Standardization. GOST 23616-79 - System for ensuring the accuracy of geometric parameters in construction. Accuracy control. OKS: General provisions. Terminology. Standardization. Documentation, Technical drawings. GOST standards. System for ensuring geometric accuracy.... class=text>
GOST 23616-79
System for ensuring the accuracy of geometric parameters in construction. Accuracy control
GOST 23616-79
Group Zh02
INTERSTATE STANDARD
System for ensuring the accuracy of geometric parameters in construction
ACCURACY CONTROL
System for ensuring the accuracy of geometrical parameters in construction. Control of accuracy
ISS 01.100.30
91.010.30
Date of introduction 1980-01-01
By Decree of the USSR State Committee for Construction Affairs dated April 12, 1979 N 55, the implementation date was set at 01/01/80
EDITION (April 2003) with Amendment No. 1, approved in May 1984 (IUS 9-84).
This standard applies to the construction of buildings and structures, the manufacture of elements for them (structures, products, parts) and establishes the basic rules and methods for monitoring the accuracy of geometric parameters.
Rules for monitoring the accuracy of geometric parameters of specific types of structures of buildings and structures and their elements, as well as work performed, are prescribed on the basis of this standard in the relevant standards or in other regulatory, technical, and technological documents.
The terms used in the standard for statistical control correspond to those given in GOST 15895-77*.
________________
* On the territory of the Russian Federation, GOST R 50779.10-2000, GOST R 50779.11-2000 are in force.
The standard corresponds to ST SEV 4234-83 (see Appendix 1a).
1. GENERAL PROVISIONS
1. GENERAL PROVISIONS
1.1. Control of the accuracy of geometric parameters is a mandatory component of quality control and is carried out by comparing the actual values of the parameters or accuracy characteristics with the established ones.
1.2. During the production process at enterprises and construction organizations, incoming, operational and acceptance control of accuracy should be performed.
1.3. Accuracy control should ensure:
determination with a given probability of compliance of the accuracy of geometric parameters with the requirements of regulatory, technical, technological and design documentation for control objects;
obtaining the necessary information to assess and regulate the accuracy of technological processes.
(Changed edition, Amendment No. 1).
1.4. The following are subject to accuracy control:
geometric parameters of elements and parameters that determine the position of landmarks of alignment axes and landmarks for installing elements, as well as the position of elements in structures (the range of tolerances for these parameters is given in GOST 21779-82 and GOST 21780-83);
geometric parameters of technological equipment, shapes and accessories that influence the accuracy of the manufacture of elements and their installation in structures and are specified in the relevant technological documents.
1.5. The rules for accuracy control are established depending on the nature of the control object and the controlled parameters, production volumes and stability of technological processes, taking into account the cost and required reliability of control.
1.6. Standards and other regulatory and technical documents establishing control rules must define:
controlled parameters;
applied control method;
control plan and procedure for its implementation;
control means, implementation rules and requirements for measurement accuracy;
method for assessing control results.
1.4-1.6. (Changed edition, Amendment No. 1).
1.7. At enterprises and construction organizations, it is necessary to develop enterprise standards, maps and control sheets and other technological documents for control processes and operations that determine for specific control objects the placement of control posts for the technological process, performers, the volume and content of control work, methods and measurement schemes , rules for collecting, processing and using information about control results.
1.8. Regulatory, technical and technological documents establishing the rules for accuracy control must undergo metrological examination in accordance with the requirements of the standards of the State System for Ensuring the Uniformity of Measurements.
2. PURPOSE OF CONTROL METHODS
2.1. Accuracy control is prescribed primarily selectively based on alternative or quantitative characteristics, and, in necessary cases, continuous.
2.2. Complete control should be prescribed:
for small production volumes, when selective control is not feasible;
when the nature of production is unstable, including during the period of adjustment of technological processes;
with increased requirements for ensuring a given accuracy associated with the need to use large samples.
2.3. Sampling control should be prescribed when stable production is established, when statistical homogeneity of the technological process is ensured.
2.4. When using the sampling method, it is preferable to use control based on an alternative characteristic.
Control by quantitative criteria is used for the most critical parameters, when their number is small and there is a need for further development of the process, and also if, due to production conditions, it is advisable to reduce the volume of samples compared to control by an alternative criterion. This method is applicable when the controlled parameters are independent of each other and have a normal distribution.
If necessary, some parameters can be controlled by a quantitative criterion, and some by an alternative one.
2.5. Inspection control should be carried out using the methods established in the relevant regulatory and technical documents for acceptance control.
2.6. Types, methods and objects of control by production stages are given in Appendix 1.
3. FULL CONTROL
3.1. During continuous control, the accuracy of this geometric parameter is checked in each control object (product unit).
3.2. Control is carried out as the relevant technological operations are completed or the finished product is released, or after the formation of batches of products or the completion of a certain volume of construction and installation work.
3.3. Control standards for continuous control are the upper and lower limit deviations from the nominal dimensions or from the nominal position of a reference point, a point on a straight line or a plane, which determine the requirements for the accuracy of the controlled parameter.
In some cases, control standards may be the largest or smallest size limits.
3.4. To determine the compliance of geometric parameters with control standards, in accordance with established measurement rules, actual deviations or actual dimensions are found.
3.5. The control object is considered suitable for this controlled parameter if one of the following conditions is met:
; (1)
. (2)
3.6. In order to reduce the labor intensity of control, verification of compliance with conditions (1) and (2) can be carried out without determining quantitative values and using limit gauges or templates.
3.3-3.6. (Changed edition, Amendment No. 1).
4. SAMPLING INSPECTION
4.1. During selective control, the accuracy of a given geometric parameter is checked according to an established control plan in a sample consisting of a certain number of control objects (product units) in the total volume of a batch (in a flow) of products or in the volume of work performed.
The possibility of using effective sampling control is established based on the results of statistical analysis of accuracy according to GOST 23615-79.
4.2. For control, random samples are formed in accordance with the requirements of GOST 18321-73.
When monitoring the accuracy of marking work and installation of elements, the sample is made up of a certain number of landmarks fixed in nature or installed elements from their total number, included in the volume of construction and installation work accepted for the batch.
