Optimal selection method for emergency disposal engineering measures of barrier lake

Abstract

The invention discloses a barrier lake emergency disposal engineering measure optimization method, and belongs to the field of barrier lake emergency disposal. The method comprises the following steps that an evaluation index set is established, wherein the evaluation index set comprises barrier lake correlation factors selected by barrier lake emergency disposal engineering measures; establishing an engineering measure set, wherein the engineering measure set comprises selectable emergency disposal engineering measures of the barrier lake; constructing an optimization model based on the evaluation index set and the engineering measure set; calculating to obtain a quantitative value of the applicability degree of each engineering measure in the engineering measure set through the optimization model; and according to the position sequence of the maximum quantized value in the engineering measure set, finding out the engineering measure in the corresponding sequence in the engineering measure set, namely obtaining the optimal engineering measure. The method has good applicability, the number of elements of the evaluation index set and the engineering measure set can be determined according to the actual situation of the barrier lake, the application degree of the engineering disposal measures is quantified through the optimization model, and the optimal engineering measure is selected according to the judgment condition.

Description

Technical Field

[0001] The invention belongs to the field of emergency disposal of dammed lakes, and in particular relates to an optimization method for engineering measures for emergency disposal of dammed lakes. Background Art

[0002] A barrier lake is a natural lake formed by a landslide, collapse, mudslide or other obstruction of a river. The accumulated material blocking the river is called a barrier body. Barrier lakes are widely distributed throughout the world, most frequently in plateau areas. There are hundreds of recorded major disasters involving barrier lakes. Emergency response to barrier lake disasters is one of the important tasks in the field of disaster prevention and mitigation.

[0003] The engineering measures for emergency disposal of barrier lakes are a powerful means to deal with barrier lake disasters. Faced with a complex environment, the choice of what type of engineering measures is one of the keys to the success or failure of emergency disposal of barrier lakes. Since barrier lakes have multiple attributes such as geological disasters, extreme meteorological disasters, and flood and drought disasters, the danger problem is very complicated. In the actual engineering rescue process, due to the different environmental boundary conditions, topographic geological conditions, and formation mechanisms, the surface morphology, material composition, and structural characteristics of each barrier body are different. The selection of emergency disposal engineering measures for barrier lakes depends largely on on-site disaster investigations and expert experience. In the "Technical Specifications for Risk Level Classification and Emergency Disposal of Barrier Lakes" (SL / T 450-2021) issued in November 2021, the selection principles for some engineering measures are stipulated, which to a certain extent provide a basis for how to select emergency disposal engineering measures for barrier lakes. However, the principles for the selection of engineering measures given in the specifications are mostly qualitative descriptions, lacking classification or quantification, and are not intuitive, which is not conducive to the rapid and comprehensive selection of the optimal engineering measures by on-site rescue decision-makers. Summary of the invention

[0004] The technical problem solved by the present invention is that the current selection of emergency disposal engineering measures for barrier lakes mostly relies on expert experience, and lacks a set of scientific and easy-to-use quantitative evaluation and selection methods for emergency disposal engineering measures, which is not conducive to the rapid and comprehensive selection of optimal engineering measures by on-site emergency rescue decision-makers. In response to this problem, the present invention proposes a method for optimizing emergency disposal engineering measures for barrier lakes. On the basis of obtaining the environmental conditions of the barrier lake, the characteristics of the barrier body, the characteristics of the barrier lake, etc., the disposal boundary conditions are comprehensively evaluated, and according to the classification indicators, through the optimization evaluation model of emergency disposal engineering measures for barrier lakes, the applicability of engineering disposal measures is quantified, providing quantitative and intuitive guidance for optimizing emergency disposal measures for barrier lakes.

