Slope safety risk evaluation method
阅读说明：本技术 一种边坡安全风险评价方法 (Slope safety risk evaluation method ) 是由 张洪达 杜岩 谢谟文 白云飞 霍磊晨 黄正均 马国星 吴志祥 张晓勇 于 2021-06-23 设计创作，主要内容包括：本发明提供一种边坡安全风险评价方法,属于边坡稳定性评价与安全监测领域。所述方法包括：确定风险评价等级和评价指标,并确定各评价指标在不同风险评价等级下取值范围；确定各评价指标权重；根据确定的各评价指标在不同风险评价等级下取值范围及各评价指标权重,确定待评价边坡在各风险评价等级下的综合关联度及待评价边坡的风险评价等级特征值；根据得到的待评价边坡在各风险评价等级下的综合关联度及待评价边坡的风险评价等级特征值,对待评价边坡进行安全风险评价。采用本发明,能够准确评估中小型边坡的安全风险。(The invention provides a slope safety risk evaluation method, and belongs to the field of slope stability evaluation and safety monitoring. The method comprises the following steps: determining risk evaluation grades and evaluation indexes, and determining value ranges of the evaluation indexes under different risk evaluation grades; determining the weight of each evaluation index; determining the comprehensive association degree of the slope to be evaluated under each risk evaluation level and the risk evaluation level characteristic value of the slope to be evaluated according to the value ranges of the determined evaluation indexes under different risk evaluation levels and the weights of the evaluation indexes; and performing safety risk evaluation on the side slope to be evaluated according to the obtained comprehensive association degree of the side slope to be evaluated under each risk evaluation level and the risk evaluation level characteristic value of the side slope to be evaluated. By adopting the method and the device, the safety risk of the small and medium-sized side slopes can be accurately evaluated.)
1. A slope safety risk evaluation method is characterized by comprising the following steps:
determining risk evaluation grades and evaluation indexes, and determining value ranges of the evaluation indexes under different risk evaluation grades;
determining the weight of each evaluation index;
determining the comprehensive association degree of the slope to be evaluated under each risk evaluation level and the risk evaluation level characteristic value of the slope to be evaluated according to the value ranges of the determined evaluation indexes under different risk evaluation levels and the weights of the evaluation indexes;
and performing safety risk evaluation on the side slope to be evaluated according to the obtained comprehensive association degree of the side slope to be evaluated under each risk evaluation level and the risk evaluation level characteristic value of the side slope to be evaluated.
2. The slope safety risk evaluation method according to claim 1, wherein the risk evaluation grades are divided into four grades, i.e. grade I, grade II, grade III and grade IV, and the corresponding slope risks are: low risk, medium high risk and high risk.
3. The slope safety risk evaluation method according to claim 1, wherein the evaluation index includes: internal friction angle, cohesion, slope height, slope gradient, non-uniformity coefficient, layer thickness ratio, rainfall intensity and site temperature.
4. The slope safety risk evaluation method according to claim 1, wherein the determining each evaluation index weight comprises:
calculating the weight of each evaluation index by adopting a comprehensive weight method combining subjective and objective weights;
wherein the weight λ of the ith evaluation indexiExpressed as:
wherein alpha isiIs a subjective weight, betaiFor objective weighting, n represents the number of evaluation indexes.
5. The slope safety risk assessment method according to claim 4, wherein the objective weight β isiExpressed as:
wherein E isiAn entropy value representing an ith evaluation index, m represents the number of risk evaluation levels,is normalized by aij，aijA function value representing the association of the ith evaluation index with respect to the jth risk evaluation level, PijAnd (3) the specific gravity of the ith evaluation index at the jth risk evaluation level.
