Suitability evaluation method for inclined shaft high-pressure pipeline lining type scheme

Abstract

The invention provides a suitability evaluation method for an inclined shaft high-pressure pipeline lining type scheme. The suitability evaluation method comprises the steps that an inclined shaft high-pressure pipeline investigation scheme is arranged; establishing a lining type suitability evaluation index system; establishing a lining type suitability evaluation system; and evaluating the adaptability of the inclined shaft high-pressure pipeline lining type. According to drilling and test result data, five influence factors such as rock mass minimum coverage thickness, internal water splitting pressure, minimum principal stress, hydraulic gradient and surrounding rock category are set as suitability evaluation indexes, suitability evaluation grades are set, and a subjective and objective combination weighting-set pair analysis lining type suitability evaluation system is established. According to the method, expert experience and difference and correlation of geological condition objective data are fused and considered, the high-pressure pipeline lining type evaluation sensitivity is improved, the suitability evaluation result of the drilling result for the corresponding part of the high-pressure pipeline is relatively comprehensive, objective and reasonable, and reference value is accurately and effectively provided for selection of the high-pressure pipeline lining type.

Description

Technical Field

[0001] The present invention relates to the technical field of high-pressure pipeline lining type evaluation, and in particular to a method for evaluating the suitability of a high-pressure pipeline lining type scheme for an inclined well. Background Art

[0002] Pumped-storage power stations are specialized power sources with diverse functions, including peak-shaving, valley-filling, phase adjustment, and emergency backup. The water transmission system connecting the upper and lower reservoirs is a key component in the design phase of a pumped-storage power station. During the feasibility study design phase, the water transmission system generally considers the project site's geological conditions, the layout of the hub, and the construction method, before selecting the vertical layout of the lower high-pressure pipeline and selecting the appropriate high-pressure pipeline lining type.

[0003] Selecting the appropriate lining type for high-pressure pipelines is essential during the design phase of a construction project and a key challenge in comparing and selecting alternatives. Currently, for vertical elevation schemes for inclined shaft high-pressure pipelines, it's difficult to comprehensively consider the interrelationship between deterministic and uncertain factors in determining lining suitability, resulting in certain limitations. Furthermore, inclined shaft high-pressure pipelines are typically located deep within a mountain. To fully determine the factors affecting these pipelines, extensive exploratory excavation is required, significantly increasing design costs and extending construction timelines.

[0004] Therefore, a suitability assessment method for inclined shaft high-pressure pipeline lining types is needed to reduce workload and cost pressure and provide a reference value for the selection of high-pressure pipeline lining types more accurately and effectively. Summary of the Invention

[0005] In view of the defects of the existing technology, the present invention provides a method for evaluating the suitability of inclined well high-pressure pipeline lining type schemes, which can effectively solve the above problems.

[0006] The technical solution adopted in the present invention is as follows:

[0007] The present invention provides a method for evaluating the suitability of a lining type scheme for a high-pressure pipeline in an inclined well, comprising the following steps:

[0008] Step S1: Arrange the survey plan for the inclined well high-pressure pipeline:

[0009] According to the elevation plan of the inclined well high-pressure pipeline to be evaluated and the terrain conditions, m exploration positions are determined, which are expressed as: exploration positions C1, C2, ..., C m , and at each exploration location C i Conduct exploration work and obtain exploration results data; where i = 1, 2, ..., m;

[0010] Step S2: Establish a lining type suitability evaluation index system:

[0011] Specifically, determine the target lining type scheme to be evaluated; according to the influencing conditions and quantitative factors of the inclined shaft high-pressure pipeline lining type design, set the suitability evaluation index and suitability evaluation level, so as to establish the lining type suitability evaluation index system; among them, there are n evaluation indicators, which are respectively expressed as: evaluation indicators B1, B2,…, B n ; There are D evaluation levels, which are respectively expressed as: evaluation level1, level2,…, level D ; and determine each evaluation indicator B j In the value range of each evaluation level, j = 1, 2, ..., n;

[0012] Step S3: Establish a lining type suitability assessment system:

[0013] According to the suitability evaluation index and suitability evaluation grade of step S2, the quantitative factors of the survey results data and the qualitative factors of expert experience obtained in step S1 are used to establish a subjective and objective combined weighting-set pair analysis lining type suitability evaluation system; the subjective and objective combined weighting-set pair analysis lining type suitability evaluation system is used to obtain each evaluation index B j The subjective and objective combined weight ω′ j ;

[0014] Step S4: Evaluate the suitability of the inclined shaft high-pressure pipeline lining type:

[0015] Specifically, according to each evaluation index B j The subjective and objective combined weight ω′ j , and each evaluation index B j The connection number with each suitability evaluation level is used to obtain a comprehensive evaluation index μ; based on the comprehensive evaluation index μ, the suitability level is obtained, thereby evaluating the suitability of the inclined well high-pressure pipeline adopting the target lining type solution.

