CN111523806A - Gravity dam risk assessment calculation method based on hierarchical analysis and fuzzy comprehensive evaluation - Google Patents
Gravity dam risk assessment calculation method based on hierarchical analysis and fuzzy comprehensive evaluation Download PDFInfo
- Publication number
- CN111523806A CN111523806A CN202010328909.5A CN202010328909A CN111523806A CN 111523806 A CN111523806 A CN 111523806A CN 202010328909 A CN202010328909 A CN 202010328909A CN 111523806 A CN111523806 A CN 111523806A
- Authority
- CN
- China
- Prior art keywords
- risk
- dam
- gravity dam
- fuzzy
- gravity
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 238000011156 evaluation Methods 0.000 title claims abstract description 112
- 230000005484 gravity Effects 0.000 title claims abstract description 112
- 238000012502 risk assessment Methods 0.000 title claims abstract description 61
- 238000004458 analytical method Methods 0.000 title claims abstract description 45
- 238000004364 calculation method Methods 0.000 title claims abstract description 43
- 238000000034 method Methods 0.000 claims abstract description 64
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 31
- 238000013461 design Methods 0.000 claims description 22
- 238000011144 upstream manufacturing Methods 0.000 claims description 20
- 230000001186 cumulative effect Effects 0.000 claims description 6
- 238000012545 processing Methods 0.000 claims description 5
- 230000006835 compression Effects 0.000 claims description 3
- 238000007906 compression Methods 0.000 claims description 3
- 238000012854 evaluation process Methods 0.000 claims description 3
- 230000002706 hydrostatic effect Effects 0.000 claims description 3
- 239000013049 sediment Substances 0.000 claims description 3
- 238000010276 construction Methods 0.000 description 27
- 230000008569 process Effects 0.000 description 14
- 230000006870 function Effects 0.000 description 11
- 238000011160 research Methods 0.000 description 7
- 239000011159 matrix material Substances 0.000 description 6
- 231100000817 safety factor Toxicity 0.000 description 6
- 238000011161 development Methods 0.000 description 5
- 239000000463 material Substances 0.000 description 4
- 230000009471 action Effects 0.000 description 3
- 238000012423 maintenance Methods 0.000 description 3
- 238000012954 risk control Methods 0.000 description 3
- 238000007405 data analysis Methods 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 238000005516 engineering process Methods 0.000 description 2
- 102000051759 human factor J Human genes 0.000 description 2
- 108700008420 human factor J Proteins 0.000 description 2
- 238000010606 normalization Methods 0.000 description 2
- 238000011002 quantification Methods 0.000 description 2
- 238000010187 selection method Methods 0.000 description 2
- 230000009897 systematic effect Effects 0.000 description 2
- 230000002411 adverse Effects 0.000 description 1
- 230000002776 aggregation Effects 0.000 description 1
- 238000004220 aggregation Methods 0.000 description 1
- 230000004075 alteration Effects 0.000 description 1
- 230000006399 behavior Effects 0.000 description 1
- 238000007664 blowing Methods 0.000 description 1
- 210000004556 brain Anatomy 0.000 description 1
- 238000004422 calculation algorithm Methods 0.000 description 1
- 230000002301 combined effect Effects 0.000 description 1
- 239000002131 composite material Substances 0.000 description 1
- 230000010485 coping Effects 0.000 description 1
- 235000013399 edible fruits Nutrition 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 230000007613 environmental effect Effects 0.000 description 1
- 230000002068 genetic effect Effects 0.000 description 1
- 239000008235 industrial water Substances 0.000 description 1
- 238000007726 management method Methods 0.000 description 1
- 238000012067 mathematical method Methods 0.000 description 1
- 238000013178 mathematical model Methods 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000012544 monitoring process Methods 0.000 description 1
- 238000010248 power generation Methods 0.000 description 1
- 230000001681 protective effect Effects 0.000 description 1
- 238000012797 qualification Methods 0.000 description 1
- 238000004451 qualitative analysis Methods 0.000 description 1
- 238000004445 quantitative analysis Methods 0.000 description 1
- 239000004576 sand Substances 0.000 description 1
- 239000007787 solid Substances 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 238000006467 substitution reaction Methods 0.000 description 1
- 238000012360 testing method Methods 0.000 description 1
- 230000007704 transition Effects 0.000 description 1
Images
Classifications
-
- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06Q—INFORMATION AND COMMUNICATION TECHNOLOGY [ICT] SPECIALLY ADAPTED FOR ADMINISTRATIVE, COMMERCIAL, FINANCIAL, MANAGERIAL OR SUPERVISORY PURPOSES; SYSTEMS OR METHODS SPECIALLY ADAPTED FOR ADMINISTRATIVE, COMMERCIAL, FINANCIAL, MANAGERIAL OR SUPERVISORY PURPOSES, NOT OTHERWISE PROVIDED FOR
- G06Q10/00—Administration; Management
- G06Q10/06—Resources, workflows, human or project management; Enterprise or organisation planning; Enterprise or organisation modelling
- G06Q10/063—Operations research, analysis or management
- G06Q10/0635—Risk analysis of enterprise or organisation activities
-
- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06F—ELECTRIC DIGITAL DATA PROCESSING
- G06F17/00—Digital computing or data processing equipment or methods, specially adapted for specific functions
- G06F17/10—Complex mathematical operations
- G06F17/16—Matrix or vector computation, e.g. matrix-matrix or matrix-vector multiplication, matrix factorization
-
- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06Q—INFORMATION AND COMMUNICATION TECHNOLOGY [ICT] SPECIALLY ADAPTED FOR ADMINISTRATIVE, COMMERCIAL, FINANCIAL, MANAGERIAL OR SUPERVISORY PURPOSES; SYSTEMS OR METHODS SPECIALLY ADAPTED FOR ADMINISTRATIVE, COMMERCIAL, FINANCIAL, MANAGERIAL OR SUPERVISORY PURPOSES, NOT OTHERWISE PROVIDED FOR
- G06Q50/00—Systems or methods specially adapted for specific business sectors, e.g. utilities or tourism
- G06Q50/06—Electricity, gas or water supply
Abstract
The invention provides a gravity dam risk assessment and calculation method based on hierarchical analysis and fuzzy comprehensive evaluation, which comprises the following steps of: designing a gravity dam comprising: drawing a section of the gravity dam, carrying out load calculation on the gravity dam, carrying out stability analysis on the gravity dam, and carrying out stress analysis on the gravity dam; performing risk assessment on the gravity dam, comprising: the method comprises the following steps of carrying out risk estimation on the gravity dam, establishing fuzzy comprehensive evaluation on risk factors, carrying out risk estimation on the gravity dam engineering, and analyzing the risk estimation result of the gravity dam engineering, wherein the risk estimation on the gravity dam comprises the following steps: and carrying out fuzzy estimation on the risk probability and establishing a risk evaluation standard.
Description
Technical Field
The invention relates to the technical field of data analysis, in particular to a gravity dam risk assessment and calculation method based on hierarchical analysis and fuzzy comprehensive evaluation.
Background
With the development of the scale of water conservancy construction in China and more risks in the project construction process, the research of the risk assessment of the water conservancy project is very important and necessary. In the design stage of the gravity dam, although the anti-skid stability analysis and the stress analysis are met, the dam cannot be considered to be safely operated due to the fact that various risk factors exist in the construction and operation stages, the risk factors in the design and operation processes of the gravity dam are identified, the risk loss is calculated, and corresponding measures for coping with the risk are provided.
The gravity dam cannot be considered to be completely safe after meeting the requirements of stability and strength, a great number of risk factors exist in the construction and operation of the gravity dam, the safety of the dam is threatened, the potential safety hazards are not inconsiderable, and the consequences of the dam are unreasonable once an accident occurs, so the risk assessment of the gravity dam is also included in the design of the gravity dam. When the traditional gravity dam is designed, the stability of the dam is checked only according to safety factors such as stress-strain and the like, and risk factors and a control method of the dam in the actual operation process are not considered.