6. The slope safety risk evaluation method according to claim 1, wherein the determining of the comprehensive association degree of the slope to be evaluated at each risk evaluation level and the risk evaluation level characteristic value of the slope to be evaluated according to the value ranges and the evaluation index weights of the determined evaluation indexes at different risk evaluation levels comprises:
determining slope object elements to be evaluated, and calculating single evaluation index association degree by using an association function according to the determined slope object elements to be evaluated and the value ranges of all evaluation indexes under different risk evaluation levels;
determining the comprehensive association degree of the slope to be evaluated under each risk evaluation level according to the obtained single evaluation index association degree and each evaluation index weight;
and determining the variable characteristic value of each risk evaluation grade of the slope to be evaluated according to the determined comprehensive association degree of the slope to be evaluated under each risk evaluation grade.
7. The slope safety risk evaluation method according to claim 6, wherein the determining of slope object elements to be evaluated and the calculating of the single evaluation index relevance degree by using the relevance function according to the determined slope object elements to be evaluated and the value ranges of the evaluation indexes under different risk evaluation levels comprise:
according to the value ranges of the determined evaluation indexes under different risk evaluation grades, the classical domain matter element R is determinedjAnd a domain-saving matter element Rp(ii) a Wherein the content of the first and second substances,
classical domain matter element RjExpressed as:
wherein N isjRepresent four risk assessment ratings, grade I-IV, with j being 1, 2, 3, 4, ci8 evaluation indexes of the slope are shown, i is 1, 2, 3, 4, 5, 6, 7, 8, vji＝<aji，bji>Indicates the evaluation index ciAt each risk evaluation level NjThe following value ranges;
node domain matter element RpExpressed as:
wherein P represents the overall risk assessment scale, vpi＝<api，bpi>Indicates the evaluation index ciAt all inValue range under risk evaluation level;
determining a slope matter element R to be evaluatedx：
Wherein, PxIndicating the side slope to be evaluated, xiIs PxRegarding the evaluation index ciActual value of (2);
according to the determined classical domain matter element RjRegion-saving matter element RpAnd the slope object element R to be evaluatedxDetermining the extension distance of each evaluation index relative to each risk evaluation grade;
and calculating the association degree of the single evaluation index by using an association function according to the determined extension distance of each evaluation index relative to each risk evaluation grade.
8. The slope safety risk evaluation method according to claim 7, wherein if the risk evaluation level belongs to level II or level III, the actual value x of the ith evaluation indexiExtension ρ (x) for jth risk assessment leveli，Xji) Expressed as:
if the risk evaluation grade belongs to grade I or grade IV, the actual value x of the ith evaluation indexiExtension ρ (x) for jth risk assessment leveli，Xji) Expressed as:
wherein, XjiDenotes the ith evaluation index with respect to the jth risk evaluation level section, Xji＝<aji，bji>，X1、X4The risk evaluation levels are represented as class I and class IV intervals.
9. The slope safety risk evaluation method according to claim 8, wherein the single evaluation index association degree is expressed as:
ρ(Xji)＝|bji-aji|
wherein, Kj(xi) A correlation function representing the ith evaluation index with respect to the jth risk evaluation level, X represents the entire section of the ith evaluation index, api、bpiUpper and lower limits respectively representing all the sections of the ith evaluation index;
the overall relevance is expressed as:
wherein, Kj(Px) And representing the comprehensive association degree of the slope to be evaluated under the jth risk evaluation level.
10. The slope safety risk evaluation method according to claim 9, wherein the variable characteristic values of each risk evaluation level of the slope to be evaluated are represented as:
wherein j is*Representing the risk evaluation grade variable characteristic value, min and max respectively representing the minimum value and the maximum value,and the normalized numerical value represents the comprehensive association degree of the slope to be evaluated under the jth risk evaluation level.
Technical Field
The invention relates to the field of slope stability evaluation and safety monitoring, in particular to a slope safety risk evaluation method.
