A Multi-Indicator-Based Method for Identifying Sliding Rock Masses

Abstract

This invention discloses a multi-index-based method for identifying slip-type unstable rock masses. The method includes acquiring the initial cohesion, internal friction angle, bond length, bottom dip angle, and self-weight of the rock mass to be identified, as well as the effective normal stress and shear stress on the sliding surface. It also involves acquiring the natural vibration frequency and damping ratio parameters of the slip-type unstable rock mass structure at different times after damage; calculating the cohesion and internal friction angle after damage; calculating the stability coefficient, bond stability coefficient, and cohesion-resistance ratio index of the slip-type unstable rock mass at different times after damage based on the rock mass's physical and mechanical parameters; and, based on the stability coefficient, bond stability coefficient, and cohesion-resistance ratio index, identifying the rock mass to be identified as a slip-type unstable rock mass according to preset identification rules, thereby obtaining the identification result. This invention is applicable to the rapid identification and early warning of slip-type unstable rock masses and can provide new technical support for better responding to slip-type collapse disasters in high-risk geological disaster areas.

Description

Technical Field

[0001] This invention relates to the field of identification and early warning technology for slip-type unstable rock masses, and in particular to a method for identifying slip-type unstable rock masses based on multiple indicators. Background Technology

[0002] In recent years, an increasing number of engineering projects have been constructed in complex and varied high mountain and canyon areas. The steep slopes that are prevalent in these areas amplify the probability of rockfall disasters, constantly threatening the safety of daily construction and maintenance. Therefore, conducting scientific and rapid identification of dangerous rock masses has significant research and application value, both in terms of engineering safety strategy and in the early warning and prevention of geological disasters in high mountain and canyon areas.

[0003] In reality, under the influence of earthquakes, prolonged rainfall, or construction blasting, the strength indicators of rock mass structural surfaces or rock bridges are highly likely to deteriorate, eventually developing into high-risk unstable rock masses. These rock masses are generally located in the shallow part of steep slopes, are numerous, and have extremely irregular shapes, making the identification of unstable rock masses a heavy burden and a great challenge. Remote sensing technologies such as laser scanning, interferometric aperture synthetic radar, UAV aerial photography, and infrared thermal imaging, combined with intelligent algorithms, can quickly and initially identify unstable rock masses in engineering projects. However, these methods mostly focus on macroscopic key area analysis from a mathematical statistical perspective, rather than strictly achieving quantitative analysis of unstable rock masses from a mechanical perspective. Engineers still need to conduct reasonable mechanical assessments during on-site investigations to confirm their status.

[0004] Currently, in the on-site investigation and identification of unstable rock masses, engineers often use the stability coefficient as a single mechanical index for assessment, typically setting a threshold ranging from 1.05 to 1.5 to perform mechanical analysis. Based on the definition of the stability coefficient, which is the ratio of resistance to sliding force to sliding force, it can directly indicate whether the rock mass has become unstable and failed. However, it cannot identify the transition from a stable stage to a separation stage, thus making it difficult to achieve quantitative mechanical identification of unstable rock masses. Its effectiveness in identifying high-risk unstable rock masses and other adverse geological formations requires further discussion. Summary of the Invention

[0005] This invention provides a multi-index-based method for identifying slip-type unstable rock masses, in order to solve the technical problem of difficulty in achieving quantitative mechanical identification of unstable rock masses in the existing technology.

[0006] To solve the above-mentioned technical problems, the present invention provides the following technical solution:

[0007] On the one hand, this invention provides a method for identifying slip-type unstable rock masses based on multiple indicators, including:

[0008] The initial cohesion, internal friction angle, bond length, bottom dip angle and self-weight of the rock mass to be identified, as well as the effective normal stress and shear stress on the sliding surface, are obtained.

[0009] The natural vibration frequency and damping ratio parameters of the slip-type unstable rock mass structure were obtained at different times after damage.

