标准编号:	GB 50009-2001(2006)
中文名称:	建筑结构荷载规范(2006)
英文名称:	Load code for the design of building structures (2006 Edition)
中标分类:	P
行业分类:	GB    国家标准
ICS分类:	91.080 91.080    建筑物结构 91.080
发布机构:	中华人民共和国建设部
发布日期:	2002-01-10
实施日期:	2002-3-1
标准状态:	被替代
被新标准替代:	GB 50009-2012 建筑结构荷载规范
被替代日期:	2012-10-1
作废日期:	2012-10-01
替代旧标准:	GBJ 9-1987 建筑结构荷载规范GBJ9-87
翻译语言:	英文
文件格式:	PDF
中文字符数:	48000 字
翻译价格(元):	300.00 元
交付时间:	付款后 1 个工作日

Codeofchina.com is in charge of this English translation. In case of any doubt about the English translation, the Chinese original shall be considered authoritative.

This Code has been overall revised in accordance with Notice of Printing and Distributing of the Establishment and Amendment of Building Construction of 1997 (JIANBIAO [1997] No.108) issued by the Ministry of Construction and the Load Code for the Design of Building Structures (GBJ 9-87) jointly approved by China Architecture Scientific Research Institute and related departments.

During the process of revising, the team has carried out monographic study, summarized design experience in recent years, referred to related contents of foreign norms and international standards, widely asked for opinions from related departments all over the country and finalized after repeated amendment.

This Code can be divided into seven chapters and seven appendices. Primary contents revised are as follows:

1. In accordance with the rule of combination stated in Unified Standard for Reliability Design of Building Structures and getting rid of Wind Combination, the combination controlled by permanent load effect was added to the load fundamental combination. In the limit design of regular service, for the short-term effect combination, characteristic and frequent combinations are listed and at the same time, the frequent value coefficient was added to the variable load. For all combination values of variable loads, respective combination value coefficient is listed.

2. Partial adjustment and amendment of floor live load.

3. Adjustment has been made to roofing rectangular distribution live load that permits no person on the roof and provisions on roof gardens and helicopter pad load have been added.

4. Character of service for crane has been changed into work classes of cranes.

5. According to new observation data, statistics of wind pressure and snow pressure from national weather stations has been collected. At the same time, the basic value of wind and snow load recurrence interval has been changed from 30 years to 50 years. In the appendix, the 10-year, 50-year and 100-year wind pressure and snow pressure in main stations all over the country have been listed.

6. One Type has been added to the terrain roughness.

7. For the wind pressure altitude variation coefficient of buildings in a mountainous area, compensation factors have been given for the consideration of terrain conditions.

8. Specific provisions have been made to wind load of envelop enclosure members.

9. The interactive influences between buildings in architectural complex have been put forward.

10. For flexible structures, the test requirements for crosswind vibration have been added. This Code may be revised as required. Information and contents revised will be published on the journal of Standardization of Engineering Constructions.

The compulsory articles in this Code shall be executed strictly. In order to improve the quality of this Code, units shall sum up experience and collect background information. For feedback of related opinions and suggestions, please contact: China Architecture Scientific Research Institute (No.30 East Road, North Third Ring).

Chief Development Organization: China Architecture Technical Research Institute

Participating Development Organizations: Construction Department of Tongji University, Building Design Institute, Beijing International Design Institute of China Light Industry, Beijing: China Institute of Architecture Standard Design Press, Beijing Institute of Architectural Design and China Weather Scientific Research Institute

Chief Drafting Staffs: Chen Jifa, Hu Dexin, Jin Xinyang, Zhang Xiangting, Gu Zicong, Wei Caiang, Cai Yiyang, Guan Guixue, Xue Hang