Background
Although there are many non-deterministic methods for evaluating the safety risk of the side slope, most of the methods are based on theories established abroad, such as a Monte Carlo method, an accident tree analysis method, a support vector machine and the like, and all of the methods need to be supported by a large data sample, so that the method has problems in application to small and medium-sized side slopes. Aiming at the defects of the research of the domestic original theory method for evaluating the safety risk of the side slope and the technical problems of the application in small and medium side slopes.
Disclosure of Invention
The embodiment of the invention provides a side slope safety risk evaluation method, which can accurately evaluate the safety risk of small and medium-sized side slopes.
The embodiment of the invention provides a slope safety risk evaluation method, which is applied to electronic equipment and comprises the following steps:
determining risk evaluation grades and evaluation indexes, and determining value ranges of the evaluation indexes under different risk evaluation grades;
determining the weight of each evaluation index;
determining the comprehensive association degree of the slope to be evaluated under each risk evaluation level and the risk evaluation level characteristic value of the slope to be evaluated according to the value ranges of the determined evaluation indexes under different risk evaluation levels and the weights of the evaluation indexes;
and performing safety risk evaluation on the side slope to be evaluated according to the obtained comprehensive association degree of the side slope to be evaluated under each risk evaluation level and the risk evaluation level characteristic value of the side slope to be evaluated.
Further, the risk evaluation grade is divided into four grades, namely I grade, II grade, III grade and IV grade, and the corresponding slope risks are as follows in sequence: low risk, medium high risk and high risk.
Further, the evaluation index includes: internal friction angle, cohesion, slope height, slope gradient, non-uniformity coefficient, layer thickness ratio, rainfall intensity and site temperature.
Further, the determining each evaluation index weight includes:
calculating the weight of each evaluation index by adopting a comprehensive weight method combining subjective and objective weights;
wherein the weight λ of the ith evaluation indexiExpressed as:
wherein alpha isiIs a subjective weight, betaiFor objective weighting, n represents the number of evaluation indexes.
Further, objective weight βiExpressed as:
wherein E isiAn entropy value representing an ith evaluation index, m represents the number of risk evaluation levels,is normalized by aij，aijA function value representing the association of the ith evaluation index with respect to the jth risk evaluation level, PijAnd (3) the specific gravity of the ith evaluation index at the jth risk evaluation level.
Further, the determining the comprehensive association degree of the slope to be evaluated under each risk evaluation level and the risk evaluation level characteristic value of the slope to be evaluated according to the value ranges of the determined evaluation indexes under different risk evaluation levels and the weights of the evaluation indexes comprises:
determining slope object elements to be evaluated, and calculating single evaluation index association degree by using an association function according to the determined slope object elements to be evaluated and the value ranges of all evaluation indexes under different risk evaluation levels;
determining the comprehensive association degree of the slope to be evaluated under each risk evaluation level according to the obtained single evaluation index association degree and each evaluation index weight;
and determining the variable characteristic value of each risk evaluation grade of the slope to be evaluated according to the determined comprehensive association degree of the slope to be evaluated under each risk evaluation grade.
Further, the determining slope object elements to be evaluated, and calculating the single evaluation index association degree by using the association function according to the determined slope object elements to be evaluated and the value ranges of the evaluation indexes under different risk evaluation levels includes:
according to the value ranges of the determined evaluation indexes under different risk evaluation grades, the classical domain matter element R is determinedjAnd a domain-saving matter element Rp(ii) a Wherein the content of the first and second substances,
classical domain matter element RjExpressed as:
wherein N isjRepresent four risk assessment ratings, grade I-IV, with j being 1, 2, 3, 4, ci8 evaluation indexes of the slope are shown, i is 1, 2, 3, 4, 5, 6, 7, 8, vji＝<aji，bji>Indicates the evaluation index ciAt each risk evaluation level NjThe following value ranges;
node domain matter element RpExpressed as:
wherein P represents the overall risk assessment scale, vpi＝<api，bpi>Indicates the evaluation index ciValue ranges under all risk evaluation levels;
determining a slope matter element R to be evaluatedx：
Wherein, PxIndicating the side slope to be evaluated, xiIs PxRegarding the evaluation index ciActual value of (2);
according to the determined classical domain matter element RjRegion-saving matter element RpAnd the slope object element R to be evaluatedxDetermining the extension distance of each evaluation index relative to each risk evaluation grade;
and calculating the association degree of the single evaluation index by using an association function according to the determined extension distance of each evaluation index relative to each risk evaluation grade.
