Some standard content:
National Standard of the People's Republic of China
Code for seismic: design of nuclear power plants
Code for seismic: design of nuclear power plantsGB 50267—97
Editing department: State
Approving department: Ministry of Construction of the People's Republic of ChinaEffective date: February 1, 1998
6—3—1
Notice on Issuing the National Standard
Code for seismic: design of nuclear power plantsJianbiao [[1997] No. 198
In accordance with the requirements of Document No. Jizong (1986) 2630 of the State Planning Commission, the "Code for seismic design of nuclear power plants" jointly formulated by the State Seismological Bureau and relevant departments has been reviewed by the relevant departments and is now approved as a mandatory national standard, which will be implemented on February 1, 1998.
This standard is managed by the State Seismological Bureau, and its interpretation, etc. are contributed by the Institute of Engineering Mechanics of the State Seismological Bureau, and its publication and issuance are organized by the Standard and Norms Research Institute of the Ministry of Construction.
Ministry of Construction of the People's Republic of China
July 31, 1997
2 Terms and symbols
2.1 Terms
2.2 Symbols
3 Basic requirements for seismic design
3.1 Calculation model...
3.2 Seismic calculation
3.3 Earthquake action
3.4 Combination of action effects and seismic verification of cross-sections3.5 Seismic structural measures
Design earthquake vibration...
4.1 General provisions
... 6-3--4
6—3—5
-3—5
6—3—5
6—3--6
-3—6
-3—6
4.2 Acceleration peak value of ultimate safety earthquake vibration…6—3—64.3 Design response spectrum
4.4 Design acceleration time process
5 Foundation and slope
5.1 General provisions
5.2 Anti-sliding verification of foundation
5.3 Judgment of foundation liquefaction
5.4 Seismic stability verification of slope·
6 Containment, buildings and structures…．
6.1--General provisions
6.2 Combination of actions and action effects
6.3 Stress calculation and section design
6.4 Foundation anti-capsulation verification
7 Underground structures and underground pipelines
General provisions
7.2 Seismic calculation of underground structures...
6—3—10
6—3—10
-3—10
7.3 Seismic calculation of underground pipelines
7.4 Seismic verification and structural measures||tt ||8 Equipment and components
· General provisions
8.2 Earthquake action·
8.3 Action effect combination and design limit
8.4 Earthquake action effect calculation
Process piping
General provisions
9.2 Action effect combination and design limit· Earthquake action effect calculation
Earthquake detection and alarm
Appendix A
Appendix B
Appendix C
Instrument setting
Instrument performance
Observation station setting
· 6—3—12
—3——12
3—12
... 6--313
· 6—3—13
6—3—13
6-3--13
—3--13
-3--15
-3--15
-3—16
Examples of classification of various items
6—3—16
The effects adopted by buildings and structures
Effect combinations and related coefficients
...... 6--3--16
Earthquake vibration attenuation law
·6—3—17
Calculation of seismic effects on underground structures
Appendix D
Methods and schematic diagrams…
Appendix E
Appendix F
Appendix G
..*. 6-3-17
Modification of design floor response spectrum 63—18
Allowable stress and
Design limit adopted for equipment and components
Verification test
+++++++++.
Explanation of terms used in this code
Appendix H
Additional explanation
... 63--18
.... 6-3—20
.......... 6-3-21
6—3—3
1.0.1This specification is formulated to implement the principle of prevention first and safety of civil nuclear facilities first in earthquake work, to ensure safe operation of nuclear power plants, to ensure quality, advanced technology and economic rationality.
This specification is applicable to the seismic design of nuclear safety-related items in pressurized water reactor nuclear power plants in areas where the peak acceleration of the ultimate safe earthquake is not greater than 0.5g. Nuclear power plants designed according to this specification should be able to operate normally when affected by earthquakes equivalent to the operation safety earthquake. When affected by earthquakes equivalent to the ultimate safe earthquake, the reactor coolant pressure boundary should be intact, the reactor should be safely shut down and maintained in a safe shutdown state, and the escape of radioactive substances should not exceed the national prescribed limit. Note: 0) The items referred to in this specification refer to containment, electrical buildings, structures, underground structures, pipes, equipment and related parts.
(3g is the gravity velocity, which is taken as 9. 81m,t. 1.0.3 Items in nuclear power plants should be divided into the following three categories according to their importance to nuclear safety:
(1) Category 1 items: important items related to nuclear safety in nuclear power plants, including items that may directly or indirectly cause accidents if damaged, items required to ensure the safe shutdown of the reactor and maintain the shutdown state and discharge residual heat; items required to mitigate the consequences of nuclear accidents during earthquakes and after earthquakes, and other items that may endanger the above items if damaged or lose their functions.
(2) Category I items: items related to nuclear safety in nuclear power plants other than Category I items, and items not related to nuclear safety that may endanger the above items if damaged or lose their functions. (3) Category II items: items not related to nuclear safety in nuclear power plants. Note: 1.1, Category I items can be divided according to the examples in Appendix A of this specification. 1.0.4 The seismic design of various items shall adopt the following resistance fortification standards: (1) Class I items shall adopt both operational safety earthquake motion and extreme safety ground motion for seismic design. (2) Class II items shall adopt operational safety earthquake motion for seismic design. (3) Class I items shall be seismically designed in accordance with the relevant national seismic design specifications in force. In the seismic design of nuclear power plants, in addition to complying with the provisions of this specification, the provisions of the relevant national standards and specifications in force shall also be complied with. 2.1.1 Ground motion Terms and symbols Ground motion The vibration of the rock and soil layer caused by an earthquake. 2.1.2 Operational safety ground motion Ground motion with an annual exceedance probability of 2% during the design reference period, with a peak acceleration of not less than 0. 075g. Usually the ground motion that can enable the normal operation of the nuclear power plant. 2.1.3 Ultimate safety ground motion Ground motion with an annual exceedance probability of 0.1% during the design reference period, with a peak acceleration of not less than 0.15g. Usually the maximum earthquake vibration that may occur in the nuclear power plant area. 2.1. 4
capable fault
fault on or near the surface that is likely to produce relative displacement. 2.1. 5
geo-active (seismotectonic) fault
faulting segment
active state and characteristics of active faults - consistent with 2.1.7
Section 1.
