Porosity-based weak rock freeze-thaw damage degree evaluation method and device, electronic equipment and storage medium

Abstract

The invention provides a porosity-based weak rock freeze-thaw damage degree evaluation method and device, electronic equipment and a storage medium. The method comprises the following steps: obtaining a freeze-thaw damage degree evaluation model pre-constructed for a weak rock; wherein the freeze-thaw damage degree evaluation model is used for representing the change relation of the uniaxial compressive strength of the weak rock along with the porosity in the freeze-thaw cycle environment; obtaining the initial uniaxial compressive strength, the initial porosity and the rock mechanical characteristic value of the rock sample of any type of weak rock before freezing and thawing; determining the porosity of the type of weak rock after the freeze-thaw cycle; and substituting the initial uniaxial compressive strength, the initial porosity, the rock mechanical characteristic value and the porosity after the freeze-thaw cycle into a freeze-thaw damage degree evaluation model to obtain a uniaxial compressive strength value after the freeze-thaw cycle, and taking the uniaxial compressive strength value as the freeze-thaw damage degree of the type weak rock. According to the method, the uniaxial compressive strength of any type of weak rock in different freeze-thaw periods can be accurately predicted through the constructed freeze-thaw damage degree evaluation model.

Description

Technical Field

[0001] The present invention relates to the field of rock engineering technology, and in particular to a porosity-based freeze-thaw damage assessment method, device, electronic equipment and storage medium for weak rock. Background Art

[0002] Freeze-thaw damage to weak rock is a key research topic in cold-region engineering geology and geotechnical engineering. In seasonally frozen soil areas, the damage and deterioration of weak rock due to freeze-thaw cycles is a key factor contributing to geological hazards such as slope instability and landslides. The mechanism of freeze-thaw damage to weak rock stems primarily from the destructive effects of frost heave forces generated during the water-to-ice phase transition on the rock structure. Under low-temperature conditions, water in rock fissures freezes into ice, expanding its volume and generating frost heave forces, which expand the rock's pores and microcracks. When temperatures rise, the ice melts into water, shrinking the rock's pores. However, irreversible damage has already occurred to the rock's internal structure. This freeze-heave-thaw cycle continues to act on the rock, causing microcracks to expand and connect, ultimately damaging the rock's overall structure and degrading its mechanical properties.

[0003] Currently, research on freeze-thaw damage in weak rocks, both domestically and internationally, is primarily based on volume expansion theory, focusing on the effects of freeze-thaw cycles on rock pore structure and mechanical properties. However, weak rocks of different lithologies exhibit significant differences in pore development and evolution, as well as porosity variations, during freeze-thaw processes. For weak rocks such as phyllite, in particular, the freeze-thaw degradation mechanism is more complex, and existing research methods and models struggle to accurately reflect the continuous and cumulative effects of freeze-thaw cycles on weak rocks. In slopes with poor drainage, freeze-thaw damage continues to extend into the rock mass, exacerbating its structural integrity and stability. However, currently, there is a lack of technical means to accurately reflect this process. Therefore, establishing an accurate freeze-thaw damage model for weak rocks and conducting in-depth research on its freeze-thaw degradation mechanism are of great significance for scientifically assessing slope stability and preventing geological disasters in cold regions. Summary of the Invention

[0004] In view of this, the purpose of the present invention is to provide a porosity-based method, device, electronic device, and storage medium for assessing the degree of freeze-thaw damage in weak rock, in order to establish an accurate freeze-thaw damage model for weak rock and accurately predict the uniaxial compressive strength of any type of weak rock after different freeze-thaw cycles. To achieve the above purpose, the technical solutions adopted by the present invention are as follows:

[0005] In a first aspect, the present invention provides a porosity-based freeze-thaw damage assessment method for weak rocks, the method comprising: obtaining a pre-constructed freeze-thaw damage assessment model for weak rocks; wherein the freeze-thaw damage assessment model is used to characterize the relationship between the uniaxial compressive strength of weak rocks and porosity under a freeze-thaw cycle environment; obtaining the initial uniaxial compressive strength, initial porosity and rock mechanical characteristic values ​​of a rock sample of any type of weak rock before freeze-thaw; determining the porosity of the type of weak rock after freeze-thaw cycles; substituting the initial uniaxial compressive strength, the initial porosity, the rock mechanical characteristic values ​​and the porosity after freeze-thaw cycles into the freeze-thaw damage assessment model to obtain the uniaxial compressive strength value after freeze-thaw cycles as the freeze-thaw damage degree of the type of weak rock.

