Support reinforcement method based on soft rock deformation analysis

Abstract

This invention relates to the field of soft rock support and reinforcement technology, and particularly to a support and reinforcement method based on soft rock deformation analysis. The method includes: acquiring geological survey data of the soft rock in the area to be reinforced, and constructing a three-dimensional numerical simulation model; determining whether the degree of fragmentation of the soft rock in the area to be reinforced is acceptable based on the rock mass integrity index, and determining the support and reinforcement method for the area to be reinforced based on the difference; determining whether the grouting effect is acceptable based on the deviation rate; determining to reduce the anchor spacing based on the absolute value of the difference between the deviation rate and a first preset deviation rate; determining to increase the grouting pressure based on the ratio of a second preset deviation rate to the deviation rate; determining whether the corresponding support and reinforcement method meets the standard for controlling soft rock deformation based on the soft rock deformation stability index, and determining whether crack propagation has an impact on soft rock deformation based on the deformation gradient characterization value; and determining to increase the diffusion radius based on the relative difference. This invention improves the efficiency of support and reinforcement.

Description

Technical Field

[0001] This invention relates to the field of soft rock support and reinforcement technology, and in particular to a support and reinforcement method based on soft rock deformation analysis. Background Technology

[0002] In underground engineering construction such as tunnel excavation, mining, and slope protection, soft rock is widely used. Under the influence of excavation disturbance, groundwater erosion, and geostress, it is prone to deformation, cracking, and even instability. Traditional support and reinforcement methods rely heavily on experience-based design and standard table lookup, lacking a precise grasp of the deformation characteristics and dynamic response of soft rock. They are unable to adapt to the dynamic changes in the mechanical behavior of soft rock over time and in the environment, and cannot effectively handle the nonlinear relationship between support parameters and soft rock deformation, resulting in poor support effects and often leading to safety accidents due to insufficient support.

[0003] Chinese Patent Application Publication No. CN109798140A discloses a method for fracturing and reinforcing soft rock in a kilometer-deep well using grouting. The method includes steps such as injecting anchor cables, grouting construction, and tensioning the anchor cables. This invention has a simple structure. Grouting reinforces the original fissures and fissures caused by excavation disturbance in the surrounding rock of the tunnel, improving the engineering mechanical properties of the surrounding rock. Furthermore, fracturing grouting increases the diffusion radius of the grout, solidifying the relatively softened soft rock in the deep surrounding rock into a high-strength "concrete" structure, forming a closed and powerful load-bearing structure with the shallow surrounding rock, maximizing the self-supporting capacity of the surrounding rock and the support capacity of the support system. Simultaneously, grouting provides a stable bearing layer for the combined anchor cables. The radial pressure provided by tensioning the combined anchor cables can change the stress state of the surrounding rock, increasing the stability creep of the surrounding rock, thereby ensuring the long-term stability of the tunnel surrounding rock.

[0004] However, the existing technology has the following problems: it relies on preset parameters and experience to determine the support process and grouting parameters, lacks dynamic monitoring of the actual deformation characteristics and geological conditions of soft rock, and cannot effectively handle the relationship between support parameters and soft rock deformation, which makes it difficult to accurately control the grouting reinforcement effect, resulting in low support reinforcement efficiency. Summary of the Invention

[0005] To address this, the present invention provides a support and reinforcement method based on soft rock deformation analysis, which overcomes the problems in the prior art that rely on preset parameters and experience to determine the support process and grouting parameters, lack dynamic monitoring of the actual deformation characteristics and geological conditions of soft rock, cannot effectively handle the relationship between support parameters and soft rock deformation, and thus makes it difficult to accurately control the grouting reinforcement effect, resulting in low support and reinforcement efficiency.

[0006] To achieve the above objectives, this invention provides a support and reinforcement method based on soft rock deformation analysis, comprising:

[0007] Geological survey data of the soft rock in the area to be reinforced is obtained in order to construct a three-dimensional numerical simulation model;

[0008] Based on the rock mass integrity index of the three-dimensional numerical simulation model, it is determined whether the degree of fragmentation of the soft rock in the area to be reinforced is qualified, so as to determine the first support reinforcement method or the second support reinforcement method of the area to be reinforced according to the difference between the rock mass integrity index and the preset rock mass integrity index.

[0009] The simulated grout diffusion rate is obtained by simulating support and reinforcement of the three-dimensional numerical simulation model, and the actual grout diffusion rate is obtained by actually supporting and reinforcing the area to be reinforced. The grouting effect under the corresponding support and reinforcement method is determined based on the deviation rate between the simulated grout diffusion rate and the actual grout diffusion rate.

[0010] Under the condition that the grouting effect is unqualified and the grouting fluid spreads too fast under the corresponding support and reinforcement method, the anchor spacing is reduced based on the absolute value of the difference between the deviation rate and the first preset deviation rate.

[0011] If the grouting effect is found to be unqualified under the corresponding support and reinforcement method and the grouting fluid diffusion is too slow, the grouting pressure is increased according to the ratio of the second preset deviation rate to the deviation rate.