[0010] Calculate the cohesion and internal friction angle after damage;

[0011] Based on the physical and mechanical parameters of the rock mass, the stability coefficient, bond stability coefficient, and cohesion anti-sliding ratio of the sliding unstable rock mass at different times after damage are calculated.

[0012] Based on the stability coefficient, bond stability coefficient, and cohesive anti-sliding ratio index, the rock mass to be identified is identified as a sliding-type unstable rock mass according to the preset identification rules, and the identification results are obtained.

[0013] Furthermore, obtaining the physical and mechanical parameters corresponding to the rock mass to be identified includes:

[0014] In-situ tests were conducted to obtain the initial cohesion, internal friction angle, bond length, bottom dip angle, and self-weight of the rock mass to be identified, as well as the effective normal stress and shear stress on the sliding surface.

[0015] Furthermore, the acquisition of the natural vibration frequency and damping ratio parameters of the slip-type unstable rock mass structure at different times after damage includes:

[0016] The natural vibration frequency of the sliding-type unstable rock mass structure was measured using non-contact remote sensing monitoring technologies such as laser Doppler vibration meters, and the damping ratio of the sliding-type unstable rock mass structure was calculated.

[0017] The formula for calculating the damping ratio Z is:

[0018]

[0019] Where h is the energy loss factor of the sliding unstable rock mass structure, D is the energy dissipation of the sliding unstable rock mass structure during two vibration cycles, and E is the total energy of the sliding unstable rock mass structure system.

[0020] Furthermore, the post-damage cohesion c j The calculation formula is:

[0021]

[0022] Among them, c j Let f be the real-time cohesion of the sliding unstable rock mass structure at time j, c0 be the initial cohesion of the sliding unstable rock mass structure, and f be the real-time cohesion of the sliding unstable rock mass structure. jLet fj be the instantaneous natural vibration frequency of the sliding unstable rock mass structure, and f0 be the initial natural vibration frequency of the sliding unstable rock mass structure. j Z0 is the instantaneous damping ratio of the slip-type unstable rock mass structure at time j, and Z0 is the initial damping ratio of the slip-type unstable rock mass structure.

[0023] Furthermore, the internal friction angle after damage The calculation formula is:

[0024]

[0025] in, Let j be the real-time internal friction angle of the slip-type unstable rock mass structure. Z represents the initial internal friction angle of the slip-type unstable rock mass structure. j Z0 is the instantaneous damping ratio of the slip-type unstable rock mass structure at time j, and Z0 is the initial damping ratio of the slip-type unstable rock mass structure.

[0026] Furthermore, the formula for calculating the stability coefficient SF is as follows:

[0027]

[0028] Among them, c i σ is the cohesion required for the stability of the i-th block rock mass. i Let be the effective normal stress on the i-th block sliding surface. Let l be the internal friction angle of the i-th block of rock. i Let τ be the bonding length of the i-th block. i Let be the shear stress on the sliding surface of the i-th block.

[0029] Furthermore, the formula for calculating the adhesion stability coefficient CSF is as follows:

[0030]

[0031] Where, ψ j ψ is the transmission coefficient. j =cos(θ) i -θ i+1 ), θ i Let θ be the inclination angle of the bottom surface of the i-th block. i+1 Let A be the slope angle of the bottom surface of the (i+1)th block; i For the cohesive force acting on the i-th block, A i =c i l i A n T represents the cohesive force acting on the nth block. i T is the component of the sliding force acting on the i-th block's sliding surface. i =W i sinθ iT n W is the component of the sliding force acting on the sliding surface of the nth block; i Let be the weight of the i-th block; n be the number of blocks.

[0032] Furthermore, the formula for calculating the cohesive anti-slip ratio η is as follows:

[0033]

[0034] Where CSF represents the bond stability coefficient and SF represents the stability coefficient.

