Accurate displacement estimation method for dam deformation monitoring

Abstract

The invention provides an accurate displacement estimation method for dam deformation monitoring. Firstly, temperature data of a dam crest observation pillar and temperature data of dam bottom bedrock are preprocessed; integrating the thermal stress of the observation pillar in the horizontal direction to obtain thermal expansion horizontal displacement of the observation pillar relative to the line hanging point; integrating the thermal stress of the bedrock in the horizontal direction to obtain the thermal expansion horizontal displacement of the reference anchoring point relative to the bedrock; estimating the dam horizontal displacement caused by the water level pressure by using the water level change data; the thermal expansion horizontal displacement of the observation pillar relative to the line hanging point, the thermal expansion horizontal displacement of the reference anchoring point relative to the bedrock, the dam horizontal displacement caused by the water level pressure intensity and the GNSS station horizontal displacement are added to estimate the refined horizontal total displacement of the dam; estimating the total horizontal displacement of the dam by using a positive and negative drooping device; and comparing and verifying the dam horizontal displacement estimated only by using the positive and negative vertical method with the refined dam horizontal displacement. According to the invention, the horizontal displacement observation precision of dam deformation monitoring can be improved.

Description

Technical Field

[0001] The invention relates to the field of deformation monitoring, and in particular to an accurate displacement estimation method for dam deformation monitoring. Background Art

[0002] The positive inverted method is a common and effective means to monitor the horizontal displacement of the dam. Its main purpose is to measure the deformation of the building in the longitudinal direction (along the axis direction) and the transverse direction (perpendicular to the axis direction). By installing the positive inverted device at the key positions of the dam (such as the benchmark points on the left and right banks and the working base points in the corridor), the offset along the axis direction of the dam and perpendicular to the axis can be observed, thereby obtaining the horizontal displacement data of the dam. This deformation monitoring technology has been widely used in large-scale water conservancy and hydropower projects such as the Three Gorges Dam on the Yangtze River, the Gezhouba Dam and the Qingjiang Geheyan Dam.

[0003] The monitoring history of the forward and reverse plumbing method is long. Initially, traditional contact methods (such as manual reading of plumb line coordinate meters) were used for monitoring. Now, it has developed into non-contact telemetry technology, including capacitive sensing, electromagnetic induction, and photoelectric sensing. However, the results obtained by the forward and reverse plumbing method still have large errors. Based on this, an accurate displacement estimation method for dam deformation monitoring is proposed. Summary of the invention

[0004] In view of the above problems, the present invention proposes an accurate displacement estimation method for dam deformation monitoring, comprising the following steps: Step 1: Preprocess the temperature data of the dam top observation pier and the dam bottom bedrock; Step 2: Integrate the thermal stress in the horizontal direction of the observation pier to obtain the thermal expansion horizontal displacement of the observation pier relative to the hanging point; Step 3: Integrate the thermal stress in the horizontal direction of the bedrock to obtain the horizontal displacement of the thermal expansion of the reference anchor point relative to the bedrock; Step 4: Use the water level change data to estimate the horizontal displacement of the dam caused by the water level pressure; Step 5: Estimate the refined total horizontal displacement of the dam by adding the thermal expansion horizontal displacement of the observation pier relative to the hanging point, the thermal expansion horizontal displacement of the benchmark anchor point relative to the bedrock, the horizontal displacement of the dam caused by the water level pressure, and the horizontal displacement of the GNSS station; Step 6: Estimate the total horizontal displacement of the dam using the positive and negative plummeting device; Step 7: Compare and verify the dam horizontal displacement estimated in step 6 with the refined dam horizontal displacement estimated in step 5.

[0005] Preferably, the specific processing process of step 1 is to firstly statistically analyze the collected temperature data of the dam observation pier and bedrock, identify the temperature data that needs to be analyzed by spectrum, and then use Fourier transform to pre-process the temperature data that needs to be analyzed by spectrum, extract the main frequency component, and thus convert the temperature data from the original time domain to the frequency domain, which is specifically expressed as: R = FFT(T); Where T is the time series of surface temperature; R is the spectrum result after discrete Fourier transform (FFT).

[0006] Preferably, the specific steps of integrating the horizontal thermal stress of the observation pier in step 2 to obtain the horizontal thermal stress of the observation pier relative to the hanging point are: The frequency domain temperature time series obtained in step 1 and the shallow surface temperature field at different depths represented by standing waves are specifically expressed as: ; ; ; Where x and y are the horizontal position and depth respectively, t is the time of the current temperature, T ω , They represent the amplitude and phase at different angular frequencies ω calculated according to the real surface temperature change, λ is the wavelength of the surface temperature standing wave, and χ is the thermal diffusion coefficient; The shallow surface temperature field at different depths is used to estimate the horizontal thermal stress of the observation pier and bedrock caused by temperature, which is specifically expressed as: ; ; Where v is Poisson's ratio and β is the coefficient of thermal expansion.