4.3. When monitoring by an alternative criterion, the control standards are maximum deviations and (or and ) and acceptance and rejection numbers and , characterizing the maximum number of defective units in the sample.
A one-stage or two-stage control method can be adopted, which are equivalent in terms of the resulting assessment.
In this case, control plans are established in accordance with Appendix 2, depending on the production conditions and the acceptance level of defects adopted for a given controlled parameter, taking into account Appendix 3.
In justified cases, the use of other control plans in accordance with GOST 18242-72* is allowed.
________________
* GOST R 50779.71-99 is in force on the territory of the Russian Federation (hereinafter).
(Changed edition, Amendment No. 1).
4.4. When monitoring by an alternative criterion, the number of defective control objects (product units) in the sample is determined by its continuous control in accordance with Section 3.
4.5. The batch is accepted if the number of defective control objects in the sample is less than or equal to the acceptance number, and is not accepted if this number is greater than or equal to the rejection number.
With two-stage inspection, in cases where the number of defective inspection objects in the sample is larger and smaller, a second sample is taken. If the total number of defective units in two samples is less than or equal to the acceptance number, the batch is accepted; if it is greater than or equal to the rejection number, it is not accepted.
(Changed edition, Amendment No. 1).
4.6. When monitoring on a quantitative basis, the control standards are , and tabular coefficients that characterize the relationship between the actual and standard accuracy characteristics acceptable for a given control plan.
Quantitative control rules are prescribed in accordance with GOST 20736-75*.
________________
* GOST R 50779.74-99 is in force on the territory of the Russian Federation (hereinafter).
4.7. Deviations during selective control of batches can be presented for complete control.
5. METHODS AND TOOLS OF MEASUREMENT
5.1. The methods and measuring instruments used to control accuracy must ensure the necessary accuracy and reliability of these measurements and are assigned in accordance with the characteristics of the object of control and the controlled parameter, taking into account their labor intensity and cost.
5.2. The accuracy of control measurements must meet the condition
Limit value of absolute measurement error;
- tolerance of the controlled parameter.
(Changed edition, Amendment No. 1).
5.3. When calculating the maximum error values, random and irremovable systematic errors of the method and measuring instruments are taken into account.
5.4. A method for taking into account the additional risk of incorrect assessment of control results caused by measurement errors is given in Appendix 4.
(Changed edition, Amendment No. 1).
5.5, 5.6. (Excluded, Amendment No. 1).
5.7. The means used, as well as measurement techniques, must be certified by the state or departmental metrological service in accordance with the requirements of the standards of the State System for Ensuring the Uniformity of Measurements.
APPENDIX 1 (recommended). TYPES, METHODS AND OBJECTS OF CONTROL BY PRODUCTION STAGE
Type of control | Production stage | Object of control | Control method |
1. Incoming control | Manufacturing of elements | Project documentation | |
Products, parts and semi-finished products entering production | |||
Working bodies and control devices of equipment and accessories | Solid |
||
Construction and installation work (when organizing work for each subsequent stage) | Project documentation | ||
Landmarks of alignment axes, marks of the bottom of the pit, elements of building structures after completion of the work of the previous stage | Selective by alternative or quantitative characteristics |
||
Elements of prefabricated structures of buildings and structures arriving at the construction site. | |||
Accessories and mounting equipment | Solid |
||
2. Operational control | Manufacturing of elements | Results of technological operations that affect the accuracy of the geometric parameters of the finished product | Selective based on quantitative or alternative characteristics; if necessary - continuous |
Technological equipment, molds and accessories | Continuous or selective |
||
Landmarks for laying out points and axes, elevations of reference planes and installation landmarks | Selective by quantitative or alternative characteristics or continuous |
||
Elements of prefabricated structures during installation and temporary fastening | Solid |
||
Equipment used to install elements | Solid |
||
3. Acceptance control | Manufacturing of elements | Elements of prefabricated structures after completion of the manufacturing cycle | Continuous or selective according to alternative or quantitative characteristics |
Construction and installation work (in the process of performing work at a certain stage) | Landmarks of alignment axes, elevations of reference planes and installation landmarks | Selective by alternative criterion |
|
Elements of prefabricated structures after permanent fastening, as well as their mating | Selective on an alternative basis; in some cases - continuous |
APPENDIX 1. (Changed edition, Amendment No. 1).
APPENDIX 1a (for reference). Information data on compliance with GOST 23616-79 ST SEV 4234-83
APPENDIX 1a
Information
Clause of this standard | Clause ST SEV 4234-83 |
5.2; 5.3 and 5.4 | |
Annex 1 | Annex 1 |
APPENDIX 2 (recommended). ALTERNATIVE SAMPLING PLANS
1 Single stage control
Notes:
The part of the plan, including the sample size, that is located under the arrow is applied.
The part of the plan, including the sample size, that is located above the arrow is applied.
3. The acceptance number is located on the left, the rejection number is on the right.
2 Two-stage control
Notes:
1. - that part of the plan, including the sample size, which is located under the arrow, is applied.
2. - that part of the plan, including the sample size, which is located above the arrow, is applied.
3. Acceptance numbers are located on the left, and rejection numbers are located on the right.
Acceptance level of defects, % | Application area |
Parameters that are components or results when calculating the accuracy of structures in accordance with GOST 21780-83 and ensure the reliability of the structure in operation, the accuracy of which is subject to increased requirements. Violation of the requirements for the accuracy of such parameters is a critical defect |
|
Parameters that are components or results when calculating the accuracy of structures according to GOST 21780-83, as well as affecting the operational properties of the test object. Violation of the requirements for the accuracy of the specified parameters is a significant defect |
|
Parameters that are not included in the initial equations when calculating the accuracy of structures according to GOST 21780-83 or are adjusted locally. Violation of the requirements for the accuracy of the specified parameters is a minor defect |
APPENDICES 2, 3. (Changed edition, Amendment No. 1).