Attenuation law
The phenomenon that the intensity of ground shaking in a region or construction site decreases with the increase of the distance from the source.
6—3—4
Hybrid probabilistic method
A probabilistic method that comprehensively considers geological structural factors and the temporal and spatial heterogeneity of earthquakes. 2.1.9
Test response
Test response spectrum
The response spectrum corresponding to the time process of the excitation acceleration used in the resistance test. &ccidenal load
2.1.10 Accident condition load
The load generated in the case of serious deviation from the operating condition during the operation of the nuclear power plant. 2. 2 Symbols
2. 2. 1Earthquake and ground motion
Earthquake intensity:
Calculate ground motion together:
Max-maximum earthquake magnitude;
upper limit of magnitude,
displacement, velocity, acceleration response spectrum values;-earthquake acceleration,
"-a coefficient in the key-level frequency relationship that represents the proportional relationship between the number of times of large and small ground motions;
apparent wave velocity of ground capsule wave:
fault distance:
-earthquake vibration saturation parameter considering magnitude and distance;·maximum ground velocity at the elevation of underground straight pipe; earthquake motion parameters (can be displacement, velocity, acceleration, response spectrum, etc.);||t t||A random quantity representing uncertainty;
-the apparent wavelength or wavelength of ground waves;
-the average annual occurrence rate of ground waves.
Actions and effects
-the standard value effect of actions generated under accident conditions: the standard value effect of earthquake actions generated by the vibration of the operating safety capsule under severe environmental conditions:
the standard value effect of earthquake actions generated by the extreme safety earthquake under extreme environmental conditions;
the standard value effect of loads generated by applying prestress;-the equivalent ground cover action vector on the structure: the standard value effect of permanent loads;
the standard value of loads generated by the internal overflow of the containment Effects: standard value effect of lateral earth pressure;
standard value effect of live load;
overturning moment caused by combination of various action effects of operation safety earthquake vibration or extreme safety ground motion;
design value of axial force acting on the pipeline;
standard value effect of external pressure load caused by internal and external pressure difference of safety pipeline:
standard value effect of pressure load under design basis accident condition; standard value effect of reaction force generated under design basis accident temperature condition;
combination of action effect (internal force or stress) design value combination of action effect of normal operation and severe environmental action; normal operation effect The combination of action effects with severe environmental effects and actions under accident conditions;
The combination of action effects of normal operation with severe environmental effects and water filtration under accident conditions:
·The combination of action effects of normal operation with extreme environmental effects; The combination of action effects of normal operation with extreme environmental effects and actions under accident conditions:
The design value of the ith action effect combination (internal force or stress)--the standard value effect of the ith action in the ith combination; the standard value effect of temperature action during normal operation or shutdown; the standard value effect of pipeline temperature action under design basis accident conditions,
(U) -——-The structural seismic displacement vector or the absolute displacement vector of the structure to be determined:
The input ground displacement vector
The standard value effect of the jet impact load generated on the structure when the pipe is broken,
The standard value effect of the impact load of the projectile applied to the structure when the pipeline is broken:
The standard value effect of the load generated by the broken pipeline on the structure when the pipeline is broken
The standard value effect of the local action generated under the design accident! The maximum storage force between the unit pipe length and the surrounding soil: -The average pressure design value at the bottom of the foundation: The maximum pressure design value at the edge of the bottom of the foundation; The maximum linear displacement or displacement at the flexible joint of the underground pipeline; The action partial coefficient of the first main action in the first combination - The maximum angular displacement at the flexible joint of the underground pipeline; - The design value of the action effect combination (stress); The maximum seismic bending stress of the pipe:
The maximum absolute seismic auxiliary stress of the pipe.
2.2.3 Material properties and resistance
——Measurement of foundation spring along the axial direction of the pipe:
Stiffness of foundation elastic balance along the transverse direction of the pipe;
Design bearing capacity of the cross section!
Damping constant in foundation damping matrix;
——Design value of material or connection strength;
s-Design value of foundation soil resistance after adjustment [K
——Foundation spring stiffness matrix;
——Foundation damping matrix.
Geometric parameters
Net cross-sectional area of the pipe;
Pipeline length between flexible joints,
——Actual grounding width of the foundation bottom under the condition of warping; Foundation width:
Distance from the stress gauge point to the neutral axis,
2.2.5 Calculation coefficient
Torque anti-sliding safety factor;
-shear anti-sliding safety factor;
wave velocity coefficient
anti-bearing capacity adjustment coefficient;
-response spectrum value correction coefficient for damping ratioOthers
mass of particle i,
~liquefaction judgment standard hammer blow number benchmark value;
liquefaction judgment standard penetration blow number critical value,
width of the structural frequency corresponding to the structural response peak value; the ratio of the fundamental frequency of the supported subsystem to the dominant frequency of the main system,
the ratio of the total mass of the supported subsystem to the total mass of the main system. ,
Basic requirements for anti-capsulation design
3. 1 Calculation model
In the anti-capsulation design of nuclear power plants, the main structure can be used as the main system, and other structures, systems and components supported by 3.1.1
can be used as subsystems, and should comply with the following provisions; 3.1. 1. 1 Under normal circumstances, the main system and subsystems should be coupled. 3.1. 1.2 When one of the following conditions is met, the main system and subsystem may not be coupled:
(1) Am.0. 01,
(2) 0. 01≤入≤0. 1, and ≤0. 8 or ≥1. 25, Note,. It is the ratio of the total mass of the supported voxel to the total mass of the main system, and the ratio of the fundamental frequency of the artificially unsupported subsystem to the dominant frequency of the main system. 3. 1. 1. 3
For the subsystem without coupling calculation, its seismic input can be determined by the calculation of the main system and can be carried out using the floor response time process or floor response spectrum. When calculating the main system, if the subsystem is rigidly connected to the main system, its mass can be included in the mass of the main system; if the subsystem is flexibly connected to the main system, the mass and stiffness of the subsystem can be ignored.
3.1.2 The determination of the calculation model should meet the following requirements (1) For items with asymmetrical distribution of mass and stiffness, the coupling effect of translation and torsion should be taken into account.