Disclosure of Invention
The object of the present invention is to solve at least one of the technical drawbacks mentioned.
Therefore, the invention aims to provide a gravity dam risk assessment and calculation method based on hierarchical analysis and fuzzy comprehensive evaluation.
In order to achieve the above object, an embodiment of the present invention provides a gravity dam risk assessment calculation method based on hierarchical analysis and fuzzy comprehensive evaluation, including the following steps:
step S1, designing a gravity dam, comprising: drawing a section of the gravity dam, carrying out load calculation on the gravity dam, carrying out stability analysis on the gravity dam, and carrying out stress analysis on the gravity dam;
wherein, the section of drawing up the gravity dam comprises: determining dam crest elevation, determining dam foundation elevation, drawing up dam crest width, drawing up section size and drawing up dam foundation width;
step S2, risk assessment is carried out on the gravity dam, and the method comprises the following steps: the method comprises the following steps of carrying out risk estimation on the gravity dam, establishing fuzzy comprehensive evaluation on risk factors, carrying out risk estimation on the gravity dam engineering, and analyzing the risk estimation result of the gravity dam engineering, wherein the risk estimation on the gravity dam comprises the following steps: carrying out fuzzy estimation on the risk probability and establishing a risk evaluation standard, wherein the fuzzy estimation on the risk probability comprises the following steps: determining expert weight, grading risk probability, carrying out expert fuzzy estimation on the risk probability, and calculating the membership degree of the risk factor occurrence probability;
the establishing of the risk evaluation standard comprises the following steps: establishing risk grading standards and risk evaluation standards, wherein the risk grading standards comprise the grade standards of the occurrence probability of the risk accident and the loss grade standards after the risk accident occurs.
Further, in step S1, the load calculation on the gravity dam includes: and calculating the dead weight, the hydrostatic pressure, the wave pressure, the sediment pressure, the uplift pressure and the earthquake load.
Further, in the step S1, the performing stability analysis on the gravity dam includes:
the method adopts a single safety factor method to calculate, and the formula is as follows:
wherein K' represents the anti-skid stability safety coefficient calculated according to the shear strength; f 'represents the shear-resistant friction coefficient of the contact surface of the dam body concrete and the dam foundation, and f' is 1.1; c 'represents the shear-resistant cohesion of the contact surface between the dam concrete and the dam foundation, KPa, and the data shows that c' is 75t/m2Reduced to 735 KPa; a represents the cross-sectional area of the dam foundation contact surface, m2(ii) a The sigma-W represents the normal value, kN, of all loads acting on the dam body to the sliding plane; Σ P denotes the tangential component, kN, of the total load acting on the dam to the sliding plane.
Further, in step S1, the performing stress analysis on the gravity dam includes:
respectively analyzing the normal stress on the horizontal section for the basic combination (1) and the special combination (1) by adopting a single safety factor method, and assuming sigmayDistributed in a straight line, so that the edge stress sigma upstream and downstream is calculated according to an eccentric compression formulayuAnd σyd。
Σ W represents the sum of the vertical components acting on all loads above the calculated cross section, kN;
the sigma M represents the sum of the moments of all loads acting on the calculated cross section to the dam foundation cross section vertical water flow direction forming mandrel, and kN.m;
b represents the length of the calculated cross section, m;
calculating the maximum principal stress of the dam body:
pu＝γH1，pd＝γH2，
σ1u＝(1+n2)σyu-pun2
σ1d＝(1+m2)σyd-pdm2
the maximum principal stress calculated is required not to exceed the allowable stress value of the concrete;
the data shows that the ultimate compressive strength of the bedrock is [ sigma ]]＝650kg/cm2I.e., [ sigma ]]＝6370kPa
Basic combination (1)
pu＝γH1＝9.8×98.7＝967.3kPa
pd＝γH2＝9.8×12.4＝121.52kPa
σ1u＝(1+n2)σyu-pun2＝(1+0.22)×557.62-969.3×0.22＝541.15kPa
σ1d＝(1+m2)σyd-pdm2＝(1+0.82)×1412.20-121.52×0.82＝2238.23kPa
Special combination (1):
pu＝γH1＝9.8×101.2＝991.76kPa，pd＝γH2＝9.8×30.8＝301.84kPa
σ1d＝(1+m2)σyd-pdm2＝(1+0.802)×1389.75-301.84×0.802＝2085.60kPa。
further, in the step S1, the determining the dam crest elevation includes:
(1) calculating the superhigh value deltah
The basic formula: the elevation of the top of the dam is higher than the check flood level, the elevation of the top of the wave wall at the upstream of the top of the dam is higher than the elevation of the top of the wave wall, the height difference delta h between the top of the wave wall and the design flood level or the check flood level is calculated according to the following formula
Δh＝h1％+hz+hc
Delta h is the height difference m between the wave wall top and the designed flood level or the check flood level;
h1％-the cumulative wave height at a frequency of 1%, m;
hz-height difference, m, from the wave centre line to the design flood level or the check flood level;
hc-safely heightening the ground,
(2) calculating dam crest elevation
Selecting a larger value from the following two formulas to obtain the crest elevation of the upstream wave wall of the dam:
the elevation of the wave wall top is set as the designed flood level + delta h
And (4) checking the flood level and delta h for the elevation of the top of the wave wall.
Further, in step S2, the establishing a fuzzy comprehensive evaluation on the risk factors includes: establishing a factor set, establishing a risk factor weight set, establishing a backup set, performing single-factor fuzzy evaluation, performing fuzzy comprehensive evaluation, establishing risk level grading and processing evaluation indexes.
Further, in the step S2, the performing risk assessment on the gravity dam engineering includes: setting risk factors, determining a risk assessment index system and weight, carrying out fuzzy estimation on risk probability and risk loss, and establishing a risk evaluation process.
Further, the establishing a risk assessment process includes: establishing a risk factor set, establishing a risk factor weight set, establishing a candidate set, performing fuzzy evaluation on the third layer of risk factors, performing fuzzy comprehensive evaluation on the second layer of risk factors, and performing fuzzy comprehensive evaluation on the first layer of risk factors.
According to the gravity dam risk assessment calculation method based on the hierarchical analysis and the fuzzy comprehensive evaluation, disclosed by the embodiment of the invention, a risk assessment theory and method are analyzed, wherein the risk assessment theory and method comprise risk connotation, risk identification, risk estimation and risk assessment. The thesis identifies the main risk factors of the gravity dam by using an expert survey method, solves the problems of ambiguity and difficult quantification in risk estimation by using a fuzzy mathematical theory, and analyzes to obtain the probability and loss estimation of the risk factors of the gravity dam; and comprehensively considering the influence of the occurrence probability and the loss severity of the risk factors on the risk level based on the R-P-C model and a fuzzy comprehensive evaluation method to obtain the grades of the risk factors of each level, thereby providing a basis for risk control.
The water conservancy construction development speed of China is high, according to statistics, the number of built dams of China is at the top of the world, and high dams of different forms are increased year by year, so that the exploration of more attractive dam bodies has extremely important significance. With the development of the scale of water conservancy construction in China and more risks in the project construction process, the research of the risk assessment of the water conservancy project is very important and necessary. With the arrival of the climax of water conservancy construction in China, gravity dam design and risk assessment thereof are inevitably paid more and more attention, and the gravity dam risk assessment system has important theoretical and practical significance for systematic research and specific research on construction risks. Based on the method, the solution is provided for the underwater tunnel risk assessment system and the construction risk assessment.
Additional aspects and advantages of the invention will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the invention.