Contents

1. General Principles 6

2. Terms and symbols 6

2.1 Terms 6

2.2 Main symbols 8

3. Classification of loads and combination of load effect 9

3.1 Classification of loads and representative values of a load 9

3.2 Load combination 10

4. Live load of floors and roofs 12

4.1 Rectangular distribution live load on floors of civilian buildings 12

4.2 Floor live load of industrial buildings 15

4.3 Roof live load 15

4.4 Roofing dust load 16

4.5 Construction and repair load as well as handrail horizontal load 18

4.6 Dynamic coefficient 19

5. Crane load 19

5.1 Vertical and horizontal load of cranes 19

5.2 The combination of several cranes 20

5.3 Dynamic coefficient of crane loads 20

5.4 The combination value, frequent value and quasi-permanent value of crane loads 20

6. Snow load 21

6.1 The characteristic value/nominal value and reference snow pressure of snow loads 21

6.2 Coefficient of snow distribution over the roof 22

7. Wind load 25

7.1 The characteristic value/nominal value and reference wind pressure of wind loads 25

7.2 Variation coefficient of wind pressure altitude 25

7.3 Wind load coefficient 27

7.4 Downwind vibration and wind vibration coefficient 42

7.5 Gustiness factor 44

7.6 Crosswind vibration 45

Appendix A Deadweight of Commonly-used Materials and Members 47

Appendix B Method for Deciding the Floor Isoeffect Rectangular Distribution Live Load 61

Appendix C Floor live load of industrial buildings 66

Appendix D Measurement Method of Fundamental Snow Pressure and Wind Pressure 72

Appendix E Empirical Formula for the Structure Which is Natural Vibration Period 114

Appendix F Approximation of the Structural Mode Factor 117

Appendix G Wording Explanation 119





1. General Principles

1.0.1 This Code is designed to meet demands in building structure design and requirements of secure application and economic feasibility.

1.0.2 This Code is applicable to the building structure design.

1.0.3 This Code has been made in accordance with principles stated in Unified Standard for Reliability Design of Building Structures (GB 50068-2001).

1.0.4 Effects involved with the building structure design include direct effect (combination of loads) and indirect effect (including subbase deformation, concrete shrinkage, welding deformations, temperature fluctuation or effects caused by earthquakes). In this Code, only provisions on combination of loads are stated.

1.0.5 The design reference period adopted in this Code is 50 years.

1.0.6 Effects or combination of loads involved with the building structure design shall be in accordance with this Code as well as other current national provisions.

2. Terms and symbols

2.1 Terms

2.1.1 Permanent load

During the utilization period of structures, the value of the combination of loads shall have no change with the passage of time or the variation is negligible compared with the average, or the variation is monotonous and tends to the limitation.

2.1.2 Variable load

During the utilization period of structures, the value of combination of loads shall be changed with the passage of time and the variation is negligible compared with the average.

2.1.3 Accidental load

During the utilization period of the structure, the combination of loads does not necessarily appear, but one it appears, the value is great but the duration is short.

2.1.4 Representative values of a load

The value of combination of loads adopted during the design for the checking of limiting state, such as characteristic value/nominal value, combination value, frequent value and quasi- permanent value.

2.1.5 Design reference period

The time parameter selected for deciding the representative value of the variable load.

2.1.6 Characteristic value/nominal value

The basic representative value of loads refers to the maximum characteristic value (such as typical value, mode, median or some place value) of statistical distribution of loads in the design reference period.

2.1.7 Combination value

The value of combination of loads that makes the load effect exceed probability during the design reference period and make the solitude appearance of the combination of loads has a unified value of combination of loads or make the structure has unified value of combination of loads with reliability index stated in the provision.

2.1.8 Frequent value

For variable load, during the design reference period, the exceeded total time is the minimum ratio or the exceeded frequency is the value of the combination of loads of the assigned frequency.

2.1.9 Quasi- permanent value

For variable load, during the design reference period, the exceeded total time is about half of the value of combination of loads in the design reference period.

2.1.10 Design value of a load

The arithmetic product of the representative values of a load and the partial load factor.

2.1.11 Load effect

Reaction of structures or structural elements caused by the combination of loads, such as internal force, distortion and crack

2.1.12 Load combination

In the limit design, to guarantee the built-in reliability, provisions for all kinds of design values of a load have been made.