[0016] Preferably, step S3 is specifically as follows:

[0017] Step S3.1: Use the continuous ordered weighted average operator method to determine each suitability evaluation index B based on expert experience. j The subjective weight λ j ;

[0018] Step S3.2: Using the optimized improved entropy weight method, determine each suitability evaluation index B based on the survey results data of step S1. j The objective weight ω j ;

[0019] Step S3.3: Use the multiplication synthesis method to perform combined weighting, and use the following formula to obtain each suitability evaluation index B: jThe subjective and objective combined weight ω′ j :

[0020]

[0021] Thus, each suitability evaluation index B j The subjective and objective combined weight ω′ j .

[0022] Preferably, step S3.1 is specifically as follows:

[0023] Step S3.1.1, for each suitability evaluation indicator B j , invite M experts to score the importance of the target lining type scheme, and obtain the suitability evaluation index B j The initial decision data set A=(x 1j , x 2j ,…,x Mj );

[0024] Step S3.1.2: rearrange the data in the initial decision dataset A according to the rule of large to small, and obtain a new decision dataset B = (y 0j ,y 1j ,…,y (M-1)j );

[0025] Step S3.1.3, use the following relationship to obtain each suitability evaluation index B j The subjective weight λ j :

[0026]

[0027] in: is the number of combinations of selecting k data from M-1 data, k = 0, 1, 2, ..., (M-1); u k is the position weight of the kth data in the new decision dataset B; P j is the suitability evaluation index B j absolute weight.

[0028] Preferably, step S3.2 is specifically as follows:

[0029] Step S3.2.1: Based on the survey results data, obtain each suitability evaluation index B j At each exploration location C i Evaluation index exploration value f ij , the suitability evaluation index exploration values ​​of each suitability evaluation index at each exploration location are integrated to form the initial index data matrix F:

[0030] F=(f ij )m×n

[0031] Step S3.2.2, explore the value f of each evaluation index in the initial index data matrix F ij Perform standardization to obtain the standardized indicator data matrix F′:

[0032] F′=(f′ ij ) m×n

[0033] Where: f′ ij is the exploration value of the evaluation index f ij The standardized value is: evaluation index B j At exploration location C i The standardized exploration value of

[0034] In step S3.2.3, the suitability evaluation index B is obtained using the following formula: j The standard deviation σ j :

[0035]

[0036] in: is the suitability evaluation index B j The mean of the normalized survey values ​​at each survey location;

[0037] In step S3.2.4, the suitability evaluation index B is obtained using the following formula: j At exploration location C i The correlation coefficient r ij :

[0038]

[0039] In step S3.2.5, the suitability evaluation index B is obtained using the following formula: j Entropy R j :

[0040]

[0041] In step S3.2.6, the suitability evaluation index B is obtained using the following formula: j Improved entropy weight e j :

[0042]

[0043] In step S3.2.7, the suitability evaluation index B is obtained using the following formula: j The initial objective weight

[0044]

[0045] Among them: CB j is the suitability evaluation index B j The comprehensive information content is obtained by the following formula:

[0046]

[0047] In step S3.2.8, use the following formula to obtain each suitability evaluation index B j The objective weight ω j :

[0048]

[0049] The process ends.

[0050] Preferably, the suitability evaluation indexes include a rock mass minimum cover thickness evaluation index, an internal water splitting pressure evaluation index, a minimum principal stress evaluation index, a hydraulic gradient evaluation index and a surrounding rock category evaluation index.

[0051] Preferably, the calculation method of each suitability evaluation index is:

[0052] (1) The minimum rock mass cover thickness evaluation index is obtained by the following formula:

[0053]

[0054] Where: C RM is the minimum cover thickness of the rock mass, in m; h s The hydrostatic pressure head at the selected position of the pipeline, in meters; γ w is the density of water, take 10KN / m 3 ; γ R is the weight of the rock mass; α is the slope angle of the mountain where the pipeline is located.

[0055] (2) The internal water splitting pressure evaluation index is obtained by the following formula:

[0056]

[0057] Where: n is the normal stress existing on the joint or crack surface;

[0058] (3) Minimum principal stress evaluation index is obtained by the following formula:

[0059]

[0060] Where: min is the minimum principal stress;

[0061] (4) Hydraulic gradient evaluation index:

[0062] The hydraulic gradient evaluation index is determined by the hydraulic gradient of the surrounding rock seepage stability condition;

[0063] (5) Evaluation indicators of surrounding rock types:

[0064] The surrounding rock category evaluation index is a core statistical value that reflects the surrounding rock category conditions based on drilling results. In order to more directly reflect the rock mass structure type and rock mass block composition, the RBI value is used as the surrounding rock category evaluation index value:

[0065] RBI=3C r3 +10C r10 +30C r30 +50C r50 +100C r100

[0066] Where: C r3 , C r10 , C r30 , C r50 , C r100 They are the core acquisition rates of 3-10, 10-30, 30-50, 50-100, and >100 cm in length respectively; 3, 10, 30, 50, and 100 are all coefficients.