[0035] Furthermore, based on the stability coefficient, bond stability coefficient, and cohesion anti-sliding ratio index, and according to preset identification rules, the rock mass to be identified is subjected to sliding-type unstable rock mass identification, and the identification result is obtained, including:

[0036] The calculated stability coefficient SF, bond stability coefficient CSF, and cohesion anti-sliding ratio η were analyzed. When both SF and CSF are greater than 1, the rock mass has no tendency to slide and is considered a stable rock mass. When SF is greater than 1 and CSF is less than 1, the rock mass has a tendency to slide and is considered a dangerous rock mass. Among these, when the rock mass is considered a dangerous rock mass, if η is greater than or equal to the ratio of the long-term strength to the failure strength of the structural surface, the rock mass is considered a dangerous rock mass without a tendency to deteriorate. If η is less than the ratio of the long-term strength to the failure strength of the structural surface, the rock mass is considered a dangerous rock mass with a tendency to deteriorate. When both SF and CSF are less than 1, the rock mass fails and slides, resulting in collapse.

[0037] The beneficial effects of the technical solution provided by this invention include at least the following:

[0038] Compared to traditional single stability coefficients, which can only determine whether failure has occurred but cannot identify the transition of rock mass from a stable stage to a separation stage, thus hindering quantitative mechanical identification of unstable rock masses, this invention introduces a bond stability coefficient to analyze the cohesion of potential sliding surfaces and its anti-sliding ratio. This enables dynamic consideration of the stable, separation, and failure stages of sliding-type unstable rock masses, improving the accuracy and scientific rigor of traditional mechanical identification methods. It provides new technical support for the early identification and warning of sliding-type unstable rock masses. Attached Figure Description

[0039] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0040] Figure 1This is a flowchart of the method for identifying slip-type unstable rock masses based on multiple indicators provided in this embodiment of the invention;

[0041] Figure 2 This is a schematic diagram of the model experiment provided in the embodiment of the present invention;

[0042] Figure 3 These are schematic diagrams of experimental models with different levels of stability provided in embodiments of the present invention;

[0043] Figure 4 These are photographs of dangerous rock masses and their stereographic projections provided in the embodiments of the present invention; wherein, (a) is a photograph of dangerous rock mass W1 and its stereographic projection; and (b) is a photograph of dangerous rock mass W2 and its stereographic projection. Detailed Implementation

[0044] To make the objectives, technical solutions, and advantages of the present invention clearer, the embodiments of the present invention will be described in further detail below with reference to the accompanying drawings.

[0045] To address the problem that traditional single stability coefficients can only determine whether failure has occurred but cannot identify the transition of rock mass from a stable stage to a separation stage, thus making it difficult to achieve quantitative mechanical identification of dangerous rock masses, this embodiment provides a multi-index-based method for identifying slip-type dangerous rock masses. By introducing new mechanical indicators, it realizes the analysis and evaluation of the mechanical state of slip-type dangerous rock masses, and establishes a set of quantitative identification methods for dangerous rock masses based on mechanical analysis, aiming to provide a reference for the scientific exploration and identification of slip-type dangerous rock masses in high-risk areas.

[0046] Specifically, the execution flow of this method is as follows: Figure 1 As shown, it includes the following steps:

[0047] S1, obtain the initial cohesion, internal friction angle, bond length, bottom dip angle and self-weight of the rock mass to be identified, as well as the effective normal stress and shear stress on the sliding surface and other physical and mechanical parameters;

[0048] One method for acquiring data is to obtain data corresponding to the rock mass to be identified through in-situ tests.

[0049] S2, obtain the natural vibration frequency and damping ratio parameters of the slip-type unstable rock mass structure at different times after damage;

[0050] Data can be acquired by using non-contact remote sensing monitoring technologies such as laser Doppler vibration meters to measure the natural vibration frequency of the sliding rock mass structure and calculate the damping ratio of the sliding rock mass structure.