(2) When a concentrated mass model is used, the number of concentrated masses should not be less than twice the number of models taken into account:
(3) In the structural calculation model, for foundations with an average shear wave velocity of no more than 1100m/s, the interaction between the foundation and the structure should be taken into account. The ratio of the foundation depth to the equivalent radius of the foundation bottom should be less than 1/3 The shallow buried structure should adopt the nested numerical model, and the deep buried structure room should adopt the finite element model. For the foundation with the average shear velocity of the bottom soil layer greater than 1100m/s, the interaction between the foundation and the structure can be ignored; (4) When the stiffness of the supporting components of the item obviously affects the dynamic effect of the item, the effect of its stiffness should be taken into account; (5) The mass of the liquid and auxiliary components in the item should be taken into account; (6) For items with internal liquid oscillation caused by the ground, the liquid anti-motion effect and other hydraulic effects should be taken into account.
Seismic calculation
3.2.1! Items of this type should be calculated according to the ground expansion effect in two mutually perpendicular horizontal directions and one vertical direction. The direction of the horizontal seismic action should be the most unfavorable direction for the item.
3.2.2 The anti-overturning calculation of nuclear power plant items can adopt the linear calculation method. The nonlinearity of the item can be handled by a larger damping; the strong nonlinearity of the item must take into account the changes in stiffness and damping when calculating. The strong nonlinearity of soil structure can be calculated by equivalent linearization method.
3.2.3 Under normal circumstances, the anti-modal design of items of type 1 should adopt the response spectrum method and time process calculation method. When there is sufficient evidence to ensure safety, the equivalent static calculation method can also be used.
3. 2.4 When the response spectrum method is used, the maximum response value of the item can be taken as the square root of the sum of the squares of the maximum response values of each vibration mode. When the ratio of the absolute value of the frequency difference between two vibration modes to the smaller frequency is not greater than 0.1, the sum of the absolute values of the maximum response values of the two vibration modes and the maximum response values of other vibration modes should be combined according to the square root of the sum of squares (SRSS): the combination can also be made by complete quadratic combination (CQC). The high-order vibration modes with a ground response value not exceeding 10% can be ignored. 3. 2. 5
When the time process method is used, the input ground motion should use the design acceleration time process at the ground or the undetermined floor plane. The response values caused by the three components of earthquake vibration, when the response spectrum method is used, 3. 2. 6
can take the maximum response value of each component causing vibration in the same direction of the item, and combine them according to the square root method of the sum of squares. When the time process method is used, the algebraic sum of the response components as a function of time can be calculated, and the prime value of the combined response value should be taken. 3. 3 Initial action
The design site vibration parameters and design response spectrum of the site shall comply with the provisions of Chapter 3. 3.1
4 of this Code.
When designing the equipment for overturning resistance, the design floor response spectrum can be determined based on the time process calculation value of the design earthquake vibration of the support system at the corresponding floor or at the specified elevation, and shall meet the following requirements:
3.3. 2. 1 The design floor response spectrum shall include two mutually perpendicular horizontal components and one vertical component. For a supporting system with symmetric mass and measurement, the floor response spectrum in each direction at a given location can be directly determined based on the seismic response in that direction. For a supporting system with asymmetric mass or stiffness, the floor response spectrum in each direction should be determined by combining the floor responses in that direction under the action of three ground motion components in two horizontal directions and one vertical direction according to the square root method. 3.3.2.2 When calculating the floor response spectrum, the frequency increment should be based on the frequency increment of the extended response spectrum in Table 3.3.2. Table 3.3.2
18.0~22.0 ~-
When determining the design floor response spectrum, the calculated floor response harmonic should be adjusted according to the following requirements:
(1) The calculated floor response spectrum should be corrected according to the uncertainty of the technical parameters such as the material properties of the structure and foundation, the damping ratio, the interaction between the foundation and the structure, and the structural frequency uncertainty caused by the approximation of the seismic calculation method; (2) Each peak value related to the structural frequency should be widened, and the widening amount can be taken as 0.15 times the structural frequency: the widened peak value is determined by the straight line parallel to the straight line segment of the original harmonic value 1. The damping ratio of Class I items shall meet the following requirements: 3.3. 3.3.3.1 The damping ratio of items may be adopted according to Table 3.3.3. Damping ratio (%) Spring-connected structures Bolted steel structures Prestressed concrete structures Reinforced concrete composite structures, superstructure Cable support Safe ground vibration Table 3.3.3 Limit safe ground vibration For mixed structures composed of different materials, the damping ratio should be determined according to the energy-weighted method.
3. 4 Action effect combination and section anti-burst calculation 3.4.1
The earthquake action effect should be combined with the service load effect under various working conditions in the nuclear power plant in the most unfavorable way. The section anti-burst calculation of the containment, buildings, structures, underground structures and underground pipelines of the concrete structure should meet the following requirements: Where:
Requirement:
Action effect (internal force) design value;
The design value of the bearing capacity of the section:
-bearing capacity adjustment factor, which should be taken as 1.0 for all types of structural components. The section anti-burst calculation of the steel structure components of buildings and structures should meet the following formula S2R
Action effect (internal force) design value:
--The design value of the bearing capacity of the section:
.-bearing capacity adjustment factor.
3.4.4 The value of the effect of equipment, components and process pipelines and the seismic calculation of their cross sections shall comply with the relevant provisions of Chapter 8 and Chapter 9 of this Code respectively. 3.5 Seismic structural measures
The containment, buildings and structures of nuclear power plants should be located on bedrock or rock with a shear wave velocity greater than 400m/s.
The seismic structural measures of concrete containment and concrete building structural components shall comply with the relevant requirements of the current national standard "Code for Design of Building Anti-slip" for concrete structural components with a first-class resistance level. The seismic structural measures of other concrete structural components and various steel structural components shall comply with the relevant requirements of the current national standard "Code for Design of Building Anti-slip" for 9-degree anti-covering.
3.5.3 The seismic structural measures of equipment, components and process pipelines shall comply with the relevant requirements of the current national standard "Code for Design of Building Anti-slip" for 9-degree anti-covering. 6—3—6
Design earthquake vibration
General provisions
Seismic design of nuclear power plants. The earthquake action of its items shall be determined based on the design earthquake vibration parameters.