[0007] Preferably, in step 2, the horizontal thermal stress at the observation pier is integrated to obtain the horizontal displacement of the observation pier relative to the hanging line point. It is expressed as: ; in, is the Poisson's ratio of the observation pier; is the thermal expansion coefficient of the observation pier; is the thermal diffusion coefficient; To observe the horizontal position of the pier; To observe the depth of the pier below the ground surface; 2π / ; is the wavelength of the standing wave of the surface temperature at the dam top.

[0008] Preferably, the horizontal thermal stress below the surface of the anchor block in step 3 is integrated to obtain the horizontal displacement of the reference anchor point relative to the bedrock. , expressed as: ; in, is the Poisson's ratio of the bedrock; is the thermal expansion coefficient of bedrock; is the depth of the anchor block below the ground surface; 2π / ; is the wavelength of the standing wave of the surface temperature at the bottom of the dam.

[0009] Preferably, the horizontal displacement of the dam caused by the water level pressure in step 4 can be expressed as: ; in, is the water level in front of the dam, is the unit length of the line load in the elastic half-space model, is the Poisson's ratio of the dam, is the shear modulus, is the band half width, is the dam far-field rate offset correction coefficient.

[0010] Preferably, in step 5, the refined total horizontal displacement of the dam is estimated by adding the thermal expansion horizontal displacement of the observation pier relative to the hanging point, the thermal expansion horizontal displacement of the reference anchor point relative to the bedrock, the horizontal displacement of the dam caused by the water level pressure, and the horizontal displacement of the GNSS station, which can be specifically expressed as: ; in, It is the horizontal displacement deformation observation data measured by the GNSS station.

[0011] Preferably, the total horizontal displacement of the dam estimated by the positive inversion device in step 6 can be expressed as: ; in, It is the horizontal displacement of the positive hammer relative to the hanging line point, which can be directly obtained by reading the vertical coordinate measuring machine; It is the horizontal displacement of the inverted part relative to the reference anchor point and can be obtained by directly reading the vertical coordinate measuring machine.

[0012] Preferably, the total horizontal displacement of the dam estimated by the positive inversion device in step 6 is The refined total horizontal displacement of the dam estimated in step 5 by adding the horizontal displacement of the observation pier relative to the hanging point due to thermal expansion, the horizontal displacement of the benchmark anchor point relative to the bedrock due to thermal expansion, the horizontal displacement of the dam caused by water level pressure, and the horizontal displacement of the GNSS station Perform comparative verification.

[0013] The present invention has the following beneficial effects: The present invention combines the thermal expansion horizontal displacement estimation theory with the forward and reverse sag deformation monitoring displacement estimation method, taking into account the influence of temperature changes on the horizontal displacement of the dam. It is more rigorous in theory and can improve the horizontal displacement observation accuracy of dam deformation monitoring. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 This is a flow chart of displacement estimation of the present invention; Figure 2 This is a schematic diagram of the dam's forward and inverted method. DETAILED DESCRIPTION

[0015] The present invention will be further described below in conjunction with the accompanying drawings and embodiments: See also Figure 1 to Figure 2 , an accurate displacement estimation method for dam deformation monitoring, comprising the following steps: Step 1: Preprocess the temperature data of the dam top observation pier and the dam bottom bedrock; Step 2: Integrate the thermal stress in the horizontal direction of the observation pier to obtain the thermal expansion horizontal displacement of the observation pier relative to the hanging point; Step 3: Integrate the thermal stress in the horizontal direction of the bedrock to obtain the horizontal displacement of the thermal expansion of the reference anchor point relative to the bedrock; Step 4: Use the water level change data to estimate the horizontal displacement of the dam caused by the water level pressure; Step 5: Estimate the refined total horizontal displacement of the dam by adding the thermal expansion horizontal displacement of the observation pier relative to the hanging point, the thermal expansion horizontal displacement of the benchmark anchor point relative to the bedrock, the horizontal displacement of the dam caused by the water level pressure, and the horizontal displacement of the GNSS station; Step 6: Estimate the total horizontal displacement of the dam using the positive and negative plummeting device; Step 7: Compare and verify the dam horizontal displacement estimated in step 6 with the refined dam horizontal displacement estimated in step 5.