[0012] Based on the soft rock surface crack data and displacement data of the supported and reinforced area collected during actual support and reinforcement, the soft rock deformation stability index is obtained to determine whether the corresponding support and reinforcement method meets the standard for soft rock deformation control, and to determine whether crack propagation has an impact on soft rock deformation based on the deformation gradient characterization value.

[0013] If the corresponding support and reinforcement method fails to control the deformation of soft rock and crack propagation affects the deformation of soft rock, the diffusion radius of the grouting fluid is increased based on the relative difference between the deformation gradient characterization value and the preset deformation gradient characterization value.

[0014] Furthermore, the determination of whether the soft rock fracture degree of the area to be reinforced is unqualified is based on a comparison of the rock mass integrity index of the three-dimensional numerical simulation model being less than or equal to the preset rock mass integrity index.

[0015] The rock mass integrity index is determined based on the longitudinal wave velocity of the rock and the actual propagation speed of the longitudinal waves in the rock mass.

[0016] Furthermore, the first support reinforcement method determines the area to be reinforced based on the comparison result of the difference between the rock mass integrity index and the preset rock mass integrity index being less than or equal to the preset difference, and determines that the grouting effect is unqualified and the grouting fluid spreads too fast based on the comparison result of the deviation rate between the actual grouting diffusion rate of the actual support reinforcement and the simulated grouting diffusion rate of the simulated support reinforcement being less than or equal to the first preset deviation rate.

[0017] Furthermore, the second support reinforcement method determines the area to be reinforced based on the comparison result of the difference between the rock mass integrity index and the preset rock mass integrity index being greater than the preset difference, and determines that the grouting effect is unqualified and the grouting fluid spreads too fast based on the comparison result of the deviation rate between the actual grouting diffusion rate of the actual support reinforcement and the simulated grouting diffusion rate of the simulated support reinforcement being less than or equal to the first preset deviation rate.

[0018] Furthermore, when it is determined that the grouting effect under the corresponding support and reinforcement method is unqualified and the grouting fluid spreads too quickly, the process of adjusting the anchor spacing under the corresponding support and reinforcement method includes:

[0019] Take the absolute value of the difference between the deviation rate and the first preset deviation rate;

[0020] Set several adjustment coefficients corresponding to the absolute values ​​of the corresponding differences;

[0021] The anchor bolt spacing is reduced based on several of the aforementioned adjustment coefficients;

[0022] Set the corresponding relationship between the absolute value of the difference and the anchor bolt spacing to adjust the anchor bolt spacing.

[0023] Furthermore, the determination of the failure of grouting effect under the corresponding support and reinforcement method and the excessively slow diffusion of grout is based on the comparison result of the deviation rate between the actual grout diffusion rate of the actual support and reinforcement and the simulated grout diffusion rate of the simulated support and reinforcement being greater than the second preset deviation rate.

[0024] Furthermore, when it is determined that the grouting effect under the corresponding support and reinforcement method is unqualified and the grout diffusion is too slow, the process of adjusting the grouting pressure under the corresponding support and reinforcement method includes:

[0025] Divide the second preset deviation rate by the deviation rate;

[0026] Set several adjustment coefficients corresponding to the respective ratios;

[0027] Increase grouting pressure based on several of the aforementioned adjustment coefficients;

[0028] Set the corresponding ratio to the grouting pressure to adjust the grouting pressure.

[0029] Furthermore, the failure of the corresponding support and reinforcement methods to control soft rock deformation was determined based on the comparison results of soft rock deformation stability indices being less than or equal to the preset soft rock deformation stability indices.

[0030] The soft rock deformation stability index is determined based on the displacement, simulated displacement, the rate of change of crack width on the soft rock surface, and the rate of change of crack width on the simulated soft rock surface.

[0031] Furthermore, the fact that crack propagation has no effect on soft rock deformation is determined based on the comparison between the deformation gradient characterization value and the preset deformation gradient characterization value.

[0032] The deformation gradient characterization value is determined based on the soft rock surface displacement convergence rate and the simulated soft rock surface displacement convergence rate.

[0033] Furthermore, when it is determined that the grouting effect under the corresponding support and reinforcement method is unqualified and the grout diffusion is too slow, the process of adjusting the diffusion radius under the corresponding support and reinforcement method includes:

[0034] The relative difference between the deformation gradient characterization value and the preset deformation gradient characterization value is calculated.

[0035] Set several optimization coefficients corresponding to the relative differences;

[0036] Increase the diffusion radius based on several of the aforementioned optimization coefficients;

[0037] The corresponding relationship between the relative difference and the diffusion radius is set to adjust the diffusion radius.

[0038] Compared with existing technologies, the beneficial effects of this invention are as follows: By constructing a three-dimensional numerical simulation model, determining the initial support method based on the rock mass integrity index, comparing the simulated and actual grout diffusion rates, dynamically adjusting the anchor spacing and grouting pressure to optimize the grouting effect, and combining soft rock surface crack and displacement convergence data to determine the deformation control situation and adjust the diffusion radius accordingly, the support parameters are determined through quantitative analysis. This improves the uniformity of grout diffusion in the support reinforcement, enhances the adequacy of the surrounding rock reinforcement, and effectively addresses the dynamic changes in the mechanical properties of soft rock by dynamically adjusting parameters according to soft rock deformation. This avoids over- or under-support, improves the bearing capacity of soft rock and the supporting force of the support system, enhances the reliability of the support reinforcement, and improves the support efficiency of the support reinforcement.