2.1.13 Fundamental combination

In the limit of bearing capacity state, the combination of permanent effect and variable effect

2.1.14 Accidental combination

In the limit of bearing capacity state, the combination of permanent effect, variable effect and an accidental combination

2.1.15 Characteristic/nominal combination

In the regular service limiting state, the characteristic value/nominal value or combination value adopted is the combination of representative values of a load.

2.1.16 Frequent combinations

In the regular service limiting state, the frequent value or permanent value is adopted in the variable load is the combination of representative values of a load.

2.1.17 Quasi- permanent combinations

In the regular service limiting state, the quasi- permanent value adopted by the variable load is the combination of the representative values of a load.

2.1.18 Equivalent uniform live load

During the structure design, the actual load of continuous distribution above or under the floor is always by substituted by the evenly distributed load. The equivalent uniform live load refers to the load effect received by the structure can keep in line with the evenly distributed load of the actual load effect.

2.1.19 Tributary area

The tributary area is adopted during the calculation of the beam column members. It refers to the floor space of the calculated member load. It shall be divided by the zero line of the floor slab. In the practical situation, it can be simplified.

2.1.20 Dynamic coefficient

Structures and members that receives dynamic load, when designed according to the static force, shall adopt the value that is the ratio of the maximum power effect of structures or members and relevant static force effect.

2.1.21 Reference snow pressure

The reference pressure of snow load shall be decided by the maximum value of the 50-year period calculated from the probability statistics according to the observation data from the deadweight of snow on the local open and equitable terrain.

2.1.22 Reference wind pressure

The reference pressure of wind load shall be decided by the maximum wind speed for a 50-year period calculated from the probability statistics according to the observation data of average speed in 10min at 10m on the local open and equitable terrain. Also, relevant air density shall be considered and the wind pressure shall be calculated according to the formula (D.2.2-4).

2.1.23 Terrain roughness

When the wind passes 2km range before reaching the structure, the class used to describe the distribution pattern of irregular barriers on the ground.

2.2 Main symbols

Gk——characteristic value/nominal value of permanent load;

Qk——characteristic value/nominal value of variable load;

GGk——characteristic value/nominal value of permanent load effect;

SQk——characteristic value/nominal value of the variable load effect;

S——load effect combination design value;

R——The design value of resisting power of structural members;

SA——Downwind load effect;

SC——Crosswind load effect;

T——Natural vibration period of structures;

H——Top height of structures;

B——Windward width of structures;

Re——Reynolds number;

St——Strouhai number;

sk——Characteristic value/nominal value of snow load;

s0——reference snow pressure;

wk——characteristic value/nominal value of wind load;

w0——reference wind pressure;

νcr——Critical wind velocity of crosswind sympathetic vibration;

α——Angle of gradient;

βz——Gust coefficient at height Z;

βgz——Gust coefficient at height Z;

γ0——Structure significance coefficient;

γG——Subentry coefficient of permanent load;

γQ——Subentry coefficient of variable load;

ψc——combination value coefficient of the variable load;

ψf——frequent value coefficient of variable load;

ψq——quasi-permanent value coefficient of variable load;

μr——Coefficient of snow distribution over the roof

μz——Variation coefficient of wind pressure altitude;

μs——Wind load coefficient;

η——Coefficient of wind load terrain and physiognomy amendment;

ξ——Aggrandizement coefficient of wind load pulsation;

ν——Impact coefficient of wind load pulsation;

φz——Structural vibration mode coefficient;

ζ——Structural damping ratio.

3. Classification of loads and combination of load effect

3.1 Classification of loads and representative values of a load

3.1.1 The structural combination of loads can be divided into three kinds:

1. Permanent load, such as dead load, earth pressure and prestress.

2. Variable load, such as floor live load, roof live load and dust load, crane load, wind load and snow load.

3. Accidental load, such as blasting power and force of percussion.

Note: Deadweight refers to the combination of loads (gravitation) caused by the weight of materials.

3.1.2 During the design of building structures, different combinations of loads shall adopt different representative values. For permanent loads, the representative value shall be the characteristic value/nominal value. While for variable loads, the representative value shall be the characteristic value/nominal value, combination value, frequent value or quasi- permanent value according to different design requirements. For accidental loads, the representative value shall be decided according to the utilization characteristics of building structures.