Further, if the risk evaluation grade belongs to grade II or grade III, the actual value x of the ith evaluation indexiExtension ρ (x) for jth risk assessment leveli，Xji) Expressed as:
if the risk evaluation grade belongs to grade I or grade IV, the actual value x of the ith evaluation indexiExtension ρ (x) for jth risk assessment leveli，Xji) Expressed as:
wherein, XjiDenotes the ith evaluation index with respect to the jth risk evaluation level section, Xji＝<aji，bji>，X1、X4The risk evaluation levels are represented as class I and class IV intervals.
Further, the single evaluation index association degree is expressed as:
ρ(Xji)＝|bji-aji|
wherein, Kj(xi) A correlation function representing the ith evaluation index with respect to the jth risk evaluation level, X represents the entire section of the ith evaluation index, api、bpiUpper and lower limits respectively representing all the sections of the ith evaluation index;
the overall relevance is expressed as:
wherein, Kj(Px) And representing the comprehensive association degree of the slope to be evaluated under the jth risk evaluation level.
Further, the variable characteristic value of each risk evaluation grade of the slope to be evaluated is represented as:
wherein j is*Representing the risk evaluation grade variable characteristic value, min and max respectively representing the minimum value and the maximum value,and the normalized numerical value represents the comprehensive association degree of the slope to be evaluated under the jth risk evaluation level.
The technical scheme provided by the embodiment of the invention has the beneficial effects that at least:
in the embodiment of the invention, risk evaluation grades and evaluation indexes are determined, and the value ranges of the evaluation indexes under different risk evaluation grades are determined; determining the weight of each evaluation index; determining the comprehensive association degree of the slope to be evaluated under each risk evaluation level and the risk evaluation level characteristic value of the slope to be evaluated according to the value ranges of the determined evaluation indexes under different risk evaluation levels and the weights of the evaluation indexes; and performing safety risk evaluation on the side slope to be evaluated according to the obtained comprehensive association degree of the side slope to be evaluated under each risk evaluation level and the risk evaluation level characteristic value of the side slope to be evaluated. Therefore, various risk factors (namely, evaluation indexes) influencing the stability of the side slope are comprehensively considered, the safety risk evaluation method suitable for the small and medium-sized side slopes is established, the safety risk of the small and medium-sized side slopes can be accurately evaluated, and the comprehensive evaluation of the safety evaluation indexes such as the mine side slope can be realized.
Drawings
In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings needed to be used in the description of the embodiments will be briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without creative efforts.
Fig. 1 is a schematic flow chart of a method for evaluating a safety risk of a side slope according to an embodiment of the present invention;
fig. 2 is a schematic diagram of a risk assessment index system provided by an embodiment of the present invention.
Detailed Description
In order to make the objects, technical solutions and advantages of the present invention more apparent, embodiments of the present invention will be described in detail with reference to the accompanying drawings.
As shown in fig. 1, an embodiment of the present invention provides a slope safety risk evaluation method, including:
s101, determining risk evaluation grades and evaluation indexes, and determining value ranges of the evaluation indexes under different risk evaluation grades;
s102, determining the weight of each evaluation index;
s103, determining the comprehensive association degree of the slope to be evaluated under each risk evaluation level and the risk evaluation level characteristic value of the slope to be evaluated according to the value ranges of the determined evaluation indexes under different risk evaluation levels and the weights of the evaluation indexes;
and S104, performing safety risk evaluation on the side slope to be evaluated according to the obtained comprehensive association degree of the side slope to be evaluated under each risk evaluation level and the risk evaluation level characteristic value of the side slope to be evaluated.