[0006] In a second aspect, the present invention provides a phyllite freeze-thaw damage assessment device, comprising: an acquisition module for obtaining a freeze-thaw damage degree assessment model pre-constructed for soft rock; wherein the freeze-thaw damage degree assessment model is used to characterize the relationship between the uniaxial compressive strength and porosity of soft rock under a freeze-thaw cycle environment; the acquisition module is also used to obtain the initial uniaxial compressive strength, initial porosity and rock mechanical characteristic values ​​of rock samples of any type of soft rock before freeze-thaw; a determination module is used to determine the porosity of the type of soft rock after the freeze-thaw cycle; an assessment module is used to substitute the initial uniaxial compressive strength, the initial porosity, the rock mechanical characteristic values ​​and the porosity after the freeze-thaw cycle into the freeze-thaw damage degree assessment model to obtain the uniaxial compressive strength value after the freeze-thaw cycle as the freeze-thaw damage degree of the type of soft rock.

[0007] In a third aspect, the present invention provides an electronic device comprising a processor and a memory, wherein the memory stores machine executable instructions that can be executed by the processor, and the processor can execute the machine executable instructions to implement the porosity-based freeze-thaw damage assessment method for weak rocks as described in any of the aforementioned embodiments.

[0008] In a fourth aspect, the present invention provides a storage medium having a computer program stored thereon, which, when executed by a processor, implements the porosity-based freeze-thaw damage assessment method for weak rock as described in any of the aforementioned embodiments.

[0009] The porosity-based freeze-thaw damage assessment method, device, electronic device, and storage medium for soft rock provided by the embodiments of the present invention first obtain a pre-constructed freeze-thaw damage assessment model for soft rock. This model is used to characterize the relationship between the uniaxial compressive strength of soft rock and porosity under a freeze-thaw cycle environment. Next, the initial uniaxial compressive strength, initial porosity, and rock mechanical characteristic values ​​of the rock sample of any type of soft rock before freeze-thaw are obtained. These data provide a basis for subsequent calculations. The porosity of this type of soft rock after the freeze-thaw cycle is then determined. These values ​​are substituted into the freeze-thaw damage assessment model to obtain the uniaxial compressive strength value after freeze-thaw. Through this method, the uniaxial compressive strength of soft rock after different freeze-thaw cycles can be accurately predicted on a macro scale, thereby providing reliable data support for engineering design and safety assessment, which is of great significance for scientifically evaluating slope stability in cold regions and preventing geological disasters.

[0010] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, preferred embodiments are given below and described in detail with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments. It should be understood that the following drawings only illustrate certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without paying any creative work.

[0012] Figure 1 A schematic diagram of the process of constructing an estimation model for the freeze-thaw disturbance factor provided in an embodiment of the present invention;

[0013] Figure 2 A schematic diagram of a process for determining a relationship model between uniaxial compressive strength and freeze-thaw disturbance factor provided by an embodiment of the present invention;

[0014] Figure 3 A schematic flow chart of a porosity-based freeze-thaw damage assessment method for weak rock provided in an embodiment of the present invention;

[0015] Figure 4 Schematic diagram of the difference between the theoretical value and the measured value of the uniaxial compressive strength for different freeze-thaw cycles provided by the embodiment of the present invention;

[0016] Figure 5 A functional module diagram of a porosity-based soft rock freeze-thaw damage assessment device provided in an embodiment of the present invention;

[0017] Figure 6 This is a structural block diagram of an electronic device provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0018] The following will be combined with the accompanying drawings to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings herein can be arranged and designed in various different configurations.

[0019] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention as claimed, but is merely intended to represent selected embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative work are within the scope of protection of the present invention.

[0020] It should be noted that relational terms such as "first" and "second" are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the terms "comprises," "comprising," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus comprising a series of elements includes not only those elements, but also other elements not explicitly listed, or elements inherent to such process, method, article, or apparatus. In the absence of further limitations, an element defined by the phrase "comprising a ..." does not exclude the presence of additional identical elements in the process, method, article, or apparatus comprising the element.

[0021] In order to establish an accurate freeze-thaw damage model for weak rock, the inventors first considered the cumulative effect of freeze-thaw cycles on the microstructure of weak rock mass during the research process, and thus defined the "freeze-thaw disturbance factor", denoted as D x , characterizing the degree of damage or the amount of damage sustained by a weak rock mass after x freeze-thaw cycles. Furthermore, the present invention derives a freeze-thaw damage model for weak rock by determining the relationship between the uniaxial compressive strength and the freeze-thaw disturbance factor after freeze-thaw cycles. This model can be applied to weak, porous rocks such as phyllite.

[0022] In order to accurately estimate the freeze-thaw disturbance factor of weak rock during the freeze-thaw cycle, the embodiment of the present invention first constructs an estimation model for the freeze-thaw disturbance factor. The construction process of the estimation model will be described in detail and clearly with reference to relevant formulas.