[0051] Specifically, the formula for calculating the damping ratio Z is:

[0052]

[0053] Where h is the energy loss factor of the sliding unstable rock mass structure, D is the energy dissipation of the sliding unstable rock mass structure during two vibration cycles, and E is the total energy of the sliding unstable rock mass structure system.

[0054] S3, calculate the cohesive force and internal friction angle after damage;

[0055] Specifically, real-time cohesion c j The calculation formula is:

[0056]

[0057] Among them, c j Let f be the real-time cohesion of the sliding unstable rock mass structure at time j, c0 be the initial cohesion of the sliding unstable rock mass structure, and f be the real-time cohesion of the sliding unstable rock mass structure. j Let fj be the instantaneous natural vibration frequency of the sliding unstable rock mass structure, and f0 be the initial natural vibration frequency of the sliding unstable rock mass structure. j Z0 is the instantaneous damping ratio of the slip-type unstable rock mass structure at time j, and Z0 is the initial damping ratio of the slip-type unstable rock mass structure.

[0058] Real-time internal friction angle The calculation formula is:

[0059]

[0060] in, Let j be the real-time internal friction angle of the slip-type unstable rock mass structure. Z represents the initial internal friction angle of the slip-type unstable rock mass structure. j Z0 is the instantaneous damping ratio of the slip-type unstable rock mass structure at time j, and Z0 is the initial damping ratio of the slip-type unstable rock mass structure.

[0061] S4, based on the physical and mechanical parameters of the rock mass, calculate the stability coefficient, bond stability coefficient and cohesion anti-sliding ratio of the sliding unstable rock mass at different times after damage;

[0062] Specifically, the formula for calculating the stability coefficient SF is as follows:

[0063]

[0064] Among them, c i σ is the cohesion required for the stability of the i-th block rock mass. i Let be the effective normal stress on the i-th block sliding surface. Let l be the internal friction angle of the i-th block of rock. i Let τ be the bonding length of the i-th block. i Let be the shear stress on the sliding surface of the i-th block.

[0065] The formula for calculating the bond stability factor (CSF) is as follows:

[0066]

[0067] Where, ψ j ψ is the transmission coefficient. j =cos(θ) i -θ i+1 ), θ i Let θ be the inclination angle of the bottom surface of the i-th block. i+1 Let A be the slope angle of the bottom surface of the (i+1)th block; i For the cohesive force acting on the i-th block, A i =c i l i A n T represents the cohesive force acting on the nth block. i T is the component of the sliding force acting on the i-th block's sliding surface. i =W i sinθ i T n W is the component of the sliding force acting on the sliding surface of the nth block; i Let be the weight of the i-th block; n be the number of blocks.

[0068] It should be noted that when CSF is greater than 1, the rock mass's anti-sliding force can be provided entirely by cohesion, with no tendency to slide down, indicating a stable rock mass in a stable stage; when it is less than 1, the rock mass's cohesion cannot fully meet the anti-sliding requirements, and the rock mass has a tendency to slide down or creep, indicating a separation stage, indicating a dangerous rock mass.

[0069] The formula for calculating the cohesive anti-slip ratio η is:

[0070]

[0071] Where CSF represents the bond stability coefficient and SF represents the stability coefficient.

[0072] It should be noted that the calculation of η can realize the dynamic consideration of the ratio of cohesion to sliding force. When a stable rock mass becomes a dangerous rock mass, its cohesion decay rate is relatively large. Therefore, compared with the SF index, the two new mechanical indices CSF and η have higher sensitivity in identifying high-risk dangerous rock masses, and are therefore more suitable for the quantitative analysis and identification of dangerous rock masses.

[0073] S5. Based on the stability coefficient, bonding stability coefficient, and cohesive anti-sliding ratio index, the rock mass to be identified is identified as a sliding-type unstable rock mass according to the preset identification rules, and the identification result is obtained.