[0016] Preferably, the specific processing process of step 1 is to firstly statistically analyze the collected temperature data of the dam observation pier and bedrock, identify the temperature data that needs to be analyzed by spectrum, and then use Fourier transform to pre-process the temperature data that needs to be analyzed by spectrum, extract the main frequency component, and thus convert the temperature data from the original time domain to the frequency domain, which is specifically expressed as: R = FFT(T); Where T is the time series of surface temperature; R is the spectrum result after discrete Fourier transform (FFT).

[0017] Preferably, the specific steps of integrating the horizontal thermal stress of the observation pier in step 2 to obtain the horizontal thermal stress of the observation pier relative to the hanging point are: The frequency domain temperature time series obtained in step 1 and the shallow surface temperature field at different depths represented by standing waves are specifically expressed as: ; ; ; Where x and y are the horizontal position and depth respectively, t is the time of the current temperature, T ω , They represent the amplitude and phase at different angular frequencies ω calculated according to the real surface temperature change, λ is the wavelength of the surface temperature standing wave, and χ is the thermal diffusion coefficient; The shallow surface temperature field at different depths is used to estimate the horizontal thermal stress of the observation pier and bedrock caused by temperature, which is specifically expressed as: ; ; Where v is Poisson's ratio and β is the coefficient of thermal expansion.

[0018] Preferably, in step 2, the horizontal thermal stress at the observation pier is integrated to obtain the horizontal displacement of the observation pier relative to the hanging line point. It is expressed as: ; in, is the Poisson's ratio of the observation pier; is the thermal expansion coefficient of the observation pier; is the thermal diffusion coefficient; To observe the horizontal position of the pier; To observe the depth of the pier below the ground surface; 2π / ; is the wavelength of the standing wave of the surface temperature at the dam top.

[0019] Preferably, the horizontal thermal stress below the surface of the anchor block in step 3 is integrated to obtain the horizontal displacement of the reference anchor point relative to the bedrock. , expressed as: ; in, is the Poisson's ratio of the bedrock; is the thermal expansion coefficient of bedrock; is the depth of the anchor block below the ground surface; 2π / ; is the wavelength of the standing wave of the surface temperature at the bottom of the dam.

[0020] Preferably, the horizontal displacement of the dam caused by the water level pressure in step 4 can be expressed as: ; in, is the water level in front of the dam, is the unit length of the line load in the elastic half-space model, is the Poisson's ratio of the dam, is the shear modulus, is the band half width, is the dam far-field rate offset correction coefficient.

[0021] Preferably, in step 5, the refined total horizontal displacement of the dam is estimated by adding the thermal expansion horizontal displacement of the observation pier relative to the hanging point, the thermal expansion horizontal displacement of the reference anchor point relative to the bedrock, the horizontal displacement of the dam caused by the water level pressure, and the horizontal displacement of the GNSS station, which can be specifically expressed as: ; in, It is the horizontal displacement deformation observation data measured by the GNSS station.

[0022] Preferably, the total horizontal displacement of the dam estimated by the positive inversion device in step 6 can be expressed as: ; in, It is the horizontal displacement of the positive hammer relative to the hanging line point, which can be directly obtained by reading the vertical coordinate measuring machine; It is the horizontal displacement of the inverted part relative to the reference anchor point and can be obtained by directly reading the vertical coordinate measuring machine.

[0023] Preferably, the total horizontal displacement of the dam estimated by the positive inversion device in step 6 is The refined total horizontal displacement of the dam estimated in step 5 by adding the horizontal displacement of the observation pier relative to the hanging point due to thermal expansion, the horizontal displacement of the benchmark anchor point relative to the bedrock due to thermal expansion, the horizontal displacement of the dam caused by water level pressure, and the horizontal displacement of the GNSS station Perform comparative verification.

[0024] The above embodiments are only preferred technical solutions of the present invention and should not be regarded as limiting the present invention. The protection scope of the present invention shall be the technical solutions recorded in the claims, including equivalent replacement solutions of the technical features in the technical solutions recorded in the claims. That is, equivalent replacement improvements within this scope are also within the protection scope of the present invention.

Claims

1. A precise displacement estimation method for dam deformation monitoring, characterized in that: The following steps are involved: Step 1: Preprocess the temperature data of the dam top observation pier and the dam bottom bedrock to obtain the frequency domain temperature time series; Step 2: Integrate the thermal stress in the horizontal direction of the observation pier to obtain the thermal expansion horizontal displacement of the observation pier relative to the hanging point; Step 3: Integrate the thermal stress in the horizontal direction of the bedrock to obtain the horizontal displacement of the thermal expansion of the reference anchor point relative to the bedrock; Step 4: Use the water level change data to estimate the horizontal displacement of the dam caused by the water level pressure; Step 5: Estimate the refined total horizontal displacement of the dam by adding the thermal expansion horizontal displacement of the observation pier relative to the hanging point, the thermal expansion horizontal displacement of the benchmark anchor point relative to the bedrock, the horizontal displacement of the dam caused by the water level pressure, and the horizontal displacement of the GNSS station; Step 6: Estimate the total horizontal displacement of the dam using the positive and negative sag device; Step 7: Compare and verify the dam horizontal displacement estimated in step 6 with the refined dam horizontal displacement estimated in step 5.