[0039] Furthermore, this invention uses a three-dimensional numerical simulation model to quantify the rock mass integrity index to determine whether the degree of soft rock fracturing is acceptable. If it is unacceptable, the support method is selected based on the difference between the rock mass integrity index and the preset rock mass integrity index, thereby achieving objective grading of the degree of soft rock fracturing, avoiding insufficient or excessive reinforcement, and improving material utilization. The low-pressure grouting and short anchor bolt scheme is suitable for slightly fractured rock masses, while the high-pressure dual-liquid grouting and prestressed anchor bolt scheme reduces deformation in the fractured zone and improves the reliability of support and reinforcement through rapid solidification and active support.

[0040] Furthermore, this invention simulates the grout diffusion rate using a three-dimensional model and compares it with the actual grout diffusion rate to calculate the deviation rate and determine the grouting effect. Based on the absolute value of the difference between the deviation rate and the preset deviation rate, the anchor spacing is dynamically adjusted, which improves the grouting qualification rate of the support reinforcement, makes the support density accurately match the degree of rock mass fissure development, improves the compactness of the support reinforcement grout, and thus reduces the risk of soft rock deformation.

[0041] Furthermore, the present invention adjusts the grouting pressure by using the ratio of the second preset deviation rate to the deviation rate, ensuring that the grouting fluid fully fills the rock mass fissures, improving the grouting qualification rate, matching the grouting pressure with the degree of development of rock mass fissures, avoiding structural damage caused by excessive pressure, identifying abnormal grouting areas in advance, adjusting the pressure in time, and reducing the risk of soft rock deformation.

[0042] Furthermore, this invention determines whether deformation control meets the standard by using the soft rock deformation stability index. If the standard is not met, the impact of crack propagation on deformation is determined based on the deformation gradient characterization value, thereby achieving a graded support effect, reducing the risk of deformation exceeding the limit, and reducing the risk of secondary reinforcement due to substandard control. The correlation between crack propagation and deformation is identified based on the deformation gradient characterization value, which improves the targeting of the support scheme and reduces ineffective reinforcement measures.

[0043] Furthermore, this invention increases the diffusion radius by the relative difference between the deformation gradient characterization value and the preset deformation gradient characterization value, thereby achieving dynamic optimization of the grouting range. This allows the grout to fully fill the fracture network, reducing the deformation of soft rock, avoiding blindly expanding the grouting range, optimizing the diffusion radius, improving the bond strength between the grout and the rock mass, reducing the long-term creep rate of soft rock, improving the reliability of support and reinforcement, and increasing the support efficiency of support and reinforcement. Attached Figure Description

[0044] Figure 1 This is a flowchart of the support and reinforcement method based on soft rock deformation analysis according to an embodiment of the present invention;

[0045] Figure 2 This is a flowchart illustrating whether the degree of soft rock fracturing in the area to be reinforced is qualified, as described in an embodiment of the present invention.

[0046] Figure 3 This is a flowchart illustrating whether the corresponding support and reinforcement method meets the standards for soft rock deformation control in the embodiments of the present invention.

[0047] Figure 4 This is a flowchart illustrating how to determine whether crack propagation affects soft rock deformation in an embodiment of the present invention. Detailed Implementation

[0048] To make the objectives and advantages of the present invention clearer, the present invention will be further described below with reference to embodiments; it should be understood that the specific embodiments described herein are merely for explaining the present invention and are not intended to limit the present invention.

[0049] Preferred embodiments of the present invention will now be described with reference to the accompanying drawings. Those skilled in the art should understand that these embodiments are merely illustrative of the technical principles of the present invention and are not intended to limit the scope of protection of the present invention.

[0050] It should be noted that the data in this embodiment are all derived from a comprehensive analysis and evaluation of historical test data and corresponding historical test results from the three months prior to this test. Those skilled in the art will understand that the determination of the above-mentioned parameters for any single item in this invention can be achieved by selecting the value with the highest percentage based on the data distribution as the preset standard parameter, using weighted summation to obtain the value as the preset standard parameter, substituting each historical data point into a specific formula and using the value obtained from that formula as the preset standard parameter, or other selection methods, as long as the invention can clearly define different specific situations in the single-item judgment process through the obtained values.

[0051] Please see Figure 1 As shown, it is a flowchart of the support and reinforcement method based on soft rock deformation analysis according to an embodiment of the present invention.

[0052] The support and reinforcement method based on soft rock deformation analysis in this invention includes:

[0053] Step S1: Obtain geological survey data of the soft rock in the area to be reinforced in order to construct a three-dimensional numerical simulation model;

[0054] Step S2: Determine whether the degree of fracturing of the soft rock in the area to be reinforced is qualified based on the rock mass integrity index of the three-dimensional numerical simulation model, so as to determine the first support reinforcement method or the second support reinforcement method of the area to be reinforced according to the difference between the rock mass integrity index and the preset rock mass integrity index.

