CN-122022009-A - Dynamic prediction method for surface horizontal movement caused by underground mining of coal mine based on side pressure coefficient

CN122022009ACN 122022009 ACN122022009 ACN 122022009ACN-122022009-A

Abstract

The invention relates to the technical field of underground mining and discloses a dynamic prediction method for surface horizontal movement caused by underground mining of a coal mine based on side pressure coefficient, comprising the following steps of S101, generating a side pressure coefficient time sequence curve and a goaf equivalent stiffness time sequence curve; step S102, obtaining dynamic horizontal movement coefficients, step S103, establishing a prediction model of the horizontal movement of the earth surface, step S104, positioning a horizontal movement curvature turning window, step S105, generating a reparameterized time axis, and step S106, generating an earth surface horizontal movement distribution map. According to the invention, through the time sequence evolution of the dynamic quantized side pressure coefficient and the goaf equivalent stiffness, the horizontal movement curvature overturning characteristic generated by coupling the dynamic quantized side pressure coefficient and the goaf equivalent stiffness is captured, and the finally output dynamic horizontal movement quantity distribution diagram can show a time-space evolution rule, so that technical support is provided for engineering decisions such as mining area building protection, water body protection and the like.

Inventors

ZHANG JIAWEI
DONG XIANGLIN
MA JUN
WEI XIANGPING
ZHANG YANHAI
ZHANG CHENG
WANG WEITING
ZHANG JIERU
LIU YANLIANG

Assignees

淮北矿业股份有限公司

Dates

Publication Date: 20260512
Application Date: 20251228

Claims (10)