[0067] Preferably, in step S4, there are five suitability evaluation levels, namely: suitability evaluation level I, II, III, IV, and V;

[0068] The comprehensive evaluation index μ is obtained using the following formula:

[0069]

[0070] a j +b j +c j +d j +e j =1

[0071] a j , b j , c j , d j , e j ∈[0, 1]

[0072] u, v, w∈[-1, 1]

[0073] l=-1

[0074] Among them: a j 、b j 、c j d j 、e j , respectively, are suitability evaluation index Bj The connection numbers corresponding to suitability evaluation levels I, II, III, IV, and V; u, v, w, and l are the connection component coefficients.

[0075] The suitability assessment method for inclined shaft high-pressure pipeline lining type schemes provided by the present invention has the following advantages:

[0076] The present invention provides a suitability assessment method for inclined shaft high-pressure pipeline lining type schemes. For inclined shaft high-pressure pipelines with good overall geological conditions and low surrounding rock permeability, a drilling exploration method is used to conduct a detailed geological survey to avoid damaging the engineering area by excavating a flat tunnel, thereby reducing the workload. Based on the drilling and test results data, the present invention sets five influencing factors, including minimum rock mass cover thickness, internal water splitting pressure, minimum principal stress, hydraulic gradient, and surrounding rock type, as suitability evaluation indicators, sets a suitability evaluation level, and establishes a subjective and objective combined weighted-set pair analysis lining type suitability assessment system. This system integrates the differences and correlations of expert experience and objective geological condition data, improves the sensitivity of high-pressure pipeline lining type evaluation, and makes the drilling results relatively comprehensive, objective, and reasonable in suitability evaluation results for corresponding parts of high-pressure pipelines, providing a more accurate and effective reference value for the selection of high-pressure pipeline lining types. BRIEF DESCRIPTION OF THE DRAWINGS

[0077] Figure 1 A flow chart of a method for evaluating the suitability of a lining type scheme for a high-pressure pipeline in an inclined well provided by the present invention;

[0078] Figure 2 It is a pumped storage survey layout diagram according to an embodiment of the present invention. DETAILED DESCRIPTION

[0079] In order to make the technical problems, technical solutions and beneficial effects solved by the present invention more clearly understood, the present invention is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0080] The present invention provides a suitability assessment method for inclined shaft high-pressure pipeline lining type schemes. For inclined shaft high-pressure pipelines with good overall geological conditions and low surrounding rock permeability, a drilling exploration method is used to conduct a detailed geological survey to avoid damaging the engineering area by excavating a flat tunnel, thereby reducing the workload. Based on the drilling and test results data, the present invention sets five influencing factors, including minimum rock mass cover thickness, internal water splitting pressure, minimum principal stress, hydraulic gradient, and surrounding rock type, as suitability evaluation indicators, sets a suitability evaluation level, and establishes a subjective and objective combined weighted-set pair analysis lining type suitability assessment system. This system integrates the differences and correlations of expert experience and objective geological condition data, improves the sensitivity of high-pressure pipeline lining type evaluation, and makes the drilling results relatively comprehensive, objective, and reasonable in suitability evaluation results for corresponding parts of high-pressure pipelines, providing a more accurate and effective reference value for the selection of high-pressure pipeline lining types.

[0081] The present invention provides a method for evaluating the suitability of a lining scheme for a high-pressure pipeline in an inclined well. Figure 1 , including the following steps:

[0082] Step S1: Arrange the survey plan for the inclined well high-pressure pipeline:

[0083] According to the elevation plan of the inclined well high-pressure pipeline to be evaluated and the terrain conditions, m exploration positions are determined, which are expressed as: exploration positions C1, C2, ..., C m , and at each exploration location C i Conduct exploration work and obtain exploration results data; where i = 1, 2, ..., m;

[0084] If the suitability evaluation indicators are the minimum rock cover thickness evaluation indicator, the internal water splitting pressure evaluation indicator, the minimum principal stress evaluation indicator, the hydraulic gradient evaluation indicator and the surrounding rock category evaluation indicator, then the survey results data include the minimum rock cover thickness, the hydrostatic pressure head at the pipeline selection location, the density of water, the density of rock mass, the slope angle of the mountain at the pipeline selection location, the normal stress on the joint or fracture surface, the minimum principal stress and other survey results data, which are specifically determined according to the category of the suitability evaluation indicator.

[0085] During the survey, appropriate exploration workload can be arranged according to the inclined well high-pressure pipeline elevation plan to ascertain the lithology, geological structure, geostress conditions, high-pressure permeability of the rock mass, and surrounding rock types of the inclined well high-pressure pipeline. The exploration workload, for example, is to arrange drilling workloads in the inclined well bend section and the middle part of the inclined well section according to the inclined well high-pressure pipeline elevation plan, set the drilling depth in accordance with the specification conditions, and arrange in-hole television, high-pressure water pressure test, and geostress test. Furthermore, the design reference requirements can be adjusted according to the inclined well high-pressure pipeline elevation plan, and a certain amount of exploration workload can be arranged in the flat section in the middle of the inclined well section to ascertain the lithology, geological structure, geostress conditions, high-pressure permeability of the rock mass, and surrounding rock types of the inclined well high-pressure pipeline.