[0055] Step S3: Simulate the support and reinforcement of the three-dimensional numerical simulation model to obtain the simulated grouting diffusion rate, and perform actual support and reinforcement on the area to be reinforced to obtain the actual grouting diffusion rate. Based on the deviation rate between the simulated grouting diffusion rate and the actual grouting diffusion rate, determine whether the grouting effect under the corresponding support and reinforcement method is qualified.

[0056] Step S4: Under the condition that the grouting effect under the corresponding support and reinforcement method is unqualified and the grouting liquid spreads too fast, the anchor spacing is reduced based on the absolute value of the difference between the deviation rate and the first preset deviation rate.

[0057] Step S5: If the grouting effect under the corresponding support and reinforcement method is unqualified and the grouting fluid spreads too slowly, determine to increase the grouting pressure according to the ratio of the second preset deviation rate to the deviation rate.

[0058] Step S6: Based on the soft rock surface crack data and displacement convergence data of the support and reinforcement area collected during actual support and reinforcement, the soft rock deformation stability index is obtained to determine whether the corresponding support and reinforcement method meets the standard for soft rock deformation control, so as to determine whether crack propagation has an impact on soft rock deformation based on the deformation gradient characterization value.

[0059] Step S7: Under the condition that the corresponding support and reinforcement method fails to meet the standard for soft rock deformation control and crack propagation has an impact on soft rock deformation, the diffusion radius of the grouting fluid is increased based on the relative difference between the deformation gradient characterization value and the preset deformation gradient characterization value.

[0060] Specifically, this invention constructs a three-dimensional numerical simulation model, determines the initial support method based on the rock mass integrity index, compares the simulated and actual grout diffusion rates, dynamically adjusts the anchor spacing and grouting pressure to optimize the grouting effect, and combines soft rock surface crack and displacement convergence data to determine the deformation control situation and adjust the diffusion radius accordingly. This quantitative analysis determines the support parameters, improving the uniformity of grout diffusion in the support reinforcement, enhancing the adequacy of the surrounding rock reinforcement, and effectively addressing the dynamic changes in the mechanical properties of soft rock by dynamically adjusting parameters based on soft rock deformation. This avoids over- or under-support, improves the bearing capacity of the soft rock and the supporting capacity of the support system, enhances the reliability of the support reinforcement, and increases the support efficiency of the support reinforcement.

[0061] Specifically, the three-dimensional numerical simulation process established in this embodiment of the invention is as follows: In the first stage, exploration boreholes are arranged in a 20m×20m grid in the area to be reinforced. Diamond drill bits are used for core sampling to obtain the core recovery rate and lithological distribution. The core is described in layers, with each 1m unit. Lithology, color, joint density, and weathering degree are recorded. The core is scanned in high definition and stitched into a continuous columnar section. The location of weak interlayers is marked. Rock samples are taken for laboratory testing to obtain the saturated compressive strength, cohesion, internal friction angle, tensile strength, and longitudinal wave velocity of the rock. A total station is used to track fault outcrops, and the strike and dip angle are recorded. The joint orientation is identified in the boreholes, and an isodensity map of extreme points is drawn. The trace length, spacing, and aperture are measured to generate a discrete fracture network (DFN) model. All the data obtained in the first stage are the geological exploration data.

[0062] In the second stage, a three-dimensional geological model was constructed. The geological exploration data obtained in the first stage was imported into Petrel software, and a continuous stratigraphic surface was generated using the radial basis function interpolation method. Interpolation was performed on both sides of the fault to avoid surface intersections. The faults exposed by surface mapping and drilling were converted into triangular mesh surfaces, and random joint surfaces were generated based on the DFN model. The stratigraphic surfaces were stitched together into closed entities, and lithological regions were divided. Finally, a three-dimensional numerical simulation model containing geometric morphology, lithological distribution, and fracture network was formed. The actual propagation velocity of longitudinal waves in the rock mass in the three-dimensional numerical simulation model was simulated by the wave equation.

[0063] Please see Figure 2 As shown, it is a flowchart for determining whether the degree of soft rock fracturing in the area to be reinforced is qualified according to an embodiment of the present invention.

[0064] Specifically, in this embodiment of the invention, under the condition of establishing a three-dimensional numerical simulation model, the degree of fracturing of the soft rock in the area to be reinforced is determined based on the comparison result between the rock mass integrity index of the three-dimensional numerical simulation model and the preset rock mass integrity index.

[0065] When the rock mass integrity index is less than or equal to the preset rock mass integrity index, the degree of soft rock fragmentation in the area to be reinforced is determined to be unqualified.

[0066] When the rock mass integrity index is greater than the preset rock mass integrity index, the degree of soft rock fragmentation in the area to be reinforced is determined to be qualified.

[0067] In this embodiment of the invention, the preset rock mass integrity index range is [0.7, 0.8], preferably 0.75, but the above value is not limited to this, and those skilled in the art can adjust the value according to actual needs.

[0068] In this embodiment of the invention, the rock mass integrity index is the square of the ratio of the rock longitudinal wave velocity to the actual propagation velocity of the rock longitudinal wave.

[0069] Specifically, in this embodiment of the invention, when it is determined that the degree of soft rock fragmentation in the area to be reinforced is unqualified, the support and reinforcement method of the area to be reinforced is determined based on the comparison result of the difference between the rock mass integrity index and the preset rock mass integrity index and the preset difference.