According to the slope safety risk evaluation method disclosed by the embodiment of the invention, risk evaluation grades and evaluation indexes are determined, and the value ranges of the evaluation indexes under different risk evaluation grades are determined; determining the weight of each evaluation index; determining the comprehensive association degree of the slope to be evaluated under each risk evaluation level and the risk evaluation level characteristic value of the slope to be evaluated according to the value ranges of the determined evaluation indexes under different risk evaluation levels and the weights of the evaluation indexes; and performing safety risk evaluation on the side slope to be evaluated according to the obtained comprehensive association degree of the side slope to be evaluated under each risk evaluation level and the risk evaluation level characteristic value of the side slope to be evaluated. Therefore, various risk factors (namely, evaluation indexes) influencing the stability of the side slope are comprehensively considered, the safety risk evaluation method suitable for the small and medium-sized side slopes is established, the safety risk of the small and medium-sized side slopes can be accurately evaluated, and the comprehensive evaluation of the safety evaluation indexes such as the mine side slope can be realized.
In a specific embodiment of the foregoing slope safety risk evaluation method, further, the risk evaluation grades are divided into four grades, i.e., grade I, grade II, grade III, and grade IV, and the corresponding slope risks are: low risk, medium high risk and high risk.
In this embodiment, with reference to the risk classification management and control principle, the slope risk evaluation levels (for example, the slope instability risk scores are four levels, i.e., I level (green), II level (blue), III level (yellow), and IV level (red), and the slope instability risks correspond to low risk, medium-high risk, and high risk in sequence.
In a specific embodiment of the foregoing slope safety risk assessment method, the assessment index further includes: internal friction angle, cohesion, slope height, slope gradient, non-uniformity coefficient, layer thickness ratio, rainfall intensity and site temperature.
In this embodiment, from the internal factors and the external factors, 8 evaluation indexes, i.e., an internal friction angle, an adhesive force, a slope height, a slope gradient, an uneven coefficient, a layer thickness ratio, a rainfall intensity, and a site temperature, are respectively selected to establish a risk evaluation index system, as shown in fig. 2.
In this embodiment, the value ranges of the evaluation indexes under different risk evaluation levels are determined by comprehensively considering the risk factors (i.e., the above 8 evaluation indexes) affecting the stability of the slope, as shown in table 1.
TABLE 1 value ranges of evaluation indexes under different risk evaluation grades
Evaluation index
Class I
Stage II
Class III
IV stage
Internal angle of friction/°
[38,50]
[31,38)
[27,31)
[0,27)
cohesion/Kpa
[40,80]
[16,40)
[8,16)
[0,8)
Side slope height-m
[0,43)
[43,98)
[98,144)
[144,200]
Slope gradient/°
[0,33)
[33,40)
[40,46)
[46,60]
Coefficient of non-uniformity
[11,20]
[6,11)
[4,6)
[1,4)
Layer thickness ratio
[1/2，3/4)
[3/4，9/10)
[9/10，19/20)
[19/20，1)
Intensity of rainfall-mm
[0,25)
[25,50)
[50,100)
[100,150)
Site temperature/. degree.C
[0,30)
[30,50)
[50,90)
[90,300)
In a specific embodiment of the foregoing slope safety risk assessment method, further determining each evaluation index weight includes:
calculating the weight of each evaluation index by adopting a comprehensive weight method combining subjective and objective weights;
wherein the weight λ of the ith evaluation indexiExpressed as:
wherein alpha isiIs a subjective weight, betaiFor objective weighting, n represents the number of evaluation indexes.
In this embodiment, the subjective weight α may be calculated by an analytic hierarchy processiSpecifically, the method comprises the following steps:
according to the 8 evaluation indexes of the internal friction angle, the cohesive force, the slope height, the slope gradient, the uneven coefficient, the layer thickness ratio, the rainfall intensity and the site temperature determined above and the index importance sequence thereof, a judgment matrix R is firstly establishedn×nAs shown in table 2.