3.1.3 Permanent load characteristic value/nominal value: for structural deadweight, it shall be decided according to the design size of structural members and the deadweight of unit volume of materials; for commonly-used materials and members, it shall be decided according to appendix 1 of this Code; for materials and members (including field fabricated heat insulators, concrete thin-wall members) with major changes in deadweight, it shall be the upper value or the lower range value according to the advantage or disadvantage state to members.

Note: For commonly-used materials and members, refer to Appendix A.

3.1.4 The characteristic value/nominal value of variable loads shall be adopted according to provisions in this Code.

3.1.5 The design of limit of bearing capacity state or the regular service limiting state shall adopt the combination value as the representative value of the variable loads. The combination value of variable loads refers to the variable load characteristic value/nominal value multiplied by the combination value coefficient of combination of loads.

3.1.6 If the regular service limiting state is designed according to the frequent combinations, the frequent value, quasi-permanent value shall be adopted as the representative value. If it is designed according to the quasi-permanent combinations, the quasi-permanent value shall be adopted as the representative value of variable loads. The frequent value of variable loads shall adopt the variable load characteristic value/nominal value multiplied by the frequent value coefficient of combination of loads. The variable load quasi- permanent value shall adopt the characteristic value/nominal value of variable loads multiplied by the quasi-permanent value coefficient of combination of loads.

3.2 Load combination

3.2.1 The design of building structures shall be in accordance with the combination of loads arising in the construction during the utilization process, according to the limit of bearing capacity state and the regular service limiting state. The design shall take the most disadvantaged combination for the combination of loads (effect).

3.2.2 For the limit of bearing capacity state, the combination of loads (effect) shall adopt the fundamental combination or accidental combination of load effect. The following design expression shall be adopted:

γ0S ≤R (3.2.2)

Where,

γ0——Structure significance coefficient;

S——The design of load effect combination;

R——The design value of resisting power of structural members shall be decided by related design specifications of building structures.

3.2.3 For the design value (S) of the fundamental combination of loads and load effect, it shall be decided by the most disadvantaged value from the following combination values:

1) Combination controlled by the variable load effect;

(3.2.3-1)

Where,

γG——Subentry coefficient of permanent load shall be adopted according to Article 3.2.5.

γQi——The ith subentry coefficient of variable load. γQi is the subentry coefficient of variable load Q1, to be adopted according to Article 3.2.5.

SGk——The load effect value calculated according to the permanent load characteristic value/nominal value Gk;

SQik——The load effect value calculated according to variable load characteristic value/nominal value Qik. SQ1k is the controller of all variable load effects.

ψci——The combination value coefficient of the variable load Qi shall be adopted according to provisions in chapters.

n——The number of variable loads forming the combination.

2) Combination controlled by the permanent load effect:

(3.2.3-2)

Note: 1 The design value of fundamental combination is applicable to the linear load effect.

2. If the SQ1k can't be decided distinctively, each variable load effect shall be taken as SQ1k and the most disadvantaged load effect combination shall be selected.

3.2.4 For common bents and frame structures, the reduction rule may be adopted in the fundamental combination and the most disadvantaged value shall be selected according to the following combination values:

1) Combination controlled by variable load effect;



(3.2.4)

2) The combination controlled by the permanent load effect shall be adopted according to formula (3.2.3-2).

3.2.5 The subentry coefficient of combination of loads in the fundamental combination shall be adopted according to the following provisions:

1. Subentry coefficient of permanent load;

1) If the effect causes disadvantages to the structure,

——for the combination controlled by the variable load effect, select 1.2;

——for the combination controlled by the permanent load effect, select 1.35.

2) If the effect causes advantages to the structure, select 1.0.

2. Subentry coefficient of variable load:

——Generally, select 1.4;

——For the characteristic value/nominal value of the live load of industrial housing floor greater than 4kN/m2, select 1.3.