[0023] See Figure 1 , Figure 1A schematic diagram of the construction process of the freeze-thaw disturbance factor estimation model provided in an embodiment of the present invention includes steps S11 to S14, which are described as follows:

[0024] S11: Obtain the probability density function used to characterize the damage variation of rock micro-units;

[0025] In the embodiment of the present invention, under the action of freeze-thaw cycles, various physical indicators of weak rocks will undergo significant changes. The uniaxial compressive strength index is closely related to some physical properties, so the uniaxial compressive strength will also change under the action of freeze-thaw. In order to determine the key indicators that affect the uniaxial compressive strength, the damage mechanism of rocks under freeze-thaw cycles can be understood from a microscopic perspective. Specifically: inside the weak rock, the rock micro-units are composed of micro-columns and micro-pores. Micro-columns are responsible for bearing loads and are the main source of rock strength. Micro-pores are channels for water entry and frost heave damage, and play an important role in rock degradation. As the number of freeze-thaw cycles increases, micro-columns may be broken due to crack expansion, and their volume decreases; at the same time, micro-pores gradually expand and connect, resulting in an increase in the overall porosity of the rock and deterioration of mechanical properties.

[0026] Based on the above-mentioned microscopic theory of rock mass, the rock micro-unit of weak rock can be decomposed into the volume of micro-columns and micro-pores, and the external load can be decomposed into the load borne by the micro-columns. The relationship between them is shown in formulas (1) and (2):

[0027]

[0028] In formula (1): V u represents the volume of the rock microunit; dx, dy, and dz represent the dimensions of the rock microunit in three orthogonal directions (x-axis, y-axis, and z-axis), respectively; V ri 、V pj represent the volume of micro-pillar i and micro-pore j respectively; F u represents the external load acting on the entire rock micro-unit; F i Refers to the load borne by micro-column i; m1 and k represent the number of micro-columns and micro-pores.

[0029] Based on the above rock mass microscopic theory, relevant researchers have proposed that the damage and failure process of rocks is random, and the strength failure of rock micro-units can be described by Weibull distribution. In order to quantitatively describe the process of rock damage and failure, relevant researchers have proposed a theoretical model, such as the probability density function of formula (3):

[0030]

[0031] In formula (3), P(F) is the probability density function, which represents the probability density of the rock micro-unit strength being F; F t is the statistical distribution variable of the strength of the rock microunit, i.e., the actual strength of the rock microunit; m and F1 are statistical distribution parameters, i.e., the rock mechanical characteristics in the embodiment of the present invention. These parameters determine the shape and scale of the Weibull distribution and are related to the mechanical properties of the rock material. Formula (3) is the probability density function used to characterize the damage variation of the rock microunit in the embodiment of the present invention.

[0032] Here, the Weibull distribution is used to describe the intensity distribution of rock microunits, that is, the probability of microunits with different intensity values ​​appearing in the rock. The Weibull distribution's probability density function quantitatively describes the intensity distribution of rock microunits, meaning that this formula can be used to calculate the probability density of rock microunits at different intensity values.

[0033] S12: Taking the uniaxial compressive strength after multiple freeze-thaw cycles as the integral range, the probability density function is integrated within the integral range to obtain the expression of rock damage after multiple freeze-thaw cycles;

[0034] Among them, the rock damage expression describes the correlation between rock damage, rock mechanical characteristics, and uniaxial compressive strength after multiple freeze-thaw cycles;

[0035] In the embodiment of the present invention, the uniaxial compressive strength after multiple freeze-thaw cycles is recorded as σ x , then the integral range of the probability density function variable of formula (3) is (0, σ x ), based on the integral range, the embodiment of the present invention integrates formula (3) to obtain Among them, P(σ x ) represents the uniaxial compressive strength σ after x freeze-thaw cycles x The probability density of P(σ x The result obtained by integrating ) can be understood as the amount of rock damage caused by the continuous damage to the rock after x freeze-thaw cycles. This rock damage amount is equivalent to the freeze-thaw disturbance factor defined in the embodiment of the present invention. Therefore, combined with formula (3), equation (4) can be obtained:

[0036]

[0037] From formula (4), we can see that the freeze-thaw disturbance factor D x It can be characterized by the porosity and rock mechanical characteristics after freezing and thawing. Among them, the rock mechanical characteristics can be calculated from the measured data in the uniaxial compression test, which is equivalent to a known quantity. This shows that the porosity after freezing and thawing is the factor that affects D x key indicators.

[0038] It should be noted that according to the statistical law of Weibull distribution, the strength of each micro-unit can be divided into two states: damaged and non-destructive. This distribution has a 0-1 characteristic, that is, each micro-unit is either completely damaged (represented by 1) or completely undamaged (represented by 0). Based on this, D x The value range is between 0 and 1, where 0 means no damage at all and 1 means complete damage. x The value range is converted to 0 to 1.

[0039] S13: Obtain the proportional relationship between the uniaxial compressive strength and porosity of rock before and after freeze-thaw based on the strain equivalence principle;

[0040] Continuing to combine the above formulas (1) and (2) from the microscopic perspective, under the assumption that the strength of the rock micro-unit satisfies the Weibull function, we can establish a proportional relationship between the volume of micro-columns and porosity, as shown in formula (5):

[0041]

[0042] In formula (5), N u0 、N ux are the volumes of micro-columns per unit volume of the rock micro-unit before and after freezing and thawing; n0 is the porosity of the rock in the initial state (i.e. before freezing and thawing); n x is the porosity of the rock after x freeze-thaw cycles.