Drawings
The above and/or additional aspects and advantages of the present invention will become apparent and readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings of which:
FIG. 1 is a flowchart of a gravity dam risk assessment calculation method based on hierarchical analysis and fuzzy comprehensive evaluation according to an embodiment of the present invention;
FIG. 2 is a cross-sectional view and a loading diagram of a water dam section according to an embodiment of the present invention;
FIG. 3 is a cross-sectional view and a load diagram of an overflow dam according to an embodiment of the present invention.
Detailed Description
Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like or similar reference numerals refer to the same or similar elements or elements having the same or similar function throughout. The embodiments described below with reference to the drawings are illustrative and intended to be illustrative of the invention and are not to be construed as limiting the invention.
The invention establishes an engineering risk model of the gravity dam, carefully identifies and arranges risks in the construction process of the gravity dam, selects a fuzzy mathematical principle to estimate the construction risks and evaluate a fuzzy comprehensive evaluation method aiming at the risk characteristics of the gravity dam, and explains a method and a principle for establishing a risk evaluation index system of the gravity dam according to an analytic hierarchy process.
As shown in fig. 1, the gravity dam risk assessment calculation method based on hierarchical analysis and fuzzy comprehensive evaluation according to the embodiment of the present invention includes the following steps:
step S1, designing a gravity dam, comprising: the method comprises the steps of planning a section of the gravity dam, carrying out load calculation on the gravity dam, carrying out stability analysis on the gravity dam and carrying out stress analysis on the gravity dam.
Specifically, the design content of the gravity dam comprises the following steps: profile planning, load calculation, stress analysis and stability analysis. According to engineering data and design specifications of the gravity dam, a water retaining dam section and an overflow dam section are drawn up, as shown in fig. 2 and 3.
1. Gravity dam profile drafting
(1) Determining dam crest elevation
(1.1) calculation of the ultra-high value Δ h
The basic formula: the elevation of the top of the dam is higher than the check flood level, the elevation of the top of the wave wall at the upstream of the top of the dam is higher than the elevation of the top of the wave wall, and the height difference delta h between the top of the wave wall and the design flood level or the check flood level can be calculated by the formula (2-1).
Δh＝h1％+hz+hc(2-1)
Delta h is the height difference m between the wave wall top and the designed flood level or the check flood level;
h1％-the cumulative wave height at a frequency of 1%, m;
hz-height difference, m, from the wave centre line to the design flood level or the check flood level;
hcsafe heightening, for first-level engineering, design case hcCheck the case h at 0.7mc＝0.5m。
TABLE 1 safe heightening of dams
H is calculated according to the formula of the office1％,hz。
L＝10.4(hl)0.8(2-3)
v0Different wind speed values are adopted for calculating the wind speed and m/s, designing the flood level and checking the flood level. Wave height hl,
Time, wave height h of 5% of cumulative frequency5％(ii) a When in use
Time, wave height h of 10% of cumulative frequency10％. The specification states that the wave height at a cumulative frequency of 1% should be adopted, corresponding to a wave height of 5%, and should be multiplied by 1.24; corresponding to 10% wave height, should be multiplied by 1.41.
First the wave height H is calculatedlAnd the wave length L and the height hz of the wave center line above the still water surface. Using average maximum wind speed v over years021.5m/s, the reservoir blowing distance D is 3.05km,
the three elements of the wave are calculated as follows:
wave height
Wavelength L10.4 (h)l)0.8＝10.4×1.110.8＝11.31m
High congestion
h1％＝1.24h5％＝1.24×1.11＝1.38m；
hz＝0.34m；
When the flood level is designed, the water level,
Δh＝h1％+hz+hc＝1.38+0.34+0.7＝2.42m
when the flood level is checked,
Δh＝h1％+hz+hc＝1.38+0.34+0.5＝2.22m
(1.2) calculation of dam crest elevation
The elevation of the top of the upstream wave wall of the dam is calculated according to the formula (3-5), and the larger value is selected
The elevation of the wave wall top is set as the designed flood level + delta h
Elevation of wave wall top (check flood level + delta h school (2-5)
And calculating the result according to the delta h of the two water levels to obtain the top elevation of the wave wall under two conditions.
(1) Designing dam crest elevation in flood level: setting the design flood level + Δ h as 224.7+2.42 as 227.12m
(2) Checking dam crest elevation during flood level: v. top elevation of wave wall ═ check flood level + Δ h ═ 227.2+2.22 ═ 229.42m
In order to ensure the safe operation of the dam, the greater value of the roof elevation 229.42m of the wave wall is selected, so that the roof elevation of the wave wall is 229.42m and is higher than the roof elevation of the wave wall. According to the specification, the height of the wall body of the wave wall can be 1.2m, so that the elevation of the dam crest is 228.22m, and the elevation of the dam crest is higher than the check flood level 227.2 m.
(1.3) determining dam foundation elevation
As the specific geological conditions of the dam site are not given by data, and the design is only an initial feasibility analysis stage, the dam foundation elevation initially determined by the design is the riverbed elevation (126.00m), the check flood level is 227.20m, the dam crest elevation is 228.22m, and the dam height is 102.22 m.
(3) Setting the width of dam crest
The width of the dam crest is determined according to the requirements of equipment arrangement, operation, maintenance, construction, traffic and the like, and the requirements of earthquake resistance, maintenance in case of extra-large flood and the like are met. Because no special requirement exists, according to the regulation of the specification, the width of the dam crest can be taken as 8-10% of the height of the dam, is not less than 2m and meets the requirements of traffic and operation management. Calculated according to 9% of the height of the dam, the height of the dam is 9.2 meters, and the width of the top of the dam is 12m in consideration of an upstream wave wall, a downstream side guardrail, a drainage ditch, sidewalks on two sides and the like, so that the passing requirement of dam maintenance operation is met.
(1.4) drawing up the cross-sectional dimensions
According to the specification SL319-2005, the basic cross-section of the non-overflow dam section is triangular, preferably with its apex near the top of the dam. The upper part of the basic section is provided with a dam crest structure. The upstream face of the dam body can be a lead straight face, an inclined face or a folded face. The upstream dam slope of the solid gravity dam is preferably 1: 0-1: 0.2, when the dam slope is folded, the elevation of a folding point should be combined with the arrangement of a water inlet, a water outlet and the like of a power station, and the downstream dam slope is preferably determined.
The downstream dam slope may be one or several slopes and should be selected simultaneously according to stability and stress requirements in combination with the upstream dam slope. The downstream dam slope is preferably 1: 0.6-1: 0.8; the integral gravity dam with the transverse joint provided with the key slot for grouting can select a dam slope by considering the combined stress of adjacent dam sections.
The shape of the dam body is drawn to be basically triangular. The downstream surface of the dam is a uniform inclined surface, the extension line of the inclined surface and the upstream dam surface are intersected at the highest reservoir water level, in order to facilitate the arrangement of inlet control equipment, a part of water weight can be used for helping the dam body to maintain stability, and the design adopts a mode that the upper part of the upstream dam surface is vertical and the lower part of the upstream dam surface is inclined. The form is a form frequently adopted in actual engineering and has relatively rich engineering experience.
The upstream is set into the folded surface to increase the dead weight of the dam body by using the silt, the folding point is set above the level of the silt, the elevation of the silt in front of the dam is 177.5m according to the data, so the folding point can be taken at the position with the elevation of 178 m. And (3) preliminarily drawing up the gradient of the dam face by referring to other similar projects: taking an upstream dam slope 1: 0.2, taking the downstream dam slope as 1: 0.8.
(1.5) setting up dam bottom width
The width of the dam bottom is about 0.7-0.9 times of the height of the dam, the height of the dam is 102.17m, and the width B of the dam bottom is finally determined to be 89.4m through the determined slope rate of the upstream dam and the downstream dam.
The overflow dam section has the same structure and is not described in detail.
