CN104636624A - Risk decision method for water retaining standard of non-overflow earth-rock cofferdam - Google Patents

Abstract

The invention belongs to the technical field of diversion risk decision for water conservancy and hydropower engineering construction, discloses a risk decision method for water retaining standard of a non-overflow earth-rock cofferdam and solves the problems caused by ignorance of decision index randomness in traditional decision methods. The method includes a, constructing a decision index system for the water retaining standard of the non-overflow earth-rock cofferdam; b, calculating dynamic water retaining risks of the non-overflow earth-rock cofferdam; c, estimating a decision index interval number by introducing an amplitude variation coefficient; d, calculating subjective entropy weight of an interval number index on the basis of an information entropy, and calculating comprehensive weight of the decision index according to the subjective weight; e, ranking schemes to decide a final one on the basis of the principle of interval number probability. The method is suitable for diversion risk decision for water conservancy and hydropower engineering construction.

Description

A kind of Application of risk decision method of only water retaining rockfill cofferdam standard

Technical field

The invention belongs to Construction for Hydroelectric Project water conservancy diversion decision in the face of risk technical field, be specifically related to a kind of Application of risk decision method of only water retaining rockfill cofferdam standard.

Background technology

Construction diversion affects the construction of hydropower plant overall situation, and engineering cost proportion is large, is generally 5% ~ 20% of hydroelectric project total expenses, and is a risk engineering, if overflow earth-rock cofferdam unrestrained top does not occur to burst event, certainly will bring huge loss to engineering.But the decision in the face of risk of water retaining rockfill cofferdam standard becomes the critical problem of Hydraulic and Hydro-Power Engineering planning, construction, investment, decision-making, management therefore.Part engineering specialist and scholar have carried out correlative study at only water retaining rockfill cofferdam standard risk decision-making level in recent years, make some progress.Wherein, applying more is minimum expectation loss Decision Method and Multiobjective Decision Making Method.

Decision-making technique utilized exact value to quantize Standard of River Diversion During Construction decision index system in the past, but had not considered the uncertainty of decision index system value.But construction diversion system contains numerous random factor, and the complicacy of engineering construction and uncertainty, decision index system value is often difficult to accurate expression.In Practical Project, decision index system has certain variability, and these desired values can be thought to change within the specific limits.Therefore, decision-making technique have ignored the randomness of decision index system in the past, a decision-making difficult problem for the only water retaining rockfill cofferdam standard that the uncertainty being difficult to adapt to practice of construction flow guide system complexity is brought.

Summary of the invention

Technical matters to be solved by this invention is: the Application of risk decision method proposing a kind of only water retaining rockfill cofferdam standard, solves the problem that traditional decision method is brought because ignoring decision index system randomness.

The technical solution adopted for the present invention to solve the technical problems is:

An only Application of risk decision method for water retaining rockfill cofferdam standard, comprises the following steps:

A. the decision-making index system of only water retaining rockfill cofferdam standard is built;

B. only water retaining rockfill cofferdam dynamic risk is calculated;

C. decision index system interval number is estimated by introducing radius variation ratio;

D. based on the objective entropy weight of information entropy computation interval number index, in conjunction with the comprehensive weight of subjective weight calculation decision index system;

E. sort to scheme based on interval number possibility degree principle, decision-making goes out final plan.

Concrete, in step a, based on initial stage construction diversion system performance, build the decision-making index system of only water retaining rockfill cofferdam standard, the decision index system chosen comprises: training works expense C _b, burst weir risk of loss expense C _bP, cofferdam construction mean intensity D.

Concrete, in step b, but water retaining rockfill cofferdam dynamic risk is flood peak level exceedes cofferdam weir crest risk, if R _bfor diversion cofferdam dash relative risk, if cofferdam water retaining year be limited to k, then the dash dynamic risk run in the time limit is:

R _B(k)＝1-(1-R _B) ^k。

Concrete, in step c, the described method by introducing radius variation ratio estimation decision index system interval number comprises:

For training works expense C _binterval number estimate: C _b=[(C _b1+ C _b2) (1-i _b), (C _b1+ C _b2) (1+i _b)]

Wherein, C _b1be the construction cost of diversion structure, comprise outlet structure escape works, upstream and downstream cofferdam expense; C _b2it is the anti-water-pumping/draining expense of base; i _bfor training works expense radius variation ratio;

For routed weir risk of loss expense C _bPinterval number estimate:

$C_{\mathrm{BP}}=[\underset{n=0}{\overset{k}{\mathrm{\Σ}}}(C_{r1}\left(n\right)+C_{r2}\left(n\right)){(1+i)}^{-n}{R}_B\left(n\right)(1-i_p),\underset{n=0}{\overset{k}{\mathrm{\Σ}}}(C_{r1}\left(n\right)+C_{r2}\left(n\right)){(1+i)}^{-n}{R}_B\left(n\right)(1+i_p)]$

Wherein, k is that tenure of use is run in cofferdam; I is the discount rate that risk of loss is converted to standard year; C _r1n () is cofferdam reconstruction expenses; C _r2n () causes postponing engineering generating expense for duration loss, can utilize Bayes statistical method, in conjunction with current electricity prices COMPREHENSIVE CALCULATING; i _pfor risk of loss expense radius variation ratio;

Interval number for cofferdam construction mean intensity D is estimated: cofferdam construction mean intensity interval number D is that decision maker is according to engineering experience, the luffing scope D=[D considering the estimation of construction speed arrangement condition _s, D _b], wherein D _s, D _bbe respectively minimum, maximum construction intensity.

Concrete, in steps d, if diversion standards scheme collection X=is (x ₁, x ₂..., x _m), decision index system collection U=(u ₁, u ₂..., u _n), corresponding scheme x _iabout u _jproperty value be a _ij, form decision matrix A=(a _ij) _{m × n}, wherein,

A _ij=[a _ij ^l, a _ij ^u] (i=1,2 ..., m; J=1,2 ..., n), to A=(a _ij) _{m × n}standardize, if the matrix after standardization is R=(r _ij) _{m × n}, then

$\left\{\begin{array}{c}{r}_{\mathrm{ij}}^L=a_{\mathrm{ij}}^L/\underset{i=1}{\overset{m}{\mathrm{\Σ}}}{\left(a_{\mathrm{ij}}^U\right)}^2\\ r_{\mathrm{ij}}^U=a_{\mathrm{ij}}^U/\underset{i=1}{\overset{m}{\mathrm{\Σ}}}{\left(a_{\mathrm{ij}}^L\right)}^2\end{array}\right.j\∈I_1$

$\left\{\begin{array}{c}{r}_{\mathrm{ij}}^L=(1/a_{\mathrm{ij}}^U)/\sqrt{\underset{i=1}{\overset{m}{\mathrm{\Σ}}}{(1/a_{\mathrm{ij}}^L)}^2}\\ r_{\mathrm{ij}}^U=(1/a_{\mathrm{ij}}^L)/\sqrt{\underset{i=1}{\overset{m}{\mathrm{\Σ}}}{(1/a_{\mathrm{ij}}^U)}^2}\end{array}\right.j\∈I_2$

In formula: I ₁, I ₂be respectively profit evaluation model and cost type property set;

Based on the definition of information entropy theory and interval numbers decision-making matrix, a jth attribute u _jentropy be defined as:

$H_j=\mathrm{\λ}(-\frac{1}{1\mathrm{nm}}\underset{i=1}{\overset{m}{\mathrm{\Σ}}}{r}_{\mathrm{ij}}^{L}1n{r}_{\mathrm{ij}}^L)+(1-\mathrm{\λ})(-\frac{1}{1\mathrm{nm}}\underset{i=1}{\overset{m}{\mathrm{\Σ}}}{r}_{\mathrm{ij}}^{U}1n{r}_{\mathrm{ij}}^U)$

In formula: λ is the coefficient of balance that decision maker provides, and meet 0< λ <1;

Each Attribute Interval Number attribute entropy power calculating formula is j ∈ N;

If index comprehensive weight is W=(w ₁, w ₂..., w _n), meet w ₁+ w ₂+ ... + w _n=1, subjective weight is F=(f ₁, f ₂..., f _n); Comprehensive weight is made up of subjective weight and objective weight, namely

$w_j=\frac{f_j{q}_j}{\underset{j=1}{\overset{n}{\mathrm{\&Sigma;}}}{f}_j{q}_j}$ j＝1,2,…,n。

Concrete, step e comprises:

The comprehensive evaluation value of each diversion standards scheme is calculated according to comprehensive weight: i=1,2 ..., m;

To m diversion plan comprehensive evaluation value interval number z ₁(w), z ₂(w), " z _mw () is sorted, first set up that interval number compares between two Possibility Degree Matrix, that is:

$P=\left[\begin{array}{cccc}0.5& p_{12}& ...& p_{1m}\\ p_{21}& 0.5& ...& p_{2m}\\ ...& ...& ...& ...\\ p_{m1}& p_{m2}& ...& 0.5\end{array}\right]$

Wherein, p _ijrepresent z _i(w)>=z _jw the possibility degree of (), if the ordering vector of Possibility Degree Matrix P is V=(v ₁, v ₂..., v _n), then the calculating formula of i-th component is

$v_i\frac{1}{m(m+1)}(\underset{j=1}{\overset{m}{\mathrm{\&Sigma;}}}{p}_{\mathrm{ij}}+\frac{m}{2}-1),$ i＝1,2,…,m

According to V=(v ₁, v ₂..., v _m) in the size of each component sort, the sequence of corresponding only water retaining rockfill cofferdam standard scheme can be obtained.

The invention has the beneficial effects as follows: the uncertainty considering During Initial Stage Construction diversion standards decision index system, introduce radius variation ratio and estimate decision index system interval number, for Standard of River Diversion During Construction Multiple Attribute Decision of Interval Numbers provides reliable basic data; Based on information entropy theory, calculate each Attribute Interval Number attribute entropy power; Combine subjective weight with objective entropy weight calculating comprehensive weight, the process that the subjective attitude better reflecting policymaker combines with objective information; Possibility degree principle is utilized to sort to scheme, make schemes ranking result with possibility degree information more good and bad between scheme, for decision maker provides more reference information, improve the reliability of the result of decision, a decision-making difficult problem for the only water retaining rockfill cofferdam standard that the uncertainty efficiently solving practice of construction flow guide system complexity is brought, the science decision for water retarding standard provides new thinking and countermeasure.

Accompanying drawing explanation

Fig. 1 is decision-making technique process flow diagram of the present invention;

Fig. 2 is the decision-making index system structural drawing of only water retaining rockfill cofferdam standard.

Embodiment

The present invention be intended to in conventional art to the weak point of only water retaining rockfill cofferdam standard risk decision-making, a kind of only water retaining rockfill cofferdam standard risk decision-making technique is newly proposed, for only the science decision of water retaining rockfill cofferdam standard provides new thinking and countermeasure.The present invention is based on interval number theory, consider the uncertainty of decision index system, overcome the defect ignoring decision index system variability in water retarding standard decision in the face of risk in the past, make only water retaining rockfill cofferdam criteria decision result science, reliable more.

Below in conjunction with drawings and Examples, the solution of the present invention is further described:

As shown in Figure 1, a kind of Application of risk decision method of only water retaining rockfill cofferdam standard, comprises the following steps:

A. the decision-making index system of only water retaining rockfill cofferdam standard is built;

B. only water retaining rockfill cofferdam dynamic risk is calculated;

C. decision index system interval number is estimated by introducing radius variation ratio;

D. based on the objective entropy weight of information entropy computation interval number index, in conjunction with the comprehensive weight of subjective weight calculation decision index system;

E. sort to scheme based on interval number possibility degree principle, decision-making goes out final plan.

On concrete enforcement, the implementation of each step of above-mentioned decision-making technique is as follows:

1, based on initial stage construction diversion system performance, as shown in Figure 2, the decision index system chosen comprises the decision-making index system building only water retaining rockfill cofferdam standard: training works expense C _b, burst weir risk of loss expense C _bP, cofferdam construction mean intensity D.

2 but water retaining rockfill cofferdam dynamic risk is flood peak level exceedes cofferdam weir crest risk, if R _bfor diversion cofferdam dash relative risk, if cofferdam water retaining year be limited to k, then the dash dynamic risk run in the time limit is:

R _B(k)＝1-(1-R _B) ^k

Consider the hydrology, waterpower is uncertain, adopt Monte Carlo method to calculate dynamic risk, concrete calculation procedure is shown in pertinent literature.

3, training works expense is determined primarily of diversion structure scale of investment, mainly comprises the construction cost of diversion structure and the expense of drawing water of foundation ditch.Introduce radius variation ratio, training works expense interval number can be estimated by following formula:

C _B＝[(C _B1+C _B2)(1-i _b),(C _B1+C _B2)(1+i _b)]

In formula: C _b1be the construction cost of diversion structure, mainly comprise outlet structure escape works, upstream and downstream cofferdam expense; C _b2it is the anti-water-pumping/draining expense of base; i _bfor training works expense radius variation ratio, decision maker provides with experience by engineering is live.

Cofferdam construction mean intensity interval number D is the luffing scope that decision maker arranges condition to estimate according to engineering experience, consideration construction speed, D=[D _s, D _b], wherein D _s, D _bbe respectively minimum, maximum construction intensity.

Construction diversion cofferdam Man Ding bursts and will bring certain loss.Introduce radius variation ratio, in the runtime of cofferdam, the risk total losses interval number that overload flood causes is:

$\begin{array}{c}{C}_{\mathrm{BP}}=[\underset{n=0}{\overset{k}{\mathrm{\&Sigma;}}}(C_{r1}\left(n\right)+C_{r2}\left(n\right)){(1+i)}^{-n}{R}_B\left(n\right)(1-i_p)\\ \underset{n=0}{\overset{k}{\mathrm{\&Sigma;}}}(C_{r1}\left(n\right)+C_{r2}\left(n\right)){(1+i)}^{-n}{R}_B\left(n\right)(1+i_p)]\end{array}$

In formula: k is that tenure of use is run in cofferdam; I is the discount rate that risk of loss is converted to standard year; C _r1n () is cofferdam reconstruction expenses; C _r2n () causes postponing engineering generating expense for duration loss, can utilize Bayes statistical method, in conjunction with current electricity prices COMPREHENSIVE CALCULATING; i _pfor risk of loss expense radius variation ratio.

In this programme, express decision index system, mainly because following reason by introducing radius variation ratio:

Construction diversion system contains various enchancement factor, makes decision index system have certain variability, and these desired values can be thought to change within the specific limits, then utilize interval number estimate each decision index system value more meet the thinking of decision maker and engineering actual.Such as: the investment of diversion tunnel is subject to the factor impacts such as reinforcing bar, fee of material, traffic expense ups and downs valency, and just estimate between investment and there is deviation, decision maker often provides the variation range of a diversion tunnel investment according to engineering experience in conjunction with result of calculation.

4, X=(x is established ₁, x ₂..., x _m) diversion standards scheme collection, decision index system collection U=(u ₁, u ₂..., u _n).Corresponding scheme x _iabout u _jproperty value be a _ij, form decision matrix A=(a _ij) _{m × n}, wherein a _ij=[a _ij ^l, a _ij ^u] (i=1,2 ..., m; J=1,2 ..., n).

To A=(a _ij) _{m × n}standardize, if the matrix after standardization is R=(r _ij) _{m × n}, then

$\left\{\begin{array}{c}{r}_{\mathrm{ij}}^L=a_{\mathrm{ij}}^L/\underset{i=1}{\overset{m}{\mathrm{\&Sigma;}}}{\left(a_{\mathrm{ij}}^U\right)}^2\\ r_{\mathrm{ij}}^U=a_{\mathrm{ij}}^U/\underset{i=1}{\overset{m}{\mathrm{\&Sigma;}}}{\left(a_{\mathrm{ij}}^L\right)}^2\end{array}\right.j\&Element;I_1$

$\left\{\begin{array}{c}{r}_{\mathrm{ij}}^L=(1/a_{\mathrm{ij}}^U)/\sqrt{\underset{i=1}{\overset{m}{\mathrm{\&Sigma;}}}{(1/a_{\mathrm{ij}}^L)}^2}\\ r_{\mathrm{ij}}^U=(1/a_{\mathrm{ij}}^L)/\sqrt{\underset{i=1}{\overset{m}{\mathrm{\&Sigma;}}}{(1/a_{\mathrm{ij}}^U)}^2}\end{array}\right.j\&Element;I_2$

In formula: I ₁, I ₂be respectively profit evaluation model and cost type property set.

Based on the definition of information entropy theory and interval numbers decision-making matrix, a jth attribute u _jentropy be defined as

$H_j=\mathrm{\&lambda;}(-\frac{1}{1\mathrm{nm}}\underset{i=1}{\overset{m}{\mathrm{\&Sigma;}}}{r}_{\mathrm{ij}}^{L}1n{r}_{\mathrm{ij}}^L)+(1-\mathrm{\&lambda;})(-\frac{1}{1\mathrm{nm}}\underset{i=1}{\overset{m}{\mathrm{\&Sigma;}}}{r}_{\mathrm{ij}}^{U}1n{r}_{\mathrm{ij}}^U)$

In formula: λ is the coefficient of balance that decision maker provides, and meet 0< λ <1.

Each Attribute Interval Number attribute entropy power calculating formula is j ∈ N

If index comprehensive weight is W=(w ₁, w ₂..., w _n), meet w ₁+ w ₂+ ... + w _n=1, subjective weight is F=(f ₁, f ₂..., f _n), subjective weight can utilize AHP method, Delphi method etc. to determine.Comprehensive weight should be made up of subjective weight and objective weight, namely

$w_j=\frac{f_j{q}_j}{\underset{j=1}{\overset{n}{\mathrm{\&Sigma;}}}{f}_j{q}_j}$ j＝1,2,…,n

In this programme, express decision index system objective weight, mainly because following reason by introducing information entropy theory:

Based on information entropy theory, the uncertainty of entropy energy photometry system state, can agriculture products objective weight more exactly.

5, assembly is weighted to each decision attribute values of diversion standards scheme, just can obtains each scheme comprehensive evaluation value, utilize WAA operator to obtain:

$z_i\left(w\right)=\underset{j=1}{\overset{n}{\mathrm{\&Sigma;}}}{w}_j{r}_{\mathrm{ij}}$ i＝1,2,…,m

If Y=is [y ^-, y ⁺], X=[x ^-, x ⁺], be denoted as l (Y)=y ⁺-y ^-, l (X)=x ⁺-x ^-, then the possibility degree of Y>=X is claimed to be

$P(Y\&GreaterEqual;X)=\frac{\min \{l\left(Y\right)+l\left(X\right),\max \{y^{+}-x^{-},0\left\}\right\}}{l\left(Y\right)+l\left(X\right)}$

More complicated when sorting for multiple interval number, needs before sequence to compare between two interval number, sets up fuzzy complementary matrix.If fuzzy matrix E=is (e _ij) _{n × n}, 0≤e _ij≤ 1, if so e _ij+ e _ji=1, then claim E to be fuzzy complementary matrix.To m diversion plan comprehensive evaluation value interval number z ₁(w), z ₂(w) ... z _mw () is sorted, first set up that interval number compares between two Possibility Degree Matrix, that is:

$P=\left[\begin{array}{cccc}0.5& p_{12}& ...& p_{1m}\\ p_{21}& 0.5& ...& p_{2m}\\ ...& ...& ...& ...\\ p_{m1}& p_{m2}& ...& 0.5\end{array}\right]$

Wherein, p _ijrepresent z _i(w)>=z _jw the possibility degree of (), if the ordering vector of Possibility Degree Matrix P is V=(v ₁, v ₂..., v _n), then the calculating formula of i-th component is

$v_i\frac{1}{m(m+1)}(\underset{j=1}{\overset{m}{\mathrm{\&Sigma;}}}{p}_{\mathrm{ij}}+\frac{m}{2}-1),$ i＝1，2，...，m

According to V=(v ₁, v ₂..., v _m) in the size of each component sort, the sequence of corresponding only water retaining rockfill cofferdam standard scheme can be obtained.

In this programme, compare possibility degree principle by interval number and carry out schemes ranking, mainly because following reason:

Possibility degree comparison principle is a kind of effective ways of interval number evaluate alternatives value sequence; In addition, utilize possibility degree principle to sort to scheme, make schemes ranking result with possibility degree information more good and bad between scheme, for decision maker provides more reference information, improve the reliability of the result of decision.

With a concrete example, embodiment of the present invention are described below:

Certain large-scale hydroelectric project of southwest is the important power station on this master stream, basin, concrete hyperboloid arched dam height of dam 278m.During Initial Stage Construction water conservancy diversion is intended adopting and is once blocked disconnected annual dash tunnel scheme.According to " hydroelectric pivotal project grade classification and design safety standard ", " flood control standard ", multi-purpose project is first-class engineering, and project scale is huge, will cause significant impact, therefore diversion structure rank is chosen to be III grade after the accident of cofferdam to engineering construction.For III grade of diversion structure, native stone class cofferdam respective design standard of flood is 20 ~ 50 years reoccurrence periods.Costly, impact is large with difficulty for construction diversion, initial stage of construction diversion standard choose difficulty, the decision-making of initial stage of construction diversion standard scheme is significant.

1, comprehensively analyze through the hydrology, geologic condition etc., draft three kinds of diversion plans, wherein diversion tunnel arrange and scale identical.According to engineering experience, training works expense radius variation ratio i _bget 5%, burst weir risk of loss expense radius variation ratio i _pget 10%, obtain each scheme decision index system value interval number in table 1 by step 3.

Table 1 decision index system interval number is estimated

The decision matrix after standardizing is obtained in table 2 by step 4.

Table 2 decision matrix

Each water retarding standard schemes synthesis evaluation of estimate is obtained by step 4,5:

z ₁(w)＝[0.5149,0.6407]，z ₂(w)＝[0.5206,0.6564]，z ₃(w)＝[0.5065,0.6332]

The Possibility Degree Matrix P that 3 kinds of diversion standards schemes compare between two is obtained as follows by step 5:

$P=\left[\begin{array}{ccc}0.5000& 0.4591& 0.5315\\ 0.5409& 0.5000& 0.5710\\ 0.4685& 0.5290& 0.5000\end{array}\right]$

The sequence ordering vector of the Possibility Degree Matrix P calculated by step 5 is:

v＝(0.1659,0.1760,0.1581)

Obtaining 3 kinds of diversion standards schemes synthesis attribute ranking interval numbers by ordering vector is: optimal case is scheme two, namely within 50 years one, meets standard of flood.

According to method of the present invention, in certain heavy construction example, be able to successful Application, obtain following important achievement: 1. introduce radius variation ratio to estimate that decision index system interval number is feasible, effective, comparatively meet engineering reality and decision maker's thinking habit; 2. take full advantage of decision index system information, calculate each Attribute Interval Number attribute entropy power, and calculating comprehensive weight that subjective weight is combined with objective entropy weight, the process that the subjective attitude better reflecting policymaker combines with objective information; 3. utilize possibility degree principle to sort to scheme, make schemes ranking result with possibility degree information more good and bad between scheme, for decision maker provides more reference information, improve the reliability of the result of decision.