[0043] When the load F0 acts on the unit volume of rock mass or rock micro-unit, under the same load area, after x freeze-thaw cycles, the load on the unit volume of rock mass is F x The relationship between it and the uniaxial compressive strength is shown in formula (6):

[0044]

[0045] In formula (6), S d It represents the area of ​​rock mass per unit volume.

[0046] The in-depth study of the Lemaitre strain equivalence principle by relevant researchers has provided key technical progress for the development of rock mechanics and material damage theory, pointing out that when applying equivalent stress under different stress states, the conversion effect of the stress state must be considered. This improvement believes that the determination of equivalent stress should be based on the actual response of the material under a specific stress state, rather than a single proportional reduction, so as to generate strain in the rock under stress. Therefore, combined with formula (6), the following equation relationship exists:

[0047]

[0048] Combining formulas (23) and (24), we have the following proportional relationship:

[0049]

[0050] Where: F0 represents the load acting on the rock micro-unit before the freeze-thaw cycle; F x represents the load acting on the rock micro-unit after x freeze-thaw cycles; σ0, σ x Respectively represent the rock micro-unit before and after freezing and thawing under loads F0 and F x Uniaxial compressive strength under action; E0, E x are the initial elastic modulus before freezing and thawing and the elastic modulus after x freeze-thaw cycles; S d Indicates area per unit volume.

[0051] From formula (9), we can see that the proportional relationship between uniaxial compressive strength and porosity is:

[0052] S14: Substitute the above rock damage expression and the uniaxial compressive strength in the above proportional relationship by equal amounts to obtain an estimation model for the freeze-thaw disturbance factor.

[0053] Step S14 can be understood as: the above formula (4) and the above proportional relationship between uniaxial compressive strength and porosity are combined into Perform an equal replacement, that is, replace the uniaxial compressive strength σ x , the estimation model of freeze-thaw disturbance factor can be obtained as shown in formula (10). This model is characterized by porosity after freeze-thaw, rock mechanical characteristics and initial uniaxial compressive strength. Rock mechanical characteristics and initial uniaxial compressive strength can be determined by measuring data in uniaxial compression test, and initial porosity can be obtained by nuclear magnetic resonance test. These parameters are equivalent to known quantities, which further shows that porosity after freeze-thaw is the factor affecting D x key indicators.

[0054]

[0055] Furthermore, based on the freeze-thaw disturbance factor, the embodiment of the present invention also constructs a freeze-thaw damage assessment model pre-constructed by phyllite. The construction process is as follows: Figure 2 As shown, Figure 2 The process of determining the relationship model between uniaxial compressive strength and freeze-thaw disturbance factor provided in an embodiment of the present invention includes steps S21 to S22:

[0056] S21: Obtain the relationship between the amount of rock damage after freeze-thaw cycles and the elastic modulus before and after freeze-thaw cycles, as well as the proportional relationship between the uniaxial compressive strength and elastic modulus before and after freeze-thaw cycles based on the strain equivalence principle;

[0057] In the embodiment of the present invention, the proportional relationship between the uniaxial compressive strength and the elastic modulus is shown in formula (7): The amount of rock damage is one of the key indicators for measuring freeze-thaw rock degradation. This indicator can also be calculated by comparing the initial elastic modulus of the rock before damage and the elastic modulus after damage. The specific formula is shown in formula (11), which characterizes D by the elastic modulus. x :

[0058] D x (E) = 1-E x / E0(11)

[0059] Where: D x (E) is the rock damage after x freeze-thaw cycles; E x is the elastic modulus after x freeze-thaw cycles; E0 is the elastic modulus before freeze-thaw cycles. Formula (11) characterizes the freeze-thaw disturbance factor through the elastic modulus.

[0060] S22: The relationship expression between the amount of rock damage after freeze-thaw cycles and the elastic modulus before and after freeze-thaw cycles and the proportional relationship between uniaxial compressive strength and elastic modulus are replaced by the elastic modulus after freeze-thaw, and a relationship model between uniaxial compressive strength and freeze-thaw disturbance factor is obtained.

[0061] Combined with the above formula (7), we can know the proportional relationship between uniaxial compressive strength and elastic modulus. For the elastic modulus E in formula (7) and formula (11), x By performing equivalent substitution, the freeze-thaw damage degree assessment model is obtained, as shown in formula (12), which characterizes the correlation model between the uniaxial compressive strength and the freeze-thaw disturbance factor:

[0062] σ x =σ0(1-D x ) (12)

[0063] Furthermore, by combining formula (10) and formula (12), the freeze-thaw damage degree assessment model in the embodiment of the present invention can be obtained as shown in formula (13):

[0064]