[0070] When the difference is less than or equal to the preset difference, the support reinforcement method for the area to be reinforced is determined to be the first support reinforcement method.

[0071] When the difference is greater than the preset difference, the support reinforcement method for the area to be reinforced is determined to be the second support reinforcement method.

[0072] The difference is the difference between the rock mass integrity index and the preset rock mass integrity index.

[0073] In this embodiment of the invention, the preset difference value range is [0.15, 0.025], preferably 0.2, but the above value is not limited to this, and those skilled in the art can also adjust the value according to actual needs.

[0074] In this embodiment of the invention, the first support reinforcement method is a silicate cement grouting method with an injection pressure of 0.5-1.0 MPa, preferably 0.7 MPa, a diffusion radius of 2-3 m, preferably 2.5 m, a mortar anchor length of 3-5 m, preferably 4 m, and a spacing of 1.5-2.0 m, preferably 1.7 m; the second support reinforcement method is a modified cement-water glass double-liquid grouting method with an injection pressure of 1.0-1.5 MPa, preferably 1.3 MPa, a diffusion radius of 1.5-2.5 m, preferably 2 m, a prestressed hollow grouting anchor length of 6-8 m, preferably 7 m, and a spacing of 1.0-1.5 m, preferably 1.3 m, while simultaneously spraying concrete with a thickness of 5-8 cm, preferably 6 cm.

[0075] Specifically, this invention uses a three-dimensional numerical simulation model to quantify the rock mass integrity index to determine whether the degree of soft rock fracturing is acceptable. If it is unacceptable, the support method is selected based on the difference between the rock mass integrity index and the preset rock mass integrity index, thereby achieving objective grading of the degree of soft rock fracturing, avoiding insufficient or excessive reinforcement, and improving material utilization. The low-pressure grouting and short anchor bolt scheme is suitable for slightly fractured rock masses, while the high-pressure dual-liquid grouting and prestressed anchor bolt scheme reduces deformation in the fractured zone and improves the reliability of support and reinforcement through rapid solidification and active support.

[0076] Specifically, in this embodiment of the invention, under the condition of determining the support and reinforcement method, the three-dimensional numerical simulation model is used to simulate support and reinforcement to obtain simulated grout diffusion rate, simulated soft rock surface crack data, and simulated displacement convergence data. Then, the area to be reinforced is actually supported and reinforced to obtain the actual grout diffusion rate. The soft rock surface crack data and the displacement convergence data of the supported and reinforced area are collected in real time during the actual support and reinforcement. The displacement convergence data includes the displacement amount and the convergence amount, and the soft rock surface crack data includes the soft rock surface crack width change rate and the soft rock surface displacement convergence rate.

[0077] In this embodiment of the invention, the actual grout diffusion rate is obtained by adding a fluorescent agent or tracer to the grout and arranging a fiber optic sensor in the monitoring borehole to monitor the arrival time of the grout front, and then calculating the distance-to-time ratio. The soft rock surface crack data is monitored using a digital crack width observation instrument, and the soft rock surface crack width change rate is calculated from the crack width change per unit time. The displacement convergence data of the support and reinforcement area is monitored using a total station, and the displacement convergence amount is the change in distance between two measuring points. The soft rock surface displacement convergence rate is calculated from the convergence change per unit time.

[0078] Specifically, in this embodiment of the invention, the grouting effect under the corresponding support reinforcement method is determined to be qualified based on the comparison between the deviation rate of the actual grouting diffusion rate of the actual support reinforcement and the deviation rate of the simulated grouting diffusion rate of the simulated support reinforcement and the preset deviation rate.

[0079] When the deviation rate is less than or equal to the first preset deviation rate, it is determined that the grouting effect under the corresponding support and reinforcement method is unqualified, and it is determined that the grouting fluid spreads too fast.

[0080] When the deviation rate is greater than the first preset deviation rate and less than or equal to the second preset deviation rate, the grouting effect under the corresponding support and reinforcement method is determined to be qualified.

[0081] When the deviation rate is greater than the second preset deviation rate, it is determined that the grouting effect under the corresponding support and reinforcement method is unqualified, and that the grouting fluid diffuses too slowly and is insufficiently filled.

[0082] In this embodiment of the invention, the preset deviation rate includes a first preset deviation rate and a second preset deviation rate. The first preset deviation rate has a value range of [-1.0, 0], preferably -0.5, and the second preset deviation rate has a value range of [0.3, 0.7], preferably 0.5. However, the above values ​​are not limited to these, and those skilled in the art can adjust the values ​​according to actual needs.

[0083] In this embodiment of the invention, the deviation rate is the ratio of the actual grouting diffusion rate minus the simulated grouting diffusion rate to the simulated grouting diffusion rate.

[0084] Specifically, in this embodiment of the invention, when it is determined that the grouting effect under the corresponding support and reinforcement method is unqualified and the grouting fluid spreads too quickly, the anchor spacing under the corresponding support and reinforcement method is reduced based on the comparison result of the absolute value of the difference between the deviation rate and the first preset deviation rate and the absolute value of the preset difference.

