Disclosure of Invention
In order to solve the technical problem, the invention provides a digital data processing method for reinforcing stress strain of a broken soft surrounding rock tunnel face, which comprises the following steps:
s100, establishing a three-dimensional model of a broken weak surrounding rock face according to project design, and carrying out virtual finite element segmentation to form a three-dimensional finite element model of the face;
s200, detecting and storing basic data of a surrounding rock face in a section excavation process;
s300, stress-strain analysis is carried out on the face by combining the basic data and the three-dimensional finite element model, and the required bonding strength of the surrounding rock face is predicted by adopting a preset algorithm;
s400, selecting a surrounding rock face reinforcing measure according to the bonding required strength, and introducing the reinforcing measure into a three-dimensional finite element model for effectiveness analysis.
Optionally, in step S100, the three-dimensional finite element model is described by using the following object elements:
in the above formula, the first and second carbon atoms are,
representing an object element;
a presentation evaluation unit;
to indicate the evaluation unit
Item influencing factors;
is shown as
A magnitude domain of term influence factor number quantization;
representing the number of influencing factors;
determining grade division of the stability of the surrounding rock, and calculating the material elements according to the following formula
Degree of association with the surrounding rock stability grade H:
in the above formula, the first and second carbon atoms are,
representing an object
Correlation degree with surrounding rock stability grade H;
is shown as
Item influencing factor No
The term index weight coefficient;
representing the relevance of each single evaluation index on each grade of the stability of the surrounding rock;
the number of indices representing each influencing factor;
then according to the object element
Degree of correlation with surrounding rock stability grade H
The results were calculated to evaluate the surrounding rock stability.
Optionally, in step S300, the preset algorithm for predicting the sticking patch demand strength is as follows:
in the above formula, the first and second carbon atoms are,
is shown as
The required strength of the wall rock bonding of the finite element units is high;
is shown as
The cohesive force of the surrounding rock of the finite element units;
is shown as
The surrounding rock normal stress of the finite element units;
representing a tangent function;
is shown as
And (3) the internal friction angle of the surrounding rock normal stress of the finite element unit.
Optionally, if the selected surrounding rock face reinforcement measure adopts an anchor rod and grouting matching mode, calculating the slurry viscosity of grouting by adopting the following formula:
in the above formula, the first and second carbon atoms are,
viscosity values representing the time-varying nature of the slurry;
represents the initial viscosity value of the slurry itself;
the viscosity time-varying coefficient of the slurry is expressed, and the values of the slurry with different water-cement ratios are different and are measured by a viscoplasticity test;
the time used in the actual grouting process is represented and belongs to a preset value;
and taking the calculated viscosity of the slurry as data for carrying out effectiveness analysis of the reinforcing measure.
Optionally, the maximum distance of slurry diffusion of the grouting is evaluated by adopting the following formula:
in the above formula, the first and second carbon atoms are,
represents the maximum distance of slurry diffusion;
represents the grouting pressure;
is the height of the surrounding rock fracture;
representing the flow rate of the slurry;
representing the width of the surrounding rock fracture;
representing the consistency factor of the slurry;
is the water-cement ratio of the slurry.
Optionally, a BP neural network model is set in the three-dimensional finite element model, and the BP neural network model is used for evaluating the stability of the surrounding rock face; the BP neural network model is obtained through the following method:
constructing a BP neural network, determining a plurality of influence factors of the stability of the tunnel face of the surrounding rock and corresponding evaluation indexes thereof, setting weights for the influence factors, wherein the sum of the weights of the influence factors is 1, performing weight distribution on the evaluation indexes of the influence factors, acquiring data of the influence factors serving as input learning samples, taking the acquired actual stable conditions of the tunnel faces as a target vector, representing the connection of each processing unit in the BP neural network by the weights, correcting the weights by errors between the actual output of the data of the influence factors after sample learning and the target vector, transmitting the change of each weight and deviation in direct proportion to the influence of network errors to each layer of the BP neural network in a back propagation manner, obtaining the success probability and the assembly work probability of each stable level by evaluation calculation, and taking the assembly work probability not less than 80 percent as an expected target, and reversely transmitting the error signals along the original connecting path through the network to modify the weight of each layer of neuron until reaching an expected target, thereby obtaining the BP neural network model.