[0074] Specifically, in this embodiment, the implementation process of S5 is as follows:

[0075] The calculated stability coefficient SF, bond stability coefficient CSF, and cohesion anti-sliding ratio η were analyzed. When both SF and CSF are greater than 1, the rock mass has no tendency to slide and is considered a stable rock mass. When SF is greater than 1 and CSF is less than 1, the rock mass has a tendency to slide and is considered a dangerous rock mass. Among these, when the rock mass is considered a dangerous rock mass, if η is greater than or equal to the ratio of the long-term strength to the failure strength of the structural surface, the rock mass is considered a dangerous rock mass without a tendency to deteriorate. If η is less than the ratio of the long-term strength to the failure strength of the structural surface, the rock mass is considered a dangerous rock mass with a tendency to deteriorate. When both SF and CSF are less than 1, the rock mass fails and slides, resulting in collapse.

[0076] Based on the above theoretical formula, rapid identification and early warning of sliding-type unstable rock masses can be achieved.

[0077] The effectiveness and practicality of the method in this embodiment will be illustrated below with practical examples.

[0078] Case 1: Indoor experimental model of sliding unstable rock mass, such as Figure 2 As shown, the rock mass consisted of rock blocks with sides of 15 cm, and the slip surface was a weak gypsum layer with a slope of 30°. Nine test cases with different bonding areas were set up, namely stable rock masses A1-A7 and unstable rock masses A8 and A9. The dimensions of the bonding structure surface are shown in the figure. Figure 3 As shown in Table 1, the stability coefficients of rock masses A1–A9 can be obtained based on the limit equilibrium method.

[0079] Table 1 Evaluation results based on traditional mechanical identification methods

[0080]

[0081] Table 1 shows that, according to the identification standard of SF < 1.15 for water conservancy projects, the stability coefficients of test cases A1-A8 are above 1.15, classifying them as stable rock masses; while A9 has a stability coefficient of 1.03, classifying it as a dangerous rock mass. However, according to the identification standard of SF < 1.5 for railway projects, the stability coefficients of A8 and A9 are below 1.5, classifying them as dangerous rock masses. Traditional mechanical identification methods cannot form a unified evaluation result due to the lack of diversified mechanical indicators.

[0082] Table 2 shows the evaluation results of the three-index identification method based on SF, CSF, and η. Table 3 shows the quantitative identification method for slip-type unstable rock masses based on SF, CSF, and η.

[0083] Table 2 Evaluation results of the three-index identification method based on SF, CSF and η

[0084]

[0085]

[0086] Table 3. Quantitative Identification Method of Slip-Type Rock Mass Based on SF, CSF, and η

[0087]

[0088] As shown in Tables 2 and 3, the SF and CSF of A1-A7 are both above 1.0, indicating a stable state; the SF of A8 and A9 is greater than 1.0, while their CSFs are 0.77 and 0.51 respectively, which are less than 1.0, and their η values ​​are both less than the ratio of long-term strength to failure strength of the structural surface, indicating that they are dangerous rocks with a tendency to deteriorate.

[0089] Comparing Tables 1 and 2, it is evident that the single SF (Self-Focus Factor) cannot accurately quantify the A8 rock mass in the experimental group due to inconsistencies in standards, making A8 easily overlooked due to engineers' subjective assumptions. However, by introducing CSF (Constant Crush Factor) and η (Increase in Equity), a unified standard for the quantitative identification of rock masses can be achieved. It is worth noting that although the SF of A7 is as high as 1.55, its CSF is close to 1.03, making it highly susceptible to entering a separation phase after disturbance, and thus requiring close monitoring.