2. The accurate displacement estimation method for dam deformation monitoring according to claim 1 is characterized by: The specific processing process of step 1 is to first statistically analyze the collected temperature data of the dam observation pier and bedrock, identify the temperature data that needs to be analyzed by spectrum, and then use Fourier transform to pre-process the temperature data that needs to be analyzed by spectrum, extract the main frequency component, and convert the temperature data from the original time domain to the frequency domain, which is specifically expressed as: R = FFT(T); Where T is the time series of surface temperature; R is the spectrum result after discrete Fourier transform (FFT).

3. The accurate displacement estimation method for dam deformation monitoring according to claim 1 is characterized by: The specific steps of integrating the horizontal thermal stress of the observation pier in step 2 to obtain the horizontal thermal stress of the observation pier relative to the hanging line point are: The frequency domain temperature time series obtained in step 1 and the shallow surface temperature field at different depths represented by standing waves are specifically expressed as: ； ； ； Where x and y are the horizontal position and depth respectively, t is the time of the current temperature, T ω , They represent the amplitude and phase at different angular frequencies ω calculated according to the real surface temperature change, λ is the wavelength of the surface temperature standing wave, and χ is the thermal diffusion coefficient; The shallow surface temperature field at different depths is used to estimate the horizontal thermal stress of the observation pier and bedrock caused by temperature, which is specifically expressed as: ； ； Where v is Poisson's ratio and β is the coefficient of thermal expansion.

4. The accurate displacement estimation method for dam deformation monitoring according to claim 3 is characterized by: In step 2, the horizontal thermal stress at the observation pier is integrated to obtain the horizontal displacement of the observation pier relative to the hanging line point. It is expressed as: ； in, is the Poisson's ratio of the observation pier; is the thermal expansion coefficient of the observation pier; is the thermal diffusion coefficient; To observe the horizontal position of the pier; To observe the depth below the ground surface of the pier; 2π / ； is the wavelength of the standing wave of the surface temperature at the dam top.

5. The accurate displacement estimation method for dam deformation monitoring according to claim 1 is characterized by: In step 3, the horizontal thermal stress below the ground surface of the anchor block is integrated to obtain the horizontal displacement of the reference anchor point relative to the bedrock. , expressed as: ； in, is the Poisson's ratio of the bedrock; is the thermal expansion coefficient of bedrock; is the depth of the anchor block below the ground surface; 2π / ； is the wavelength of the standing wave of the surface temperature at the bottom of the dam.

6. The accurate displacement estimation method for dam deformation monitoring according to claim 1 is characterized by: The horizontal displacement of the dam caused by the water level pressure in step 4 can be expressed as: ； in, is the water level in front of the dam, is the unit length of the line load in the elastic half-space model, is the Poisson's ratio of the dam, is the shear modulus, is the band half width, is the dam far-field rate offset correction coefficient.

7. The accurate displacement estimation method for dam deformation monitoring according to claim 1 is characterized by: In step 5, the refined total horizontal displacement of the dam is estimated by adding the thermal expansion horizontal displacement of the observation pier relative to the hanging point, the thermal expansion horizontal displacement of the reference anchor point relative to the bedrock, the horizontal displacement of the dam caused by the water level pressure, and the horizontal displacement of the GNSS station. Specifically, it can be expressed as: ； in, It is the horizontal displacement deformation observation data measured by the GNSS station.

8. The accurate displacement estimation method for dam deformation monitoring according to claim 1 is characterized in that: The total horizontal displacement of the dam estimated by the positive inverted device in step 6 can be expressed as: ； in, It is the horizontal displacement of the positive hammer relative to the hanging line point, which can be directly obtained by reading the vertical coordinate measuring machine; It is the horizontal displacement of the inverted part relative to the reference anchor point and can be obtained by directly reading the vertical coordinate measuring machine.

9. The accurate displacement estimation method for dam deformation monitoring according to claim 1 is characterized in that: The total horizontal displacement of the dam estimated by the positive inverted device in step 6 The refined total horizontal displacement of the dam estimated in step 5 by adding the horizontal displacement of the observation pier relative to the hanging point due to thermal expansion, the horizontal displacement of the benchmark anchor point relative to the bedrock due to thermal expansion, the horizontal displacement of the dam caused by water level pressure, and the horizontal displacement of the GNSS station Perform comparative verification.

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