Optionally, in step S200, the reinforced surrounding rock face is further imaged by using an imaging technique to obtain a face image, and the face image is preprocessed.
Optionally, the preprocessed palm surface image is filtered by using the following formula:
in the above formula, the first and second carbon atoms are,
representing a filter function;
,
respectively representing the space translation amount on an x axis and a y axis;
the value of the envelope of the function is represented,
,
representing the ratio between the center frequency and the bandwidth,
represents the center frequency;
is the wavelength of a sine wave;
representing the argument of the complex modulated part function;
represents the aspect ratio of a gaussian function;
representing an imaginary symbol;
represents the degree of offset;
and then performing median filtering by adopting the following formula:
in the above formula, the first and second carbon atoms are,
representing the palm surface image after median filtering processing;
representing the palm surface image before median filtering processing;
representing the coordinate values of the palm surface image;
a sliding template representing a 5 x 21 matrix region;
and then, carrying out crack identification on the tunnel face image after median filtering.
Optionally, the attribute values of the face image are extracted, and the surrounding rock stability analysis model calculates the face image change rate by using the following formula:
in the above formula, the first and second carbon atoms are,
representing the crack rate of change of the face image;
representing the number of attributes of each palm surface image;
representing the number of the face images saved in front;
is shown as
First of the palm face image
An item attribute value;
is shown as
First of the palm face image
An item attribute value;
is shown as
First of the palm face image
An item attribute value;
and if the crack change rate reaches the change threshold value, indicating that the surrounding rock has instability risk, and sending out warning information of the instability risk of the surrounding rock.
Optionally, in step S400, the effectiveness analysis process of the reinforcing measure is as follows:
firstly, calculating the minimum surrounding rock reinforcement thickness of each finite element unit position by adopting the following formula:
in the above formula, the first and second carbon atoms are,
is shown as
Minimum surrounding rock reinforcement thickness of the finite element unit positions;
representing a safety factor;
representing the maximum dimension of the face;
represents the poisson's ratio;
the tensile strength of the reinforced surrounding rock is shown and is measured through tests;
is shown as
Pressure at the location of the finite element;
if the reinforcing thickness of the surrounding rock face is not smaller than the calculated minimum reinforcing thickness of the surrounding rock, the surrounding rock face after the reinforcing measure is implemented meets the stability requirement, otherwise, the reinforcing thickness of the surrounding rock face needs to be increased.
The method for processing the reinforcing stress-strain digital data of the broken soft surrounding rock face introduces finite element analysis to the surrounding rock face, performs stress-strain analysis by combining basic data detected in section excavation and a three-dimensional finite element model, and predicts the bonding required strength of the surrounding rock face by adopting a preset algorithm; selecting a surrounding rock face reinforcing measure according to the bonding and repairing required strength, and introducing the reinforcing measure into a three-dimensional finite element model for effectiveness analysis; by the method, the analysis efficiency and effectiveness of the reinforcing stress-strain data of the tunnel face of the broken weak surrounding rock can be improved, the analysis precision is improved, the method is used for guiding the surrounding rock to be reinforced, the reinforcing effect can be guaranteed, the reinforcing failure is avoided, and the reinforcing cost of the surrounding rock is controlled.
Additional features and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The objectives and other advantages of the invention will be realized and attained by the structure particularly pointed out in the written description and claims hereof as well as the appended drawings.
The technical solution of the present invention is further described in detail by the accompanying drawings and embodiments.
Detailed Description
The preferred embodiments of the present invention will be described in conjunction with the accompanying drawings, and it will be understood that they are described herein for the purpose of illustration and explanation and not limitation.
