What is the relationship between the standard value of the load and the design value of the load

The design value of the load is equal to the standard value of the load multiplied by the partial factor of the load.

Examples of live loads: such as live loads on industrial buildings, live loads on floors, live loads on roofs, ash loads on roof surfaces, vehicle loads, crane loads, wind loads, snow loads, ice loads, wave loads, etc.

For the value of common live loads, please refer to:

1. The standard value of the equivalent uniform load of the fire truck: 20kN;

2. Roof garden: 3kN;

3. Venerable roof: 2kn;

4. Live load of construction at the podium level: 4kN;

5. Elevator machine room: 7kn.

m2 20mm thick steel plate in 20mm thick cement mortar.

Layer m2150 mm thick reinforced concrete slab gypsum cast m2Self weight: m2Live load: m2

Standard Value: The basic representative value of the load, which is the characteristic value (e.g., mean, modest, median, or a quantile value) of the statistical distribution of the maximum load during the design base period.

Load Design Value: The product of the load representative value and the load partial factor.

The general load code is the standard value. The actual design calculation usually uses [Design Value].

The design value of the load is equal to the standard value of the load multiplied by the partial factor of the load.

The partial coefficient shall be adopted in accordance with the regulations:

1) Partial factor of permanent load.

When its effects are unfavorable to the structure.

The combination of variable load effect control should be taken;

The combination of the control of the permanent load effect should be taken;

When its effects are structurally favorable.

In general, it should be taken;

The overturning, slippage or floating design of the structure should be taken.

2) Partial factors for variable loads.

In general, it should be taken;

The standard value of the live load of the floor structure of the industrial building with a standard value greater than 4kn m2 should be taken.

The standard value is usually at the time of operation, and only the design responsibility should be designed according to the upper limit of the maximum value.

The design value of the load is equal to the standard value of the load multiplied by the partial factor of the load. This is clearly specified in the load code, and the partial factor for permanent loads is or; Variable loads are or.

So the design value will be larger than the standard value.

The load is quasi-permanent.

The value refers to the part of the load that the variable load often acts on in the structural design reference period t, and its impact on the structure is similar to that of a permanent load, and the ratio of the total duration of reaching and exceeding the quasi-permanent value to the entire design reference period is generally not greater than that.

The quasi-permanent value of the load is actually a reduction of the standard value of the variable load in consideration of the long-term combination of load effects.

The load standard value is the maximum load that can occur under normal conditions during the use of the structural member. Due to the inherent randomness, the maximum load during service is also a random variable. The standard value of the load is determined by a certain sub-position of the probability distribution of the maximum load value during the design reference period.

m2 20mm thick steel plate in 20mm thick cement mortar layer m2150mm thick reinforced concrete slab gypsum cast m2 dead weight: m2 live load: m2

Standard value: the maximum estimate of the force that is likely to occur under normal conditions;

Design value: the force acting after taking into account the necessary safety reserves; The design value of the force is equal to its standard value multiplied by the partial factor.

See 3 2 of the Code for Loads on Building Structures

Load combinations.

What is a Load Design Value? What is a Load Standard Value? What is the relationship between the two? The following is an introduction to the relationship between the load standard value and the design value brought by Zhongda Consulting for reference.

Load Design Value: The product of the load representative value and the load partial factor.

Standard Value: The basic representative value of the load, which is the characteristic value (e.g., mean, modest, median, or a quantile value) of the statistical distribution of the maximum load during the design base period. This concept often appears in the building foundation code, pile foundation code, concrete design code, and the previous national and local code use is a bit confusing, many people can not distinguish the specific use of the design value and the standard value, often according to their own wishes.

We know that any load has different degrees of variability, but in the design, it is impossible to directly refer to various statistical parameters that reflect the variability of the load, and carry out the specific design through complex probability operations, so in addition to adopting the design expression that can be used by the designer, the load should still be given a specified value, that is, the load representative value, and the load can be specified according to different design requirements, so that it can more accurately reflect its characteristics in the design. There are four representative values given in the load code: standard value, combined value, frequency value, and quasi-permanent value.

Standard values should be used as representative values for permanent loads, and standard values, combined values, frequent encounters, and quasi-permanent values should be used as representative values for variable loads according to design requirements. The standard value of the load is the basic representative value of the load, and all other representative values can be multiplied by the corresponding coefficient on the basis of the standard value.

Due to the randomness of the load itself, the maximum load during the use is also a random variable, which can be described by its statistical distribution, according to the provisions of the "Unified Standard for the Design of Building Structure Reliability" (GB50068-2001), the standard value is determined by a certain quantile value of the maximum load probability distribution during the design reference period (but the quantile value is not specified, this is a mathematical statistical concept, which can be simply understood as conforming to the normal distribution), and the design reference period is unified for 50 years. When there is enough information about the load and it is possible to make a reasonable estimate of its statistical distribution, the quantile value is taken as the representative value of the load, and in principle, the eigenvalue of the distribution can be taken. At present, not all loads can be fully informed, according to the engineering practice agreement a nominal value as a representative value, the above two ways to determine the representative value is collectively called the load standard value.

Relationship between the standard and design values of the load:

The value of the load representative value multiplied by the load partial factor is called the load design value.

In the design, the load partial factors are only referenced in the formula for calculating the combined design values of the load effects in terms of the ultimate limit state. Therefore, the load partial factors and design values need to be considered only when designing according to the ultimate limit state of the load. In the serviceability limit state design, when considering the standard combination of loads, the standard values are used for both dead and live loads; When considering load frequency and quasi-permanent combinations, standard values are used for dead loads, and frequencies and quasi-permanent values are used for live loads, or only quasi-permanent values are used.

Load standard value: The basic representative value of the load, which is the characteristic value of the statistical distribution of the maximum load during the design reference period.

For example, mean, mean, median, or a quantile value.

Load Design Value: The product of the load representative value and the load partial factor.

Relation: The design value of the load is equal to the standard value of the load multiplied by the partial factor of the load.

Used for: The standard values are found in the load code.

The actual design calculation usually uses [Design Value].

Extended Information: Application of Loads:

1. Industrial buildings.

During the production, use, maintenance and installation of industrial building floors, the load generated by the weight of equipment, means of transportation, raw materials, finished products and the weight of operators. Heavy objects such as industrial equipment are usually local or concentrated loads, which should be determined according to actual data. However, in order to facilitate the design, the equivalent uniform live load that causes the same effect on the structural members can generally be used instead.

2. Civil buildings.

Civil buildings during their use by the crowd.

Loads on objects, furniture, equipment, etc. For common residential buildings, offices, hotels, hospitals, schools, auditoriums, theaters, gymnasiums, exhibition halls, shops, station halls, waiting rooms, stacks, bathrooms, balconies and other civil buildings, the floor load value is specified by the national load code.

3. Roofing. Loads generated by people, tools, and appropriate stacking during the construction, use, and maintenance of roofing. For rainy areas, the roof live load also includes the water load caused by the possible roof water.

Roof ash load For a plant with a large amount of ash discharge in production, the roof load specified to consider the safety of the roof structure. For example, casting workshops, steelmaking workshops, sintering workshops, blast furnaces, cement plants, etc., as well as their adjacent buildings, should consider the ash load of the roof area. The standard value of this load can be specified according to the nature of the ash source, the distance between the building and the ash source, the shape of the roof and the ash cleaning system.