degree of the local crack of the slope by adopting time sequence analysis;

And S3, triggering an early warning mechanism when the inclination degree of the predicted slope local crack exceeds an early warning threshold value.

7. The method of monitoring a sector-shaped slope crack monitoring system of claim 6, wherein the slope crack internal stress variation analysis comprises the steps of:

S1, establishing a stress state equation;

s2, establishing a stress observation equation;

s3, predicting the stress state at the current moment, namely predicting the state at the current moment based on the state estimation and control input of the last moment;

s4, predicting covariance:

S5, calculating Kalman gain according to the prediction covariance and the observation matrix;

s6, updating state estimation according to the observed stress value and the Kalman gain;

S7, updating a covariance matrix of the state estimation;

And S8, early warning judgment, namely triggering an early warning mechanism when the predicted stress value exceeds an early warning threshold value.

8. The method of monitoring a sector-shaped slope crack monitoring system of claim 7, wherein the acoustic frequency analysis comprises the steps of:

s1, decomposing signals, namely decomposing sound wave frequency signals to different scales by utilizing a wavelet basis function;

S2, extracting features, namely extracting the energy distribution and frequency component features of the signals on each scale;

S3, crack identification, namely judging whether cracks exist or not according to the change of the characteristics;

s4, quantifying the crack degree, namely quantifying the crack degree through the amplitude change of the features;

and S5, early warning judgment, namely triggering an early warning mechanism when the detected crack change degree exceeds an early warning threshold value.