[0090] In the process of cumulative damage leading to unstable rock masses, the weakening effect of the internal friction angle of the rock bridge is relatively small, while the weakening of cohesion is severe. As mechanical indicators that directly reflect changes in cohesion, CSF and η have good sensitivity and accuracy in identifying stable rock masses turning into unstable rock masses. Taking a 30° sliding unstable rock mass as an example in the experiment, from the perspective of solid mechanics, when the cohesion stability coefficient decreases to below 1.0, it indicates that the cohesion of the rock mass is insufficient to resist the sliding force, and it has a tendency to slide, making it a high-risk unstable rock mass. From the perspective of damage mechanics, when the proportion of cohesion resisting sliding is less than the ratio of its long-term strength to its failure strength, it indicates that the internal cracks of the rock mass will expand unstablely over time and begin to separate from the bedrock, making it a unstable rock mass with a tendency to deteriorate. The introduction of CSF and η can provide an objective and unified evaluation standard for the mechanical identification of unstable rock masses in the field.

[0091] To verify the effectiveness of the method, rock masses in several regions were selected as examples, and the on-site evaluation results of dangerous rock masses are shown in Table 4.

[0092] Table 4. Results of on-site dangerous rock identification based on the method of this embodiment.

[0093]

[0094] Tables 3 and 4 show that the CSF of rock masses BHP, WDD, and W4-12 is less than 1, and their η is less than the ratio of long-term strength to failure strength, indicating they are unstable rock masses with a tendency to deteriorate. Although the SF of rock mass W31 in the test area is 1.23, its CSF is 1.10, and its η is greater than the ratio of long-term strength to failure strength, showing no tendency to deteriorate, thus it is a stable rock mass. The evaluation results are completely consistent with the actual exploration results.

[0095] It is worth noting that the SF (force distribution) of the WDD unstable rock mass is greater than that of the W31 stable rock mass. This indirectly indicates that the current single mechanical index of SF is insufficient for the quantitative identification of unstable rock masses, leading to frequent misjudgments or omissions of unstable rock masses in engineering sites. However, by introducing sensitive mechanical parameters such as CSF and η, it was found that when both SF and CSF are greater than 1, the rock mass shows no tendency to slide and is considered stable. When SF is greater than 1 and CSF is less than 1, the rock mass shows a tendency to slide and is considered unstable. Specifically, when η is greater than or equal to the ratio of the long-term strength to the failure strength of the structural surface, it is an unstable rock mass without a deterioration trend; when η is less than the ratio of the long-term strength to the failure strength of the structural surface, it is an unstable rock mass with a deterioration trend. When both SF and CSF are less than 1, the rock mass fails and slides, resulting in collapse. This new quantitative identification method can provide field engineers with an objective and unified mechanical judgment standard, thereby improving the accuracy and scientific rigor of current identification of slope sliding-type unstable rock masses and effectively reducing casualties and property losses caused by human error.

[0096] Previous experimental studies have shown that parameters such as natural vibration frequency and damping ratio obtained through vibration monitoring can effectively identify rock mass penetration rate, and thus enable the evaluation and analysis of indicators such as rock mass CSF and cohesion-resistance ratio. Therefore, in future engineering applications, this method can be combined with novel remote sensing vibration technology to further address the problems of insufficient mechanical indicator information sources and inconsistent evaluation standards in current traditional methods for identifying dangerous rock masses. The next step is to conduct remote laser vibration monitoring on a steep slope rock mass. By monitoring vibration characteristics such as natural vibration frequency, we can analyze diversified mechanical indicators such as CSF, SF, and η of the rock mass on the steep slope, thereby providing technical support for better identification of sliding-type dangerous rock masses in high-risk areas.

[0097] Case 2: To verify the engineering application effect of the method in this embodiment, a dangerous rock mass on a steep slope was selected as the research object. The area where the dangerous rock mass is located is a tectonic erosion mid-mountain landform, with a relatively steep slope overall, a slope aspect of about 140°, and an average slope of 45°; the bedrock in this area is exposed and has a rectangular shape. Figure 4 The images show on-site photographs and stereographic projections of unstable rock masses W1 and W2, including:

[0098] Dangerous Rock 1 (W1): Located on a steep cliff with a slope of 48° and an elevation of 1278m, the main collapse direction is 143°. The dangerous rock mass is approximately 2m long, 2m wide, and 2.5m thick. The rock mass is characterized by well-developed fissures, primarily consisting of three sets: L1: 228°∠63°, L2: 56°∠72°, and L3: 324°∠64°. The free face dips at 143°∠67°.