3. For the overturn, slippage or floating calculation, the load subentry coefficient shall be adopted according to provisions in related design codes for structures.

3.2.6 For the design value of accidental combination and load effect combination, it shall be in accordance with the following provisions: the representative value of the accidental loads doesn't multiply subentry coefficient; if it appears together with the accidental loads and other combinations of loads, the representative value shall be adopted according to the observational data and project experience. Under different circumstances, the formula of design value of the load effect shall be decided by contrary provisions.

3.2.7 In the regular service limiting state, according to different design requirement, the characteristic/nominal combination, frequent combinations or quasi-permanent combinations may be adopted and the design shall be carried out according to the following design expression:

S≤C (3.2.7)

Where,

C——The limitation of structures or structural members when they are in regular service, such as the limitation of distortion, crack, amplitude, acceleration and stress, shall be adopted according to related design codes for building structures.

3.2.8 The design value (S) characteristic/nominal combination and load effect combinations shall be adopted according to the following formula:

(3.2.8)

Note: The design value of the combination is applicable to the linear combination of loads and load effect.

3.2.9 The design value (S) of frequent combinations and load effect combinations shall be adopted according to the following formula:

(3.2.9)

Where,

ψf1——The frequent coefficient of variable load Q1 shall be adopted according to provisions in chapters.

ψqi——The quasi value coefficient of the variable load Qi shall be adopted according to provisions in chapters.

Note: The design value of the combination is applicable to the linear combination of loads and load effect.

3.2.10 The design value (S) of quasi-permanent combinations and load effect combinations shall be adopted according to the following formula:

(3.2.10)

Note: The design value of the combination is applicable to the linear combination of loads and load effect.

Contents
1. General Principles
2. Terms and symbols
2.1 Terms
2.2 Main symbols
3. Classification of loads and combination of load effect
3.1 Classification of loads and representative values of a load
3.2 Load combination
4. Live load of floors and roofs
4.1 Rectangular distribution live load on floors of civilian buildings
4.2 Floor live load of industrial buildings
4.3 Roof live load
4.4 Roofing dust load
4.5 Construction and repair load as well as handrail horizontal load
4.6 Dynamic coefficient
5. Crane load
5.1 Vertical and horizontal load of cranes
5.2 The combination of several cranes
5.3 Dynamic coefficient of crane loads
5.4 The combination value, frequent value and quasi-permanent value of crane loads
6. Snow load
6.1 The characteristic value/nominal value and reference snow pressure of snow loads
6.2 Coefficient of snow distribution over the roof
7. Wind load
7.1 The characteristic value/nominal value and reference wind pressure of wind loads
7.2 Variation coefficient of wind pressure altitude
7.3 Wind load coefficient
7.4 Downwind vibration and wind vibration coefficient
7.5 Gustiness factor
7.6 Crosswind vibration
Appendix A Deadweight of Commonly-used Materials and Members
Appendix B Method for Deciding the Floor Isoeffect Rectangular Distribution Live Load
Appendix C Floor live load of industrial buildings
Appendix D Measurement Method of Fundamental Snow Pressure and Wind Pressure
Appendix E Empirical Formula for the Structure Which is Natural Vibration Period
Appendix F Approximation of the Structural Mode Factor
Appendix G Wording Explanation

１ 总 则
１．０．１为了适应建筑结构设计的需要，以符合安全适用、经济合理的要求，制定本规范。
１．０．２本规范适用于建筑工程的结构设计。
１．０．３本规范是根据《建筑结构可靠度设计统一标准》（ＧＢ５００６８—２００１）规定的原则制订的。
１．０．４建筑结构设计中涉及的作用包括直接作用（荷载）和间接作用（如地基变形、混凝土收缩、焊接变形、温度变化或地震等引起的作用）。本规范仅对有关荷载作出规定。
１．０．５本规范采用的设计基准期为５０年。
１．０．６建筑结构设计中涉及的作用或荷载，除按本规范执行外，尚应符合现行的其他国家标准的规定。