[0005] In order to solve the above technical problems, the present invention is implemented by the following technical solutions:

[0006] A method for optimizing engineering measures for emergency disposal of a barrier lake comprises the following steps:

[0007] S1. Establish an evaluation index set, including the relevant factors of the barrier lake that affect the selection of emergency disposal engineering measures for the barrier lake;

[0008] S2. Establish a set of engineering measures, including optional emergency engineering measures for barrier lakes;

[0009] S3. Construct an optimization model based on the evaluation index set and engineering measure set;

[0010] S4. Calculate the quantitative value of the applicability of each engineering measure in the engineering measure set through the optimization model;

[0011] S5. Sort the engineering measures set according to the position of the largest quantitative value, find the engineering measures in the engineering measures set with the corresponding ranking, and obtain the preferred engineering measures.

[0012] Preferably, in step S1, the evaluation index set is as shown in formula (1):

[0013] (1);

[0014] In formula (1), vector P is the evaluation index set; p i is the i-th element of the evaluation index set, i=1~n, corresponding to the 1st to nth evaluation indicators respectively.

[0015] Preferably, in step S1, the evaluation indicators include the storage capacity of the barrier lake, the amount of water from upstream, the volume of the barrier body, the particle size of the barrier body material, the lithology of the barrier body material, and the existing discharge conditions; the existing discharge conditions include diversion tunnels, open channels, and passes.

[0016] Preferably, in step S2, the engineering measure set is as shown in formula (2):

[0017] (2);

[0018] In formula (2), vector G is the set of engineering measures; g j is the jth element of the measure set, j=1~m, corresponding to the 1st to mth engineering measures respectively.

[0019] Preferably, in step S2, the engineering measures include digging a drainage trough, digging a drainage channel, digging a drainage tunnel, pumping out water, utilizing existing drainage conditions, and removing the dam body.

[0020] Preferably, in step S3, the fuzzy algorithm for dynamic quantitative evaluation of the risk level of the barrier lake is as shown in formula (3):

[0021] (3);

[0022] In formula (3), vector A is the weight vector of the evaluation index set P, , ai is the i-th element of the weight vector, i=1~n, corresponding to the weights of the 1st to the nth evaluation indicators, respectively. and ; Matrix R is the influence matrix of the evaluation index set P on the engineering measures set G, as shown in formula (4):

[0023] (4);

[0024] In formula (4), r ij is the influence of the i-th evaluation index on the j-th engineering measure, i=1~n, j=1~m, And the sum of the elements in each row of the matrix is ​​1, that is .

[0025] Preferably, in step S5, when two or more equal maximum elements appear in the engineering measure set, one of them is arbitrarily selected or two or more are adopted simultaneously.

[0026] The method for optimizing the emergency disposal engineering measures of the barrier lake of the present invention has the following advantages and beneficial effects:

[0027] (1) The quantitative evaluation and selection of engineering measures for emergency response to barrier lakes has been realized, and the selection of engineering measures is intuitive.

[0028] (2) Improved the scientific nature of the selection of emergency engineering measures for barrier lakes. Barrier lakes have multiple attributes such as geological disasters, extreme meteorological disasters, and flood and drought disasters. The dangerous situation is very complicated, and the disposal conditions are numerous and the impacts are complex. By establishing (constructing) the evaluation index set, engineering measure set, and optimization model through the optimization method for emergency engineering measures for barrier lakes, we can comprehensively consider the boundary conditions that affect the selection of engineering measures and their mutual influence according to the actual situation of barrier lakes.

[0029] (3) The method of the present invention has good applicability. The number of elements in the evaluation index set and the engineering measure set can be determined according to the actual situation of the barrier lake. The applicability of the engineering disposal measures can be quantified through the optimization model, and the optimal engineering measures can be selected according to the judgment conditions. DETAILED DESCRIPTION

[0030] The specific implementation modes of the present invention are described below to facilitate those skilled in the art to understand the present invention. Obviously, the present invention is not limited to the scope of the specific implementation modes.