[0085] When the absolute value of the difference is less than or equal to the absolute value of the preset difference, it is determined that the anchor spacing under the corresponding support and reinforcement method will be reduced to the corresponding value by the first preset spacing reduction adjustment coefficient of 0.97.

[0086] When the absolute value of the difference is greater than the absolute value of the preset difference, it is determined that the anchor spacing under the corresponding support and reinforcement method will be reduced to the corresponding value by the second preset spacing reduction adjustment coefficient of 0.95.

[0087] The absolute value of the difference is the absolute value of the difference between the deviation rate and the first preset deviation rate.

[0088] In this embodiment of the invention, the preset absolute value of the difference is [0.35, 0.45], preferably 0.4, but the above value is not limited to this, and those skilled in the art can adjust the value according to actual needs.

[0089] In this embodiment of the invention, the reduced anchor spacing is the product of the anchor spacing and the preset spacing reduction adjustment coefficient. The preset spacing reduction adjustment coefficient includes a first preset spacing reduction adjustment coefficient with a value of 0.97 and a second preset spacing reduction adjustment coefficient with a value of 0.97. The anchor spacing includes the anchor spacing corresponding to the first support reinforcement method and the second support reinforcement method, respectively. In order to ensure that the adjusted anchor spacing meets the actual needs, the adjustment range should not be too large. Therefore, an adjustment coefficient is set to control the adjustment range.

[0090] Specifically, this invention simulates the grout diffusion rate using a three-dimensional model and compares it with the actual grout diffusion rate to calculate the deviation rate and determine the grouting effect. Based on the absolute value of the difference between the deviation rate and the preset deviation rate, the anchor spacing is dynamically adjusted, which improves the grouting qualification rate of the support reinforcement, makes the support density accurately match the degree of rock mass fissure development, improves the compactness of the support reinforcement grout, and thus reduces the risk of soft rock deformation.

[0091] Specifically, in this embodiment of the invention, when it is determined that the grouting effect under the corresponding support and reinforcement method is unqualified and the grouting fluid spreads too slowly, the grouting pressure under the corresponding support and reinforcement method is increased based on the comparison result of the second preset deviation rate and the ratio of the deviation rate with the preset ratio.

[0092] When the ratio is less than or equal to the preset ratio, it is determined that the grouting pressure under the corresponding support and reinforcement method will be increased to the corresponding value by the first preset pressure increase adjustment coefficient of 1.03.

[0093] When the ratio is greater than the preset ratio, it is determined that the grouting pressure under the corresponding support and reinforcement method will be increased to the corresponding value by the second preset pressure increase adjustment coefficient of 1.05.

[0094] The ratio is the ratio of the deviation rate to the first preset deviation rate.

[0095] In this embodiment of the invention, the preset ratio is [0.6, 0.8], preferably 0.7, but the above value is not limited to this, and those skilled in the art can adjust the value according to actual needs.

[0096] In this embodiment of the invention, the increased grouting pressure is the product of the grouting pressure and the preset pressure increase adjustment coefficient. The preset pressure increase adjustment coefficient includes a first preset pressure increase adjustment coefficient with a value of 1.03 and a second preset pressure increase adjustment coefficient with a value of 1.05. The grouting pressure includes the grouting pressure corresponding to the first support reinforcement method and the second support reinforcement method, respectively. In order to ensure that the adjusted grouting pressure meets the actual needs, the adjustment range should not be too large. Therefore, an adjustment coefficient is set to control the adjustment range.

[0097] Specifically, the present invention adjusts the grouting pressure by the ratio of the second preset deviation rate to the deviation rate, ensuring that the grouting fluid fully fills the rock mass fissures, improving the grouting qualification rate, making the grouting pressure match the degree of development of rock mass fissures, avoiding structural damage caused by excessive pressure, identifying abnormal grouting areas in advance, adjusting the pressure in time, and reducing the risk of soft rock deformation.

[0098] Please see Figure 3 As shown, it is a flowchart of an embodiment of the present invention for determining whether the corresponding support and reinforcement method meets the standard for soft rock deformation control.

[0099] Specifically, in this embodiment of the invention, under the condition that the grouting effect under the corresponding support and reinforcement method is qualified, the method determines whether the control of soft rock deformation by the corresponding support and reinforcement method meets the standard based on the comparison result between the soft rock deformation stability index and the preset soft rock deformation stability index.

[0100] When the soft rock deformation stability index is less than or equal to the preset soft rock deformation stability index, it is determined that the corresponding support and reinforcement method has not met the standard for soft rock deformation control.

[0101] When the soft rock deformation stability index is greater than the preset soft rock deformation stability index, it is determined that the corresponding support and reinforcement method meets the standard for soft rock deformation control.

[0102] In this embodiment of the invention, the preset range of the soft rock deformation stability index is [0.5, 0.75], preferably 0.6, but the above value is not limited to this, and those skilled in the art can adjust the value according to actual needs.

[0103] In this embodiment of the invention, the soft rock deformation stability index is the ratio of the displacement to the simulated displacement multiplied by the ratio of the rate of change of the crack width on the soft rock surface to the rate of change of the crack width on the simulated soft rock surface.

[0104] Please see Figure 4 As shown, it is a flowchart of an embodiment of the present invention for determining whether crack propagation has an impact on soft rock deformation.