1. The dynamic prediction method for the horizontal movement of the ground surface caused by underground mining of the coal mine based on the side pressure coefficient is characterized by comprising the following steps: s101, collecting initial ground stress state and goaf filling medium parameters, and respectively generating a lateral pressure coefficient time sequence curve and a goaf equivalent stiffness time sequence curve; step S102, using a side pressure coefficient time sequence curve as an amplification factor, using a goaf equivalent stiffness time sequence curve as an inhibition factor, and performing time-varying correction on an initial horizontal movement coefficient to obtain a dynamic horizontal movement coefficient; Step S103, coupling the dynamic horizontal movement coefficient with a space direction influence kernel and a reference time function, and establishing a prediction model of the ground surface horizontal movement quantity; Step S104, solving a second derivative related to time for the prediction model, identifying a period when the sign of the second derivative is reversed, and positioning a horizontal movement curvature turning window on a time domain; Step S105, extracting second derivative composition items in a horizontal movement curvature turning window to construct time stretching weights, and mapping an original time axis by using the time stretching weights to generate a re-parameterized time axis; And S106, substituting the re-parameterized time axis into the prediction model to replace the reference time axis, calculating the horizontal movement vector of each point of the earth surface under the re-parameterized time, and synthesizing and outputting an earth surface horizontal movement quantity distribution map.
2. The dynamic prediction method for the horizontal movement of the ground surface caused by underground mining of a coal mine based on the side pressure coefficient according to claim 1, wherein the initial side pressure coefficient is calculated according to the effective internal friction angle; calculating a vertical total stress increment according to the average volume weight of the overburden rock and the equivalent unloading thickness, and calculating a horizontal total stress increment according to the poisson ratio and the vertical total stress increment; Summing the initial horizontal total stress and the horizontal total stress increment to obtain instantaneous horizontal total stress, summing the initial vertical total stress and the vertical total stress increment to obtain instantaneous vertical total stress, calculating the ratio of the instantaneous horizontal total stress to the instantaneous vertical total stress, and generating a side pressure coefficient time sequence curve; Calculating the unconfined compressive strength changing with time according to the unconfined compressive strength limit value and the age strength increase rate constant, and calculating the goaf equivalent stiffness according to the conversion coefficient and the unconfined compressive strength to generate a goaf equivalent stiffness time sequence curve.
3. The method for dynamically predicting the horizontal movement of the ground surface caused by underground mining of the coal mine based on the side pressure coefficient according to claim 1 is characterized by calculating the difference value between a time sequence curve of the side pressure coefficient and an initial side pressure coefficient, multiplying the difference value by the side pressure sensitivity coefficient, summing the multiplied value with a unit reference value to generate an amplification factor, calculating the ratio of the equivalent stiffness time sequence curve of the goaf to the reference modulus, multiplying the multiplied value by the stiffness sensitivity coefficient, summing the multiplied value with the unit reference value, taking the reciprocal of the summation result to generate an inhibition factor, and multiplying the initial horizontal movement coefficient, the amplification factor and the inhibition factor to obtain the dynamic horizontal movement coefficient.
4. The method for dynamically predicting the horizontal movement of the ground surface caused by underground mining of the coal mine based on the side pressure coefficient according to claim 1, wherein the equivalent distance between an observation point and the center of a mined unit is calculated, and an exponential type influence function is constructed according to the influence radius and the equivalent distance; Calculating the projection quantity of the plane coordinate difference in the trend direction and the trend direction, calculating the ratio of the projection quantity to the square of the influence radius, taking a negative sign, multiplying the ratio by the influence function, accumulating and summing the sampled units, and respectively generating a trend direction influence core and a trend direction influence core.
5. The method for dynamically predicting the horizontal movement of the ground surface caused by underground mining of a coal mine based on a side pressure coefficient according to claim 4, wherein the product of a time variable and a time influence parameter is calculated, the shape parameter of the product is calculated to be the power of the power, the negative exponent is obtained for the power result, the difference value between a unit reference value and the negative exponent result is calculated, and a reference time function is generated; Multiplying the dynamic horizontal movement coefficient, the trend direction influence kernel and the reference time function to obtain the trend direction earth surface horizontal movement; and multiplying the dynamic horizontal movement coefficient and the trend direction influence kernel by a reference time function to obtain the trend direction earth surface horizontal movement quantity.
6. The method for dynamically predicting the horizontal movement of the ground surface caused by underground mining of a coal mine based on the side pressure coefficient according to claim 1, wherein a first derivative and a second derivative with respect to time are respectively obtained for the dynamic horizontal movement coefficient and a reference time function; multiplying the second derivative of the dynamic horizontal movement coefficient by a reference time function to obtain a first term, multiplying the first derivative of the dynamic horizontal movement coefficient by the first derivative of the reference time function and expanding twice to obtain a second term, multiplying the dynamic horizontal movement coefficient by the second derivative of the reference time function to obtain a third term, summing the first term, the second term and the third term, and multiplying the first term, the second term and the third term by a trend direction influencing kernel and a trend direction influencing kernel respectively to generate a trend direction second derivative and a trend direction second derivative.
7. The method for dynamically predicting the horizontal movement of the ground surface caused by underground mining of the coal mine based on the side pressure coefficient according to claim 6, wherein a moment point when the second derivative of the trend direction is equal to zero is calculated, whether the product of the second derivatives in the vicinity of the moment point is smaller than zero is judged, and when the product is smaller than zero, the moment point is judged to be the symbol inversion moment; Selecting a front zero point moment and a rear zero point moment which are adjacent to the current symbol reversal moment in a time sequence of the symbol reversal moment, and determining a time period between the front zero point moment and the rear zero point moment as a horizontal movement curvature turning window in the trend direction; And executing the same operation on the second derivative of the trend direction, determining a horizontal movement curvature turnover window of the trend direction, and combining the horizontal movement curvature turnover windows of the trend direction and the trend direction into a time domain window set.
8. The method for dynamically predicting the surface horizontal movement caused by underground coal mining based on side pressure coefficients according to claim 1, wherein the first derivative of the dynamic horizontal movement coefficient, the second derivative of the dynamic horizontal movement coefficient, the first derivative of the reference time function and the second derivative of the reference time function are calculated respectively; calculating the product of the second derivative of the dynamic horizontal movement coefficient and the reference time function to generate a first intermediate term; calculating the product of the first derivative of the dynamic horizontal movement coefficient and the first derivative of the reference time function, and expanding the product by two times to generate a second intermediate term; the absolute value of the first intermediate item, the absolute value of the second intermediate item and the absolute value of the third intermediate item are calculated, and the three absolute values are summed to be used as denominator items.
9. The dynamic prediction method for the horizontal movement of the ground surface caused by underground mining of the coal mine based on the side pressure coefficient according to claim 8, wherein the ratio of a molecular term to a denominator term is calculated, and whether the current moment is located in a time domain window set is judged; when the current moment is positioned in the time domain window set, calculating the sum of the unit reference value and the continuous product of the time stretching intensity coefficient and the ratio to generate a time stretching weight; when the current moment is not located in the time domain window set, taking the unit reference value as a time expansion weight; And performing fixed integral calculation on the time expansion weight in the interval from the zero time to the current time to generate a re-parameterized time axis.
10. The dynamic prediction method for the underground mining induced surface horizontal movement of the coal mine based on the side pressure coefficient according to claim 1, wherein a re-parameterized time axis is substituted as an independent variable into a reference time function to generate a re-parameterized time term; multiplying the dynamic horizontal movement coefficient, the trend direction influence kernel and the re-parameterized time term to generate a re-parameterized trend movement component; Multiplying the dynamic horizontal movement coefficient, the trend direction influence kernel and the re-parameterized time term to generate a re-parameterized trend movement component; traversing the surface discrete grid set and the time sampling set, and extracting a heavy parameterization trend moving component and a heavy parameterization trend moving component of the current grid point and the current time; Calculating the square of the heavy parameterized trend moving component and the square of the heavy parameterized trend moving component, summing the two square results, and performing open square operation to obtain a ground surface horizontal moving vector module; taking the heavy parameterized trend movement component as a first variable and the heavy parameterized trend movement component as a second variable, and executing binary arctangent operation to obtain a horizontal movement azimuth angle of the earth surface; The earth surface horizontal movement vector model is combined with the earth surface horizontal movement azimuth to generate an earth surface horizontal movement amount distribution map.