APPENDIX 4 (for reference). METHOD FOR ACCOUNTING THE ADDITIONAL RISK OF INCORRECT EVALUATION OF CONTROL RESULTS CAUSED BY MEASUREMENT ERROR
APPENDIX 4
Information
1. When assigning accuracy and choosing measurement tools, it should be taken into account that measurement errors increase the risk of incorrect assessment of control results. At the same time, the probability of rejecting a suitable control object or accepting a defective object as suitable increases.
2. If it is necessary to maintain the standard values of the specified risk adopted in control plans in accordance with GOST 18242-72 and GOST 20736-75, when assigning sampling plans, the sample volume can be increased.
The table shows the values of the increased sample size, calculated for the normal distribution of the controlled parameter and the measurement error according to the formula
where is the sample size according to the control plan;
- standard deviation of the measured geometric parameter;
- mean square measurement error.
The criteria for assessing control results for an increased sample size are adopted according to the control plan for the sample.
Maximum measurement error in fractions of the technological tolerance of the controlled parameter | Increased sample size at acceptance level of defects, % |
|||
GOST 21780-83
(ST SEV 3740-82)
UDC 69.001.2:006.354 Group Zh02
STATE STANDARD OF THE USSR UNION
System for ensuring geometric accuracy
parameters in construction
ACCURACY CALCULATION
System of ensuring the accuracy of geometrical
parameters in construction. Accuracy calculation
Date of introduction 1984-01-31
APPROVED AND ENTERED INTO EFFECT by Resolution of the USSR State Committee for Construction Affairs dated December 13, 1983 No. 320
INSTEAD GOST 21780-76
REISSUE. February 1985
This standard applies to the design of buildings, structures and their elements and establishes general provisions, methodological principles and the procedure for calculating the accuracy of geometric parameters in construction.
Based on this standard, methodological documents are being developed that establish the features of calculating the accuracy of the geometric parameters of structures of various types.
The standard complies with ST SEV 3740-82 in the part specified in reference Appendix 1.
The terms used in this standard and explanations are given in mandatory Appendix 2.
1. BASIC CONCEPTS
1.1. Calculation of the accuracy of geometric parameters must be carried out in the process of designing standard, experimental and individual structures of buildings and structures and their elements in order to ensure the assembly of structures with specified operational properties at the lowest cost.
1.2. Accuracy is calculated based on:
functional requirements for building structures of buildings and structures;
data on the accuracy of the applied technological processes and operations for manufacturing elements, laying out axes and assembling structures.
1.3. In the process of calculating the accuracy in accordance with the adopted design scheme, based on the accuracy characteristics of the component geometric parameters, the calculated limit values of the resulting parameter are determined, which are then compared with the permissible limit values of this parameter established on the basis of functional requirements (by calculating strength and stability, in accordance with test results or based on insulation, aesthetic and other requirements).
1.4. Compliance of the accuracy of the resulting parameter with the functional requirements is ensured if the following conditions are met:
where and are the calculated limit values of the resulting parameter;
And - permissible limit values of the resulting parameter. The difference is the functional tolerance.
1.5. The task of calculating accuracy can be:
direct, when the calculated limit values of the resulting parameter are determined based on the known accuracy characteristics of the component parameters (test calculation);
reverse, when the necessary requirements for the accuracy of the component parameters are determined based on the established permissible limit values of the resulting parameter.
1.6. According to the accuracy calculation results:
in the regulatory and technical documentation for the building structures of buildings, structures and their elements and in the working drawings, the nominal values of the resulting and component parameters are specified, if necessary, the requirements for the accuracy of these parameters and the rules for accuracy control are established;
in the technological documentation for the manufacture of elements, the layout of axes and the performance of construction and installation work, they establish the methods and sequence of performing technological processes and operations, methods and means of ensuring their accuracy.
2. METHODOLOGICAL PRINCIPLES FOR CALCULATING ACCURACY
2.1. The decisions made as a result of calculating the accuracy should ensure minimal labor and material costs during the construction of building structures of buildings and structures and the manufacture of their elements.
For this purpose, the maximum possible tolerance values should be provided, as well as design and technological measures to reduce the influence of the accuracy of technological processes and operations on the accuracy of the resulting parameters.
2.2. Accuracy calculations should be made, as a rule, based on the condition of complete assembly of structures.
In some cases, if technically feasible and economically feasible, incomplete collection may be provided. In this case, for cases where the actual values of the resulting parameter will go beyond the limits, additional operations must be provided for selecting elements or adjusting individual sizes.
2.3. The initial equation for calculating accuracy is equation (3), which expresses the relationship between the resulting and component parameters included in the calculation scheme:
, (3)
where is the resulting parameter;
Component parameter;
The number of component parameters in the design scheme;
As a rule, the resulting parameters in the preparation of design diagrams are the dimensions at the interface nodes of the elements and other dimensions with which, in the accepted sequence of assembly of the structure, a certain cycle of technological operations is completed that determines the accuracy of the component parameters, and in which the errors of these operations are compensated (recommended Appendix 3 ).
The constituent parameters are considered to be the dimensions of the elements, the dimensions that determine the distances between axes, elevations and other landmarks, as well as other parameters obtained as a result of performing the specified technological operations, the accuracy of which affects the accuracy of the resulting parameter.
If the component geometric parameters are statistically dependent, then when determining the calculated characteristics of the accuracy of the resulting parameter, this dependence must be taken into account. Statistical dependence can be characterized by a correlation coefficient.
2.4. Accuracy is calculated based on statistical methods. In the general case, during statistical calculations, the calculated limit values of the resulting parameter and for checking conditions (1) and (2) are determined using the following accuracy equations:
where is the nominal value of the resulting parameter;
Systematic deviation of the resulting parameter;
Standard deviation of the resulting parameter;
And - values of a standardized random variable, depending on the permissible probability of occurrence of values of the resulting parameter below and above .
The resulting parameter according to statistical characteristics using equations 4 and 5 is produced in accordance with the mandatory Appendix 4.