[0105] Specifically, in this embodiment of the invention, when it is determined that the corresponding support and reinforcement method does not meet the standard for controlling soft rock deformation, the impact of crack propagation on soft rock deformation is determined based on the comparison between the deformation gradient characterization value and the preset deformation gradient characterization value.

[0106] When the deformation gradient characterization value is less than or equal to the preset deformation gradient characterization value, it is determined that crack propagation has no effect on soft rock deformation.

[0107] When the deformation gradient characterization value is greater than the preset deformation gradient characterization value, it is determined that crack propagation has an impact on soft rock deformation.

[0108] In this embodiment of the invention, the preset deformation gradient characterization value ranges from [0.63, 0.76], preferably 0.68. However, the above value is not limited to this, and those skilled in the art can adjust the value according to actual needs.

[0109] In this embodiment of the invention, the deformation gradient characterization value is the ratio of the soft rock surface displacement convergence rate to the simulated soft rock surface displacement convergence rate.

[0110] Specifically, this invention determines whether deformation control meets the standard by using the soft rock deformation stability index. If the standard is not met, the impact of crack propagation on deformation is determined based on the deformation gradient characterization value, thereby achieving a graded support effect, reducing the risk of deformation exceeding the limit, and reducing the risk of secondary reinforcement due to substandard control. The correlation between crack propagation and deformation is identified based on the deformation gradient characterization value, which improves the targeting of the support scheme and reduces ineffective reinforcement measures.

[0111] Specifically, in this embodiment of the invention, under the condition that the corresponding support and reinforcement method fails to meet the standard for controlling soft rock deformation and crack propagation has no impact on soft rock deformation;

[0112] Specifically, in this embodiment of the invention, when it is determined that the corresponding support and reinforcement method does not meet the standard for controlling soft rock deformation and that crack propagation has an impact on soft rock deformation, the parameters of the corresponding support and reinforcement method are adjusted based on the comparison result of the relative difference between the deformation gradient characterization value and the preset deformation gradient characterization value and the preset relative difference.

[0113] When the relative difference is less than or equal to the preset relative difference, it is determined that the diffusion radius of the grouting fluid under the corresponding support and reinforcement method will be increased to the corresponding value by the first preset diffusion radius adjustment coefficient of 1.09.

[0114] When the relative difference is greater than the preset relative difference, it is determined that the diffusion radius of the grouting fluid under the corresponding support and reinforcement method will be increased to the corresponding value by the second preset diffusion radius adjustment coefficient of 1.12.

[0115] The relative difference is the relative difference between the deformation gradient characterization value and the preset deformation gradient characterization value.

[0116] In this embodiment of the invention, the preset relative difference range is [0.17, 0.26], preferably 0.21, but the above value is not limited to this, and those skilled in the art can adjust the value according to actual needs.

[0117] In this embodiment of the invention, the increased diffusion radius is the product of the diffusion radius and the preset diffusion radius adjustment coefficient. The preset diffusion radius adjustment coefficient includes a first preset diffusion radius adjustment coefficient with a value of 1.09 and a second preset diffusion radius adjustment coefficient with a value of 1.12. In order to ensure that the adjusted diffusion radius meets the actual needs, the adjustment range should not be too large. Therefore, an adjustment coefficient is set to control the adjustment range.

[0118] Specifically, this invention increases the diffusion radius by the relative difference between the deformation gradient characterization value and the preset deformation gradient characterization value, thereby achieving dynamic optimization of the grouting range. This allows the grout to fully fill the fracture network, reducing the deformation of soft rock, avoiding blindly expanding the grouting range, optimizing the diffusion radius, improving the bond strength between the grout and the rock mass, reducing the long-term creep rate of soft rock, improving the reliability of support and reinforcement, and increasing the support efficiency of support and reinforcement.

[0119] The technical solution of the present invention has been described above with reference to the preferred embodiments shown in the accompanying drawings. However, it will be readily understood by those skilled in the art that the scope of protection of the present invention is obviously not limited to these specific embodiments. Without departing from the principles of the present invention, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will all fall within the scope of protection of the present invention.

Claims

1. A support and reinforcement method based on soft rock deformation analysis, characterized in that, include: Geological survey data of the soft rock in the area to be reinforced is obtained in order to construct a three-dimensional numerical simulation model; Based on the rock mass integrity index of the three-dimensional numerical simulation model, it is determined whether the degree of fragmentation of the soft rock in the area to be reinforced is qualified, so as to determine the first support reinforcement method or the second support reinforcement method of the area to be reinforced according to the difference between the rock mass integrity index and the preset rock mass integrity index. The simulated grout diffusion rate is obtained by simulating support and reinforcement of the three-dimensional numerical simulation model, and the actual grout diffusion rate is obtained by actually supporting and reinforcing the area to be reinforced. The grouting effect under the corresponding support and reinforcement method is determined based on the deviation rate between the simulated grout diffusion rate and the actual grout diffusion rate. Under the condition that the grouting effect is unqualified and the grouting fluid spreads too fast under the corresponding support and reinforcement method, the anchor spacing is reduced based on the absolute value of the difference between the deviation rate and the first preset deviation rate. If the grouting effect is found to be unqualified under the corresponding support and reinforcement method and the grouting fluid diffusion is too slow, the grouting pressure is increased according to the ratio of the second preset deviation rate to the deviation rate. Based on the soft rock surface crack data and displacement data of the supported and reinforced area collected during actual support and reinforcement, the soft rock deformation stability index is obtained to determine whether the corresponding support and reinforcement method meets the standard for soft rock deformation control, and to determine whether crack propagation has an impact on soft rock deformation based on the deformation gradient characterization value. If the corresponding support and reinforcement method fails to control the deformation of soft rock and crack propagation affects the deformation of soft rock, the diffusion radius of the grouting fluid is increased based on the relative difference between the deformation gradient characterization value and the preset deformation gradient characterization value.