The determination of the design earthquake vibration parameters of nuclear power plants shall meet the following requirements 4.1.2
4.1.2.1 The design earthquake vibration parameters shall include the design acceleration peaks of two horizontal directions and one vertical direction, the design response spectra of two horizontal directions and one vertical direction, and the design acceleration time processes of no less than three groups of three components. 4.1.2.2 The design acceleration peaks of the two horizontal directions shall be the same value, and the vertical design acceleration peak shall be 2/3 of the horizontal design acceleration peak. 4.1.2.3 The acceleration time process of the design earthquake vibration shall be determined according to the method of Section 4.4 of this Code.
4.1.3 The design earthquake motion parameters should adopt the values of free ground; when calculating the earthquake motion parameters of the covering soil layer, the stiffness and vibration of the soil layer should be taken into account; the top surface of the soil layer with a shear wave velocity greater than 700m/s can be used to calculate the bedrock surface, and there should be no soil layer with a lower wave velocity below it. 4.1.4 The peak acceleration of earthquake vibration should meet the following requirements: The acceleration peak value of the ultimate safety ground vibration should be adopted in accordance with the provisions of Article 4.1.4.1
4.2.1 of this Code.
4.1.4.2 The peak acceleration value of the operational safety earthquake vibration shall not be less than 1/2 of the corresponding ultimate safety ground vibration acceleration value. 4.1.5 The search, investigation and analysis of ground vibration data shall meet the following requirements; 4.1.5.1 The earthquake vibration data shall include all ground data and ground geological data in the working area.
4. 1. 5. 2
The contents of the earthquake vibration site survey shall comply with the requirements of HAF0100 of the Safety Regulations for Site Selection of Nuclear Power Plants.
4. 1. 5. 3The earthquake vibration analysis report shall include the determination of seismic active faults, seismic tectonic maps and the geological and tectonic conditions for strong earthquakes in the working area. 4. 2.2.1 The maximum value of the acceleration of the ultimate safety earthquake vibration shall be the maximum value of the results determined by the tectonic method, the maximum historical earthquake method and the comprehensive slow rate method, and its horizontal acceleration peak value shall not be less than 0.15g. Requirements: When the tectonic method is used to determine the ultimate safety earthquake vibration, the following should be met. 4.2.2.1 Based on the geological data in the work area, the analysis of the active faults and historical earthquakes should be carried out, the geological structural zone should be divided, and the spatial position of the active faults and the maximum earthquake magnitude Mm should be determined. Based on the nature and activity of the fault, the maximum earthquake that may occur should be divided. 2.2.2
of the active fault segment,
4.2.2.3For each active fault segment, the maximum possible seismic magnitude Mm can be determined based on the following factors: the maximum magnitude of historical earthquakes on the fault segment; the maximum magnitude of historical earthquakes closely related to the active fault segment; the length of the active fault segment; the Quaternary slip rate of the active fault segment; the extension depth of the fault and the width of the fault zone; the form and dynamics of the fault activity.
In each active fault segment, the maximum magnitude of seismic will occur at the location closest to the wide area of the fault segment, and the seismic vibration of the plant area shall be calculated according to the seismic vibration attenuation law specified in this code, and then the maximum value of the seismic vibrations in the plant area caused by all active fault segments shall be taken.
4. 2. 2. 5 In the geotectonic zone, for historical earthquakes that have no clear relationship with the active faults of the earth, the largest earthquake should be taken and moved to the nearest place to the site, and the resulting seismic movement of the site should be calculated.
4. 2.3 When using the maximum historical earthquake method to determine the ultimate safety earthquake vibration, the following requirements should be met;
4. 2.3.1 Based on the epicenter position, epicenter intensity and magnitude of each historical earthquake, the ground predominant motion caused by each earthquake in the factory area should be determined according to the ground predominant motion attenuation law, and the maximum value should be taken.
4.2.3.2 When historical geological parameters are incomplete, the maximum earthquake vibration value can be determined according to the highest intensity recorded in the factory area or nearby sites in the past. 4.2.4 When the comprehensive probability method is used to determine the limit safe earthquake, the following requirements shall be met. 4.2.4.1 When the comprehensive probability method is used, the zones shall be divided first according to the characteristics of earthquake geology and seismic activity. Then, the potential earthquake source area shall be determined based on the analysis of geophysical activity, seismic active faults, geophysical fields and other geogeological data, on the basis of the following work results: (1) The spatiotemporal distribution characteristics of moderate and strong earthquakes in the earthquake zone; (2) The spatial distribution of weak earthquakes; (3) The characteristics and distribution of active faults and ancient earthquake relics; (4) The characteristics of new structures and modern structures; (5) The deep structure reflected by geophysical field data; (6) The parts of the work area where moderate and strong earthquakes have occurred and the structural conditions for the occurrence of moderate and strong earthquakes have been met.
4. 2. 4. 2 The seismic activity parameters of potential earthquake source areas should include the following! (1) Upper limit of the development level:
(2) Proportional relationship between the number of large and small earthquakes; (3) Annual average occurrence rate of earthquake fumigation;
(4) The starting development level can be 4.
The upper limit of earthquake magnitude should be determined based on the following factors: 4.2. 4. 3
(1) The maximum magnitude of historical earthquakes in the potential source area; (2) Characteristics of the seismic activity pattern; (3) Fault activity and the size of the active fault segment; (4) Analogy of tectonic characteristics and scale. 4.2.4.4 The proportional relationship coefficient of the number of earthquake occurrences should be determined based on the following requirements: (1) There is a sufficient sample size of the statistical earthquake data and the corresponding magnitude; (2) The time period and magnitude domain covered by the statistical earthquake data have sufficient credibility
(3) The consistency and correlation of the attenuation activities within the divided zones. The average annual occurrence rate of earthquakes should be determined based on the following factors: 4. 2. 4. 5
(1) The level of earthquake activity that may occur within a certain period of time; (2) The average annual occurrence rate of earthquakes in the earthquake zone should be equal to the sum of the values in each potential earthquake source area; Www.bzxZ.net
(3) The unevenness of future earthquake activity in time, intensity and location; (4) The possibility of a strong earthquake in a potential earthquake source area. 4.2.4.6 Select an appropriate ground cover model, such as the Poisson model or modified Poisson model, or other models that can be demonstrated to represent the temporal and spatial characteristics of ground cover in this work area, calculate the sum of the probabilities of all potential seismic source areas for the seismic vibration in the plant area exceeding a certain given value, draw the exceedance probability curve of the seismic hazard in the plant area, and make uncertainty correction.