[0065] It can be seen that σ0, n0, F1 and m can all be obtained through experimental data and are known quantities. Then the factors that affect the degree of freeze-thaw damage σ xThe key indicator is porosity. Based on this, the embodiment of the present invention provides a method for evaluating the degree of freeze-thaw damage of weak rock based on porosity. Figure 3 , Figure 3 A schematic flow chart of a porosity-based freeze-thaw damage assessment method for weak rock provided in an embodiment of the present invention includes steps S301 to S304, which are described as follows:

[0066] S301: Obtain a freeze-thaw damage assessment model pre-built for weak rock;

[0067] S302: Obtain the initial uniaxial compressive strength, initial porosity and rock mechanical characteristic values ​​of a rock sample of any type of weak rock before freezing and thawing;

[0068] S303: Determine the porosity of weak rock after freeze-thaw cycles;

[0069] S304: Substitute the initial uniaxial compressive strength, initial porosity, rock mechanical characteristic values, and porosity after freeze-thaw cycles into the freeze-thaw damage assessment model to obtain the uniaxial compressive strength value after freeze-thaw cycles as the freeze-thaw damage degree of the type of weak rock.

[0070] In one embodiment of the present invention, the initial porosity can be obtained through a nuclear magnetic resonance analysis test. During implementation, the initial porosity of the rock before freeze-thaw can be directly obtained by saturating the rock sample with water through a nuclear magnetic resonance analysis test. The initial uniaxial compressive strength can be measured in a uniaxial compression test, and the rock mechanical characteristic values ​​can be calculated using the initial elastic modulus, peak stress, and peak strain measured in the uniaxial compression test. Therefore, for step S302, the parameters required in the valuation model can be obtained in sequence as follows:

[0071] Step 1: Obtain the initial porosity of the rock sample measured in the nuclear magnetic resonance analysis test and the initial elastic modulus, peak stress and peak strain measured in the uniaxial compression test;

[0072] Step 2: Calculate the rock mechanical characteristic values ​​based on the initial elastic modulus, peak stress and peak strain.

[0073] In the embodiment of the present invention, the rock mechanical characteristic values ​​m and F1 in formula (13) can be obtained according to formula (14) and formula (15):

[0074]

[0075] F1=σ f m b -1 / m (15)

[0076] Where: E0 is the initial elastic modulus (unit: GPa); σf is the peak stress (unit: MPa); ε0 is the peak strain.

[0077] In one embodiment of the present invention, the porosity after freeze-thaw in step S303 can be determined by a porosity measurement calculation model. The porosity measurement calculation model is obtained by fitting the porosity obtained by nuclear magnetic resonance tests under different freeze-thaw cycles. As shown in formula (16):

[0078] n x = n0 +0.04294x-6.44665 ＊10 -4x 2 (16)

[0079] Where x is the number of freeze-thaw cycles; nx is the porosity (%) after x freeze-thaw cycles; and n0 is the initial porosity, which is 1.91585. It should be noted that formula (16) is only applicable to porosity calculations within 40 freeze-thaw cycles, that is, 0 ≤ x ≤ 40.

[0080] Therefore, the implementation method of step S303 can be: obtaining a porosity measurement calculation model; wherein the porosity measurement calculation model is obtained by fitting the porosity obtained by nuclear magnetic resonance tests under different freeze-thaw cycles; inputting the initial porosity and the freeze-thaw cycle number into the porosity measurement calculation model to obtain the porosity after the freeze-thaw cycle.

[0081] In step S304, based on the pre-constructed freeze-thaw damage assessment model (Formula 13), the initial uniaxial compressive strength σ0, initial porosity n0 and rock mechanics characteristic values ​​F1 and m are substituted into the model to obtain the uniaxial compressive strength value after freeze-thaw cycles as the freeze-thaw damage degree of the type of weak rock.

[0082] Steps S301 to S304 provided in the embodiment of the present invention can not only effectively capture the cumulative impact of freeze-thaw cycles on the microstructure of the rock mass, but also accurately predict the uniaxial compressive strength of phyllite after different freeze-thaw cycles on a macro scale, thereby providing reliable data support for engineering design and safety assessment, which is of great significance for scientifically evaluating the stability of slopes in cold regions and preventing geological disasters.

[0083] The following takes phyllite as an example to verify the accuracy and rationality of the freeze-thaw damage degree assessment model constructed by the embodiment of the present invention in assessing the freeze-thaw damage degree in a freeze-thaw cycle environment. The embodiment of the present invention uses Weibull distribution for analysis. Assuming that the sample numbers of the collected phyllite rock samples are A1 and A2, the test data measured in the uniaxial compression test are substituted into the following formulas (14) and (15), and the rock mechanical characteristic values ​​F1 and m are obtained respectively: shape parameter F z and the scale parameter m b, as shown in Table 1.

[0084] Table 1

[0085]

[0086] The shape parameter F z , scale parameter m b And the initial uniaxial compressive strength are substituted into formula (10), and the estimation model of the freeze-thaw disturbance factor of phyllite with porosity as the variable can be obtained:

[0087]

[0088] This formula can effectively capture the cumulative effects of freeze-thaw cycles on the microstructure of phyllite.