2. The support and reinforcement method based on soft rock deformation analysis according to claim 1, characterized in that, The failure to meet the required level of soft rock fragmentation in the area to be reinforced was determined based on a comparison of the rock mass integrity index of the three-dimensional numerical simulation model being less than or equal to the preset rock mass integrity index. The rock mass integrity index is determined based on the longitudinal wave velocity of the rock and the actual propagation speed of the longitudinal waves in the rock mass.

3. The support and reinforcement method based on soft rock deformation analysis according to claim 2, characterized in that, The first support reinforcement method determines the area to be reinforced based on the comparison result of the difference between the rock mass integrity index and the preset rock mass integrity index being less than or equal to the preset difference, and determines that the grouting effect is unqualified and the grouting fluid spreads too fast based on the comparison result of the deviation rate between the actual grouting diffusion rate of the actual support reinforcement and the simulated grouting diffusion rate of the simulated support reinforcement being less than or equal to the first preset deviation rate.

4. The support and reinforcement method based on soft rock deformation analysis according to claim 3, characterized in that, The second support reinforcement method determines the area to be reinforced based on the comparison result of the difference between the rock mass integrity index and the preset rock mass integrity index being greater than the preset difference. It also determines that the grouting effect is unqualified and the grouting fluid spreads too fast based on the comparison result of the deviation rate between the actual grouting diffusion rate of the actual support reinforcement and the simulated grouting diffusion rate of the simulated support reinforcement being less than or equal to the first preset deviation rate.

5. The support and reinforcement method based on soft rock deformation analysis according to claim 4, characterized in that, When the grouting effect under the corresponding support and reinforcement method is found to be unqualified and the grouting fluid spreads too quickly, the process of adjusting the anchor spacing under the corresponding support and reinforcement method includes: Take the absolute value of the difference between the deviation rate and the first preset deviation rate; Set several adjustment coefficients corresponding to the absolute values ​​of the corresponding differences; The anchor bolt spacing is reduced based on several of the aforementioned adjustment coefficients; Set the corresponding relationship between the absolute value of the difference and the anchor bolt spacing to adjust the anchor bolt spacing.

6. The support and reinforcement method based on soft rock deformation analysis according to claim 5, characterized in that, The grouting effect under the corresponding support and reinforcement method is unqualified and the grouting fluid diffusion is too slow. This is determined by comparing the deviation rate between the actual grouting diffusion rate of the actual support and reinforcement and the simulated grouting diffusion rate of the simulated support and reinforcement, which is greater than the second preset deviation rate.

7. The support and reinforcement method based on soft rock deformation analysis according to claim 6, characterized in that, When the grouting effect under the corresponding support and reinforcement method is found to be unqualified and the grout diffusion is too slow, the process of adjusting the grouting pressure under the corresponding support and reinforcement method includes: Divide the second preset deviation rate by the deviation rate; Set several adjustment coefficients corresponding to the respective ratios; Increase grouting pressure based on several of the aforementioned adjustment coefficients; Set the corresponding ratio to the grouting pressure to adjust the grouting pressure.

8. The support and reinforcement method based on soft rock deformation analysis according to claim 7, characterized in that, The corresponding support and reinforcement methods failed to meet the standards for soft rock deformation control. This was determined based on the comparison results of the soft rock deformation stability index being less than or equal to the preset soft rock deformation stability index. The soft rock deformation stability index is determined based on the displacement, simulated displacement, the rate of change of crack width on the soft rock surface, and the rate of change of crack width on the simulated soft rock surface.

9. The support and reinforcement method based on soft rock deformation analysis according to claim 8, characterized in that, The fact that crack propagation has no effect on soft rock deformation is determined based on the comparison between the deformation gradient characterization value and the preset deformation gradient characterization value. The deformation gradient characterization value is determined based on the soft rock surface displacement convergence rate and the simulated soft rock surface displacement convergence rate.

10. The support and reinforcement method based on soft rock deformation analysis according to claim 9, characterized in that, When the grouting effect under the corresponding support and reinforcement method is found to be unqualified and the grout diffusion is too slow, the process of adjusting the diffusion radius under the corresponding support and reinforcement method includes: The relative difference between the deformation gradient characterization value and the preset deformation gradient characterization value is calculated. Set several optimization coefficients corresponding to the relative differences; Increase the diffusion radius based on several of the aforementioned optimization coefficients; The corresponding relationship between the relative difference and the diffusion radius is set to adjust the diffusion radius.

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