As shown in fig. 1, an embodiment of the present invention provides a method for processing digitized data of reinforcing stress and strain of a rock face of a broken weak surrounding rock, including the following steps:
s100, establishing a three-dimensional model of a broken weak surrounding rock face according to project design, and carrying out virtual finite element segmentation to form a three-dimensional finite element model of the face;
s200, detecting and storing basic data of a surrounding rock face in a section excavation process;
s300, stress-strain analysis is carried out on the face by combining the basic data and the three-dimensional finite element model, and the required bonding strength of the surrounding rock face is predicted by adopting a preset algorithm;
s400, selecting a surrounding rock face reinforcing measure according to the bonding required strength, and introducing the reinforcing measure into a three-dimensional finite element model for effectiveness analysis.
The working principle and the beneficial effects of the technical scheme are as follows: according to the scheme, finite element analysis is introduced into the surrounding rock face, stress-strain analysis is carried out by combining basic data detected in section excavation and a three-dimensional finite element model, and the required bonding strength of the surrounding rock face is predicted by adopting a preset algorithm; selecting a surrounding rock face reinforcing measure according to the bonding and repairing required strength, and introducing the reinforcing measure into a three-dimensional finite element model for effectiveness analysis; by the method, the analysis efficiency and effectiveness of the reinforcing stress-strain data of the tunnel face of the broken weak surrounding rock can be improved, the analysis precision is improved, the method is used for guiding the surrounding rock to be reinforced, the reinforcing effect can be guaranteed, the reinforcing failure is avoided, and the reinforcing cost of the surrounding rock is controlled.
In one embodiment, in step S100, the following object element descriptions are used in the three-dimensional finite element model:
in the above formula, the first and second carbon atoms are,
representing an object element;
a presentation evaluation unit;
to indicate the evaluation unit
Item influencing factors;
is shown as
A magnitude domain of term influence factor number quantization;
representing the number of influencing factors;
determining grade division of the stability of the surrounding rock, and calculating the material elements according to the following formula
Degree of association with the surrounding rock stability grade H:
in the above formula, the first and second carbon atoms are,
representing an object
Correlation degree with surrounding rock stability grade H;
is shown as
Item influencing factor No
The term index weight coefficient;
representing the relevance of each single evaluation index on each grade of the stability of the surrounding rock;
the number of indices representing each influencing factor;
then according to the object element
Degree of correlation with surrounding rock stability grade H
The results were calculated to evaluate the surrounding rock stability.
The working principle and the beneficial effects of the technical scheme are as follows: according to the scheme, the following object element description and analysis are adopted in the three-dimensional finite element model, the relevance quantification of the evaluation index of the influence factor and the stability grade of the surrounding rock is realized, the understanding of the relation between the influence factor and the stability of the surrounding rock can be improved, the accurate evaluation of the stability degree of the surrounding rock is facilitated, and the reasonable selection of the reinforcing measures of the tunnel face of the surrounding rock is better facilitated.
In one embodiment, in step S300, the preset algorithm for predicting the sticking requirement strength is as follows:
in the above formula, the first and second carbon atoms are,
is shown as
The required strength of the wall rock bonding of the finite element units is high;
is shown as
The cohesive force of the surrounding rock of the finite element units;
is shown as
The surrounding rock normal stress of the finite element units;
representing a tangent function;
is shown as
And (3) the internal friction angle of the surrounding rock normal stress of the finite element unit.
The working principle and the beneficial effects of the technical scheme are as follows: according to the scheme, the required bonding strength of the surrounding rock face is calculated, the required bonding strength of the surrounding rock is used as prediction data and is used as a quantitative analysis basis for selecting the reinforcement measures subsequently, the effectiveness of reinforcement measure selection can be guaranteed, and the situation that the stability of the reinforced surrounding rock cannot be guaranteed is avoided.