Description

Dynamic prediction method for surface horizontal movement caused by underground mining of coal mine based on side pressure coefficient Technical Field The invention relates to the technical field of underground mining, in particular to a dynamic prediction method for surface horizontal movement caused by underground mining of a coal mine based on side pressure coefficients. Background Underground mining of a coal mine can cause horizontal movement of the earth surface, and the phenomenon directly affects safety and stability of structures, railways and water bodies around a mining area, so that accurate dynamic prediction of the horizontal movement of the earth surface is one of key technologies of coal mine safety mining. At present, the mainstream in the industry adopts a probability integration method and Knothe types of time functions to predict, and the method realizes the calculation of the earth surface movement amount by constructing a coupling model of a space influence core and a time evolution function. However, the prior art has significant drawbacks, which lead to a systematic deviation in prediction accuracy, particularly in peak time judgment. On one hand, the traditional method regards the lateral pressure coefficient as a fixed constant, ignores the horizontal stress dynamic evolution caused by the vertical stress unloading in the mining process, directly amplifies or weakens the horizontal movement capacity of the surface water by the time sequence change of the lateral pressure coefficient, and the fixed parameter cannot reflect the dynamic driving effect. On the other hand, the strength of the goaf filling body increases along with the age, the caving rock mass is compacted along with time, so that the equivalent rigidity of the goaf is dynamically improved, and the dynamic inhibition effect of the goaf filling body on horizontal movement is difficult to embody by adopting fixed rigidity parameters in the traditional method. More importantly, the expansion effect of the lateral pressure coefficient and the suppression effect of the equivalent stiffness of the goaf have asynchronism on the time scale, and the two are coupled to enable the second derivative of horizontal movement to have curvature turning characteristics with reversed signs, so that the traditional single time function cannot adapt to the dynamic change, and further the misjudgment of a system at the moment of moving peak values is caused. The problems make the existing method difficult to accurately describe the dynamic evolution rule of the horizontal movement of the earth surface, and the requirements of high-precision prediction in engineering practice are difficult to meet. Disclosure of Invention The invention provides a dynamic prediction method for the horizontal movement of the ground surface caused by underground mining of a coal mine based on side pressure coefficients, which solves the technical problems in the background technology. The invention provides a dynamic prediction method for the horizontal movement of the ground surface caused by underground mining of a coal mine based on side pressure coefficient, which comprises the following steps: s101, collecting initial ground stress state and goaf filling medium parameters, and respectively generating a lateral pressure coefficient time sequence curve and a goaf equivalent stiffness time sequence curve; step S102, using a side pressure coefficient time sequence curve as an amplification factor, using a goaf equivalent stiffness time sequence curve as an inhibition factor, and performing time-varying correction on an initial horizontal movement coefficient to obtain a dynamic horizontal movement coefficient; Step S103, coupling the dynamic horizontal movement coefficient with a space direction influence kernel and a reference time function, and establishing a prediction model of the ground surface horizontal movement quantity; Step S104, solving a second derivative related to time for the prediction model, identifying a period when the sign of the second derivative is reversed, and positioning a horizontal movement curvature turning window on a time domain; Step S105, extracting second derivative composition items in a horizontal movement curvature turning window to construct time stretching weights, and mapping an original time axis by using the time stretching weights to generate a re-parameterized time axis; And S106, substituting the re-parameterized time axis into the prediction model to replace the reference time axis, calculating the horizontal movement vector of each point of the earth surface under the re-parameterized time, and synthesizing and outputting an earth surface horizontal movement quantity distribution map. The method has the advantages that horizontal movement curvature overturning characteristics generated by coupling of the dynamic quantification lateral pressure coefficient and the goaf are captured through time sequence evolution of