[0099] Dangerous Rock 2 (W2): Located on a steep cliff with a slope of 54°, an elevation of 1276m, and a main collapse direction of 145°. The dangerous rock mass is approximately 2.5m long, 1.5m wide, and 2m thick. The rock mass is characterized by well-developed fissures, primarily consisting of three sets: L1: 225°∠66°, L2: 52°∠75°, and L3: 324°∠57°. The free face dips at 145°∠70°.

[0100] According to on-site investigation and monitoring data, the fractures at the rear edges of both W1 and W2 rock masses have expanded to varying degrees, and under the influence of their own weight, water pressure, and vibration, they are both likely to slide towards the free surface.

[0101] The rock mass stability evaluation results obtained by applying the method of this embodiment are shown in Table 5.

[0102] Table 5 Evaluation results of rock masses W1 and W2

[0103]

[0104] Table 5 shows that although the SF values ​​of rock masses W1 and W2 are both above 1.0, their CSF values ​​are both below 1.0. Furthermore, the η values ​​of both rock masses W1 and W2 are less than the ratio of long-term strength to failure strength of the structural plane, indicating that both are unstable rock masses with a tendency to deteriorate, which is completely consistent with the actual investigation results. It is worth noting that the SF value of rock mass W1 is as high as 1.67. Traditional methods could easily misclassify W1 as a stable rock mass, but the new quantitative identification method and judgment index effectively avoid this misclassification. Engineering application case results show that, compared with traditional analysis methods, the new method has significant theoretical analytical advantages and engineering application potential in the identification of unstable rock mass stability.

[0105] In summary, during the process of cumulative damage to transform slip-type rock masses into unstable rock masses, the rate of cohesion decay is the greatest. Therefore, compared to the single mechanical index of stability coefficient SF, this invention introduces mechanical parameters such as CSF and η, which can provide relatively sensitive mechanical parameters for the identification of slip-type unstable rock masses. Compared to traditional mechanical identification methods for unstable rock masses, the new identification method presented in this invention can provide a set of objective and unified identification criteria, realizing dynamic consideration of the stability stage, separation stage, and failure stage of slip-type unstable rock masses. Field case studies show that the new mechanical identification method effectively distinguishes slip-type unstable rock masses with a stability coefficient around 1.2, improving the accuracy and scientific rigor of traditional mechanical identification of unstable rock masses, and providing a new reference for engineers engaged in geological disaster investigation to better identify slip-type unstable rock masses.

[0106] Furthermore, it should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or terminal device that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or terminal device. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or terminal device that includes said element.

[0107] Finally, it should be noted that the above description represents a preferred embodiment of the present invention. It should be pointed out that although preferred embodiments have been described, those skilled in the art, once they understand the basic inventive concept of the present invention, can make various improvements and modifications without departing from the principles described herein. These improvements and modifications should also be considered within the scope of protection of the present invention. Therefore, the appended claims are intended to be interpreted as including both the preferred embodiments and all changes and modifications falling within the scope of the embodiments of the present invention.