In one embodiment, if the selected surrounding rock face reinforcement measure adopts an anchor rod and grouting matching mode, calculating the slurry viscosity of grouting by adopting the following formula:
in the above formula, the first and second carbon atoms are,
viscosity values representing the time-varying nature of the slurry;
represents the initial viscosity value of the slurry itself;
the viscosity time-varying coefficient of the slurry is expressed, and the values of the slurry with different water-cement ratios are different and are measured by a viscoplasticity test;
the time used in the actual grouting process is represented and belongs to a preset value;
and taking the calculated viscosity of the slurry as data for carrying out effectiveness analysis of the reinforcing measure.
The working principle and the beneficial effects of the technical scheme are as follows: the formula of the relation between the grouting time and the slurry viscosity is utilized, the time change of the grouting process can be intuitively and quantitatively reflected, the effectiveness analysis of grouting reinforcement is carried out, in practice, the method can be used for improving the grouting efficiency by changing the water-cement ratio of the slurry, and the grouting efficiency is improved under the condition of ensuring the slurry viscosity and the grouting effect.
In one embodiment, the following formula is used to calculate the maximum distance of slurry diffusion for evaluating a slurry slip:
in the above formula, the first and second carbon atoms are,
represents the maximum distance of slurry diffusion;
represents the grouting pressure;
is the height of the surrounding rock fracture;
representing the flow rate of the slurry;
representing the width of the surrounding rock fracture;
representing the consistency factor of the slurry;
in the form of a slurryWater to cement ratio.
The working principle and the beneficial effects of the technical scheme are as follows: the grouting maximum distance of slurry diffusion of grouting is calculated through real-time detection grouting pressure, the influence range of grouting is quantized, grouting reinforcement requirements formed by analyzing surrounding rock data are combined, grouting intervals and arrangement modes can be obtained through analysis, and therefore the optimized grouting scheme is selected, efficiency is improved, and grouting cost is saved.
In one embodiment, a BP neural network model is arranged in the three-dimensional finite element model, and the BP neural network model is used for evaluating the stability of the surrounding rock tunnel face; the BP neural network model is obtained through the following method:
constructing a BP neural network, determining a plurality of influence factors of the stability of the tunnel face of the surrounding rock and corresponding evaluation indexes thereof, setting weights for the influence factors, wherein the sum of the weights of the influence factors is 1, performing weight distribution on the evaluation indexes of the influence factors, acquiring data of the influence factors serving as input learning samples, taking the acquired actual stable conditions of the tunnel faces as a target vector, representing the connection of each processing unit in the BP neural network by the weights, correcting the weights by errors between the actual output of the data of the influence factors after sample learning and the target vector, transmitting the change of each weight and deviation in direct proportion to the influence of network errors to each layer of the BP neural network in a back propagation manner, obtaining the success probability and the assembly work probability of each stable level by evaluation calculation, and taking the assembly work probability not less than 80 percent as an expected target, and reversely transmitting the error signals along the original connecting path through the network to modify the weight of each layer of neuron until reaching an expected target, thereby obtaining the BP neural network model.
The working principle and the beneficial effects of the technical scheme are as follows: according to the scheme, the BP neural network model is arranged in the three-dimensional finite element model to evaluate the stability of the surrounding rock face, so that the accuracy of evaluation of the stability of the surrounding rock face is improved; the acquisition of the BP neural network model is realized by determining the influence factors of the stability of the surrounding rock face and the corresponding evaluation indexes thereof, setting the weight, and performing the basic formation of weight optimization adjustment through sample learning and expectation comparison on the basis that the weight value represents the initial BP neural network of the connection of each processing unit, thereby ensuring the applicability and reliability of the BP neural network model to the stability evaluation of the surrounding rock face and improving the reliability of the evaluation result.