[0089] Initial porosity, initial uniaxial compressive strength, rock mechanical characteristic value (shape parameter F z and the scale parameter m b) Substituting into formula (16), the freeze-thaw damage assessment model of phyllite after x times can be obtained as follows:

[0090]

[0091] This formula shows on a macroscopic level the effect of porosity changes of phyllite under freeze-thaw cycles on its uniaxial compressive strength.

[0092] Based on the above model, the predicted values ​​of the uniaxial compressive strength of sample A1 and sample A2 after different numbers of freeze-thaw cycles can be calculated. See Table 2, which shows the comparison results of the theoretical and measured values ​​of the uniaxial compressive strength of sample A1 and sample A2 after different numbers of freeze-thaw cycles.

[0093] Table 2

[0094]

[0095] As can be seen from Table 2, under different freeze-thaw cycles, the errors between the theoretical and measured values ​​of the uniaxial compressive strength of Samples A1 and A2 are small, indicating the rationality and reliability of the model constructed in the embodiment of the present invention in evaluating the degree of freeze-thaw damage of phyllite. In order to more intuitively observe the difference between the theoretical values ​​calculated by the model and the measured values, please refer to Figure 4 , Figure 4 Schematic diagram of the difference between the theoretical value and the measured value of the uniaxial compressive strength at different freeze-thaw cycles provided by the embodiment of the present invention.

[0096] from Figure 4It can be seen that the theoretical values ​​of the uniaxial compressive strength of phyllite after 5, 10, 20, and 40 freeze-thaw cycles are obtained by formula (17). The calculated theoretical values ​​of the uniaxial compressive strength of phyllite are basically lower than the measured values, which are in good agreement with the experimental results, with a correlation coefficient of 0.91963. Among them, when the phyllite freeze-thaw cycle is 20 times, the theoretical value and the measured value show a large difference. It is speculated that the reason is that the anisotropy of the phyllite sample is large, and the porosity fitting formula has a certain error, which leads to a large error between the theoretical value and the measured value at 20 times. Therefore, porosity is used to characterize and estimate the freeze-thaw rock disturbance coefficient D x The value of has a certain rationality. At the same time, the porosity of rock can also be used to predict the uniaxial compressive strength of rock after different freeze-thaw cycles, providing a scientific basis for the design accuracy and safety of engineering structures, and greatly improving the reliability of geotechnical engineering construction.

[0097] In order to execute the corresponding steps in the above embodiments and various possible methods, the following is an implementation method of a device for evaluating the degree of freeze-thaw damage of weak rock based on porosity. Figure 5 , Figure 5 This is a functional module diagram of a porosity-based soft rock freeze-thaw damage assessment device provided in an embodiment of the present invention. It should be noted that the basic principles and technical effects of the porosity-based soft rock freeze-thaw damage assessment device provided in this embodiment are the same as those of the above-mentioned embodiments. For the sake of simplicity, any parts not mentioned in this embodiment can be referred to the corresponding content in the above-mentioned embodiments. The porosity-based soft rock freeze-thaw damage assessment device 50 includes: an acquisition module 501, a determination module 502, and an assessment module 503.

[0098] Acquisition module 501 is used to obtain a freeze-thaw damage assessment model pre-built for weak rock; wherein the freeze-thaw damage assessment model is used to characterize the relationship between the uniaxial compressive strength and porosity of weak rock under a freeze-thaw cycle environment;

[0099] The acquisition module 501 is further used to obtain the initial uniaxial compressive strength, initial porosity and rock mechanical characteristic values ​​of a rock sample of any type of weak rock before freezing and thawing;

[0100] Determination module 502, for determining the porosity of the type of weak rock after freeze-thaw cycles;

[0101] Evaluation module 503 is used to substitute the initial uniaxial compressive strength, initial porosity, rock mechanical characteristic values ​​and porosity after freeze-thaw cycles into the freeze-thaw damage degree evaluation model to obtain the uniaxial compressive strength value after freeze-thaw cycles as the freeze-thaw damage degree of the type of weak rock.

[0102] It is understandable that the acquisition module 501, the determination module 502 and the evaluation module 503 can be executed in a coordinated manner. Figure 2 Each step in the process is performed to achieve the corresponding technical effects.

[0103] It should be noted that the division of modules in the above embodiments of the present application is illustrative and is only a logical functional division. In actual implementation, there may be other division methods. In addition, the functional units in the various embodiments of the present application may be integrated into a processing unit, or may exist separately physically, or two or more units may be integrated into a single unit. The above-mentioned integrated units may be implemented in the form of hardware or in the form of software functional units.

[0104] If the integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present application, or the part that contributes to the prior art, or all or part of the technical solution can be embodied in the form of a software product. The computer software product is stored in a storage medium and includes several instructions for enabling an electronic device (which can be a personal computer, server, or network device, etc.) or a processor to execute all or part of the steps of the various embodiments of the present application. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM), random access memory (RAM), disk or optical disk, and other media that can store program executable code.