4.2.4.7 After uncertainty correction, the peak value of acceleration corresponding to the annual exceedance rate of 10°" shall be taken as the limit safe ground cover value determined by this method. 4.2.5 The attenuation law of seismic vibration shall comply with the following provisions: 4.2.5.1 The intensity attenuation law shall be determined by statistical calculation according to the following steps: (1) Collect strong seismic isoseismal lines or intensity survey data in the work area or in a larger area, as well as the magnitude, focal depth, epicenter location and epicenter intensity of each strong earthquake. (2) Statistically calculate the seismic intensity attenuation law of this work area. There may be different attenuation relationships along the long and short axes of the isoseismal lines.
4. 2.5,2 The attenuation law of the peak acceleration should be determined according to the following situations: (1) In areas with many strong earthquake acceleration records, the acceleration attenuation law can be determined by statistical methods;
(2) In areas lacking strong earthquake acceleration records but with sufficient intensity data, the intensity attenuation law of the local area and the intensity attenuation and acceleration attenuation laws of other areas can be used to convert the acceleration attenuation law suitable for the local area; (3) In areas lacking both strong models such as velocity records and intensity data, the acceleration attenuation law of areas with similar geological structure conditions can be selected after reasonable demonstration. 4.3 Design response spectrum
4.3.1 The design response spectrum should adopt the standard response spectrum or the site earthquake-related response spectrum approved by the relevant competent authorities.
4.3. 2 The horizontal and vertical standard response spectra of bedrock sites shall be adopted according to Table 4.3.2-1 and Table 4.3.2-2 respectively according to the damping ratio (Figure 4.3.2-1 and Figure 4.3.2-2). The horizontal and vertical standard response spectra of hard soil sites shall be adopted according to Table 4.3.23 and Table 4.3.2-4 respectively according to the damping ratio (Figure 4.3.2-3 and Figure 4.3.2-4). Note: The spectrum is based on the peak acceleration of 1.0g The given design earthquake acceleration end value to be used in application is adjusted according to Appendix C of this code. 4.3.3. The bedrock earthquake response spectrum in North China can be determined according to Appendix C of this code. 4.3.4 The site ground response spectrum of hard soil site can be determined according to the bedrock earthquake response spectrum. The steps are as follows: (1) Determine the time process envelope function of the plant earthquake overburden according to the working area ground environment; (2) Determine the bedrock ground response spectrum according to the intensity data of the working area; (3) Determine the time process envelope function and the free bedrock ground motion acceleration time process that is consistent with the bedrock earthquake response spectrum according to the design acceleration time process generation method specified in this code; (4) Determine the incident wave upward from the bedrock top surface under the plant soil layer or the earthquake acceleration time process of the bedrock top surface according to the free bedrock earthquake overburden acceleration time process, and calculate the ground motion of the plant site. Zuni ratio:
Period s
Figure 4.3.2-1 Standard response spectrum of bedrock site in horizontal direction 0.51
Figure 4.3.2-2 Standard response spectrum of bedrock site in vertical direction 6—3—7
6—3-8
Zuni ratio (%)
Damping ratio (
Figure 4.3.2-3 Standard response spectrum of hard soil site in horizontal direction Period
Figure 4.3.2-4 Standard response spectrum of hard soil site in vertical direction Standard response spectrum of bedrock site in horizontal direction Control point period and spectrum value A (0. 03s)
Acceleration
Acceleration
(m/s）
Acceleration
2, 49
C (0. 07s)
Acceleration
Acceleration
C(0. 07s)
Acceleration
Acceleration
(m/s）
Acceleration
Speed
Table 4. 3. 2-1
Table 4. 3. 2-2
Damper ratio ()
Damping ratio (%)
Additional shielding
A(0. 03s)
acceleration
hard soil site horizontal standard response spectrum control point period and its spectrum value B (0.04a)
acceleration
acceleration
acceleration
hard soil site horizontal standard response spectrum control point period and its spectrum value B (0.04b)
acceleration
4. 4 Design acceleration time process
acceleration
4. . 1 The design acceleration time process can be generated by trigonometric series addition or actual ground acceleration record.
4. 4. 2 When the angular series number addition is used, the following requirements shall be met: 4. 4. 2.1 The phase angle of the actual acceleration record equivalent to the ground conditions of the factory area can be used, or the phase angle with a random uniform distribution within 0 ~ 2 can be added. 4. 4. 2. 2. Under the condition of sufficient time process envelope function, the amplitude of each harmonic should be adjusted so that the response spectrum of the designed velocity time process can envelope the given target response spectrum with a damping ratio of 5%~20%. For the replacement ground motion, the number of control points lower than the standard response spectrum shall not exceed five, and the relative error shall not exceed 10%, and the sum of the ordinates at the response spectrum control points shall not be lower than the corresponding value of the standard response spectrum. When adjusting the amplitude of the triangular series spectrum wave, for the bedrock ground motion, within the period domain of 0.034.4.2.3
~5.00%, the number of response spectrum control points shall not be less than 75, and shall be roughly evenly distributed on the logarithmic coordinates of the period, and the frequency increment of each frequency band can be adopted according to Table 4.4.2 The range and increment of the control points for artificially generated simulated earthquake motion
Grape grass increment calculation
18.0-22.0-
4.4.3 When the actual earthquake intensity record is used, the response spectrum of the generated acceleration record shall meet the requirements of Section 4.4.2.2 of this Code. Velocity
(m/s）
Additional shielding
Additional shielding
(area)
Acceleration
Table 4.3.2-3
E(4.00)）
Table 4.3.2-4
Foundation and slope
5.1 Age requirements
5.1.1 This chapter applies to the safety assessment of the foundation of Class I items and the slopes related to the safety of Class I and Class II items. The stability verification of the foundation shall comply with the provisions of Section 6.4 of this Code for foundation seismic verification. 5.1.2 The classification of rock and soil and foundation shall be in accordance with the provisions of the current national standards "Code for Design of Building Foundations" and "Code for Seismic Design of Buildings". 5.1.3 Rock and soil with large mechanical differences in the horizontal direction shall not be selected, nor shall foundations with one part being an artificial foundation and the other part being a natural foundation be selected as the same structural unit.