In one embodiment, in step S200, an imaging technique is further used for imaging the reinforced surrounding rock working face to obtain a working face image, and the working face image is preprocessed; filtering the preprocessed palm surface image by adopting the following formula:
in the above formula, the first and second carbon atoms are,
representing a filter function;
,
respectively representing the space translation amount on an x axis and a y axis;
the value of the envelope of the function is represented,
,
representing the ratio between the center frequency and the bandwidth,
represents the center frequency;
is the wavelength of a sine wave;
representing the argument of the complex modulated part function;
represents the aspect ratio of a gaussian function;
representing an imaginary symbol;
represents the degree of offset;
and then performing median filtering by adopting the following formula:
in the above formula, the first and second carbon atoms are,
representing the palm surface image after median filtering processing;
representing the palm surface image before median filtering processing;
representing the coordinate values of the palm surface image;
a sliding template representing a 5 x 21 matrix region;
and then, carrying out crack identification on the tunnel face image after median filtering.
The working principle and the beneficial effects of the technical scheme are as follows: the tunnel face image after pretreatment is filtered, the accuracy of identifying the cracks possibly existing in the tunnel surrounding rock tunnel face is improved, the crack identification efficiency is improved, a good foundation is provided for the surrounding rock tunnel face crack inclusion evaluation, the surrounding rock stability evaluation can be achieved by the surrounding rock face crack inclusion, the evaluation is more comprehensive, the accuracy is higher, and the improvement of the crack identification efficiency prevents misjudgment caused by the crack identification error.
In one embodiment, the attribute values of the tunnel face image are extracted, and the surrounding rock stability analysis model calculates the change rate of the tunnel face image by adopting the following formula:
in the above formula, the first and second carbon atoms are,
representing the crack rate of change of the face image;
representing the number of attributes of each palm surface image;
representing the number of the face images saved in front;
is shown as
First of the palm face image
An item attribute value;
is shown as
First of the palm face image
An item attribute value;
is shown as
First of the palm face image
An item attribute value;
and if the crack change rate reaches the change threshold value, indicating that the surrounding rock has instability risk, and sending out warning information of the instability risk of the surrounding rock.
The working principle and the beneficial effects of the technical scheme are as follows: according to the scheme, various attribute values of the face image are extracted, the crack change rate of the face image is calculated according to the formula, and the change of the face image is inevitably brought by the crack change of the surrounding rock, so that the instability risk condition of the surrounding rock can be indirectly reflected through the crack change rate of the face image, the change trend can be known through the analysis of the face images continuously collected at different times, the risk is predicted in advance, the response is made in time, and the risk is eliminated by taking reinforcement measures.
In one embodiment, in step S400, the effectiveness analysis process of the reinforcement measure is as follows:
firstly, calculating the minimum surrounding rock reinforcement thickness of each finite element unit position by adopting the following formula:
in the above formula, the first and second carbon atoms are,
is shown as
Minimum surrounding rock reinforcement thickness of the finite element unit positions;
representing a safety factor;
representing the maximum dimension of the face;
represents the poisson's ratio;
the tensile strength of the reinforced surrounding rock is shown and is measured through tests;
is shown as
Pressure at the location of the finite element;
if the reinforcing thickness of the surrounding rock face is not smaller than the calculated minimum reinforcing thickness of the surrounding rock, the surrounding rock face after the reinforcing measure is implemented meets the stability requirement, otherwise, the reinforcing thickness of the surrounding rock face needs to be increased.
The working principle and the beneficial effects of the technical scheme are as follows: according to the scheme, the minimum surrounding rock reinforcement thickness is calculated through the formula, and the effectiveness of the reinforcement measure is judged according to the comparison condition between the planned or implemented reinforcement measure reinforced surrounding rock tunnel face reinforcement thickness and the calculation result; the tensile strength of the reinforced surrounding rock in the formula is directly related to the characteristics of the surrounding rock and the reinforcing scheme; the formula is simple to calculate and easy to operate, and can correctly guide and implement the reinforcing scheme in construction, so that the stability of the surrounding rock face after reinforcement is improved, evaluation errors are avoided, and safety risks are reduced.
It will be apparent to those skilled in the art that various changes and modifications may be made in the present invention without departing from the spirit and scope of the invention. Thus, if such modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include such modifications and variations.