[0086] Step S2: Establish a lining type suitability evaluation index system:

[0087] Specifically, determine the target lining type to be evaluated, for example, reinforced concrete lining type; according to the influencing conditions and quantitative factors of the inclined shaft high-pressure pipeline lining type design, set the suitability evaluation index and suitability evaluation level, so as to establish the lining type suitability evaluation index system; wherein, the evaluation index is n, which are respectively expressed as: evaluation index B1, B2,…, B n ; There are D evaluation levels, which are respectively expressed as: evaluation level1, level2,…, level D ; and determine each evaluation indicator B j In the value range of each evaluation level, j = 1, 2, ..., n;

[0088] As a specific embodiment, the suitability evaluation index is composed of five influencing factors: minimum rock mass cover thickness, internal water splitting pressure, minimum principal stress, hydraulic gradient and surrounding rock type, which are respectively expressed as evaluation indexes B1 to B5.

[0089] The suitability evaluation level is determined by quantitatively grading five evaluation indicators based on the safety requirements in industry standards and industry experience, combined with the quantitative values ​​of drilling results. The suitability evaluation level is divided into five levels: extremely suitable (Level I), relatively suitable (Level II), basically suitable (Level III), relatively unsuitable (Level IV), and extremely unsuitable (Level V).

[0090] As an example, the five evaluation indicators B1 to B5 and quantitative classification of lining types are detailed as follows:

[0091] Evaluation index B1 of minimum rock mass cover thickness: the index value is in the range of 1.3 to 1.5, and the evaluation level is relatively suitable (Level II).

[0092] Internal water splitting pressure evaluation index B2: The index value is in the range of 1.2 to 1.3, and the evaluation level is relatively suitable (Level II).

[0093] Minimum principal stress evaluation index B3: The index value is in the range of 1.2 to 1.3, and the evaluation level is relatively suitable (Level II).

[0094] Hydraulic gradient evaluation index B4: The hydraulic gradient factor is the recommended hydraulic gradient value considering the seepage stability of the surrounding rock. Based on the experience of similar high-pressure pipeline projects, the high-pressure hydraulic gradient is generally controlled to be no greater than 10-15 under Class II-III hard surrounding rock conditions. The recommended hydraulic gradient value for seepage damage in fault fracture zones and impact zones is 3.0-6.0. Therefore, the hydraulic gradient is selected as 6-10, and the evaluation level is basically suitable (Level III).

[0095] Surrounding rock category evaluation index B5: The surrounding rock category factor is the core statistical value that reflects the surrounding rock category conditions based on the drilling results. In order to more directly reflect the rock structure type and rock block composition, the RBI value is used as the surrounding rock category factor.

[0096] The established lining type suitability evaluation index system is shown in Table 1:

[0097] Table 1: Lining type suitability evaluation index system

[0098]

[0099] Step S3: Establish a lining type suitability assessment system:

[0100] According to the suitability evaluation index and suitability evaluation grade of step S2, the quantitative factors of the survey results data and the qualitative factors of expert experience obtained in step S1 are used to establish a subjective and objective combined weighting-set pair analysis lining type suitability evaluation system; the subjective and objective combined weighting-set pair analysis lining type suitability evaluation system is used to obtain each evaluation index B j The subjective and objective combined weight ω′ j ;

[0101] Step S3 is specifically as follows:

[0102] Step S3.1: Use the continuous ordered weighted average operator method to determine each suitability evaluation index B based on expert experience. j The subjective weight λ j ;

[0103] Step S3.1 is specifically as follows:

[0104] Step S3.1.1, for each suitability evaluation indicator B j , using a 10-point system to invite M experts to score the importance of the target lining type scheme, and obtain the suitability evaluation index Bj The initial decision data set A=(x 1j , x 2j ,…,x Mj );

[0105] Step S3.1.2: rearrange the data in the initial decision dataset A according to the rule of large to small, and obtain a new decision dataset B = (y 0j ,y 1j ,…,y (M-1)j );

[0106] Step S3.1.3, use the following relationship to obtain each suitability evaluation index B j The subjective weight λ j :

[0107]

[0108] in: is the number of combinations of selecting k data from M-1 data, k = 0, 1, 2, ..., (M-1); u k is the position weight of the kth data in the new decision dataset B; P j is the suitability evaluation index B j absolute weight.

[0109] Step S3.2: Using the optimized improved entropy weight method EWM, according to the survey results data of step S1, determine each suitability evaluation index B j The objective weight ω j In this step, the discreteness, correlation and contrast strength of the suitability evaluation index data are fully taken into account to more effectively reflect the differences and correlations of the objective data of the suitability evaluation index, making the objective results more reasonable.

[0110] Step S3.2 is specifically as follows:

[0111] Step S3.2.1: Based on the survey results data, obtain each suitability evaluation index B j At each exploration location C i Evaluation index exploration value f ij , the suitability evaluation index exploration values ​​of each suitability evaluation index at each exploration location are integrated to form the initial index data matrix F:

[0112] F=(f ij ) m×n

[0113] In this step, the suitability evaluation indicators include the minimum cover thickness evaluation index of the rock mass, the internal water splitting pressure evaluation index, the minimum principal stress evaluation index, the hydraulic gradient evaluation index and the surrounding rock type evaluation index. For these five suitability evaluation indicators, the calculation method of the evaluation index exploration value is as follows:

[0114] (1) The minimum rock mass cover thickness evaluation index is obtained by the following formula:

[0115]

[0116] Where: C RM is the minimum cover thickness of rock mass; h s Select the hydrostatic head at the location of the pipe; γ w is the density of water; γ R is the rock mass; α is the slope angle of the mountain where the pipeline is located;

[0117] (2) The internal water splitting pressure evaluation index is obtained by the following formula:

[0118]

[0119] Where: n is the normal stress existing on the joint or crack surface;

[0120] (3) Minimum principal stress evaluation index is obtained by the following formula:

[0121]

[0122] Where: min is the minimum principal stress;

[0123] (4) Hydraulic gradient evaluation index:

[0124] The hydraulic gradient evaluation index is determined by the hydraulic gradient of the surrounding rock seepage stability condition;

[0125] (5) Evaluation indicators of surrounding rock types:

[0126] The surrounding rock category evaluation index is the core statistical value that reflects the surrounding rock category conditions based on the drilling results. The RBI value is used as the surrounding rock category evaluation index value:

[0127] RBI=3C r3 +10C r10 +30C r30 +50C r50 +100C r100

[0128] Where: C r3 , C r10 , C r30 , C r50, C r100 They are the core acquisition rates of 3-10, 10-30, 30-50, 50-100, and >100 cm in length respectively; 3, 10, 30, 50, and 100 are all coefficients.

[0129] Step S3.2.2, explore the value f of each evaluation index in the initial index data matrix F ij Perform standardization to obtain the standardized indicator data matrix F′:

[0130] F′=(f′ ij ) m×n

[0131] Where: f′ ij is the exploration value of the evaluation index f ij The standardized value is: evaluation index B j At exploration location C i The standardized exploration value of

[0132] In this step, two standardization methods can be used:

[0133] The bigger the better. The standardized calculation formula for the benefit-based evaluation index is:

[0134]

[0135] The smaller the better. The standardized calculation formula for cost-based evaluation indicators is:

[0136]

[0137] Where: min(f ij ): represents the evaluation index B j The minimum value of the exploration value at all exploration locations; max(f ij ): represents the evaluation index B j The maximum value of the exploration value at all exploration locations;

[0138] In step S3.2.3, the suitability evaluation index B is obtained using the following formula: j The standard deviation σ j :

[0139]

[0140] in: is the suitability evaluation index B j The mean of the normalized survey values ​​at each survey location;

[0141] In step S3.2.4, the suitability evaluation index B is obtained using the following formula: j At exploration location C i The correlation coefficient rij :

[0142]

[0143] In step S3.2.5, the suitability evaluation index B is obtained using the following formula: j Entropy R j :

[0144]

[0145] In step S3.2.6, the suitability evaluation index B is obtained using the following formula: j Improved entropy weight e j :

[0146]

[0147] In step S3.2.7, the suitability evaluation index B is obtained using the following formula: j The initial objective weight :

[0148]

[0149] Among them: CB j is the suitability evaluation index B j The comprehensive information content is obtained by the following formula:

[0150]

[0151] In step S3.2.8, use the following formula to obtain each suitability evaluation index B j The objective weight ω j :

[0152]

[0153] The process ends.

[0154] Step S3.3: Use the multiplication synthesis method to perform combined weighting, and use the following formula to obtain each suitability evaluation index B: j The subjective and objective combined weight ω′ j :

[0155]

[0156] Thus, each suitability evaluation index B j The subjective and objective combined weight ω′ j .

[0157] Step S4: Evaluate the suitability of the inclined shaft high-pressure pipeline lining type:

[0158] Specifically, based on the exploration results and the lining type suitability evaluation system, the suitability evaluation results of the inclined well high-pressure pipeline lining type are determined, and based on the overall core drilling results, additional suggestions on the inclined well high-pressure pipeline lining type are made.

[0159] Furthermore, according to each evaluation index B j The subjective and objective combined weight ω′ j , and each evaluation index B j The connection number with each suitability evaluation level is used to obtain a comprehensive evaluation index μ; based on the comprehensive evaluation index μ, the suitability level is obtained, thereby evaluating the suitability of the inclined well high-pressure pipeline adopting the target lining type solution.

[0160] There are five suitability evaluation levels, namely: suitability evaluation level I, II, III, IV, and V;

[0161] The following formula is used to establish the corresponding relationship between the five-element connection number of the lining type suitability index and the suitability grade using the set pair analysis method SPA based on the equal partition principle, and the comprehensive evaluation index μ is obtained:

[0162]

[0163] a j +b j +c j +d j +e j =1

[0164] 0 j , b j , c j , d j , e j ∈[0, 1]

[0165] u, v, w∈[-1, 1]

[0166] l=-1

[0167] Among them: a j 、b j 、c j d j 、e j , respectively, are suitability evaluation index B j The connection numbers corresponding to suitability evaluation levels I, II, III, IV, and V; u, v, w, and l are the connection component coefficients.

[0168] As an example, the principle of equal division is adopted, with u = 0.5, v = 0, and w = -0.5, so that their values ​​are located at the three quarters of the interval [-1, 1]. The comprehensive evaluation five-element connection value, namely the comprehensive evaluation index μ, is calculated to determine the suitability level of the reinforced concrete lining type. The corresponding relationship between the five-element connection number and the suitability level of the reinforced concrete lining type is shown in Table 2:

[0169] Table 2 Correspondence between five-element connection number and lining type applicability grade

[0170] Suitability level Very suitable (I) More suitable (Ⅱ) Basic suitability (III) Less suitable (IV) Extremely unsuitable (V) μ [0.6,1] [0.2,0.6) [-0.2,0.2) [-0.6,-0.2) [-1,-0.6)

[0171] Therefore, based on the exploration results and evaluation system, the evaluation results of the lining type suitability evaluation position of the inclined well high-pressure pipeline drilling site were determined, and based on the overall core results of the drilling, additional suggestions were made on the lining type of the inclined well high-pressure pipeline.

[0172] Through the following examples, combined with the attached Figure 1 The technical solution of the present invention is described in detail:

[0173] In this example, a pumped-storage power station with a planned installed capacity of 1500MW is located on the mountain ridge between the upper and lower reservoirs. The water supply system consists of a water diversion system and a tailwater system, both utilizing a one-pipe, two-machine layout. Two high-pressure main pipes are arranged in parallel, with a horizontal spacing of 28.04m. The lengths of the 1# and 2# high-pressure main pipes are 1338.93m and 1370.11m, respectively. The high-pressure main pipes utilize a buried three-inclined well layout, consisting of an upper inclined well, a middle-upper flat section, a middle inclined well, a middle-lower flat section, and a lower inclined well section. The lithologies in the project area are primarily biotite plagioclase gneiss and biotite plagioclase amphibolite. The gneiss exhibits a blocky structure, with primary gneissism primarily characterized by streamlined undulations. Influenced by later tectonic movements, faults are well-developed within the rock mass. The amphibolite exhibits a blocky structure with xenolithic morphology. There is no clear lithologic boundary between the two lithologies, with fractures and molten contacts predominantly present.

[0174] In this embodiment, based on the elevation plan of the three inclined wells high-pressure pipelines of the project and according to the basic geological conditions along the high-pressure pipelines of the water supply system, the feasibility of the reinforced concrete lining type of the upper inclined well section is investigated in detail, and the suitability of the reinforced concrete lining type of the upper flat section, the middle inclined well and the middle and lower flat section is studied, and geological survey arrangements and suitability assessments of the reinforced concrete lining type are carried out.

[0175] This embodiment includes four processes: arranging an inclined shaft high-pressure pipeline survey plan A, establishing a lining type suitability evaluation index system B, establishing a lining type suitability evaluation system C, and evaluating the suitability of the inclined shaft high-pressure pipeline lining type D.

[0176] 1. Process of Arranging the Scheme A for High-Pressure Pipeline in Inclined Wells

[0177] In this process, according to the elevation plan of the high-pressure pipeline of the three-inclined well and the terrain conditions, six exploration positions from Z1 to Z6 are arranged. At each exploration position, exploration drilling and in-hole TV, ground stress, and high-pressure water pressure tests are carried out to complete process A. Figure 2 shown.

[0178] 2. Establishing the lining type suitability evaluation index system B process

[0179] This process uses the reinforced concrete lining type as the initial design scheme. Based on industry standards and reference criteria, five influencing factors were selected as suitability evaluation indicators: minimum rock cover thickness, internal water splitting pressure, minimum principal stress, hydraulic gradient, and surrounding rock type at the high-pressure pipeline design location (i.e., each exploration location). Combined with the quantitative values ​​of drilling results, these five suitability evaluation indicators were quantitatively graded to establish lining type suitability evaluation levels: extremely suitable (Level I), relatively suitable (Level II), basically suitable (Level III), relatively unsuitable (Level IV), and extremely unsuitable (Level V). The established lining type suitability evaluation indicator system is shown in Table 1.

[0180] 3. Establishing lining type suitability assessment system C process

[0181] This process is based on the lining type suitability evaluation indicators and suitability evaluation levels of process B, the quantitative factors of exploration results and the qualitative factors of expert experience, and establishes a subjective and objective combined weighted set pair analysis lining type suitability evaluation system.

[0182] In this process, eight experts in pumped storage power station geological engineering and hydraulic design were selected to rate the importance of each suitability evaluation indicator on a 10-point scale. The scoring results are as follows:

[0183] Table 3 Expert scoring results

[0184] index Expert 1 Expert 2 Expert 3 Expert 4 Expert 5 Expert 6 Expert 7 Expert 8 <![CDATA[B1]]> 3 2.5 2 1 1.5 1 1.5 1 <![CDATA[B2]]> 1 2 1.5 2 1.5 2 1 1.5 <![CDATA[B3]]> 2 2.5 2.5 2.5 2.5 3 2.5 3 <![CDATA[B4]]> 2.5 2.5 2 2.5 1.5 2 2.5 1.5 <![CDATA[B5]]> 1.5 1 2 2 3 2.5 2.5 3

[0185] The subjective weight of each reinforced concrete lining suitability evaluation index is calculated by the method of the present invention. The subjective weights λ1 to λ5 of the five suitability evaluation indexes are 0.1546, 0.1560, 0.2492, 0.2188, and 0.2215, respectively.

[0186] Then, the method of the present invention is used to calculate the comprehensive objective weight of each reinforced concrete lining suitability evaluation index. The objective weights ω1 to ω5 of the five suitability evaluation indexes are: 0.3343, 0.1612, 0.0924, 0.2471, and 0.1650 respectively;

[0187] Finally, the subjective and objective combined weights of each reinforced concrete lining suitability evaluation index can be calculated. The subjective and objective combined weights ω′1 to ω′5 of the five suitability evaluation indicators are 0.2714, 0.1320, 0.1209, 0.2838, and 0.1918, respectively.

[0188] 4. Process D of suitability assessment of inclined shaft high-pressure pipeline lining type

[0189] This process is to determine the lining type suitability assessment results of the inclined well high-pressure pipeline drilling area based on the Z1 to Z6 exploration results and the lining type suitability assessment system.

[0190] The suitability assessment method for inclined shaft high-pressure pipeline lining type schemes provided by the present invention has the following advantages:

[0191] The present invention provides a suitability assessment method for inclined shaft high-pressure pipeline lining type schemes. For inclined shaft high-pressure pipelines with good overall geological conditions and low surrounding rock permeability, a drilling exploration method is used to conduct a detailed geological survey to avoid damaging the engineering area by excavating a flat tunnel, thereby reducing the workload. Based on the drilling and test results data, the present invention sets five influencing factors, including minimum rock mass cover thickness, internal water splitting pressure, minimum principal stress, hydraulic gradient, and surrounding rock type, as suitability evaluation indicators, sets a suitability evaluation level, and establishes a subjective and objective combined weighted-set pair analysis lining type suitability assessment system. This system integrates the differences and correlations of expert experience and objective geological condition data, improves the sensitivity of high-pressure pipeline lining type evaluation, and makes the drilling results relatively comprehensive, objective, and reasonable in suitability evaluation results for corresponding parts of high-pressure pipelines, providing a more accurate and effective reference value for the selection of high-pressure pipeline lining types.

[0192] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A method for evaluating the suitability of a lining type scheme for a high-pressure pipeline in an inclined shaft, characterized in that: The following steps are involved: Step S1, arranging the inclined well high-pressure pipeline survey plan: According to the elevation plan and terrain conditions of the inclined shaft high-pressure pipeline to be evaluated, m exploration positions are determined, which are expressed as: exploration positions C1, C2, …, C m , and at each exploration location C i Conduct exploration work and obtain exploration results data; where i = 1, 2, ..., m; Step S2, establish a lining type suitability evaluation index system: Specifically, determine the target lining type scheme to be evaluated; set the suitability evaluation index and suitability evaluation level according to the influencing conditions and quantitative factors of the inclined shaft high-pressure pipeline lining type design, so as to establish a lining type suitability evaluation index system; among them, there are n evaluation indicators, which are respectively expressed as: evaluation indicators B1, B2,…, B n ; There are D evaluation levels, which are respectively expressed as: evaluation level1, level2,…, level D ; and determine each evaluation indicator B j In the value range of each evaluation level, j = 1, 2, ..., n; Step S3, establish a lining type suitability assessment system: According to the suitability evaluation index and suitability evaluation grade of step S2, the quantitative factors of the survey results data and the qualitative factors of expert experience obtained in step S1 are used to establish a subjective and objective combined weighting-set pair analysis lining type suitability evaluation system; the subjective and objective combined weighting-set pair analysis lining type suitability evaluation system is used to obtain each evaluation index B j The subjective and objective combined weight ω′ j ; Step S4, evaluating the suitability of the inclined shaft high-pressure pipeline lining type: Specifically, according to each evaluation index B j The subjective and objective combined weight ω′ j , and each evaluation index B j The connection number with each suitability evaluation level is used to obtain a comprehensive evaluation index μ; based on the comprehensive evaluation index μ, the suitability level is obtained, thereby evaluating the suitability of the inclined shaft high-pressure pipeline adopting the lining type target solution.

2. A method for evaluating the suitability of a lining type scheme for a high-pressure pipeline in an inclined shaft according to claim 1, characterized in that: Step S3 is specifically as follows: Step S3.1: Use the continuous ordered weighted average operator method to determine each suitability evaluation index B based on expert experience. j The subjective weight λ j ; Step S3.2, using the optimized improved entropy weight method, according to the survey results data of step S1, determine each suitability evaluation index B j The objective weight ω j ; Step S3.3, use the multiplication synthesis method to perform combined weighting, and use the following formula to obtain each suitability evaluation index B j The subjective and objective combined weight ω j ′: Thus, each suitability evaluation index B j The subjective and objective combined weight ω j ′.

3. A method for evaluating the suitability of a lining type scheme for a high-pressure pipeline in an inclined shaft according to claim 2, characterized in that: Step S3.1 is specifically as follows: Step S3.1.1: for each suitability evaluation indicator B j , invite M experts to score the importance of the target lining type scheme, and obtain the suitability evaluation index B j The initial decision data set A=(x 1j , x 2j , …, x Mj ); Step S3.1.2, rearrange the data in the initial decision data set A according to the rule from large to small, and obtain a new decision data set B = (y 0j ,y 1j , …, y (M-1)j ); Step S3.1.3, use the following relationship to obtain each suitability evaluation index B j The subjective weight λ j : in: is the number of combinations of selecting k data from M-1 data, k = 0, 1, 2, ..., (M-1); u k is the position weight of the kth data in the new decision data set B; P j is the suitability evaluation index B j absolute weight.

4. A method for evaluating the suitability of a lining type scheme for a high-pressure pipeline in an inclined shaft according to claim 2, characterized in that: Step S3.2 is specifically as follows: Step S3.2.1, based on the survey results data, obtain each suitability evaluation index B j At each exploration location C i Evaluation index exploration value f ij , the suitability evaluation index exploration values ​​of each suitability evaluation index at each exploration location are integrated to form the initial index data matrix F: F=(f ij ) m×n Step S3.2.2, explore the value f of each evaluation index in the initial index data matrix F ij Perform standardization to obtain the standardized indicator data matrix F′: F′=(f′ ij ) m×n Where: f′ ij is the exploration value of the evaluation index f ij The standardized value is: Evaluation index B j At exploration location C i The standardized exploration value of Step S3.2.3, use the following formula to obtain the suitability evaluation index B j The standard deviation σ j : in: is the suitability evaluation index B j The mean of the standardized survey values ​​at each survey location; Step S3.2.4, use the following formula to obtain the suitability evaluation index B j At exploration location C i The correlation coefficient r ij : Step S3.2.5, use the following formula to obtain the suitability evaluation index B j The entropy R j : Step S3.2.6, use the following formula to obtain the suitability evaluation index B j The improved entropy weight e j : Step S3.2.7, use the following formula to obtain the suitability evaluation index B j The initial objective weight Among them: CB j is the suitability evaluation index B j The comprehensive information content of is obtained by the following formula: Step S3.2.8, use the following formula to obtain each suitability evaluation index B j The objective weight ω j : The process ends.

5. A method for evaluating the suitability of a lining type scheme for a high-pressure pipeline in an inclined shaft according to claim 2, characterized in that: The suitability evaluation indexes include a rock mass minimum cover thickness evaluation index, an internal water splitting pressure evaluation index, a minimum principal stress evaluation index, a hydraulic gradient evaluation index and a surrounding rock category evaluation index.

6. A method for evaluating the suitability of a lining type scheme for a high-pressure pipeline in an inclined shaft according to claim 5, characterized in that: The calculation method of each suitability evaluation index is as follows: (1) The minimum rock mass cover thickness evaluation index is obtained by the following formula: Where: C RM is the minimum cover thickness of rock mass; h s Select the location of the pipeline and the hydrostatic pressure head; γ w is the density of water; R is the weight of the rock mass; α is the slope angle of the mountain where the pipeline is located; (2) The internal water splitting pressure evaluation index is obtained by the following formula: Where: n is the normal stress existing on the joint or crack surface; (3) The minimum principal stress evaluation index is obtained by the following formula: Where: min is the minimum principal stress; (4) Hydraulic gradient evaluation index: The hydraulic gradient evaluation index is determined by the hydraulic gradient of the surrounding rock seepage stability condition; (5) Evaluation indicators of surrounding rock types: The surrounding rock category evaluation index is the core statistical value that takes into account the drilling results to reflect the surrounding rock category conditions, and the RBI value is used as the surrounding rock category evaluation index value: RBI=3C r3 +10C r10 +30C r30 +50C r50 +100C r100 Where: C r3 , C r10 , C r30 , C r50 , C r100 They are the core acquisition rates with lengths of 3-10, 10-30, 30-50, 50-100, and >100 cm respectively; 3, 10, 30, 50, and 100 are all coefficients.

7. A method for evaluating the suitability of a lining type scheme for a high-pressure pipeline in an inclined shaft according to claim 1, characterized in that: In step S4, there are five suitability evaluation levels, namely: suitability evaluation level I, II, III, IV, and V; The comprehensive evaluation index μ is obtained by the following formula: a k +b j +c j +d k +e k =1 a j ,b j ,c j ,d j ,e j ∈[0,1] u,v,w∈[-1,1] l＝-1 Among them: a j , b j 、c j d j 、e j , respectively, are suitability evaluation index B j The connection numbers corresponding to suitability evaluation levels I, II, III, IV, and V; u, v, w, and l are the connection component coefficients.

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