5.1.4 Foundations composed of relatively high soil, liquefied soil or fill shall not be selected. 5.2 Anti-sliding test of foundation
5.2.1 This section applies to foundations with a standard value of static bearing stress greater than 0.34MPa or a shear wave velocity greater than 400m/s.
5.2.2 The design value of the anti-sliding bearing capacity of the foundation may be adopted as 75% of the bearing capacity value specified in the current national standard "Code for Design of Anti-sliding Buildings". 5.2.3 The anti-sliding calculation of foundation shall be carried out by sliding surface method, static finite element method and dynamic finite element method in sequence until one of the methods verifies that the foundation is stable. The unfavorable combination of self-weight, horizontal ground action, vertical ground action, structural load sensitivity, etc. shall be taken into account during the calculation. 5.2.4 When the sliding surface method and static finite element method are used, the horizontal ground coefficient of the geological 6-3-9
action produced by soil and weight shall be 0.2, and the vertical seismic coefficient shall be 0.1. 5.2.5 When the dynamic finite element method is used, the bedrock seismic vibration shall be converted into the corresponding calculated bedrock acceleration time process according to the given ground acceleration time process and the specific stratum conditions at the bottom of the foundation, or the bedrock acceleration time process shall be directly used. 5.2.6 The safety factor shall be used to calculate the anti-sliding of foundation, and the partial coefficient of each action shall be 1.0. The anti-sliding safety factor shall be used according to Table 5.2.6. Safety factor against sliding
Sliding surface method
Static finite element method
Table 5. 2. 6
Dynamic finite element method
5. 3 Identification of foundation liquefaction
For foundations with saturated sand and saturated silt, liquefaction identification and 5.3.1
hazard calculation should be carried out.
5.3.2 The standard penetration test identification method specified in the current national standard "Code for Design of Buildings against Sliding" can be used for foundation liquefaction identification. The reference value of the number of standard penetration hammer blows should be calculated according to the following formula:
No-ZisN,/Ms
m=exp[-(“)\1
reference value of standard penetration chain blows;
(5.3.2-1)
(5.3.2-2)
M——ground acceleration value (g) at the screening location calculated from the specified earthquake acceleration bee value according to the type of item; serial number:
—calculation coefficient;
N,,bt,——calculation parameters, which can be adopted according to Table 5.3.2. Calculation parameters
seismic stability verification of slopes
Table 5.3.2
5.4.1Seismic stability verification must be carried out for slopes related to the structural safety of Class 1,1 items.
5. 4.2 The calculation of the anti-lightning stability of the slope can be carried out in sequence according to the sliding surface method, the static finite element method and the dynamic finite element method until one of the methods has verified that the slope is stable. The seismic action for slope stability calculation should be determined based on the limit safety ground motion and should include the combination of horizontal and vertical ground motions in the unfavorable direction. When the sliding surface method and the static finite element method are used, the horizontal seismic coefficient in the ground motion should be 0.3 and the vertical seismic coefficient should be 0.2.
5.4.4 The safety factor for slope anti-lightning stability verification should be adopted according to Table 5.4.4. Anti-sliding safety factor
Table 5. 4. 4
Moving surface method
Static finite element method
Dynamic finite element method
Containment, buildings and structures
6. 1 General provisions
6.1.1 This chapter applies to concrete containment and Class 1I buildings and structures. 6.1.2 The design of anti-seismic joints should meet the following requirements: The width of the anti-seismic joint should be determined according to the deformation calculation and should be equal to or greater than twice the sum of the ground deformation of the two items. The design of expansion joints and settlement joints should meet the requirements of anti-seismic joints. 6.2 Actions and combinations of action effects
6.2.1 The structural seismic design of containment, buildings and structures should consider the following types of actions or action combinations:
6.2.1.1 The actions N to be avoided during normal operation and shutdown include the standard value effects of the following actions:
(1) Standard value effect of permanent load G, including deadweight, hydrostatic pressure and fixed equipment load:
(2) Standard value effect of live load L. Including any movable equipment load and temporary construction load before and after construction:
(3) Standard value effect of load F caused by prestressing, (4) Standard value effect of temperature action T during normal operation or shutdown. (5) Standard value effect of pipeline and equipment reaction during normal operation or shutdown 6--3--10
Ro, but excluding the standard value effect of reaction caused by permanent load and earthquake action, (6) Standard value effect of load P caused by the pressure difference between the inside and outside of the safety platform. (7) Standard value effect of lateral earth pressure (H.) 6.2.1.2 Standard value effect of ground action caused by operational safety earthquake vibration under severe environmental conditions E, including the standard value effect of pipeline and equipment reaction caused by operational safety earthquake vibration.
6. 2.1.3 The standard value effect of earthquake action E2 caused by the extreme safety earthquake vibration under extreme environmental conditions. Including the standard value effect of pipeline and equipment reaction force caused by the extreme safety earthquake vibration
6. 2. 1. 4 The action A produced under accident conditions, including the standard value effect of the following actions:
(1) The standard value effect of pressure load P under the design basis accident condition. (2) The standard value effect of temperature action T under the design basis accident condition, including the standard value effect of temperature action T during normal operation or shutdown. (3) The standard value effect of pipeline and equipment reaction force R produced under the design basis accident condition, including the standard value effect of pipeline reaction force R during normal operation or shutdown. (4) Standard value effect Y of local actions generated under design basis accident conditions, including: Standard value effect Y of load generated by the ruptured pipeline on the structure when the pipeline ruptures; Standard value effect Y of jet impact load generated on the structure when the pipeline ruptures; Standard value effect Y of impact load of projectiles applied on the structure when the pipeline ruptures. 6.2.1.5 Standard value effect H of load generated by internal water leakage in the containment. 6.2.2 The combination of action effects of the following actions shall be considered in the containment design: 6.2.2.1 Class 1 buildings and structures including safety vessels (1) The combination of action effects S1 of normal operation action and severe environmental action, when the temperature effect T is included in the action effect combination. =S\1 t (2) The combination of normal operation, severe environmental action and accident conditions S2
(3) The combination of normal operation, severe environmental action and flooding after accident conditions S (this combination is only applicable to containment); (4) The combination of normal operation and extreme environmental action S4 (5) The combination of normal operation, extreme environmental action and accident conditions Ss.