(2) Gravity dam load calculation
The main loads of the gravity dam are as follows: dead weight, hydrostatic pressure, wave pressure, sediment pressure, uplift pressure, seismic load and the like, and the dam length of 1m is usually taken for calculation. The load combinations can be divided into basic combinations and special combinations. Normal water storage level conditions and check flood level conditions are considered in the design; the results of the calculations are shown in the table below.
Table 2 table of load calculation results when normal water storage level of water retaining dam section
Table 3 check flood level load calculation result table for water retaining dam section
Table 4 design flood level lower overflow dam section load calculation result table
1.3 gravity dam stability analysis
And calculating and checking the anti-slip stability analysis of the gravity dam according to a single safety coefficient method. The purpose of the anti-skid stability analysis is to calculate the safety degree of the anti-skid stability of the dam body along the dam base surface or the deep soft structural surface of the foundation. And taking the single width as a calculation unit during the anti-skid stability calculation.
The method adopts a single safety factor method to calculate, and the formula is as follows:
in the formula:
k' — the anti-skid stability safety factor calculated from the shear strength;
f '-the shear-resistant friction coefficient of the contact surface of the dam body concrete and the dam foundation, wherein f' is 1.1;
c' -shear-resistant cohesion of contact surface between dam concrete and dam foundation, KPa, data to give c ═ 75t/m2Reduced to 735 KPa;
a-area of contact surface of dam foundation, m2。
Sigma W is the normal value of all loads acting on the dam body to the sliding plane, kN;
sigma P is the tangential value of all loads acting on the dam body to the sliding plane, kN;
the checking results are recorded as follows:
TABLE 5 stability analysis results table
Comparing K in corresponding tablessThe invention can show that K is in various conditionssAnd if the thickness is more than 3.0, the dam meets the stability requirement.
1.4 gravity dam stress analysis
And calculating the edge stress by using a material mechanics method. When the dam body stress is analyzed by adopting a material mechanics method, the strength indexes specified in SL 319-. The vertical stress of the dam heel and the dam toe of the dam foundation surface of the gravity dam meets the following requirements: under various load combinations (except earthquake loads), the vertical stress of the dam heel does not have tensile stress; the vertical stress of the dam toe is smaller than the allowable pressure stress of the dam foundation; the maximum main compressive stress of the dam body is not more than the allowable compressive stress value of concrete.
The normal stress on the horizontal section is respectively analyzed for the basic combination (1) and the special combination (1) by adopting a single safety factor method. Suppose σyDistributed in a straight line, so that the edge stress sigma upstream and downstream is calculated according to an eccentric compression formulayuAnd σyd。
Σ W — the sum of the vertical components acting on all loads above the calculated cross section, kN;
the sigma M is used for calculating the sum of the moments of all loads above the cross section to the dam foundation cross section vertical water flow direction forming mandrel, namely kN.m;
b-calculate the length of the cross section, m.
Calculating the maximum principal stress of the dam body:
pu＝γH1，pd＝γH2， (2-9)
σ1u＝(1+n2)σyu-pun2
σ1d＝(1+m2)σyd-pdm2(2-10)
the calculated maximum principal stress is required not to exceed the allowable stress value of the concrete.
The data shows that the ultimate compressive strength of the bedrock is [ sigma ]]＝650kg/cm2I.e., [ sigma ]]＝6370kPa
Basic combination (1)
pu＝γH1＝9.8×98.7＝967.3kPa
pd＝γH2＝9.8×12.4＝121.52kPa
σ1u＝(1+n2)σyu-pun2＝(1+0.22)×557.62-969.3×0.22＝541.15kPa
σ1d＝(1+m2)σyd-pdm2＝(1+0.82)×1412.20-121.52×0.82＝2238.23kPa
Special combination (1):
pu＝γH1＝9.8×101.2＝991.76kPa，pd＝γH2＝9.8×30.8＝301.84kPa
σ1d＝(1+m2)σyd-pdm2＝(1+0.802)×1389.75-301.84×0.802＝2085.60kPa
the calculation shows that the pressure stress is applied to the heel of the dam under two working conditions, the stress value at the toe of the dam meets the strength requirement of the bedrock of the dam, and the maximum main stress value at the upstream and downstream under the two working conditions is smaller than the concrete strength allowable value required by the concrete dam, so that the design is feasible.
The stress analysis method of the overflow dam section is the same as that of the water retaining dam section, and after analysis, the stress value of the overflow dam section meets the strength requirement, and details are not repeated here.
1.5 gravity dam innovation design
The gravity dam is characterized in that the dam body meets the stability requirement and the strength requirement, the ornamental performance of the dam is enhanced, and the dam is not consistent. The invention assumes that building epitomes rich in Chinese characteristic national culture, such as the budalagons, Mongolian yurt, great wall and the like, are used on the exterior of the dam. Or statues of a generation of great men, which contributes to the dam construction. Or a representative collection of objects submerged by dam construction. Or the special plants and fruits in China for tourists to watch and pick.
Step S2, risk assessment is carried out on the gravity dam, and the method comprises the following steps: the method comprises the steps of carrying out risk estimation on the gravity dam, establishing fuzzy comprehensive evaluation on risk factors, carrying out risk estimation on the gravity dam engineering and analyzing the risk estimation result of the gravity dam engineering.
(1) Risk refers to the degree of variation in the various adverse outcomes that an action may have under certain conditions and over a certain period of time.
Mathematically described as:
R＝P×C
where R is an action, P is the probability of occurrence of a risk situation of a potential wind in the action, and C is the result (loss) caused by it.
(2) Risk estimation and risk assessment
The risk assessment is an important intermediate link of the risk assessment, and the risk assessment is to estimate the identified risk source, estimate the occurrence probability of the potential loss and the degree or scale of the loss, namely estimate the occurrence probability of the loss and estimate the severity of the loss so as to evaluate the relative importance of various potential losses, thereby providing a basis for the risk assessment. In other words, the risk estimation is to measure the identified risk sources, and to give a certain risk occurrence probability to measure the probability of risk occurrence and the resulting consequences, i.e. based on the past loss data analysis, the probability theory and the mathematical statistics are used to make quantitative or qualitative analysis on the probability of occurrence of a certain or several specific risk accidents and the severity of the possible loss after occurrence of the risk accidents.
The risk evaluation refers to that on the basis of risk identification and risk estimation, the risk occurrence probability and the loss severity are considered comprehensively by combining other factors to obtain the risk degree of the risk occurrence of the project, and then the risk degree is compared with the risk evaluation standard to determine the risk level of the project. It is then decided whether and to what extent control measures need to be taken, depending on the risk level of the project.
There are many methods for risk assessment, such as expert scoring, analytic hierarchy process, fault tree analysis, etc., and fuzzy comprehensive evaluation is used herein. The ambiguity of a thing mainly refers to the ambiguity of the property difference between objective things in the transition process, namely the unclear boundary for judging the property of the thing. The concepts formed in the human brain are almost all fuzzy, and the judgments and inferences formed therefrom are also fuzzy. Ambiguity, uncertainty problems are commonly studied using ambiguity mathematics. Fuzzy comprehensive evaluation is an evaluation mode which relates to fuzzy factors or fuzzy concepts in the process of overall evaluation of things or phenomena influenced by various factors. The theory system of fuzzy comprehensive evaluation is established on the basis of fuzzy set theory, and meanwhile, the theory system has a strict theory system. The fuzzy comprehensive evaluation can meet the evaluation requirements of multiple factors and multiple layers.
(3) Gravity dam risk estimation
3.1 fuzzy mathematics theory
The concept of fuzzy aggregation was first proposed by american scholars l.a.zadeh in 1965, modeling fuzzy behavior and activities. Fuzzy mathematics move from binary logic to continuous logic, changing absolute 'yes' and 'no' into more flexible things, dividing 'yes' and 'no' relatively on a considerable limit, which does not let the mathematics give up its rigor to move on the fuzziness, but instead, takes strict mathematical methods to deal with the fuzzy phenomenon.