[0031] The present invention provides a method for optimizing engineering measures for emergency disposal of a barrier lake, which mainly includes an evaluation index set, an engineering measure set, an optimization model, and optimization judgment:

[0032] (1) Establishing an evaluation index set

[0033] The evaluation index set P includes the relevant factors of the dammed lake that affect the selection of emergency disposal engineering measures for the dammed lake:

[0034] (1);

[0035] Where, vector P is the evaluation index set of emergency disposal engineering measures for barrier lakes; i is the i-th element of the evaluation index set, i=1~n, corresponding to the 1st to nth evaluation indexes, such as the reservoir capacity of the barrier lake, the amount of water coming from upstream, the volume of the barrier body, the particle size of the barrier body material, the lithology of the barrier body material, and the existing discharge conditions (such as diversion tunnels, open channels, and passes), etc. The number of evaluation indicators is determined according to the actual situation of the barrier lake, that is, the number of elements in the evaluation index set is determined. Among them, the reservoir capacity of the barrier lake, the amount of water coming from upstream, the volume of the barrier body, the particle size of the barrier body material, and the lithology of the barrier body material are generally selected evaluation indicators; the actual situation of the barrier lake refers to whether there are existing discharge conditions such as diversion tunnels, open channels, and passes in the area where the barrier lake is located. Because the presence or absence of discharge conditions can be directly judged based on the on-site situation, it can be considered whether to select it as an evaluation indicator based on the actual situation.

[0036] (2) Establish a set of engineering measures

[0037] Engineering measures set G includes optional emergency disposal engineering measures for barrier lakes:

[0038] (2);

[0039] Where, vector G is the set of emergency response measures for barrier lake; g j is the jth element of the measure set, j=1~m, corresponding to the 1st to mth engineering measures, such as digging diversion channels, digging spillways, digging spillways, pumping and draining, using existing discharge conditions, removing the barrier, etc. The number of engineering measures is determined according to the actual situation of the barrier lake and expert experience, that is, the number of elements in the engineering measure set is determined. According to the actual situation of the barrier lake and expert experience, it means that the measures that are obviously adopted unconditionally are not included in the engineering measure set. For example, if the reservoir capacity of the barrier lake is large (tens of millions of cubic meters or more), the pumping and draining measures have little effect on reducing the water in the barrier lake, and they are not included in the engineering measure set; for example, if there are no diversion tunnels, open channels, or passes in the barrier lake area, the measure of using existing discharge conditions is not included in the engineering measure set; for example, if the barrier body is huge (millions of cubic meters or more) and the lake water rises significantly, there is no condition to remove the barrier body, and it is not included in the engineering measure set.

[0040] (3) Constructing the optimal model

[0041] The optimization model of emergency disposal engineering measures for barrier lake is as follows:

[0042] (3);

[0043] In the formula, vector A is the weight vector of the evaluation index set, , where a i is the i-th element of the weight vector, i=1~n, corresponding to the weights of the 1st to the nth evaluation indicators, respectively. and ; Matrix R is the influence matrix of the evaluation index set (P) on the engineering measures set (G), which is expressed as follows:

[0044] (4);

[0045] Among them, r ij is the influence of the i-th evaluation index on the j-th engineering measure, i=1~n, j=1~m, And the sum of the elements in each row of the matrix is ​​1, that is ; r ij The determination of r can be divided into multiple levels according to the degree of influence, such as 3 levels (0, 0.5, 1), 5 levels (0, 0.25, 0.5, 0.75, 1), etc., or the membership function can be used to calculate the value of each element and determine r using the classification method or membership function. ij When the value is larger, the stronger the influence; if the 5-level grading method is used, 0 represents no correlation, 0.25 represents weak correlation, 0.5 represents general correlation, 0.75 represents strong correlation, and 1 represents strong correlation.

[0046] (4) Determine the optimal engineering measures

[0047] Through the above optimization model, we can get the vector G. The size of each element in G represents the difference in the applicability of each engineering measure. Find the largest element in vector G g j According to the position of the element, the j-th engineering measure corresponding to the engineering measure set is found, which is the preferred engineering measure.

[0048] G 优 =j if g j =MAX(G) (5);

[0049] In formula (5), G 优 is the preferred engineering measure, and j is the order of the largest element of the preferred engineering measure in vector G.

[0050] When two or more equal maximum elements appear in vector G, one of them can be selected arbitrarily or two or more can be used at the same time. It can also be determined based on the experience of emergency rescue experts to select one of them or use them at the same time. In addition, according to the actual situation of the landslide lake rescue, engineering measures corresponding to multiple larger elements in vector G can also be selected and used in combination to further improve the emergency response effect of the landslide lake.

[0051] Through the above steps, the implementation of the optimization method for emergency disposal engineering measures of the barrier lake of the present invention is completed.

[0052] Next, the present invention will be further described by taking a certain emergency disposal project of a barrier lake as an example.

[0053] Case description: A landslide occurred again on the right bank of a river, and the deposited body into the river was about 2.6 million m 3 This is the first landslide after the previous one (the deposit in the river is about 25 million m 3 After the natural flood, about 19 million m 3 ) blocked the river on a large scale, forming a barrier lake again.

[0054] The basic information of the barrier lake is as follows:

[0055] The reservoir capacity of the barrier lake is about 770 million m 3 ;

[0056] Water flow from upstream: 600m 3 / s;

[0057] Dam volume: about 22 million m 3 ;

[0058] Grain size of the dam material: except for the local quartz schist-rich area, the particles are generally fine (d 50 =40mm), gravel accounts for about 75%, clay accounts for about 3%, broken stones account for about 22%, and stones larger than 50cm account for about 8%.

[0059] Lithology of dam body: hornblende schist, serpentinite;

[0060] Discharge conditions: There is a natural low trough on the right side of the landslide body, which is favorable for flow through the landslide body. There are no existing discharge conditions such as diversion holes and open channels in the surrounding area.

[0061] Based on the above basic information, the method of the present invention is implemented as follows:

[0062] (1) Establishing an evaluation index set

[0063] According to the basic situation of the barrier lake, the evaluation index set P is established.

[0064] P = [p1, p2, p3, p4, p5, p6] = [capacity of the barrier lake, upstream water flow, barrier volume, barrier material particle size, barrier material lithology, discharge conditions] = [770 million m 3 , 600m 3 / s, 22 million m 3 , which is generally thinner (d 50=40mm), hornblende schist, serpentinite, the weir has a pass and no existing discharge conditions]

[0065] (2) Establish a set of engineering measures

[0066] According to the basic situation of the barrier lake, a set of engineering measures G is established.

[0067] G=[g1, g2, g3, g4, g5, g6]=[digging diversion channels, digging spillway channels, digging spillway tunnels, pumping out water, utilizing existing spillway conditions, and removing dams]

[0068] (3) Determine the weight vector A and matrix R

[0069] Based on expert experience and engineering experience, the weight vector A=[0.2, 0.2, 0.2, 0.15, 0.15,0.1] is determined.

[0070] Expert experience and engineering experience refer to a classification of the importance of evaluation indicators based on the emergency response cases of landslide lakes in which the participants participated in the implementation and investigation. The importance of indicators can be divided according to the Technical Specifications for Risk Grading and Emergency Response to Landslide Lakes (SL / T450). The greater the risk of the evaluation, the greater the importance. Considering that the reservoir capacity of the landslide lake and the upstream water inflow in this case are extremely dangerous, the particle size of the landslide body material is medium dangerous, the volume of the landslide body is huge in the investigated cases, the composition of the landslide body material is plagioclase amphibolite and serpentinite rather than soil, which is medium to low dangerous, and the discharge conditions are not obviously favorable, the evaluation indicators in this case are ranked according to their importance as "reservoir capacity of the landslide lake = upstream water inflow = volume of the landslide body ≥ particle size of the landslide body material = lithology of the landslide body material ≥ discharge conditions".

[0071] This case adopts a grading method, and selects a 5-level grading method, combined with the experience of experts and similar projects to determine r ij . Among them, expert experience and engineering experience refer to the degree of influence of the selected evaluation indicators on the selected engineering measures based on the implementation of the emergency response measures for the barrier lake that they participated in and investigated, and the basic information of the barrier lake. Taking the second evaluation indicator "barrier lake storage capacity" in this case as an example, since the storage capacity of the barrier lake in this case is nearly 800 million cubic meters, the storage capacity is extremely large. For the engineering measures set "excavating diversion channels, excavating spillways, excavating spillways, pumping out water, using existing spillway conditions, and removing barrier bodies", pumping out water and using existing spillway conditions are unrealistic. The use of these two measures has almost no effect on reducing the storage capacity of the barrier lake, so the degree of influence is 0; while the engineering measures of excavating diversion channels, excavating spillways, excavating spillway tunnels, and removing barrier bodies are effective in reducing the storage capacity of the barrier lake, and the degree of influence is the same, so the total amount is controlled as 1, and each element is 0.25.

[0072] The final matrix R is as follows:

[0073]

[0074] (4) Determine the optimal engineering measures

[0075] According to formula (3), we get the vector G = [0.45, 0.275, 0.1, 0, 0, 0.175].

[0076] According to formula (5), the largest element in vector G is g1=MAX(G)=0.45, G 优 =1, the corresponding engineering measure in engineering measure G is excavating a drainage channel, that is, the preferred engineering measure for emergency disposal of the barrier lake in this case is excavating a drainage channel.

[0077] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

[0078] The contents not described in detail in the specification of the present invention belong to the prior art known to the professional and technical personnel in this field.

Claims

1. A method for optimizing engineering measures for emergency disposal of a barrier lake, characterized in that: The steps include: S1. Establish an evaluation index set, including the relevant factors of the barrier lake that affect the selection of emergency disposal engineering measures for the barrier lake; S2. Establish a set of engineering measures, including optional emergency engineering measures for barrier lakes; S3. Construct an optimization model based on the evaluation index set and engineering measure set; S4. Calculate the quantitative value of the applicability of each engineering measure in the engineering measure set through the optimization model; S5. Sort the engineering measures set according to the position of the largest quantitative value, find the engineering measures in the engineering measures set with the corresponding ranking, and obtain the preferred engineering measures.

2. The method for optimizing emergency disposal engineering measures for a barrier lake according to claim 1, characterized in that: In step S1, the evaluation index set is shown in formula (1): （1）； In formula (1), vector P is the evaluation index set; p i is the i-th element of the evaluation index set, i=1~n, corresponding to the 1st to nth evaluation indicators respectively.

3. The method for optimizing emergency treatment engineering measures for a barrier lake according to claim 2, characterized in that: In step S1, the evaluation indicators include the storage capacity of the barrier lake, the amount of water from upstream, the volume of the barrier body, the particle size of the barrier body material, the lithology of the barrier body material, and the existing discharge conditions; the existing discharge conditions include diversion tunnels, open channels, and passes.

4. The method for optimizing emergency disposal engineering measures for a barrier lake according to claim 1, characterized in that: In step S2, the engineering measures set is shown in formula (2): （2）； In formula (2), vector G is the set of engineering measures; g j is the jth element of the measure set, j=1~m, corresponding to the 1st to mth engineering measures respectively.

5. The method for optimizing emergency disposal engineering measures for barrier lake according to claim 4, characterized in that: In step S2, the engineering measures include digging drainage channels, digging spillway channels, digging spillway tunnels, pumping out water, utilizing existing spillway conditions, and removing dam bodies.

6. The method for optimizing emergency treatment engineering measures for a barrier lake according to claim 1, characterized in that: In step S3, the fuzzy algorithm for dynamic quantitative evaluation of the risk level of the barrier lake is shown in formula (3): （3）； In formula (3), vector A is the weight vector of the evaluation index set P, , a i is the i-th element of the weight vector, i=1~n, corresponding to the weights of the 1st to the nth evaluation indicators, respectively. and ; Matrix R is the influence matrix of the evaluation index set P on the engineering measures set G, as shown in formula (4): （4）； In formula (4), r ij is the influence of the i-th evaluation index on the j-th engineering measure, i=1~n, j=1~m, And the sum of the elements in each row of the matrix is ​​1, that is .

7. The method for optimizing emergency disposal engineering measures for a barrier lake according to claim 1, characterized in that: In step S5, when two or more equal maximum elements appear in the engineering measure set, one of them is selected arbitrarily or two or more are adopted simultaneously.

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