6.2.2.2
For Class 1 buildings and structures, only various combinations S,,S.S2 related to the standard value effect E. of the earthquake action generated by the operational safety ground vibration are taken. 6.2.3 When making various action effect combinations, the following requirements shall be met; 6.2.3.1 When the action effect caused by uneven settlement, change or contraction is relatively significant, the various action effect combinations other than those in 6.2.2.1 shall be added to the combination as permanent loads. The effect should be calculated according to the actual situation. 6.2.3.2 According to the standard value effect P., T., R., Y determined in Article 6.2.1,All should be multiplied by the corresponding dynamic coefficient, and the standard value effect H of lateral earth pressure should include the dynamic earth pressure, and the standard value effect L of live load should include the impact effect of moving load. In various action effect combinations including the standard value effect Y, of local actions generated under the design basis accident conditions, the bearing capacity can be verified without considering Y, and it is allowed to add Y, provided that any safety-related system does not lose its proper function (after sufficient demonstration). In the action effect combination, the standard value effects P., T., R. and Y, determined according to Article 6.2.1, should all take the maximum value, but after the time process calculation and judgment, the lag effect of the above actions can be considered. 6.2.4 The various action partial coefficients of the action effect combination can be adopted according to the provisions of Appendix B of this Code.
6.3 Stress calculation and cross-section design
6.3.1 Stress calculation shall meet the following requirements: (1) The finite element model should be used for the containment shell, and the finite element, plate, shell and other calculation models should also be used for buildings and structures. When the model used for stress calculation is different from the model used for ground response calculation, the results of seismic response calculation can be converted into equivalent effects in the stress calculation model;
(2) The integral foundation slab should be subjected to stress analysis using the finite element or thick plate model. The foundation around the slab can be divided by finite elements and analyzed as a whole together with the slab, or it can be simulated using a concentrated parameter model;
(3) Elastic analysis method can be used for stress calculation. 6.3.2 The following bearing capacities shall be verified for the concrete containment: (1) Compression, tension and bending bearing capacities on the positive load surface; (2) Radial shear bearing capacity; (3) Tangential shear bearing capacity, which may not be included in the shear strength of the concrete; (4) Punching shear bearing capacity under concentrated force, which may not be included in the punching shear strength of the concrete when axial tension exists; (5) Torsion bearing capacity under torque. 6.4 Seismic verification of foundations In addition to meeting the bearing capacity requirements specified in this chapter, the crack width of the concrete containment and the concrete foundation slabs of Class I and Class II buildings and structures shall also be verified. The partial coefficients for various actions shall be taken as 1.0, and the maximum crack width shall not exceed 0.3 mm. 6.4.2 The bearing capacity verification of natural foundations shall meet the following requirements: (1) When combined with the effect of the relevant standard value effect E, the ground contact ratio of the foundation bottom surface (see Article 6.4.3) shall be greater than 75% and shall comply with the following formula: P≤0.75fsE
Pm≤0.90fsE
wherein P and Pmx-**
(6.4.2-1)
(6.4.2-2)
are the average pressure design value of the combination of the effect of the standard value effect E, at the foundation bottom surface and the maximum pressure at the foundation bottom surface edge, respectively. Design value:
—The adjusted design value of the foundation soil anti-bearing capacity is adopted in accordance with the current national standard "Code for Design of Building Anti-Blouse Capacity". (2) When combined with the effect of the relevant standard value effect E, the grounding rate of the bottom surface of the foundation should be greater than 50%, and the structure should not lose its function and meet the requirements of formula (6.4.2-1) and formula (6.4.2-2)
6.4.3 The grounding rate of the bottom surface of the rectangular foundation can be calculated as follows (see Figure 6.4.3): β = number × 100%
a 3b(-
where β
grounding rate of foundation bottom surface (%);
actual grounding width of foundation bottom surface under the condition of separation (m); (6.4.3-1)
(6.4.3-2)
foundation width (m)
-is respectively the operational safety earthquake vibration SL1 or the ultimate safety ground vibration M, N-
SL.2 the overturning moment (N ~ m) and vertical force (N) caused by various action effects, the latter including the self-weight of structure and equipment, vertical earthquake action (direction opposite to the weight) and buoyancy. Figure 6.4.3 Calculation of grounding rate of rectangular foundation bottom surface The safety factor of foundation anti-sliding and anti-overturning stability verification shall comply with the requirements of Table 6.4.4.
foundation sugar fixed safety factor
safety factor
anti-frustration acid
cover 6.4. 4
Note, ① When there is a bracket that produces an adverse effect, the above combination should also include the after-load effect, (Figure 1) For all items of Class 1, the action effect combination in the table should be calculated. Underground structures and underground pipelines
7.1 General provisions
This chapter applies to Class I and Class II underground structures and underground pipelines. 7.1.1
7.1.2 Underground structures and underground pipelines should be built on dense, uniform and stable foundations. 7.1.3 In addition to meeting the strength requirements specified in this chapter, reinforced concrete underground structures and underground pipelines that bear water pressure shall also meet the provisions on crack resistance and the provisions on the maximum allowable crack width in the current national standard "Design Code for Hydraulic Reinforced Concrete Structures". 7. 2 Seismic calculation of underground structures
7.2.1 This section applies to underground water inlets, water outlets, transition sections and underground shafts. 7.2.2 The following methods can be used to calculate the ground reaction of underground structures. (1) For underground structures, the reaction displacement method should be adopted; (2) For semi-underground structures, the multi-point input elastic support dynamic analysis method should be adopted.
(3) In the above two calculation methods, the effect of the foundation around the underground structure can be simulated by concentrated springs. The calculation diagram and calculation formula can be adopted according to Appendix D of this code, or the plane finite element overall dynamic calculation method can be adopted. 7.2.3 The foundation springs used in the calculation include compression springs and shear springs. The spring constant is related to the dynamic characteristics of the foundation soil, the shape and stiffness characteristics of the underground structure, and can be determined by test or calculation methods. The static plane finite element method can be used for preliminary calculation.
7.2.4 The seismic vibration effect at each elevation of the underground structure is only applied to the side compression springs and the shear springs on the top and bottom surfaces, and is determined according to the calculation method for the vibration of the covering soil layer in Article 4.1.3 of this code. In the multi-point input elastic support dynamic calculation method, the ground time process should be input, and in the reaction displacement method, only the relative value of the maximum seismic displacement along the elevation can be input.