The advantages of fuzzy mathematics are: it provides a sufficient conceptualization structure for the fuzzy and unclear problems existing in the real world, and analyzes and solves them in the mathematical language. It is particularly well suited for handling variables that are ambiguous, difficult to define, difficult to numerically describe and easy to describe in language. The various risk factors potentially included in the construction and operation of the gravity dam are a large part which is difficult to accurately and quantitatively describe by using numbers, but the properties of the various risk factors and the possible influence results of the various risk factors can be vividly described by using historical experience or expert knowledge. Moreover, most of the existing risk analysis models are based on quantitative technology requiring numbers, and most of information related to risk analysis is difficult to represent numerically but is easy to describe by characters or sentences, so that the property is most suitable for solving problems by adopting fuzzy mathematical models.
The variables of the fuzzy mathematics processing, which are not digitalized, fuzzy and hard to mean, have unique points, reasonable mathematical rules can be provided to solve the variable problem, and the corresponding obtained mathematical results can be converted into language description through a certain method. This feature is well suited to address the potential risks prevalent in the construction and operation of gravity dams.
Several concepts in fuzzy mathematics are described below:
fuzzy set
Let x be the universe of discourse, called uA→x∈{0,1}，x∈uAA fuzzy subset of X, referred to as fuzzy set for short, is determined, denoted as a. u. ofAIt is called membership function of fuzzy set a. u. ofA(x) The degree of membership of the element X to A is referred to as the degree of membership.
Membership function
The determination of the membership functions is the basis of fuzzy theory, and the determination of the membership functions has subjective factors, but can never be assumed arbitrarily and must be based on objective rules. The determination of the membership functions generally comprises the steps of primarily determining rough membership functions, gradually correcting and perfecting through continuous practice tests, and finally achieving the objective and subjective consistency.
There are many methods of determining membership functions, for example: a five-point method, a three-division method, a selection method, a genetic algorithm, an expert experience method, a typical function method, a fuzzy statistic method, a variable model method, a relative selection method and the like.
3.2 Risk probability fuzzy estimation
Aiming at the characteristics of the gravity dam engineering, an expert experience method is selected to determine a membership function, and the risk probability and the risk loss are estimated through the experience and the learning of an expert.
1. Determining expert weights
The data obtained by an expert experience method are processed by adopting a weighted average method, and the membership degree of the risk probability is determined. According to the age, qualification, experience and the like of experts, the experts are roughly divided into four categories, the weights of the experts are respectively 1.0, 0.8, 0.5 and 0.3, the judgment made by one category of experts is the most reliable, and the data is the most reliable.
2. Risk probability ranking
The risk occurrence probability P is divided into five grades according to the international general grading method for the risk occurrence probability qualitative.
TABLE 6 Risk probability ratings table
3. Expert fuzzy estimation
The ith expert evaluates the membership of 5 occurrence probability levels of the jth risk factor, which can be expressed by the following formula:
wherein the content of the first and second substances,
4. membership of probability of occurrence of risk factor
And (3) carrying out weighted average according to the probability membership evaluation result of n experts on a certain risk factor J to obtain a fuzzy set of the occurrence probability of the risk factor J:
in the formula, n represents the number of experts, and y represents the weight of experts.
3.3 Risk assessment criteria
Whether the engineering risk generated during the construction and operation of the gravity dam can be accepted or not and how much the engineering risk can be accepted determine different risk control countermeasures and treatment measures, and the risk evaluation of the underwater tunnel needs to define the risk grade and the acceptance criterion.
3.3.1 Risk Classification Standard
The risk classification standard comprises a grade standard of the occurrence probability of the risk accident (called risk probability grade for short) and a loss grade standard after the occurrence of the risk accident (called risk loss standard for short).
TABLE 7 Risk loss rating Standard Table
3.3.2 Risk assessment criteria
Risk evaluation standard table
Table 8 Risk reception criteria table
4 fuzzy comprehensive evaluation theory
4.1 establishing a set of factors
The factor set is a common set of various risk factors affecting the evaluation object. I.e. U ═ U1,u2,……um}. Wherein U is a set of factors, UiRepresenting each risk factor, qin. These factors, which are usually ambiguous to varying degrees, are set as U. U shapeiIs the ith risk factor in the first (highest) level of risk, and is determined by several factors in the second level of risk. I.e. ui＝{ui1,……uij}，uijThe second level risk factor is determined by the third level risk factor.
4.2 establishing a set of Risk factor weights
The importance of each risk factor is not the same in the factor set. To reflect the importance of each risk factor, for each risk factor uiShould be given a correspondenceWeight w ofi. Set of weights: w ═ W1,w2,……wi) Referred to as a weight set.
In general, each weight wiThe conditions of normalization and nonnegativity should be satisfied:
4.3 creating alternate sets
The alternative set is a set formed by various total evaluation results which can be made by an evaluator on an evaluation object, and is generally represented by a capital letter V, and each element Vi(i ═ 1, 2.. n) represents various possible overall evaluation results. The fuzzy evaluation aims to obtain an optimal evaluation result from alternative sets on the basis of comprehensively considering all risk factors. The evaluation results were to derive a most reasonable risk rating from V.
4.4 Single factor fuzzy evaluation
And (3) evaluating from a basic risk factor alone to determine the membership degree of an evaluation object to the alternative set elements, which is called single-factor fuzzy evaluation.
Setting the ith factor u in the evaluation object according to the factor seti(i-1, 2, … … m) and the jth element v in the alternative setijDegree of membership of rijAccording to the ith factor ui(i ═ 1,2, … … m), the results of the evaluations can be expressed in fuzzy sets as: rijAnd is called a single-factor risk evaluation set.
And (3) a matrix R consisting of rows with the membership degree of each basic factor evaluation set is called a single factor evaluation matrix.
4.5 fuzzy comprehensive evaluation
And the single-factor fuzzy evaluation only reflects the influence of one basic risk factor on an evaluation object. This is clearly insufficient. And comprehensively considering the influence of all basic risk factors to obtain the scientific evaluation result of the previous level of risk factors, which is fuzzy comprehensive evaluation.
From the one-factor evaluation matrix R, it can be seen that: the ith row of the R reflects the degree that the ith risk factor influences the evaluation object to take each alternative element; the jth column of R reflects the degree that all risk factors influence the evaluation object to take the jth alternative element. The contribution of each term in R by a weight w of the corresponding factori(i 1.. m), the combined effect of all risk factors can be reasonably reflected. Therefore, the fuzzy comprehensive evaluation can be expressed as:
B＝W×R
the weight w can be regarded as a fuzzy matrix of m rows, and the above formula can be operated on by multiplication of the fuzzy matrix, i.e.
And B is a fuzzy comprehensive evaluation set, which refers to the membership degree of an evaluation object to the n-th element in the alternative set when the influence of all basic risk factors below the previous level risk factor is comprehensively considered, and is called as a fuzzy comprehensive evaluation index, which is called as an evaluation index for short.
4.6 Risk level grading
TABLE 9 Risk level grading Table
4.7 treatment of evaluation index
Obtaining an evaluation index bjThereafter, the processing is generally performed by a weighted average method:
5 gravity dam engineering risk assessment
5.1 engineering overview
The reservoir is positioned on the main flow of the L river, and the area of the watershed is controlled to be 33700Km2Total storage capacity of 25.5 hundred million m3. The reservoir hub is composed of a retaining dam, an overflow dam,Power station and pool water bottom hole. The main tasks of the reservoir are to adjust the water quantity, supply urban industrial water and domestic water for people, and combine water diversion and power generation to realize comprehensive utilization of flood control and the like. According to the engineering scale of the reservoir and the function of the reservoir in national economy, the pivot engineering and the like are I and the like. The dam is a class I building (namely a retaining dam and an overflow dam), and other buildings (such as a power station and a drainage bottom hole) are considered as class 2 buildings.