Claims

1. A method for identifying slip-type unstable rock masses based on multiple indicators, characterized in that, include: Obtain the physical and mechanical parameters of the rock mass to be identified, including: the initial cohesion, internal friction angle, bond length, bottom dip angle and self-weight of the rock mass, as well as the effective normal stress and shear stress on the sliding surface; The natural vibration frequency and damping ratio parameters of the slip-type unstable rock mass structure were obtained at different times after damage. Calculate the cohesion and internal friction angle after damage; Based on the physical and mechanical parameters of the rock mass, the stability coefficient, bond stability coefficient, and cohesion anti-sliding ratio of the sliding-type unstable rock mass were calculated at different times after damage. Based on the stability coefficient, bond stability coefficient, and cohesion anti-sliding ratio index, the rock mass to be identified is identified as a sliding-type unstable rock mass according to the preset identification rules, and the identification results are obtained. The formula for calculating cohesion after damage is: ； in, for Real-time cohesion of slip-type unstable rock mass structures The initial cohesion of the slip-type unstable rock mass structure, for The instantaneous natural vibration frequency of the slip-type unstable rock mass structure. The initial natural vibration frequency of the sliding-type unstable rock mass structure. for Instantaneous damping ratio of a slip-type unstable rock mass structure The initial damping ratio of the sliding-type unstable rock mass structure; The formula for calculating the internal friction angle after damage is: ； in, for Real-time internal friction angle of slip-type unstable rock mass structure The initial internal friction angle of the sliding-type unstable rock mass structure. for Instantaneous damping ratio of a slip-type unstable rock mass structure The initial damping ratio of the sliding-type unstable rock mass structure; Stability coefficient SF The calculation formula is: ； in, For the first The cohesion required for the stability of block rock masses For the first Effective normal stress on the sliding surface of the strip block For the first The internal friction angle of the block rock mass For the first Strip bonding length, For the first Shear stress on the sliding surface of the strip; Bond stability coefficient CSF The calculation formula is: ； in, For the transmission coefficient, , For the first The angle of inclination of the base of the strip. For the first Inclination angle of the base of the strip; To act on the first The cohesive force of strips, , To act on the first The cohesive force of strips; To act on the first The downward component of the force on the sliding surface of the strip. , To act on the first The downward component of the sliding force on the sliding surface of the strip; For the first The weight of the strip; The number of strips; The proportion of cohesive anti-slip ratio The calculation formula is: ； in, CSF Indicates the bond stability coefficient. SF Represents the stability coefficient; Based on the stability coefficient, bond stability coefficient, and cohesion anti-sliding ratio index, and according to preset identification rules, the rock mass to be identified is subjected to sliding-type unstable rock mass identification, and the identification results are obtained, including: For the calculated stability coefficient SF Bond stability coefficient CSF and cohesive anti-slip ratio When conducting analysis, SF and CSF When both are greater than 1, the rock mass has no tendency to slide down, and the rock mass is stable; when SF Greater than 1 and CSF When the value is less than 1, the rock mass has a tendency to slide, and at this time the rock mass is a dangerous rock mass; among them, when the rock mass is a dangerous rock mass, if If the ratio of the long-term strength to the failure strength of the structural plane is greater than or equal to the ratio of the long-term strength to the failure strength, then the rock mass is a dangerous rock mass with no tendency to deteriorate; if If the ratio of the long-term strength to the failure strength of the structural plane is less than that of the rock mass, then the rock mass is a dangerous rock mass with a tendency to deteriorate; when SF and CSF When all values ​​are less than 1, the rock mass breaks down and slides, resulting in collapse.

2. The method for identifying slip-type unstable rock masses based on multiple indicators as described in claim 1, characterized in that, The acquisition of the physical and mechanical parameters of the rock mass to be identified includes: The initial cohesion, internal friction angle, bond length, bottom dip angle, and self-weight of the rock mass to be identified, as well as the effective normal stress and shear stress on the sliding surface, were obtained through in-situ tests.

3. The method for identifying slip-type unstable rock masses based on multiple indicators as described in claim 1, characterized in that, The acquisition of the natural vibration frequency and damping ratio parameters of the slip-type unstable rock mass structure at different times after damage includes: The natural vibration frequency of the sliding-type unstable rock mass structure was measured using non-contact remote sensing monitoring technology, and the damping ratio of the sliding-type unstable rock mass structure was calculated; the damping ratio... The calculation formula is: ； in, The energy loss factor of sliding-type unstable rock mass structures. This refers to the energy dissipation during two cycles of vibration in a sliding-type unstable rock mass structure. This represents the total energy of a sliding-type unstable rock mass structure system.

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