2.5. In most practical cases, the calculation of accuracy should be carried out according to tolerances using a simplified statistical method, the use of which makes it possible to ensure complete assembleability of the structure when using acceptance control plans for the accuracy of component parameters established by current standards with an acceptance level of defects of 4% according to GOST 23616-79.
In this case, the accuracy equations for determining the calculated limit values of the resulting parameter take the form:
, (6)
, (7)
where is the nominal value of the resulting parameter;
Estimated deviation of the middle of the tolerance field of the resulting parameter;
The calculated tolerance of the resulting parameter.
2.6. The nominal values and calculated characteristics of the accuracy of the resulting parameter with statistically independent component parameters are determined on the basis of the original equation (3) using the following formulas:
, (8)
, (9)
, (10)
where are the nominal values of the component parameters;
Deviations of the midpoints of the technological tolerance fields of the component parameters;
Technological tolerances of component parameters.
2.7. If the number of component parameters is small (up to three) and there is no data on the statistical characteristics of their distribution, accuracy calculations can be performed using the “minimum-maximum” method in accordance with mandatory Appendix 5.
3. PROCEDURE FOR CALCULATING ACCURACY
3.1. To calculate the accuracy in accordance with clause 2.2, the resulting geometric parameters are identified, the accuracy of which determines the fulfillment of the functional requirements for the building structures of the building and structure, and in accordance with clause 1.3 the permissible limit values of these parameters are determined.
In this case, those of the same type of repeating parameters whose calculated accuracy characteristics can obtain the greatest absolute value are selected for calculation.
3.2. For each of the selected resulting parameters, in accordance with the designed technology and the sequence of alignment and assembly work, a base is established that serves as the beginning of a certain cycle of technological operations and is the beginning of the accumulation of errors that must be compensated by this parameter, the constituent parameters are identified and a design diagram and initial equation are drawn up .
3.3. For each design scheme, a calculation method is selected and accuracy equations are drawn up, as well as equations for determining the nominal size and accuracy characteristics of the resulting parameter.
The accuracy characteristics of the component parameters resulting from a certain technological process or operation are accepted based on the requirements of the relevant standards or assigned according to GOST 21779-82. In cases where a component parameter is the result of several technological processes or operations, its accuracy characteristics should be determined using calculation.
When drawing up equations to determine the accuracy characteristics of the resulting parameter, one should also take into account the own deviations of the component parameters that arise during the installation and operation of structures as a result of temperature and other external influences.
3.4. Depending on the type of problem, accuracy equations are solved using trial calculations based on the condition of fulfilling requirements (1) and (2).
In the direct problem, based on the accepted accuracy characteristics and nominal values of the component parameters, the calculated nominal and limiting values of the resulting parameter are determined and the accuracy conditions are checked.
In the inverse problem, based on accuracy conditions, the nominal values and accuracy characteristics of some component parameters are determined from the permissible limit and nominal values of the resulting parameter.
3.5. If, as a result of the calculation, it is established that the accepted design decisions, production technology and other initial data do not meet the accuracy conditions, then, depending on the technical feasibility and economic feasibility, one of the following decisions should be made:
increase the accuracy of the component parameters that have the greatest impact on the accuracy of the resulting parameter through the introduction of more advanced technological processes;
reduce the influence of component parameters on the accuracy of the resulting parameter by reducing the number of these parameters in the design scheme by changing the method of orientation (base) and the sequence of technological processes and operations;
revise design solutions for components of building structures of buildings, structures and their elements in order to change the permissible limit and nominal values of the resulting parameter;
provide for incomplete assembly of structures.
ANNEX 1
Information
COMPLIANCE INFORMATION
GOST 21780-83 ST SEV 3740-82
The first paragraph of the introductory part of GOST 21780-83 corresponds to the introductory part of ST SEV 3740-82.
Clause 1.1 of GOST 21780-83 includes the requirements of clause 1.1 of ST SEV 3740-82.
Clause 1.2 of GOST 21780-83 corresponds to clause 1.2 of ST SEV 3740-82.
Clause 1.4 of GOST 21780-83 corresponds to clause 1.4 of ST SEV 3740-82.
Clause 1.5 of GOST 21780-83 corresponds to clause 3.4 of ST SEV 3740-82.
Clause 1.6 of GOST 21780-83 corresponds to clause 1.5 of ST SEV 3740-82.
The first paragraph of clause 2.1 of GOST 21780-83 corresponds to clause 1.6 of ST SEV 3740-82.
Clause 2.3 GOST 21780-83 includes the requirements of clauses. 2.4 and 2.10 ST SEV 3740-82.
Clause 2.4 GOST 21780-83 includes the requirements of paragraphs. 1.7 and 2.3 ST SEV 3740-82.
Clause 2.5 GOST 21780-83 includes the requirements of clauses. 2.6 and 2.7 ST SEV 3740-82.
Clause 2.6 of GOST 21780-83 includes the requirements of clause 2.8 of ST SEV 3740-82.
Clause 2.7 of GOST 21780-83 includes the requirements of clause 1.7 of ST SEV 3740-82.
Clause 3.1 of GOST 21780-83 includes the requirements of clause 3.1 of ST SEV 3740-82.
Clause 3.2 GOST 21780-83 includes the requirements of clauses. 2.1 and 3.2 ST SEV 3740-82.
Clause 3.3 of GOST 21780-83 includes the requirements of clause 3.3 of ST SEV 3740-82.
Clause 3.5 of GOST 21780-83 corresponds to clause 3.5 of ST SEV 3740-82.
Mandatory appendix 2 GOST 21780-83 includes information appendix 1 ST SEV 3740-82.
Mandatory Appendix 4 of GOST 21780-83 includes the requirements of clause 2.4 of ST SEV 3740-82.
Mandatory Appendix 5 of GOST 21780-83 includes the requirements of clause 2.11 of ST SEV 3740-82.
APPENDIX 2
Mandatory
TERMS AND THEIR EXPLANATIONS
Calculation scheme- a graphic representation of the relationships between the resulting and component geometric parameters, which take into account the structural and technological features of buildings, structures and their elements, including the methods and sequence of technological processes and operations.
Component parameter- a parameter obtained directly during the execution of a certain technological process or operation and included in the calculation scheme.
Resulting parameter- a parameter included in the design scheme and depending on a number of constituent parameters.
Collectability- GOST 21778-81.
Full collection- collection rate, the level of which is equal to or exceeds 99.73%.
Incomplete collection- collection rate, the level of which is below 99.73%.
Base- a surface or axis relative to which the position of other surfaces or axes is determined.
MAIN TYPES OF RESULTING PARAMETERS
Name of the result controlling parameter |
Designation |
|
1. Gap between elements |
Nominal value of the gap; ; - permissible maximum clearance values; Functional clearance tolerance |
|
2. Depth of element support |
|
Nominal value of support depth; ; - permissible limit values of support depth; Functional tolerance of support depth |
3. Misalignment elements |
Rated misalignment value; ; - permissible limit values of misalignment; Functional alignment tolerance |
|
4. Mismatch surfaces elements |
Nominal value of surface mismatch; ; - permissible limit values of surface mismatch; Functional surface matching tolerance |
|
5. Non-verticality |
Nominal value of non-verticality; ; - permissible limit values of non-verticality; Functional vertical tolerance |
Note: When considering the parameters characterizing the position of the elements, it should be taken into account that =0, a and are equal in absolute value and determine the maximum deviation of the elements relative to each other. The min and max indices are taken conditionally to indicate the direction of the shift.
APPENDIX 4
Mandatory
DETERMINATION OF DESIGN LIMIT VALUES
RESULTING PARAMETER BY STATISTICAL CHARACTERISTICS
(General case of statistical accuracy calculation)
1. In the general case of statistical calculation of the accuracy of structures and elements of buildings and structures, the calculated limit values of the resulting parameter for checking conditions (1) and (2) are determined using formulas (4) and (5) of this standard.
2. The calculated nominal value of the resulting parameter based on the original equation (3) is determined by formula (8) of this standard, and the calculated characteristics of accuracy and - by the formulas:
, (1)
where are systematic deviations of the component parameters;
Mean square deviations of the component parameters.
3. Characteristics and, depending on the initial data available for calculation, should be determined based on the results of a statistical analysis of the accuracy of the relevant technological processes and operations in accordance with GOST 23615-79 or according to the accuracy characteristics and control plans established in the relevant standards or other regulatory and technical documents.
4. To move from accuracy characteristics and control plans established in standards and other regulatory and technical documents to statistical accuracy characteristics, the following expressions are used:
, (3)
, (4)
where is the deviation of the middle of the technological tolerance field of the component parameter;
Technological tolerance of the component parameter;
The value of a standardized random variable characterizing the acceptance level of defects in a plan for monitoring the accuracy of a component parameter according to GOST 23616-79.
5. The values of quantities: and in equations (4) and (5) of this standard, as well as the values for each component parameter, are determined according to Table 1, depending, respectively, on the level of collectability and acceptance level of defects adopted in the calculation of the established plan for monitoring the accuracy of the component parameter.
Table 1
Level of assembly of the structure, % |
||||
Acceptance level of defects, % |
||||
Meaning |
6. The share of assembly work that requires additional operations to select elements or adjust individual parameters is determined separately for cases when and according to Table 2.
table 2
APPENDIX 5
Mandatory
DETERMINATION OF DESIGN LIMIT VALUES
RESULTING PARAMETER BY METHOD
"MINIMUM - MAXIMUM"
The calculated limit values and the resulting parameter in conditions (1) and (2) using the “minimum-maximum” method are determined using the formulas of this standard
, (1)
where is the calculated nominal value of the resulting parameter, determined by formula (8) of this standard;
Estimated deviation of the middle of the tolerance field of the resulting parameter, determined by formula (9) of this standard;
The calculated tolerance value of the resulting parameter.
The calculated tolerance value of the resulting parameter is determined taking into account the most unfavorable combination of deviations of the component parameters according to the formula compiled on the basis of the original equation (3) of this standard
, (3)
where is the tolerance of the component parameter;
A coefficient characterizing the geometric dependence of the resulting parameter on the component parameter.
SYSTEM FOR ENSURING ACCURACY OF GEOMETRICAL PARAMETERS IN CONSTRUCTION
(ST SEV 3740-82)
USSR STATE COMMITTEE FOR CONSTRUCTION
STATE STANDARD OF THE USSR UNION
By Decree of the USSR State Committee for Construction Affairs dated December 13, 1983 No. 320, the introduction date was established
This standard applies to the design of buildings, structures and their elements and establishes general provisions, methodological principles and the procedure for calculating the accuracy of geometric parameters in construction.
Based on this standard, methodological documents are being developed that establish the features of calculating the accuracy of the geometric parameters of structures of various types.
The standard complies with ST SEV 3740-82 in the part specified in reference Appendix 1.
The terms used in this standard and explanations are given in mandatory Appendix 2.
1. BASIC CONCEPTS
1.1. Calculation of the accuracy of geometric parameters must be carried out in the process of designing standard, experimental and individual structures of buildings and structures and their elements in order to ensure the assembly of structures with specified operational properties at the lowest cost.
1.2. Accuracy is calculated based on:
functional requirements for building structures of buildings and structures;
data on the accuracy of the applied technological processes and operations for manufacturing elements, laying out axes and assembling structures.
1.3. In the process of calculating the accuracy in accordance with the adopted design scheme, based on the accuracy characteristics of the component geometric parameters, the calculated limit values of the resulting parameter are determined, which are then compared with the permissible limit values of this parameter established on the basis of functional requirements (by calculating strength and stability, in accordance with test results or based on insulation, aesthetic and other requirements).
1.4. Compliance of the accuracy of the resulting parameter with the functional requirements is ensured if the following conditions are met:
where and are the calculated limit values of the resulting parameter x;
and - permissible limit values of the resulting parameter x. The difference constitutes the functional tolerance.
1.5. The task of calculating accuracy can be:
direct, when the calculated limit values of the resulting parameter are determined based on the known accuracy characteristics of the component parameters (test calculation);
reverse, when the necessary requirements for the accuracy of the component parameters are determined based on the established permissible limit values of the resulting parameter.
1.6. According to the accuracy calculation results:
in the regulatory and technical documentation for the building structures of buildings, structures and their elements and in the working drawings, the nominal values of the resulting and component parameters are specified, if necessary, the requirements for the accuracy of these parameters and the rules for accuracy control are established;
in the technological documentation for the manufacture of elements, the layout of axes and the performance of construction and installation work, they establish the methods and sequence of performing technological processes and operations, methods and means of ensuring their accuracy.
2. METHODOLOGICAL PRINCIPLES FOR CALCULATING ACCURACY
2.1. The decisions made as a result of calculating the accuracy should ensure minimal labor and material costs during the construction of building structures of buildings and structures and the manufacture of their elements.
For this purpose, the maximum possible tolerance values should be provided, as well as design and technological measures to reduce the influence of the accuracy of technological processes and operations on the accuracy of the resulting parameters.
2.2. Accuracy calculations should be made, as a rule, based on the condition of complete assembly of structures.
In some cases, if technically feasible and economically feasible, incomplete collection may be provided. In this case, for cases where the actual values of the resulting parameter will go beyond the limits, additional operations must be provided for selecting elements or adjusting individual sizes.
2.3. The initial equation for calculating accuracy is equation (3), which expresses the relationship between the resulting and component parameters included in the calculation scheme:
where is the resulting parameter;
Component parameter;
The number of component parameters in the design scheme;
A coefficient characterizing the geometric dependence of the resulting parameter x on the component parameter xk.
As a rule, the resulting parameters in the preparation of design diagrams are the dimensions at the interface nodes of the elements and other dimensions with which, in the accepted sequence of assembly of the structure, a certain cycle of technological operations is completed that determines the accuracy of the component parameters, and in which the errors of these operations are compensated (recommended Appendix 3 ).
The constituent parameters are considered to be the dimensions of the elements, the dimensions that determine the distances between axes, elevations and other landmarks, as well as other parameters obtained as a result of performing the specified technological operations, the accuracy of which affects the accuracy of the resulting parameter.
If the component geometric parameters are statistically dependent, then when determining the calculated characteristics of the accuracy of the resulting parameter, this dependence must be taken into account. Statistical dependence can be characterized by a correlation coefficient.
2.4. Accuracy is calculated based on statistical methods. In the general case, during statistical calculations, the calculated limit values of the resulting parameter and for checking conditions (1) and (2) are determined using the following accuracy equations
where is the nominal value of the resulting parameter x;
Systematic deviation of the resulting parameter x;
The standard deviation of the resulting parameter x;
and are the values of a standardized random variable, depending on the permissible probability of the occurrence of values of the resulting parameter below and.
Determination of the calculated limit values of the resulting parameter based on statistical characteristics using equations 4 and 5 is carried out in accordance with the mandatory Appendix 4.
2.5. In most practical cases, calculation of accuracy should be carried out according to tolerances using a simplified statistical method, the use of which makes it possible to ensure complete assembly of the structure when using acceptance control plans for the accuracy of component parameters established by current standards with an acceptance level of defects of 4% according to GOST 23616-79.
In this case, the accuracy equations for determining the calculated limit values of the resulting parameter take the form:
where is the nominal value of the resulting parameter;
Estimated deviation of the middle of the tolerance field of the resulting parameter;
The calculated tolerance of the resulting parameter.
2.6. The nominal values and calculated characteristics of the accuracy of the resulting parameter with statistically independent component parameters are determined on the basis of the original equation (3) using the following formulas:
where are the nominal values of the component parameters;
Deviations of the midpoints of the technological tolerance fields of the component parameters;
Technological tolerances of component parameters.
2.7. If there is a small number of component parameters (up to three) and there is no data on the statistical characteristics of their distribution, accuracy calculations can be performed using the “minimum-maximum” method in accordance with mandatory Appendix 5.
3. PROCEDURE FOR CALCULATING ACCURACY
3.1. To calculate the accuracy in accordance with clause 2.2, the resulting geometric parameters are identified, the accuracy of which determines the fulfillment of the functional requirements for the building structures of the building and structure, and in accordance with clause 1.3 the permissible limit values of these parameters are determined.
In this case, those of the same type of repeating parameters whose calculated accuracy characteristics can obtain the greatest absolute value are selected for calculation.
3.2. For each of the selected resulting parameters, in accordance with the designed technology and the sequence of alignment and assembly work, a base is established that serves as the beginning of a certain cycle of technological operations and is the beginning of the accumulation of errors that must be compensated by this parameter, the constituent parameters are identified and a design diagram and initial equation are drawn up .
3.3. For each design scheme, a calculation method is selected and accuracy equations are drawn up, as well as equations for determining the nominal size and accuracy characteristics of the resulting parameter.
The accuracy characteristics of the component parameters resulting from a certain technological process or operation are adopted based on the requirements of the relevant standards or are assigned according to. In cases where a component parameter is the result of several technological processes or operations, its accuracy characteristics should be determined using calculation.
When drawing up equations to determine the accuracy characteristics of the resulting parameter, one should also take into account the own deviations of the component parameters that arise during the installation and operation of structures as a result of temperature and other external influences.
3.4. Depending on the type of problem, accuracy equations are solved using trial calculations based on the condition of fulfilling requirements (1) and (2).
In the direct problem, based on the accepted accuracy characteristics and nominal values of the component parameters, the calculated nominal and limiting values of the resulting parameter are determined and the accuracy conditions are checked.
In the inverse problem, based on accuracy conditions, the nominal values and accuracy characteristics of some component parameters are determined from the permissible limit and nominal values of the resulting parameter.
3.5. If, as a result of the calculation, it is established that the accepted design decisions, production technology and other initial data do not meet the accuracy conditions, then, depending on the technical feasibility and economic feasibility, one of the following decisions should be made:
increase the accuracy of the component parameters that have the greatest impact on the accuracy of the resulting parameter through the introduction of more advanced technological processes;
reduce the influence of component parameters on the accuracy of the resulting parameter by reducing the number of these parameters in the design scheme by changing the method of orientation (base) and the sequence of technological processes and operations;
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1INTERSTATE STANDARD
System for ensuring the accuracy of geometric parameters in construction
RULES FOR MEASUREMENT OF PARAMETERS OF BUILDINGS AND STRUCTURES
System of ensuring geometric parameters accuracy in building. Rules for measuring parameters of buildings and works
OKS 91.040 OKSTU 2009 Date of introduction 1996-01-01
Preface
1 DEVELOPED by the St. Petersburg Zonal Research and Design Institute of Housing and Civil Buildings (SPb ZNIPI)
INTRODUCED by the Main Directorate of Standardization, Technical Standardization and Certification of the Ministry of Construction of Russia
2 ADOPTED by the Interstate Scientific and Technical Commission on Standardization and Technical Regulation in Construction on November 17, 1994
3 ENTERED INTO EFFECT from 01/01/96 as a state standard of the Russian Federation by Resolution of the Ministry of Construction of Russia dated 04/20/95 No. 18-38
4 INTRODUCED FOR THE FIRST TIME
Application area
This standard establishes the basic rules for measuring geometric parameters during the performance and acceptance of construction and installation work completed by the construction of buildings, structures and their parts. The range of parameters measured in accordance with this standard is defined by GOST 21779 and GOST 26607.
Normative references
This standard uses references to the following standards: GOST 427-75 Metal measuring rulers. Technical specifications GOST 3749-77 Test squares 90°. Technical specifications GOST 5378-88 Goniometers with vernier. Technical specifications GOST 7502-89 Metal measuring tapes Technical specifications GOST 7948-80 Steel construction plumbs. Technical specifications GOST 9389-75 Carbon steel spring wire. Technical specifications GOST 10528-90 Levels. General technical conditions GOST 10529-86 Theodolites. General technical conditions GOST 17435-72 Drawing rulers. Technical specifications GOST 19223-90 Geodetic rangefinders. General technical conditions GOST 21779-82 System for ensuring the accuracy of geometric parameters in construction. Technological tolerances GOST 26433.0-85 System for ensuring the accuracy of geometric parameters in construction. Rules for performing measurements. General provisions GOST 26433.1-89 System for ensuring the accuracy of geometric parameters in construction. Rules for performing measurements. Factory-made elements GOST 26607-85 System for ensuring the accuracy of geometric parameters in construction. Functional tolerances
Designations
Requirements
4.1 General requirements for the selection of methods and measuring instruments, performing measurements and processing their results - in accordance with GOST 26433.0.
4.2 Measurements are carried out in accordance with the diagrams given in Appendix A. Direct measurements of the parameter are preferred. If direct measurement is impossible or ineffective, indirect measurement is performed. In this case, the value of the parameter is determined from the given dependencies based on the results of direct measurements of other parameters. When taking measurements using geodetic instruments, one should take into account methods certified in the prescribed manner.
4.3 To measure linear dimensions and their deviations, rulers in accordance with GOST 427 and GOST 17435, tape measures in accordance with GOST 7502, light range finders in accordance with GOST 19223 and other special measuring instruments certified in the prescribed manner are used.
4.4 To measure horizontal and vertical angles, theodolites are used in accordance with GOST 10529, for measuring vertical angles - optical quadrants according to the current NTD, and for measuring angles between the faces and edges of building structures and their elements - inclinometers in accordance with GOST 5378 and calibration squares in accordance with GOST 3749.
4.5 To measure elevations between points, levels in accordance with GOST 10528 and hydrostatic altimeters are used.
4.6 To measure deviations from verticality, plumb lines in accordance with GOST 7948 and theodolites are used together with linear measuring instruments, as well as specially manufactured equipment certified in the prescribed manner.
4.7 To measure deviations from straightness (openness) and flatness, theodolites, levels, sighting tubes, as well as specially made means (steel strings, marking cord, nylon fishing lines, optical plane meters, laser sighting devices, etc.) are used together with linear measuring instruments.
4.8 The rules for measurements performed with caliper tools, bore gauges, staples, gauges, dial indicators, probes, microscopes are adopted in accordance with GOST 26433.1.
4.9 Measuring instruments that provide the measurement accuracy required by GOST 26433.0, as well as the values of the maximum errors of measuring instruments that can be used when choosing measurement instruments and methods, are given in Appendix B. Examples of calculating measurement accuracy, choosing methods and means of ensuring it are given in Appendix IN.
4.10 Locations for measuring geometric parameters for operational control during construction and installation work and acceptance control of completed stages or finished buildings and structures are accepted in accordance with the design and technological documentation. In the absence of instructions in the design and technological documentation, measurement locations are taken according to this standard.
4.11 Dimensions of rooms - length, width, height are measured in extreme sections drawn at a distance of 50-100 mm from the edges and in the middle section with the dimensions of the rooms being St. 3 m no more than 12 m. With dimensions of St. 12 m between the extreme sections, measurements are carried out in additional sections.
4.12 Deviations from the flatness of the surfaces of structures and deviations from the plane of the installation horizon are measured at points marked on the controlled surface along a rectangular grid or grid of squares with a step of 0.5 to 3 m. In this case, the extreme points should be located 50-100 mm from the edge of the controlled surfaces.
4.13 Deviations from straightness are determined by the results of measuring the distances of the real line from the base line at three points, marked at distances of 50-100 mm from its edges and in the middle, or at points marked with a pitch specified in the project.
4.14 Deviation from verticality is determined by measuring the distance from the plumb base line to two points of the structure, marked in one vertical section at distances of 50-100 mm from the top and bottom edges of the structure. The verticality of columns and tower-type structures is controlled in two mutually perpendicular sections, and the verticality of walls is controlled in the extreme sections, as well as in additional sections, depending on the design features.
4.15 Measurements of gaps, ledges, depth of support, eccentricities are carried out in characteristic places that affect the operation of butt joints.
4.16 Measurement of the deviation of structural elements, as well as buildings and structures from a given position in plan and height, is carried out at points located in the extreme sections or at distances of 50-100 mm from the edge.
4.17 Geodetic points of alignment networks and landmarks of axes are fixed on the ground and on building structures with signs that ensure the required accuracy of alignment work and the safety of landmarks during construction and operation (if necessary).
4.18 Depending on the material, dimensions, features of the geometric shape and purpose of buildings and structures, means not provided for by this standard may also be used to ensure the required measurement accuracy in accordance with GOST 26433.0.
1 area of use
3 Designations
1 Basic means of ensuring the accuracy of alignment work
2 Errors of the main methods and means of measuring deviations from the alignment axis or alignment
3 Errors of basic methods and instruments for measuring deviations from a plumb line
4 Errors of the main methods and instruments for measuring deviations from design elevations and a given slope
The choice of measuring instruments for specific measurement purposes is determined by many factors. The selection task can be either very simple or quite complex, when it is necessary to check whether the properties of a measuring instrument meet the requirements for speed, reliability, degree of protection from certain influences, etc.
But the main requirement is, as a rule, security required measurement accuracy.
To justify this requirement, it is necessary to know the purpose of the measurement. There are two such goals. They have the following fundamental differences:
Determination of the actual size of the measured value in given units;
Determination of compliance of the measured quantity with the prescribed (nominal) size, for which permissible maximum deviations are specified.
In the first case, the measured value is assigned a size, the reliability of which is completely determined by the error that occurred at the time of measurement. The permissible error is assigned based on specific sizing tasks.
For example, when manually finishing a part to a given geometric size, a worker controls this size using a caliper and stops finishing when the strokes corresponding to the given size completely coincide. The choice of calipers is determined by the fact that the maximum measurement error is less than or equal to the specified tolerance.
In the second case, using measurement, it is checked whether the size of the measured value is within a given interval (in the tolerance zone), for example, during acceptance inspection of products based on geometric dimensions. In this case, changing (correcting) the size during the measurement process is impossible. The measurement result is used only to determine suitability.
In this case, the measurement error affects the final acceptance results (“pass” or “defect”) only for those products whose actual dimensions are close to the tolerance limits. An increase in measurement error increases the likelihood that some products will be incorrectly accepted (type 1 error), and some products will be incorrectly rejected (type 2 error).
Accuracy Specifications
Geometric parameter accuracy, which is a random variable, is determined by the accuracy characteristics. In this case, the accuracy of angular values can be characterized by the accuracy of linear sizes , which determine these quantities.
Accuracy Specifications geometric parameters in construction and their relationship are indicated in Figure 1.7.1.
Where x i– actual value of the parameter;
– nominal value of the parameter.
The actual deviation is a quantitative expression of systematic and random errors accumulated during technological operations and measurements.
The accuracy of geometric parameters in standards and other regulatory documents, as well as in working drawings, is characterized by minimum and maximum maximum dimensions, lower And top maximum deviations from the nominal value, admission And deviation middle tolerance fields from the nominal value of the parameter. Half tolerance 
is the maximum deviation of the parameter from the middle of the tolerance field.
The relationship between these accuracy characteristics is determined by the formulas:
| (1.7.2) |
| (1.7.3) |
| (1.7.4) |
| (1.7.5) |
It should be taken into account that the values of the lower and upper limit deviations are substituted into the formulas with their own signs.
Accuracy of a geometric parameter in the totality of its actual values x i, obtained as a result of performing a certain technological process or mass and serial production operation, is determined by statistical characteristics of accuracy.
As statistical characteristics of the accuracy of a geometric parameter, its mean value and standard deviation are used. In necessary cases, with different distribution laws of the parameter, it is allowed to use other statistical characteristics of accuracy.
With a normal distribution of the geometric parameter, the estimates of the characteristics are the sample mean and sample standard deviation, which are calculated using the formulas:
An assessment of systematic deviation, with a normal distribution of a geometric parameter, is the sample mean deviation, i.e. the average value of deviations in the sample, determined by the formula
| , | (1.7.11) |
where t min and t max are the values of a standardized random variable, depending on the probability of occurrence of values below x min and above x max, and the type of statistical distribution of the parameter.
As a rule, the probability of occurrence of values below x min and above x max is assumed to be the same, but not more than 0.05.
Preferred values of a quantity with a normal distribution of a parameter depending on the permissible probability of occurrence of values below x min and above x max, characterized by the acceptance level of defects according to GOST 23616-79, installed GOST 23615-79.
In the case of a symmetrical (for example, normal) distribution of the geometric parameter (Figure 1.7.1 b) and the same probability of occurrence of values x 1 below x min and above x max t min =t max =t, and the relationship between the accuracy characteristics is represented by the formulas:
 | (1.7.16) |
 | (1.7.17) |
 | (1.7.18) |
Precision assignment
The accuracy of geometric parameters at all stages of construction design and production should be established depending on the functional, structural, technological and economic requirements for buildings, structures and their individual elements.
Compliance of the assigned accuracy with functional, design, technological and economic requirements is established by calculating the accuracy in accordance with GOST 21780-83 or other methods.
The accuracy of the geometric parameters should be established by the accuracy characteristics given in paragraph 1. The preferred characteristics are maximum deviations relative to the nominal value of the parameter X, taken, as a rule (at ), equal in absolute value to half the value of the corresponding functional or technological tolerance adopted in calculating the accuracy.
In justified cases, if it is necessary to partially compensate for systematic errors in technological processes and operations that increase over time, the maximum deviations should be set asymmetrical ().
Functional tolerances regulate the accuracy of geometric parameters in mates and the accuracy of the position of elements in structures.
The range of functional tolerances has been established GOST 21780-83, and their specific values are determined by formula (1.7.4), in which x min and x max or and are taken based on the functional (strength, insulation or aesthetic) requirements for structures.
Technological tolerances regulate the accuracy of technological processes and operations for the manufacture and installation of elements, as well as the performance of marking work.
The nomenclature and specific values of technological tolerances for accuracy classes of processes and operations should be taken according to GOST 21779-82.
Accuracy classes are selected when performing accuracy calculations depending on the accepted means of technological support and control of accuracy and production capabilities.
Related information.