5.2 Risk factors recognition:
TABLE 10 Risk factors
5.3 Risk assessment index systems and weight determination
And establishing a gravity dam risk assessment index system according to the risk factors obtained from the upper layer and a combined layer analysis method. The weights of the factors are obtained by a 1-9 scale method and root approximate calculation.
The risk assessment index system of the gravity dam is divided into three layers:
the first layer is the target layer: u shape
The second layer is risk factors: u shape1～U4
The third layer is the risk factors belonging to the second layer: u shape11～U12，U21～U23，U31～U33，U41～U42
The specific process of determining the weights is as follows (in u)21～u23For example):
1. construct pairwise judgment matrix
After the hierarchical structure is established, membership of elements between upper and lower levels is determined. Assuming the element U of the previous layer as a criterion, the element U of the next layer is subjected to1,u2........unThere is a dominating relationship, under the criterion U, given a corresponding weight in terms of its relative importance. In this step, the question is repeatedly answered: for criterion U, two elements UiAnd ujWhich is more important and how much important. Need to be aligned withThe important values are given, and a proportion scale of 1-9 is used, and the meanings of the values are shown in the following table.
TABLE 111-9 Scale Table
a1＝(1,2,5)，
2. Approximate calculation of w using the root methodi
(1) To find
In the same way, the method for preparing the composite material,
(2) normalization process
In the same way, w2＝0.309，w3＝0.109
Thus, the weight values of all the factors are calculated, the weight values of all the other risk factors are calculated by the same method,
the list is as follows:
table 12 table of calculation results of weight of each risk factor of gravity dam
5.4 Risk estimation
5.4.1 Risk probability fuzzy estimation
TABLE 13 fuzzy estimation of risk probability table
5.4.2 fuzzy estimation of Risk loss
TABLE 14 fuzzy estimation of risk loss table
5.5 Risk assessment procedure
The risk evaluation is carried out on the gravity dam engineering by adopting a fuzzy comprehensive evaluation method.
5.5.1 establishing a set of risk factors
The risk factors of the gravity dam engineering are divided into three layers
5.5.2 establishing a set of Risk factor weights
2.5.5.3 creating alternative sets
The alternative set is a set formed by various total evaluation results which can be made by an evaluator on an evaluation object. The embodiment divides the alternative set into five grades, namely, first grade, second grade, third grade, fourth grade and fifth grade, and has the significance.
2.5.5.4 fuzzy evaluation of third-tier risk factors
Now with the geological condition risk zone (u)11And u12) The description is given for the sake of example:
TABLE 15 geological condition Risk factors evaluation Table (excerpted from tables 13 and 14)
1. Calculating risk factor evaluation index
The calculation formula of the risk factor evaluation index is as follows:
wherein u isRj1＝uC1j·uPAj+uC1j·uPBj+uC1j·uPCj+uC2j·uPAj(2-12)
uRj2＝uC1j·uPDj+uC1j·uPEj+uC2j·uPBj+uC2j·uPCj+uC3j·uPAj(2-13)
uRj3＝uC2j·uPDj+uC2j·uPEj+uC3j·uPBj+uC3j·uPCj+uC4j·uPAj+uC4j·uPBj(2-14)
uRj4＝uC3j·uPDj+uC3j·uPEj+uC4j·uPCj+uC4j·uPDj+uC5j·uPAj+uC5j·uPBj(2-15)
uRj5＝uC4j·uPEj+uC5j·uPCj+uC5j·uPDj+uC5j·uPEj(2-16)
Substituting the data into the above equation:
uR11＝uC11·uPA1+uC11·uPB1+uC11·uPC1+uC21·uPA1
＝0.00×0.15+0.00×0.49+0.00×0.29+0.07×0.15＝0.01
uR12＝uC11·uPD1+uC11·uPE1+uC21·uPB1+uC21·uPC1+uC31·uPA1
＝0.00×0.07+0.00×0.00+0.07×0.49+0.07×0.29+0.35×0.15＝0.11
uR13＝uC21·uPD1+uC21·uPE1+uC31·uPB1+uC31·uPC1+uC41·uPA1+uC41·uPB
＝0.07×0.07+0.07×0.00+0.35×0.49+0.35×0.29+0.58×0.15+0.58×0.49＝0.65
uR14＝uC31·uPD1+uC31·uPE1+uC41·uPC1+uC41·uPD1+uC51·uPA1+uC51·uPB1
＝0.35×0.07+0.35×0.00+0.58×0.29+0.58×0.07+0.00×0.15+0.00×0.49＝0.23
uR15＝uC41·uPE1+uC51·uPC1+uC51·uPD1+uC51·uPE1
＝0.58×0.00+0.00×0.29+0.00×0.07+0.00×0.00＝0.00
in the same way, can obtain
R2＝(0.02,0.13,0.67,0.18,0.00)
2. Calculating a risk level
The risk level is calculated by adopting a weighted average method, and the risk level of each single factor can be obtained by adopting value calculation:
3. determining a risk level rating
40＜v1< 60, three levels
40＜v2< 60, three levels
The third layer of other risk factor evaluations was as described above, with the results given in the following table:
TABLE 16 third-layer Risk factors evaluation results Table
5.5.5 fuzzy comprehensive evaluation of second-tier Risk factors
Single-factor Risk evaluation index R obtained in the above mannerjAnd the individual factor weight, the evaluation index b of the second-layer risk factor can be obtainedj. The following description will be made by taking the geological condition risk layer as an example:
from the above, the risk factor pricing index b of the geological condition risk layerjThe calculation formula of (A) is as follows:
weight w1,w2Substituting the risk evaluation index set R of the geological condition risk layer into the formula to obtain
And (3) obtaining the fuzzy comprehensive and evaluation risk level of the geological condition risk factors by adopting weighted average processing:
40＜v1< 60, the risk level is of the third order
For construction risk layer U2The risk indicator of (a) is calculated as follows:
40＜v2＜60
the risk classes belong to three classes
For environmental risk layer U3The risk indicator of (a) is calculated as follows:
40＜v3＜60
the risk level is of the third order
For operation risk U4Is calculated as follows
40＜v4＜60
The risk level is of the third order
The results of the above calculations are tabulated below:
TABLE 17 second-layer Risk factor evaluation results Table
5.5.6
Fuzzy comprehensive evaluation of first layer (total target layer)
Through the primary fuzzy comprehensive evaluation, a risk factor evaluation index R' below a total target layer (second layer) can be obtained, and the total target layer risk evaluation index is calculated according to a formula B of W × R in combination with the weight of the second layer risk factor, and the specific process is as follows:
40＜v＜60
therefore, the risk level of the gravity dam project is of the third order.
6. Risk assessment result analysis of gravity dam engineering
It can be seen from the third-layer risk factor evaluation result that the construction technology risk belongs to the fourth-level and is unacceptable, so all parties required to participate in the engineering must study and make a strict construction technical scheme to avoid the risk and make corresponding protective measures. Other risk factors belong to the second level or the third level and belong to the acceptable range, but all parties participating in the engineering should pay enough attention to develop relevant schemes to prevent the risk.
From the second layer risk factor evaluation results, the levels of all risk factors belong to three levels and belong to an acceptable range, namely, each party participating in the engineering pays attention to each risk factor and makes monitoring and protection measures.
According to the gravity dam risk assessment calculation method based on the hierarchical analysis and the fuzzy comprehensive evaluation, disclosed by the embodiment of the invention, a risk assessment theory and method are analyzed, wherein the risk assessment theory and method comprise risk connotation, risk identification, risk estimation and risk assessment. The thesis identifies the main risk factors of the gravity dam by using an expert survey method, solves the problems of ambiguity and difficult quantification in risk estimation by using a fuzzy mathematical theory, and analyzes to obtain the probability and loss estimation of the risk factors of the gravity dam; and comprehensively considering the influence of the occurrence probability and the loss severity of the risk factors on the risk level based on the R-P-C model and a fuzzy comprehensive evaluation method to obtain the grades of the risk factors of each level, thereby providing a basis for risk control.