TABLE 2 decision matrix
Evaluation index
Internal friction angle
Cohesion force
Height
Slope of slope
Coefficient of non-uniformity
Layer thickness ratio
Intensity of rainfall
Temperature of field
Internal friction angle
1
1/2
3
2
5
4
2
3
Cohesion force
2
1
4
3
6
5
3
4
Height
1/3
1/4
1
1/3
3
2
1/2
1
Slope of slope
1/2
1/3
3
1
4
3
1
2
Coefficient of non-uniformity
1/5
1/6
1/3
1/4
1
1/2
1/4
1/3
Layer thickness ratio
1/4
1/5
1/2
1/3
2
1
1/3
1/2
Intensity of rainfall
1/2
1/3
2
1
4
3
1
2
Temperature of field
1/3
1/4
1
1/2
3
2
1/2
1
Based on the obtained judgment matrix Rn×nThe subjective weights of 8 evaluation indexes of the internal friction angle, the cohesive force, the slope height, the slope gradient, the uneven coefficient, the layer thickness ratio, the rainfall intensity and the site temperature are respectively 0.2045, 0.3080, 0.0723, 0.1349, 0.0321, 0.0471, 0.1261 and 0.0751 through the calculation of an analytic hierarchy process.
In this embodiment, the entropy method may be used to calculate the objective weight βiThe method specifically comprises the following steps:
when introducing conditional information entropy into attribute importance and weight analysis, first of all, it is necessary toEstablishing a judgment matrix Rm×nThen, the judgment matrix R is pairedm×nNormalization processing is carried out, m represents the number of risk evaluation grades, wherein the cohesion, the internal friction angle and the uneven coefficient are normalized according to an expression (2), other evaluation indexes are normalized according to an expression (3), and the expressions (2) and (3) are as follows:
wherein, i is 1, 2, 3, 4, 5, 6, 7, 8, j is 1, 2, 3, 4, aijThe value of the correlation function for the ith evaluation index with respect to the jth risk evaluation level, i.e. aij＝Kj(xi)，Kj(xi) Value x representing the ith evaluation indexiWith respect to the correlation function for the jth risk assessment level,is normalized by aij，The maximum value and the minimum value of the correlation function value of the ith evaluation index relative to the jth risk evaluation level are respectively.
Calculating an evaluation index entropy value E according to the formula (4)i：
Wherein E isiEntropy, P, representing the i-th evaluation indexijIndicates that the ith evaluation index isSpecific gravity at the jth risk assessment scale;
if PijIs 0, is guaranteed lnPijThe meaningful correction is made as per equation (6):
further, objective weights of 8 evaluation indexes can be calculated according to equation (7):
in a specific embodiment of the slope safety risk evaluation method, further, the determining, according to the value ranges of the determined evaluation indexes at different risk evaluation levels and the weights of the evaluation indexes, the comprehensive association of the slope to be evaluated at each risk evaluation level and the risk evaluation level characteristic value of the slope to be evaluated includes:
a1, determining slope object elements to be evaluated, and calculating single evaluation index association degree by using an association function according to the determined slope object elements to be evaluated and the value ranges of all evaluation indexes under different risk evaluation levels; the method specifically comprises the following steps:
a11, determining classical domain matter element R according to the value ranges of the determined evaluation indexes under different risk evaluation gradesjAnd a domain-saving matter element Rp(ii) a Wherein the content of the first and second substances,
classical domain matter element RjExpressed as:
wherein N isjRepresent four risk assessment ratings, grade I-IV, with j being 1, 2, 3, 4, ci8 evaluation indexes of the slope are shown, i is 1, 2, 3, 4, 5, 6, 7, 8, vji＝<aji，bji>Indicates the evaluation index ciAt each risk evaluation level NjThe following value ranges;
node domain matter element RpExpressed as:
wherein P represents the overall risk assessment scale, vpi＝<api，bpi>Indicates the evaluation index ciValue ranges under all risk evaluation levels;
a12, determining the object element R of the side slope to be evaluated (called as evaluation object element for short)x：
Wherein, PxIndicating the side slope to be evaluated, xiIs PxRegarding the evaluation index ciActual value of (2);