[0105] The present invention also provides an electronic device. Figure 6 , Figure 6 The electronic device provided in an embodiment of the present invention includes a memory 601, a processor 602, and a communication interface 603. The memory 601, processor 602, and communication interface 603 are electrically connected to each other, directly or indirectly, to enable data transmission or interaction. For example, these components may be electrically connected to each other via one or more communication buses or signal lines.

[0106] Optionally, the bus can be a Peripheral Component Interconnect (PCI) bus or an Extended Industry Standard Architecture (EISA) bus. The bus can be divided into an address bus, a data bus, a control bus, etc. For ease of representation, Figure 6 Only one thick line is used in the diagram, but this does not mean that there is only one bus or one type of bus.

[0107] In an embodiment of the present invention, the processor 602 may be a general-purpose processor, a digital signal processor, an application-specific integrated circuit, a field programmable gate array or other programmable logic device, a discrete gate or transistor logic device, or a discrete hardware component, and may implement or execute the various methods, steps, and logic block diagrams disclosed in the embodiments of the present invention. A general-purpose processor may be a microprocessor or any conventional processor, etc. The steps of the method disclosed in conjunction with the embodiments of the present invention may be directly embodied as being executed by a hardware processor, or may be executed by a combination of hardware and software modules in the processor. The software module may be located in the memory 601, and the processor 602 reads the program instructions in the memory 601 and performs the steps of the above-mentioned method in conjunction with its hardware.

[0108] In an embodiment of the present invention, the memory 601 may be a non-volatile memory, such as a hard disk drive (HDD) or a solid-state drive (SSD), or a volatile memory (Volatile Memory), such as RAM. The memory may also be any other medium that can be used to carry or store the desired program executable code in the form of instructions or data structures and can be accessed by a computer, but is not limited thereto. The memory in an embodiment of the present invention may also be a circuit or any other device that can implement a storage function, for storing instructions and / or data.

[0109] The memory 601 can be used to store software programs and modules, such as the instructions / modules of the porosity-based weak rock freeze-thaw damage assessment device 50 provided in an embodiment of the present invention, which can be stored in the memory 601 in the form of software or firmware (Firmware) or in the operating system (OS) of the solidified electronic device 60. The processor 602 executes the software programs and modules stored in the memory 601 to perform various functional applications and data processing. The communication interface 603 can be used for signaling or data communication with other node devices.

[0110] Those skilled in the art will clearly understand that, for the convenience and brevity of description, the specific working processes of the above-described devices and units can refer to the corresponding processes in the aforementioned method embodiments and will not be repeated here.

[0111] I understand. Figure 6 The structure shown is for illustration only. The electronic device 60 may also include Figure 6 More or fewer components than shown, or with Figure 6 Different configurations shown. Figure 6 The components shown may be implemented in hardware, software, or a combination thereof.

[0112] Based on the above embodiments, the present application also provides a storage medium, in which a computer program is stored. When the computer program is executed by a computer, the computer executes the porosity-based freeze-thaw damage assessment method for weak rock provided in the above embodiments.

[0113] Based on the above embodiments, an embodiment of the present invention further provides a computer program. When the computer program is run on a computer, the computer executes the porosity-based freeze-thaw damage assessment method for weak rock provided in the above embodiments.

[0114] Based on the above embodiments, an embodiment of the present invention further provides a chip, which is used to read a computer program stored in a memory and to execute the porosity-based freeze-thaw damage assessment method for weak rock provided in the above embodiments.

[0115] A computer program product is also provided in an embodiment of the present invention, comprising instructions, which, when executed on a computer, enable the computer to execute the porosity-based freeze-thaw damage assessment method for weak rock provided in the above embodiment.

[0116] The embodiments of the present invention are described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the embodiments of the present invention. It should be understood that each process and / or block in the flowchart and / or block diagram, as well as the combination of the processes and / or blocks in the flowchart and / or block diagram, can be implemented by instructions. These instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the process in the flowchart and / or block diagram. Figure 1 a process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0117] These computer program instructions may also be stored in a computer readable memory that can direct a computer or other programmable data processing device to work in a specific manner, so that the instructions stored in the computer readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 a process or multiple processes and / or boxes Figure 1 The function specified in one or more boxes.

[0118] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operational steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing the instructions executed on the computer or other programmable device for implementing the process. Figure 1 a process or multiple processes and / or boxes Figure 1A step that specifies a function in one or more boxes.

[0119] The above are merely specific embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in the present invention should be included in the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be based on the scope of protection of the claims.

Claims

1. A porosity-based method for assessing freeze-thaw damage in weak rock, characterized by: The method comprises: Obtaining a pre-built freeze-thaw damage assessment model for weak rock; wherein the freeze-thaw damage assessment model is used to characterize the relationship between the uniaxial compressive strength and porosity of weak rock under a freeze-thaw cycle environment; Obtain the initial uniaxial compressive strength, initial porosity and rock mechanical characteristic values ​​of any type of weak rock sample before freeze-thaw; Determine the porosity of the type of weak rock after freeze-thaw cycles; The initial uniaxial compressive strength, the initial porosity, the rock mechanical characteristic value and the porosity after freeze-thaw cycles are substituted into the freeze-thaw damage degree assessment model to obtain the uniaxial compressive strength value after freeze-thaw cycles as the freeze-thaw damage degree of the type of weak rock.