The water conservancy construction development speed of China is high, according to statistics, the number of built dams of China is at the top of the world, and high dams of different forms are increased year by year, so that the exploration of more attractive dam bodies has extremely important significance. With the development of the scale of water conservancy construction in China and more risks in the project construction process, the research of the risk assessment of the water conservancy project is very important and necessary. With the arrival of the climax of water conservancy construction in China, gravity dam design and risk assessment thereof are inevitably paid more and more attention, and the gravity dam risk assessment system has important theoretical and practical significance for systematic research and specific research on construction risks. Based on the method, the solution is provided for the underwater tunnel risk assessment system and the construction risk assessment.
In the description herein, references to the description of the term "one embodiment," "some embodiments," "an example," "a specific example," or "some examples," etc., mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, the schematic representations of the terms used above do not necessarily refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.
Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention, and that variations, modifications, substitutions and alterations can be made in the above embodiments by those of ordinary skill in the art without departing from the principle and spirit of the present invention. The scope of the invention is defined by the appended claims and equivalents thereof.
Claims (8)
1. A gravity dam risk assessment calculation method based on hierarchical analysis and fuzzy comprehensive evaluation is characterized by comprising the following steps:
step S1, designing a gravity dam, comprising: drawing a section of the gravity dam, carrying out load calculation on the gravity dam, carrying out stability analysis on the gravity dam, and carrying out stress analysis on the gravity dam;
wherein, the section of drawing up the gravity dam comprises: determining dam crest elevation, determining dam foundation elevation, drawing up dam crest width, drawing up section size and drawing up dam foundation width;
step S2, risk assessment is carried out on the gravity dam, and the method comprises the following steps: the method comprises the following steps of carrying out risk estimation on the gravity dam, establishing fuzzy comprehensive evaluation on risk factors, carrying out risk estimation on the gravity dam engineering, and analyzing the risk estimation result of the gravity dam engineering, wherein the risk estimation on the gravity dam comprises the following steps: carrying out fuzzy estimation on the risk probability and establishing a risk evaluation standard, wherein the fuzzy estimation on the risk probability comprises the following steps: determining expert weight, grading risk probability, carrying out expert fuzzy estimation on the risk probability, and calculating the membership degree of the risk factor occurrence probability;
the establishing of the risk evaluation standard comprises the following steps: establishing risk grading standards and risk evaluation standards, wherein the risk grading standards comprise the grade standards of the occurrence probability of the risk accident and the loss grade standards after the risk accident occurs.
2. The gravity dam risk assessment calculation method based on hierarchical analysis and fuzzy comprehensive evaluation as claimed in claim 1, wherein in said step S1, said performing load calculation on the gravity dam comprises: and calculating the dead weight, the hydrostatic pressure, the wave pressure, the sediment pressure, the uplift pressure and the earthquake load.
3. The gravity dam risk assessment calculation method based on hierarchical analysis and fuzzy comprehensive evaluation as claimed in claim 1, wherein in said step S1, said performing stability analysis on gravity dam includes:
the method adopts a single safety factor method to calculate, and the formula is as follows:
wherein K' represents the anti-skid stability safety coefficient calculated according to the shear strength;f 'represents the shear-resistant friction coefficient of the contact surface of the dam body concrete and the dam foundation, and f' is 1.1; c 'represents the shear-resistant cohesion of the contact surface between the dam concrete and the dam foundation, KPa, and the data shows that c' is 75t/m2Reduced to 735 KPa; a represents the cross-sectional area of the dam foundation contact surface, m2(ii) a The sigma-W represents the normal value, kN, of all loads acting on the dam body to the sliding plane; Σ P denotes the tangential component, kN, of the total load acting on the dam to the sliding plane.
4. The gravity dam risk assessment calculation method based on hierarchical analysis and fuzzy comprehensive evaluation as claimed in claim 1, wherein in said step S1, said performing stress analysis on gravity dam includes:
respectively analyzing the normal stress on the horizontal section for the basic combination (1) and the special combination (1) by adopting a single safety factor method, and assuming sigmayDistributed in a straight line, so that the edge stress sigma upstream and downstream is calculated according to an eccentric compression formulayuAnd σyd。
Σ W represents the sum of the vertical components acting on all loads above the calculated cross section, kN;
the sigma M represents the sum of the moments of all loads acting on the calculated cross section to the dam foundation cross section vertical water flow direction forming mandrel, and kN.m;
b represents the length of the calculated cross section, m;
calculating the maximum principal stress of the dam body:
pu＝γH1，pd＝γH2，
σ1u＝(1+n2)σyu-pun2
σ1d＝(1+m2)σyd-pdm2
the maximum principal stress calculated is required not to exceed the allowable stress value of the concrete;
the data shows that the ultimate compressive strength of the bedrock is [ sigma ]]＝650kg/cm2I.e., [ sigma ]]＝6370kPa
Basic combination (1)
pu＝γH1＝9.8×98.7＝967.3kPa
pd＝γH2＝9.8×12.4＝121.52kPa
σ1u＝(1+n2)σyu-pun2＝(1+0.22)×557.62-969.3×0.22＝541.15kPa
σ1d＝(1+m2)σyd-pdm2＝(1+0.82)×1412.20-121.52×0.82＝2238.23kPa
Special combination (1):
pu＝γH1＝9.8×101.2＝991.76kPa，pd＝γH2＝9.8×30.8＝301.84kPa
σ1d＝(1+m2)σyd-pdm2＝(1+0.802)×1389.75-301.84×0.802＝2085.60kPa。
5. the gravity dam risk assessment calculation method based on hierarchical analysis and fuzzy comprehensive evaluation according to claim 1, wherein in the step S1, the determining the dam crest elevation comprises:
(1) calculating the superhigh value deltah
The basic formula: the elevation of the top of the dam is higher than the check flood level, the elevation of the top of the wave wall at the upstream of the top of the dam is higher than the elevation of the top of the wave wall, the height difference delta h between the top of the wave wall and the design flood level or the check flood level is calculated according to the following formula
Δh＝h1％+hz+hc
Delta h is the height difference m between the wave wall top and the designed flood level or the check flood level;
h1％-the cumulative wave height at a frequency of 1%, m;
hz-height difference, m, from the wave centre line to the design flood level or the check flood level;
hc-safely heightening the ground,
(2) calculating dam crest elevation
Selecting a larger value from the following two formulas to obtain the crest elevation of the upstream wave wall of the dam:
the elevation of the wave wall top is set as the designed flood level + delta h
And (4) checking the flood level and delta h for the elevation of the top of the wave wall.
6. The gravity dam risk assessment calculation method based on hierarchical analysis and fuzzy comprehensive evaluation as claimed in claim 1, wherein in said step S2, said establishing fuzzy comprehensive evaluation for risk factors includes: establishing a factor set, establishing a risk factor weight set, establishing a backup set, performing single-factor fuzzy evaluation, performing fuzzy comprehensive evaluation, establishing risk level grading and processing evaluation indexes.
7. The gravity dam risk assessment calculation method based on hierarchical analysis and fuzzy comprehensive evaluation as claimed in claim 1, wherein in said step S2, said performing risk assessment on gravity dam engineering comprises: setting risk factors, determining a risk assessment index system and weight, carrying out fuzzy estimation on risk probability and risk loss, and establishing a risk evaluation process.