The invention provides thinking and the method for the decision-making of a kind of only water retaining rockfill cofferdam standard risk; the method and access of this technical scheme of specific implementation is a lot; the above is only the preferred embodiment of the present invention; should be understood that; for those skilled in the art; under the premise without departing from the principles of the invention, can also make some equivalent substitutions and modifications, these substitutions and modifications also should be considered as protection scope of the present invention.The all available prior art of each ingredient not clear and definite in the present embodiment is realized.

Claims (6)

1. an Application of risk decision method for only water retaining rockfill cofferdam standard, is characterized in that, comprise the following steps:

A. the decision-making index system of only water retaining rockfill cofferdam standard is built;

B. only water retaining rockfill cofferdam dynamic risk is calculated;

C. decision index system interval number is estimated by introducing radius variation ratio;

D. based on the objective entropy weight of information entropy computation interval number index, in conjunction with the comprehensive weight of subjective weight calculation decision index system;

E. sort to scheme based on interval number possibility degree principle, decision-making goes out final plan.

2. the Application of risk decision method of a kind of only water retaining rockfill cofferdam standard as claimed in claim 1, it is characterized in that, in step a, based on initial stage construction diversion system performance, build the decision-making index system of only water retaining rockfill cofferdam standard, the decision index system chosen comprises: training works expense C _b, burst weir risk of loss expense C _bP, cofferdam construction mean intensity D.

3. the Application of risk decision method of a kind of only water retaining rockfill cofferdam standard as claimed in claim 1, is characterized in that, in step b, but water retaining rockfill cofferdam dynamic risk is flood peak level exceedes cofferdam weir crest risk, if R _bfor diversion cofferdam dash relative risk, if cofferdam water retaining year be limited to k, then the dash dynamic risk run in the time limit is:

R _B(k)＝1-(1-R _B) ^k。

4. the Application of risk decision method of a kind of only water retaining rockfill cofferdam standard as claimed in claim 1, is characterized in that, in step c, describedly estimates that the method for decision index system interval number comprises by introducing radius variation ratio:

For training works expense C _binterval number estimate: C _b=[(C _b1+ C _b2) (1-i _b), (C _b1+ C _b2) (1+i _b)]

Wherein, C _b1be the construction cost of diversion structure, comprise outlet structure escape works, upstream and downstream cofferdam expense; C _b2it is the anti-water-pumping/draining expense of base; i _bfor training works expense radius variation ratio;

For routed weir risk of loss expense C _bPinterval number estimate: $\begin{array}{c}{C}_{\mathrm{BP}}=[\underset{n=0}{\overset{k}{\mathrm{\&Sigma;}}}(C_{r1}\left(n\right)+C_{r2}\left(n\right)){(1+i)}^{-n}{R}_B\left(n\right)(1-i_p),\\ \underset{n=0}{\overset{k}{\mathrm{\&Sigma;}}}(C_{r1}\left(n\right)+C_{r2}\left(n\right)){(1+i)}^{-n}{R}_B\left(n\right)(1+i_p)]\end{array}$

Wherein, k is that tenure of use is run in cofferdam; I is the discount rate that risk of loss is converted to standard year; C _r1n () is cofferdam reconstruction expenses; C _r2n () causes postponing engineering generating expense for duration loss, can utilize Bayes statistical method, in conjunction with current electricity prices COMPREHENSIVE CALCULATING; i _pfor risk of loss expense radius variation ratio;

Interval number for cofferdam construction mean intensity D is estimated: cofferdam construction mean intensity interval number D is that decision maker is according to engineering experience, the luffing scope D=[D considering the estimation of construction speed arrangement condition _s, D _b], wherein D _s, D _bbe respectively minimum, maximum construction intensity.