2. The porosity-based freeze-thaw damage assessment method for weak rock according to claim 1, characterized in that: The freeze-thaw damage assessment model is as follows: Among them, σ x represents the uniaxial compressive strength value after x freeze-thaw cycles; σ0 represents the initial uniaxial compressive strength; n0 and n x represent the initial porosity and the porosity after x freeze-thaw cycles respectively; F1 and m are the rock mechanical characteristic values.

3. The porosity-based freeze-thaw damage assessment method for weak rock according to claim 1 or 2, characterized in that: Access pre-built freeze-thaw damage assessment models for weak rock, including: Constructing an estimation model for the freeze-thaw disturbance factor; wherein the freeze-thaw disturbance factor is used to quantify the amount of rock damage sustained by the rock mass under freeze-thaw cycles; the estimation model is used to characterize the relationship between the freeze-thaw disturbance factor and porosity under freeze-thaw cycles; Determining a relationship model between uniaxial compressive strength and the freeze-thaw disturbance factor; The freeze-thaw damage degree assessment model is determined based on the freeze-thaw disturbance factor estimation model and the relationship model.

4. The porosity-based freeze-thaw damage assessment method for weak rock according to claim 3, characterized in that: The valuation model and the relationship model are as follows: s x =σ0(1-D x ) Among them, D x Represents the freeze-thaw disturbance factor after x freeze-thaw cycles.

5. The porosity-based freeze-thaw damage assessment method for weak rock according to claim 3, characterized in that: Construct a valuation model for freeze-thaw disturbance factors, including: Obtain the probability density function used to characterize the damage variation of rock micro-units; The probability density function is integrated within the integral range using the uniaxial compressive strength after multiple freeze-thaw cycles as the integral range to obtain an expression for the amount of rock damage after multiple freeze-thaw cycles; wherein the expression for the amount of rock damage describes the correlation between the amount of rock damage and the mechanical characteristics of the rock and the uniaxial compressive strength after freeze-thaw cycles; Obtain the proportional relationship between the uniaxial compressive strength and porosity of rock before and after freeze-thaw based on the strain equivalence principle; The rock damage expression and the uniaxial compressive strength after freeze-thaw in the proportional relationship are replaced by equal amounts to obtain the valuation model.

6. The porosity-based freeze-thaw damage assessment method for weak rock according to claim 1, characterized in that: Determine the porosity of the type of weak rock after freeze-thaw cycles, including: Obtaining a porosity measurement calculation model; wherein the porosity measurement calculation model is obtained by fitting the porosity obtained from nuclear magnetic resonance tests under different freeze-thaw cycles; The initial porosity and the number of freeze-thaw cycles are input into the porosity measurement calculation model to obtain the porosity after freeze-thaw cycles.

7. The porosity-based freeze-thaw damage assessment method for weak rock according to claim 1, characterized in that: Obtain the initial uniaxial compressive strength, initial porosity and rock mechanical characteristic values ​​of any type of weak rock sample before freeze-thaw, including: Obtaining the initial porosity of the rock sample measured in a nuclear magnetic resonance analysis test and the initial elastic modulus, peak stress, and peak strain measured in a uniaxial compression test; The rock mechanical characteristic value is calculated based on the initial elastic modulus, the peak stress and the peak strain.

8. A porosity-based device for evaluating freeze-thaw damage in soft rock, characterized in that: include: An acquisition module is used to obtain a freeze-thaw damage assessment model pre-built for weak rock; wherein the freeze-thaw damage assessment model is used to characterize the relationship between the uniaxial compressive strength and porosity of weak rock under a freeze-thaw cycle environment; The acquisition module is further used to obtain the initial uniaxial compressive strength, initial porosity and rock mechanical characteristic values ​​of a rock sample of any type of weak rock before freezing and thawing; a determination module for determining the porosity of the type of weak rock after freeze-thaw cycles; An evaluation module is used to substitute the initial uniaxial compressive strength, the initial porosity, the rock mechanical characteristic value and the porosity after freeze-thaw cycles into the freeze-thaw damage degree evaluation model to obtain the uniaxial compressive strength value after freeze-thaw cycles as the freeze-thaw damage degree of the type of weak rock.

9. An electronic device, characterized in that: The method comprises a processor and a memory, wherein the memory stores machine executable instructions that can be executed by the processor, and the processor can execute the machine executable instructions to implement the porosity-based weak rock freeze-thaw damage degree assessment method as described in any one of claims 1 to 7.

10. A storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the method for evaluating the degree of freeze-thaw damage of weak rock based on porosity as described in any one of claims 1 to 7 is implemented.

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