8. The gravity dam risk assessment calculation method based on hierarchical analysis and fuzzy comprehensive evaluation as claimed in claim 7, wherein said establishing a risk evaluation process comprises: establishing a risk factor set, establishing a risk factor weight set, establishing a candidate set, performing fuzzy evaluation on the third layer of risk factors, performing fuzzy comprehensive evaluation on the second layer of risk factors, and performing fuzzy comprehensive evaluation on the first layer of risk factors.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010328909.5A CN111523806A (en) | 2020-04-23 | 2020-04-23 | Gravity dam risk assessment calculation method based on hierarchical analysis and fuzzy comprehensive evaluation |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010328909.5A CN111523806A (en) | 2020-04-23 | 2020-04-23 | Gravity dam risk assessment calculation method based on hierarchical analysis and fuzzy comprehensive evaluation |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN111523806A true CN111523806A (en) | 2020-08-11 |
Family
ID=71903578
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202010328909.5A Pending CN111523806A (en) | 2020-04-23 | 2020-04-23 | Gravity dam risk assessment calculation method based on hierarchical analysis and fuzzy comprehensive evaluation |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN111523806A (en) |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112183894A (en) * | 2020-10-29 | 2021-01-05 | 四川大学 | Gravity dam earthquake risk probability analysis method |
| CN112270503A (en) * | 2020-11-18 | 2021-01-26 | 中铁第五勘察设计院集团有限公司 | Construction risk evolution system, construction method and construction risk assessment method |
| CN112529267A (en) * | 2020-11-27 | 2021-03-19 | 山东大学 | Advanced geological prediction method and system based on fuzzy comprehensive evaluation method |
| CN112651139A (en) * | 2021-01-05 | 2021-04-13 | 黄河勘测规划设计研究院有限公司 | Reservoir dam technical condition evaluation method |
| CN115788590A (en) * | 2023-01-31 | 2023-03-14 | 中国矿业大学(北京) | Control method and system for anti-seismic deformation and monitoring of cross-fault tunnel surrounding rock |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20020060084A1 (en) * | 2001-12-11 | 2002-05-23 | Hilton Robert M. | Flip-chip package with underfill dam that controls stress at chip edges |
| CN1487146A (en) * | 2003-07-11 | 2004-04-07 | 姜建华 | Gravity dam of reinforced concrete |
| US20150212534A1 (en) * | 2014-01-24 | 2015-07-30 | International Business Machines Corporation | Generating electric substation load transfer control parameters |
| CN105205329A (en) * | 2015-09-29 | 2015-12-30 | 南京南瑞集团公司 | Comprehensive evaluation method for dam safety |
| US20200033312A1 (en) * | 2017-04-11 | 2020-01-30 | Agerpoint, Inc. | Forestry management tool for assessing risk of catastrophic tree failure due to weather events |
-
2020
- 2020-04-23 CN CN202010328909.5A patent/CN111523806A/en active Pending
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20020060084A1 (en) * | 2001-12-11 | 2002-05-23 | Hilton Robert M. | Flip-chip package with underfill dam that controls stress at chip edges |
| CN1487146A (en) * | 2003-07-11 | 2004-04-07 | 姜建华 | Gravity dam of reinforced concrete |
| US20150212534A1 (en) * | 2014-01-24 | 2015-07-30 | International Business Machines Corporation | Generating electric substation load transfer control parameters |
| CN105205329A (en) * | 2015-09-29 | 2015-12-30 | 南京南瑞集团公司 | Comprehensive evaluation method for dam safety |
| US20200033312A1 (en) * | 2017-04-11 | 2020-01-30 | Agerpoint, Inc. | Forestry management tool for assessing risk of catastrophic tree failure due to weather events |
Non-Patent Citations (3)
| Title |
|---|
| FENHUA LI，HUI MA: "Risk assessment of gravity dam with machine properties", 《RESEARCH ON MECHANICAL ENGINEERING, CIVIL ENGINEERING AND MATERIAL ENGINEERING》, vol. 454, pages 43 * |
| 姜震: "吉林省靖宇青龙河水库工程设计", 《中国优秀硕士学位论文全文数据库 工程科技II辑》, no. 04, pages 037 - 141 * |
| 杨晋营，高超: "胶凝砂砾石坝坝坡比分析研究", 《水利与建筑工程学报》, vol. 15, no. 1, pages 83 * |
Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112183894A (en) * | 2020-10-29 | 2021-01-05 | 四川大学 | Gravity dam earthquake risk probability analysis method |
| CN112183894B (en) * | 2020-10-29 | 2021-07-06 | 四川大学 | Gravity dam earthquake risk probability analysis method |
| CN112270503A (en) * | 2020-11-18 | 2021-01-26 | 中铁第五勘察设计院集团有限公司 | Construction risk evolution system, construction method and construction risk assessment method |
| CN112529267A (en) * | 2020-11-27 | 2021-03-19 | 山东大学 | Advanced geological prediction method and system based on fuzzy comprehensive evaluation method |
| CN112651139A (en) * | 2021-01-05 | 2021-04-13 | 黄河勘测规划设计研究院有限公司 | Reservoir dam technical condition evaluation method |
| CN112651139B (en) * | 2021-01-05 | 2024-04-02 | 黄河勘测规划设计研究院有限公司 | Reservoir dam technical condition assessment method |
| CN115788590A (en) * | 2023-01-31 | 2023-03-14 | 中国矿业大学(北京) | Control method and system for anti-seismic deformation and monitoring of cross-fault tunnel surrounding rock |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN111523806A (en) | Gravity dam risk assessment calculation method based on hierarchical analysis and fuzzy comprehensive evaluation | |
| Shouyu et al. | Variable fuzzy sets and its application in comprehensive risk evaluation for flood-control engineering system | |
| CN104408900B (en) | Neutral net flood warning devices and methods therefor based on dynamic optimization | |
| CN103729550B (en) | Multiple-model integration Flood Forecasting Method based on propagation time cluster analysis | |
| Chiang et al. | Auto-control of pumping operations in sewerage systems by rule-based fuzzy neural networks | |
| CN114548725A (en) | Deep foundation pit stability evaluation method based on entropy weight-level analysis fuzzy comprehensive evaluation method | |
| CN111178712B (en) | Rescue early warning method and system for diversion project accident | |
| CN109726902B (en) | Slope stability evaluation method | |
| CN110033164A (en) | A kind of Risk assessment and decision method of multi-reservoir joint Flood Control Dispatch | |
| CN112101737A (en) | Method for evaluating feasibility of barrier lake development based on cloud model | |
| CN108681844B (en) | Flood resource utilization risk evaluation method for water diversion project | |
| CN115809800A (en) | Flood disaster risk assessment method | |
| CN115330127A (en) | System and method for controlling operation risk of hydro-junction in real time | |
| CN114492233B (en) | Watershed water simulation method based on webGIS platform and considering comprehensive utilization requirements | |
| CN113902308A (en) | Pumped storage power station safety condition evaluation method based on Internet | |
| CN111090921B (en) | Safety evaluation method for slope anchoring structure system | |
| Kang et al. | A sensitivity analysis approach of multi-attribute decision making technique to rank flood mitigation projects | |
| CN110599011A (en) | Aqueduct safety evaluation method, system and storage medium based on improved AHP-FCE method | |
| CN112016857B (en) | Polyethylene pipeline earthquake vulnerability assessment method based on cloud theory | |
| CN105590034A (en) | Flood prevention and disaster reduction capability evaluation model | |
| CN116562537B (en) | Floodgate pump group flood control and drainage real-time optimal scheduling method, system and storage medium | |
| Tu et al. | Regional flood resilience grading based on GEM-AHPSort II method: an objective and managerial factors integrated perspective | |
| CN115293241A (en) | River bank collapse early warning method and device based on multi-source data fusion | |
| Moosavian et al. | Sequential quadratic programming and analytic hierarchy process for nonlinear multiobjective optimization of a hydropower network | |
| Moradi Kia et al. | Uncertainty analysis and risk identification of the gravity dam stability using fuzzy set theory |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination |