GB 50959-2013Load code of nonferrous metals engineering structures (English PDF)

1.0.1 This Code is formulated, in order to meet the needs of non-ferrous metal

engineering construction, AND meet the requirements of industrial buildings and structures, that are safe, applicable, economically reasonable.

1.0.2 This Code is applicable to the structural design of the main works and auxiliary

facilities, for new construction and expansion of non-ferrous metal mining, smelting, processing projects.

1.0.3 The actions, which are involved in the design of non-ferrous metal engineering structures, shall include direct actions (i.e., loads) and indirect actions (including temperature, deformation, etc.). This Code mainly stipulates the direct effect; the relevant provisions also apply to the indirect effect.

1.0.4 All kinds of loads and actions, which are used in non-ferrous metal engineering

structures, shall not only comply with this Code, but also comply with the current relevant national standards.

2.1 Terms

2.1.1 Action

It is divided into direct action and indirect action. The concentrated or distributed force, which is exerted on the structure, is a direct action, that is, a load; the cause of the external deformation or restrained deformation of the structure is an indirect action.

2.1.2 Permanent load

A load, whose value does not change with time, OR whose change is negligible as compared to the average value, OR whose change is monotonic and can approach the limit value, during the service life of the structure.

2.1.3 Variable load

A load, whose value varies with time AND whose variation is not negligible, as compared to the mean, during the service life of the structure.

2.1.4 Accidental load

A load, which does not necessarily occur, during the service life of the structure;

however, once it occurs, its value is large AND has a short duration.

2.1.5 Equivalent uniform live load

A load, whose actual load that is discontinuously distributed is replaced by a uniform load, so that the load effect obtained on the structure can be consistent with the actual load effect.

2.1.6 Working load

Under normal production conditions, the load on the floors and grounds, which is comprehensively generated by operators and their routine tools and appliances, the quantitative materials, semi-finished products, finished products, small mobile conveying devices necessary for production, as temporally stored in the production process.

2.2 Symbols

Gk - The nominal value of permanent load;

Qk - The nominal value of variable load;

SGk - The nominal value of permanent load effect;

SQk - The nominal value of variable load effect;

SAd - The design value of accidental load effect;

Sd - The design value of the load combination effect, in the limit state of the bearing capacity;

Sds - The design value of the load combination effect, in the limit state of normal use;

Rd - The design value of the resistance of the structural member;

C - The specified limits required for normal use, which are reached by the structure or member;

3.1 Classification of loads

3.1.1 The load of non-ferrous metal engineering structure can be divided into three types. permanent load, variable load, accidental load.

3.1.2 The permanent load shall include the weight of various devices, such as equipment, furnace, pipeline, silo, facilities, etc., including the fixed configurations, which meet the production process requirements; the constant weight of materials; the self-weight of components, accessories, protective layers of the building structure; the fixed soil, bulk material, liquid pressure, prestress.

3.1.3 The variable loads shall include the working loads on floor and ground, as well as the loads such as dynamic machines, cranes, storage materials, etc. under normal annual production conditions; the maintenance and installation loads under abnormal production conditions; the load of wind, snow, ash deposits; the temperature actions, deformation actions, frequent earthquake actions.

3.1.4 Accidental loads shall include explosions, impacts, fires, or other huge but short-

term loads, which are caused by accidental accidents, loss of control and other accidental factors, as well as rare earthquake actions.

3.2 Representative values of loads

4.1 General requirement

4.1.1 The structural design of non-ferrous metal engineering shall distinguish the design conditions, according to different production conditions and environmental conditions. The corresponding load combination shall meet the following conditions.

4.1.2 Under permanent design conditions, maintenance and installation loads and accidental loads shall not be involved in the load combination.

4.2 Combination values of load effect

4.2.1 For the engineering structure design, it shall be based on the actual production process, equipment configuration, etc., to carry out load combinations, respectively, under the limit state of bearing capacity and the limit state of normal use of the structure, for the loads, which may occur simultaneously in the process of use; meanwhile it shall adopt each most unfavorable combination. Commonly used load combinations shall be divided into basic combination, nominal combination, quasi-permanent combination, frequent combination, accidental combination.

4.3 Load coefficients

4.3.1 The partial load coefficient of the basic combination shall be adopted, according to the following provisions.

4.3.4 The combination value coefficient, frequent value coefficient, quasi-permanent value coefficient of the variable load of the factory floor and ground can be adopted, according to the actual project. However, in any case, the combination value coefficient shall not be less than 0.70; the frequent value coefficient shall not be less than 0.70; the quasi-permanent value coefficient shall not be less than 0.60.

4.4 Reduction of variable loads

4.4.1 For the floor working load of the factory building, it shall not be reduced, when calculating the primary beam, secondary beam, slab; when calculating the walls, columns, foundations of multi-floor and high-rise factory buildings, it can be reduced, according to the number of floors, OR according to the engineering experience and actual situation.

4.4.3 For the variable load on the ground of the factory building, it can be reduced when it is used for checking and calculating the underground structural components. When the variable load is greater than 5.0 kN/m2 AND the subordinate area is greater than or equal to 50 m2, the reduction coefficient of the load can be taken as 0.80.For the factory floor of non-ferrous metal processing engineering, the reduction of variable load shall comply with the relevant provisions of Appendix C of this Code.

6.1 Variable load on floor and ground

6.1.1 The variable load of the floor can be divided into working load and overhauling load, which should meet the following requirements.

6.1.2 The working loads on the floors of the following areas, in the workshop building, shall be determined, according to the relevant professional load conditions. It should not be less than the following limits.

6.2 Dynamic machine load

6.2.1 When all kinds of machines perform translation, rotation, reciprocating motion or impact operation, for the nominal value or related parameter value of dynamic load, which act on its supporting structure or foundation, the manufacturer shall provide the formal information and data, after ordering the equipment. When it is really difficult, it can be obtained, by approximate calculation.

6.3 Crane load

6.3.1 The vertical load of the crane shall be the maximum wheel pressure value and the minimum wheel pressure value, that occur during the operation of the crane. The standard load value shall be determined, according to the selection and configuration of the crane.

6.3.2 The horizontal load of the crane can be divided into horizontal longitudinal load and horizontal lateral load. The nominal value of its load shall comply with the relevant provisions of the current national standard "Load code for the design of building structures" GB 50009.

6.5 Load of pipeline and equipment

6.5.1 The load of the pipe network shall include the vertical load, that is, the weight of the pipeline and the medium, as well as the weight increased or decreased during the pressure test of the pipeline. It shall also include the horizontal load, such as unbalanced force and frictional force in the pipeline. When the reciprocating and pulsed pumps are used to transport the medium, the dynamic load effect of the pipe network system shall also be calculated. Various loads shall comply with the relevant provisions of the design standards of pipe network.

6.6 Load of storage material

6.7 Other loads

6.7.1 Variable loads, such as roof live load, amassed ash load, wind load, snow load, etc., shall comply with the relevant provisions of the current national standard "Load code for the design of building structures" GB 50009, as well as the relevant added and supplemented provisions, in the area where the project is located.

7.1 Thermal action

7.2 Other actions

7.2.1 Measures shall be taken to avoid large deformation of the foundation, in the engineering design. When abnormal deformation of the foundation occurs and a large secondary stress occurs in the relevant structure, meanwhile its action is unavoidable, the effect of the foundation deformation shall be checked, according to the actual situation. The selection of the deformation action value shall be selected, according to the actual engineering. The relevant check calculation shall comply with the relevant provisions of the current national standard "Code for design of building foundation" GB 50007.

8.1 General requirement

8.1.1 For the engineering structure, when carrying out engineering evaluation of out-of-control of major production operations or unexpected accidents, in accordance with the requirements of current national and industry regulations or approved design documents, it shall use the accidental loads, to calculate the limit bearing capacity of the structure and the overall stability of the engineering structure. The accidental loads of non-ferrous metal engineering shall include the following types.

8.2 Explosion load

8.2.1 The explosion load, which is caused by gas leakage or dust accumulation, should be adopted, according to the equivalent uniform static load. The nominal value of the equivalent uniform static load of structural members can be determined, by the following formula.

8.3 Other loads

8.3.1 For the load value of the accidental impact of the high-speed power production device, when the parameters such as the mass, movement speed, impact time of the impact object are obtained, the nominal value of the maximum impact force shall be calculated as follows.

8.3.2 For large-scale and special production machines and equipment, when short-circuit, sudden stop and other abnormalities or accidents may occur during operation, the parameters, such as load, for checking the supporting structure and components, can be selected from the equipment data.

8.3.3 For engineering structures, such as mine headframes and well towers, the selection of the sudden rope breaking load, the braking load of the anti-falling device, the overwinding load shall comply with the relevant provisions of the current national standard "Code for design of the mine headframes" GB 50385.

9.1 General requirement

9.1.1 Various production process loads, which are used in engineering design, shall

be provided by the process and related majors. The conditions mentioned must be comprehensive, accurate, clear; the load conditions and information shall be formally provided, in words, tables or diagrams.

9.2 Content of load condition

9.2.1 The permanent load value and its name, item and action area of various equipment, devices and facilities, in the production process, shall be provided by the process and related majors. It shall include the following contents.

9.2.2 For the nominal values of variable loads on industrial floors and grounds, processes and related majors shall make selection, according to the actual project;

propose it after comparing and checking with Appendix A ~ Appendix C of this Code.

It shall meet the following requirements.

9.3 Assessment of load condition

9.3.1 The load conditions, which are provided by the process and related majors, shall be reviewed and identified; meanwhile it shall comply with the relevant provisions on the quality management of the design input process in the engineering design.

9.3.2 The engineering structure major shall check the obtained load conditions and data, in terms of content and depth. For major and critical loads or special and abnormal loads, they shall be adopted, after passing the relevant review procedures.

9.4 Other regulations