5. the Application of risk decision method of a kind of only water retaining rockfill cofferdam standard as claimed in claim 1, is characterized in that, in steps d, if diversion standards scheme collection X=is (x ₁, x ₂..., x _m), decision index system collection U=(u ₁, u ₂..., u _n), corresponding scheme x _iabout u _jproperty value be a _ij, form decision matrix A=(a _ij) _{m × n}, wherein, a _ij=[a _ij ^l, a _ij ^u] (i=1,2 ..., m; J=1,2 ..., n), to A=(a _ij) _{m × n}standardize, if the matrix after standardization is then

$\left\{\begin{array}{c}{r}_{\mathrm{ij}}^L=a_{\mathrm{ij}}^L/\underset{i=1}{\overset{m}{\mathrm{\&Sigma;}}}{\left(a_{\mathrm{ij}}^U\right)}^2\\ r_{\mathrm{ij}}^U=a_{\mathrm{ij}}^U/\underset{i=1}{\overset{m}{\mathrm{\&Sigma;}}}{\left(a_{\mathrm{ij}}^L\right)}^2\end{array}\right.---j\&Element;I_1$

$\left\{\begin{array}{c}{r}_{\mathrm{ij}}^L=(1/a_{\mathrm{ij}}^U)/\sqrt{\underset{i=1}{\overset{m}{\mathrm{\&Sigma;}}}{(1/a_{\mathrm{ij}}^L)}^2}\\ r_{\mathrm{ij}}^U=(1/a_{\mathrm{ij}}^L)/\sqrt{\underset{i=1}{\overset{m}{\mathrm{\&Sigma;}}}{(1/a_{\mathrm{ij}}^U)}^2}\end{array}\right.---j\&Element;I_2$

In formula: I ₁, I ₂be respectively profit evaluation model and cost type property set;

Based on the definition of information entropy theory and interval numbers decision-making matrix, a jth attribute u _jentropy be defined as

$H_j=\mathrm{\&lambda;}(-\frac{1}{\ln m}\underset{i=1}{\overset{m}{\mathrm{\&Sigma;}}}{r}_{\mathrm{ij}}^L\ln r_{\mathrm{ij}}^L)+(1-\mathrm{\&lambda;})(-\frac{1}{\ln m}\underset{i=1}{\overset{m}{\mathrm{\&Sigma;}}}{r}_{\mathrm{ij}}^U\ln r_{\mathrm{ij}}^U)$

In formula: λ is the coefficient of balance that decision maker provides, and meet 0< λ <1;

Each Attribute Interval Number attribute entropy power calculating formula is

If index comprehensive weight is W=(w ₁, w ₂..., w _n), meet w ₁+ w ₂+ ... + w _n=1, subjective weight is F=(f ₁, f ₂..., f _n); Comprehensive weight is made up of subjective weight and objective weight, namely

$w_j=\frac{f_j{q}_j}{\underset{j=1}{\overset{n}{\mathrm{\&Sigma;}}}{f}_j{q}_j},j=\mathrm{1,2},\&CenterDot;\&CenterDot;\&CenterDot;,n.$

6. the Application of risk decision method of a kind of only water retaining rockfill cofferdam standard as claimed in claim 5, it is characterized in that, step e comprises:

The comprehensive evaluation value of each diversion standards scheme is calculated according to comprehensive weight:

To m diversion plan comprehensive evaluation value interval number z ₁(w), z ₂(w) ... z _mw () is sorted, first set up that interval number compares between two Possibility Degree Matrix, that is:

$P=\left[\begin{array}{cccc}0.5& p_{12}& ...& p_{1m}\\ p_{21}& 0.5& ...& p_{2m}\\ ...& ...& ...& ...\\ p_{m1}& p_{m2}& ...& 0.5\end{array}\right]$

Wherein, p _ijrepresent z _i(w)>=z _jw the possibility degree of (), if the ordering vector of Possibility Degree Matrix P is V=(v ₁, v ₂..., v _n), then the calculating formula of i-th component is

$v_i=\frac{1}{m(m+1)}(\underset{j=1}{\overset{m}{\mathrm{\&Sigma;}}}{p}_{\mathrm{ij}}+\frac{m}{2}-1),i\mathrm{1,2},...,m$

According to V=(v ₁, v ₂..., v _m) in the size of each component sort, the sequence of corresponding only water retaining rockfill cofferdam standard scheme can be obtained.