7.2.5 When calculating the ground response of underground structures, the vertical component of the ground motion may not be taken into account.
7.3 Seismic calculation of underground pipelines
7.3.1 This section applies to underground structures such as underground direct buried pipelines, pipe galleries and tunnels. When the cross-section of underground pipe galleries and tunnels is large and the wall thickness is relatively thin, the hoop strain caused by earthquakes may be supplemented by the method described in Section 7.2 of this Code. 7.3.2 For underground straight pipes in uniform foundations far away from joints, bends, bifurcations, etc., the upper limit of the maximum axial seismic stress of the cross section can be calculated as follows: o, E
wherein α,
the upper limit of the maximum axial seismic stress of the underground straight pipe (N/m2); E--material elastic modulus (N/m);
the maximum ground velocity at the elevation of the underground straight pipe (m/s); the apparent wave velocity of the seismic wave propagating along the pipeline in the foundation (m/s); - the axial stress wave velocity coefficient, which should be adopted according to Table 7.3.2 based on the controlling ground wave type.
wave velocity coefficient
compression wave
axial stress wave velocity coefficientα
curvature stress wave velocity coefficient
shear wave
Table 7.3. 2
7.3.3 For underground straight pipes in uniform foundations far away from joints, joints, partitions, etc., the upper limit of the maximum axial stress on the pipe cross section caused by the friction between the pipe wall and the surrounding soil caused by earthquake action can be calculated according to the following formula 6-3--11
武中f.
The maximum friction force between the unit pipe length and the surrounding soil (N): (7.3.3)
The apparent wavelength of the ground wave that controls the elevation of the underground straight pipe. When the underground straight pipe is divided into sections by flexible joints, the pipe length between the sections should be taken#
The net cross-sectional area of the underground straight pipe.
7.3.4 The maximum seismic bending stress of the underground straight pipe in uniform foundations can be calculated according to the following formula:
ar=(aey
The maximum seismic bending stress of the underground straight pipe (N /m*)#Where-
The maximum seismic acceleration at the elevation of the underground straight pipe (m /s*); Distance from stress calculation point to the neutral axis of the pipe section (m); (7.3.4)
The bending stress wave velocity coefficient shall be adopted according to Table 7.3.2 based on the controlling seismic wave type.
The maximum axial stress generated by the propagation of seismic waves in the above-mentioned underground straight pipe shall be the smaller value calculated by formula (7.3.2) and formula (7.3.3), and the design shall be carried out according to the maximum axial stress and the maximum bending stress.
7.3.6 When the terrain and geological conditions along the underground pipeline have obvious changes, a special earthquake response calculation should be carried out. The axial stress and bending stress can be calculated according to the elastic foundation beam. 7.3.6.1 The earthquake vibration used in the vibration calculation can be calculated by selecting one of the following models in turn according to the complexity of the terrain and geological conditions along the pipeline: (1) Segmented one-dimensional model. The foundation soil is divided into segments along the length of the pipeline, and the seismic response of each segment is calculated independently according to the one-dimensional shear wave model. The nonlinear characteristics of the foundation soil should be considered in the calculation;
(2) Concentrated mass model. The foundation soil is divided into segments along the length of the pipeline, and each segment is simulated by an equivalent concentrated mass and spring, and the space between each mass is simulated by a spring that counteracts the elasticity of the foundation soil.
(3) Plane finite element model. The energy transmission boundary can be used on the side, and the viscous boundary or transmission boundary can be used on the bottom.
7.3.6.2 The design earthquake vibration should take the amplitude of the ground capsule at the pipeline elevation. 7.3.6.3 The damping ratio of the foundation soil may be taken as 5% in vibration calculation. 7.3.6.4 The spring stiffness of the foundation soil may be determined by field tests or calculation methods based on the dynamic characteristics of the soil. The following formula can be used for preliminary calculation: K,=3G
K,=BK,
Yes,= DLK,
wherein K,, K,—
(7.3.6-1)
(7.3. 6-2)
(7.3.6-3)
(7. 3. 6-4)
elastic stiffness of foundation soil per unit length along the axial and transverse direction of the pipeline (MPa/m);
shear modulus of foundation soil corresponding to the maximum strain amplitude of seismic vibration:
conversion coefficient, the value of which can be taken as 1/3;
concentrated spring constant of foundation (10°N/m); pipe diameter (m),
concentrated spring spacing (m).
When calculating the internal forces generated by the propagation of seismic waves in the curved section, bifurcated section and anchorage point of the underground pipeline, the section can be analyzed as an elastic foundation beam. The axial and transverse spring constants of the foundation around the pipeline can be determined according to the relevant provisions of Section 7.3.6.4 of this Code. Flexible joints in the pipeline should be simulated by axial and rotational springs. 7.3.8 At the connection between the underground pipeline and the engineering structure or the turning point of the pipeline, the additional stress generated in the pipeline due to the relative movement between the pipeline and the surrounding soil or between the two end points of the pipeline should be calculated. The additional stress in the pipeline caused by the relative movement and the pipeline stress caused by the propagation of seismic waves along the pipeline can be combined according to the square root of the sum of squares method. 7.3.9 When the underground pipeline is divided into sections by flexible joints, its deformation should be calculated so that the joints will not be detached during an earthquake. The maximum relative displacement and angular displacement at the joint can be calculated according to the following formula:
6—3—12
u, g-
(7. 3. 9-1)
(7. 3. 9-2)
are the maximum linear displacement and angular displacement at the flexible joints of underground pipelines, respectively,
the length of the pipeline between the flexible joints, but not more than half the apparent wavelength of the seismic wave.
7. 4 Anti-seismic verification and structural measures
7.4.1 The bearing capacity and stability of the foundations and subgrades of underground structures and underground pipelines during earthquakes shall comply with the following provisions:
(1) The anti-seismic stability of the foundations around underground structures and underground pipelines shall be tested in accordance with the relevant provisions of Section 5.2 of this Code;
(2) The bearing capacity and anti-sliding stability of the foundations of underground structures such as water intakes and discharge ports during earthquakes shall be tested in accordance with the relevant provisions of Section 6.4 of this Code. 7.4.2 The combination of action effects of underground structures and underground pipelines shall comply with the following requirements: (1) The normal action effect combination of Class 1 underground structures and underground pipelines shall include the action effect of the ult
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