a13, according to the determined classical domain element RjRegion-saving matter element RpAnd the slope object element R to be evaluatedxDetermining the extension distance of each evaluation index relative to each risk evaluation grade;
in this embodiment, if the risk evaluation level belongs to level II or level III, that is, j is 2 or 3, the actual value x of the ith evaluation index is obtainediExtension ρ (x) for jth risk assessment leveli，Xji) Expressed as:
if the risk evaluation grade belongs to grade I or IV, i.e. j is 1 or 4, the actual value x of the ith evaluation indexiExtension ρ (x) for jth risk assessment leveli，Xji) Expressed as:
wherein, XjiDenotes the ith evaluation index with respect to the jth risk evaluation level section, Xji＝<aji，bji>，X1、X4The risk evaluation levels are represented as class I and class IV intervals.
And A14, calculating the association degree of the single evaluation index by using an association function according to the determined extension distance of each evaluation index on each risk evaluation level.
In the present embodiment, the single evaluation index relevance is expressed as
ρ(Xji)＝|bji-aji| (16)
Wherein, Kj(xi) A correlation function representing the ith evaluation index with respect to the jth risk evaluation level, X represents the entire section of the ith evaluation index, api、bpiThe upper limit and the lower limit of the entire section of the i-th evaluation index are indicated.
A2, determining the comprehensive association degree of the slope to be evaluated under each risk evaluation level according to the obtained single evaluation index association degree and each evaluation index weight;
in this embodiment, the comprehensive association degree is expressed as:
wherein, Kj(Px) Showing the slope to be evaluated under the jth risk evaluation levelAnd (5) integrating the association degree.
And A3, determining each risk evaluation grade variable characteristic value of the slope to be evaluated according to the determined comprehensive association degree of the slope to be evaluated under each risk evaluation grade.
In this embodiment, the variable characteristic value of each risk evaluation level of the slope to be evaluated is represented as:
wherein j is*Representing the risk evaluation grade variable characteristic value, min and max respectively representing the minimum value and the maximum value,and the normalized numerical value represents the comprehensive association degree of the slope to be evaluated under the jth risk evaluation level.
In this embodiment, according to the obtained comprehensive association degree of the side slope to be evaluated at each risk evaluation level and the risk evaluation level characteristic value of the side slope to be evaluated, performing security risk evaluation on the side slope to be evaluated, specifically:
judging the risk evaluation grade according to the comprehensive relevance degree, if Kj(Rk)＝maxKj(Rk) Then, the side slope R is to be evaluatedkThe corresponding risk evaluation grade is j;
and when the risk evaluation grade characteristic value is increased, indicating that the slope instability risk is increased, otherwise, indicating that the slope instability risk is reduced.
In order to verify the effectiveness of the slope safety risk evaluation method provided by the embodiment of the invention, the case of selecting the gangue slope of the coal mine of the Wangjialing mountain of inner Mongolia is taken, the area of the slope belongs to the warm zone semiarid continental monsoon climate, the highest temperature is 42.5 ℃, and the lowest temperature is-19.9 ℃. The annual average rainfall is 496.7mm, the maximum rainfall intensity is 122.9mm, and the rainfall is mostly concentrated in 7-9 months. The selected slope height is 60m, and the slope gradient is 26.6 degrees. The internal friction angle was determined by laboratory tests to be 30.54 °, the cohesion 6.48kPa, the non-uniformity coefficient 16, and the layer thickness ratio of gangue to soil was 10/11. Through on-site monitoring, 2 working conditions of 7 months, 7 days and 8 months, 14 days are respectively selected for analysis, and the table 3 shows risk evaluation index values under two working conditions.
TABLE 3 Risk assessment index values under two conditions
Evaluation index
2018/7/7
2018/8/14
Internal angle of friction/°
30.54
30.54
cohesion/Kpa
6.48
6.48
Side slope height-m
60
60
Slope gradient/°
26.6
26.6
Coefficient of non-uniformity
16
16
Layer thickness ratio
10/11
10/11
Intensity of rainfall-mm
0
41
Field temperature/° c
63.79
51.58
After the slope evaluation index and the risk evaluation grade corresponding table are normalized, the classical domains R corresponding to the risk evaluation grades I, II, III and IV1、R2、R3、R4Respectively as follows:
slope object element R to be evaluated corresponding to 2 working conditionsx1、Rx2Respectively as follows:
the evaluation index weights are obtained from the formula (1), and are shown in table 4.
TABLE 4 evaluation index weights
Evaluation index weight
2020/7/7
2020/8/14
C1
0.0994
0.1440
C2
0.1875
0.2717
C3
0.0632
0.0916
C4
0.1454
0.2107
C5
0.0602
0.0872
C6
0.0180
0.0261
C7
0.3161
0.1230
C8
0.1103
0.0458
The risk evaluation level variable characteristic values and the risk evaluation level calculation results are shown in table 5. As can be seen from table 5, the risk evaluation level from 7/2020 to 24/8/2020 was increased from level I to level II, and the low risk was changed to the medium-low risk; the risk evaluation grade variable characteristic value is increased to 2.263 from the original 1.284, the risk evaluation grade variable characteristic value is biased to II grade, and the precaution work needs to be strengthened. And the field stability evaluation result is consistent with the field survey analysis result. Based on the field application case, the risk evaluation model can dynamically evaluate the risk evaluation level of the slope and the variable characteristic value of the risk evaluation level by analyzing the real-time monitoring data, and provides reliable technical support for a field engineer to more accurately master the instability risk of the slope.
TABLE 5 Risk evaluation level variable eigenvalues and risk evaluation level calculation results
Date of monitoring
2020/7/7
2020/8/14
j*
1.284
2.263
Risk assessment rating
I
II
TABLE 6 comprehensive evaluation results of risks of different engineering cases
Engineering case
Coefficient of stability
Characteristic value of risk evaluation grade
Risk assessment rating
Middle beam mountain side slope
1.293
1.464
Low risk
Wild goose side slope
1.31
1.116
Low risk
Tun blue side slope
0.927
3.402
High and high risk
Master Tian side slope
1.203
1.961
Low to medium risk
Southern tung side slope
1.079
1.788
Low to medium risk
Table 6 shows the results of the comprehensive risk assessment for different engineering cases. As can be seen from table 6, the method is used in combination with the conventional stability evaluation technology, so that the comprehensive consideration based on stability and risk evaluation can be realized, and further technical support is provided for better scientific risk management and control of small and medium-sized slopes.
In summary, the embodiment of the invention comprehensively considers 8 evaluation indexes influencing slope stability by applying an extension theory, and establishes a new slope safety risk evaluation method on the basis. The method not only considers the actual monitoring data of rainfall, temperature and the like on site to carry out instability probability analysis, but also does not need large sample training and complex numerical simulation calculation, so that the method can be effectively applied to the risk management of various small and medium-sized slopes. In addition, as the method comprehensively analyzes monitoring data such as on-site rainfall and the like, the method can be used for analyzing the real-time monitoring data in the slope safety monitoring, make up for the defect of excessive subjective qualitative conclusions of engineering monitoring report conclusions, and change the current situation of 'heavy acquisition and light analysis' of the slope engineering safety monitoring at present.
The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents, improvements and the like that fall within the spirit and principle of the present invention are intended to be included therein.