２ 术语及符号
２．１术语
２．１．１永久荷载
在结构使用期间，其值不随时间变化，或其变化与平均值相比可以忽略不计，或其变化是单调的并能趋于限值的荷载。
２．１．２可变荷载
在结构使用期间，其值随时间变化，且其变化与平均值相比不可以忽略不计的荷载。
２．１．３偶然荷载
在结构使用期间不一定出现，一旦出现，其值很大且持续时间很短的荷载。
２．１．４荷载代表值
设计中用以验算极限状态所采用的荷载量值，例如标准值、组合值、频遇值和准永久值。
２．１．５设计基准期
为确定可变荷载代表值而选用的时间参数。
２．１．６标准值
荷载的基本代表值，为设计基准期内最大荷载统计分布的特征值（例如均值、众值、中值或某个分位值）。
２．１．７组合值
对可变荷载，使组合后的荷载效应在设计基准期内的超越概率，能与该荷载单独出现时的相应概率趋于一致的荷载值；或使组合后的结构具有统一规定的可靠指标的荷载值。
２．１．８频遇值
对可变荷载，在设计基准期内，其超越的总时间为规定的较小比率或超越频率为规定频率的荷载值。
２．１．９准永久值
对可变荷载，在设计基准期内，其超越的总时间约为设计基准期一半的荷载值。


２．１．１０荷载设计值
荷载代表值与荷载分项系数的乘积。
２．１．１１荷载效应
由荷载引起结构或结构构件的反应，例如内力、变形和裂缝等。
２．１．１２荷载组合
按极限状态设计时，为保证结构的可靠性而对同时出现的各种荷载设计值的规定。
２．１．１３基本组合
承载能力极限状态计算时，永久作用和可变作用的组合。
２．１．１４偶然组合
承载能力极限状态计算时，永久作用、可变作用和一个偶然作用的组合。
２．１．１５标准组合
正常使用极限状态计算时，采用标准值或组合值为荷载代表值的组合。
２．１．１６频遇组合
正常使用极限状态计算时，对可变荷载采用频遇值或准永久值为荷载代表值的组合。
２．１．１７准永久组合
正常使用极限状态计算时，对可变荷载采用准永久值为荷载代表值的组合。
２．１．１８等效均布荷载
结构设计时，楼面上不连续分布的实际荷载，一般采用均布荷载代替；等效均布荷载系指其在结构上所得的荷载效应能与实际的荷载效应保持一致的均布荷载。
２．１．１９从属面积
从属面积是在计算梁柱构件时采用，它是指所计算构件负荷的楼面面积，它应由楼板的剪力零线划分，在实际应用中可作适当简化。
２．１．２０动力系数
承受动力荷载的结构或构件，当按静力设计时采用的系数，其值为结构或构件的最大动力效应与相应的静力效应的比值。
２．１．２１基本雪压
雪荷载的基准压力，一般按当地空旷平坦地面上积雪自重的观测数据，经概率统计得出５０年一遇最大值确定。
２．１．２２基本风压
风荷载的基准压力，一般按当地空旷平坦地面上１０ｍ高度处１０ｍｉｎ平均的风速观测数据，经概率统计得出５０年一遇最大值确定的风速，再考虑相应的空气密度，按公式（Ｄ．２．２／４）确定的风压。
２．１．２３地面粗糙度
风在到达结构物以前吹越过２ｋｍ范围内的地面时，描述该地面上不规则障碍物分布状况的等级。











３ 荷载分类和荷载效应组合
３．１荷载分类和荷载代表值

３．１．１结构上的荷载可分为下列三类：
１永久荷载，例如结构自重、土压力、预应力等。
２可变荷载，例如楼面活荷载、屋面活荷载和积灰荷载、吊车荷载、风荷载、雪荷载等。
３偶然荷载，例如爆炸力、撞击力等。
注：自重是指材料自身重量产生的荷载（重力）。
３．１．２建筑结构设计时，对不同荷载应采用不同的代表值。对永久荷载应采用标准值作为代表值。对可变荷载应根据设计要求采用标准值、组合值、频遇值或准永久值作为代表值。对偶然荷载应按建筑结构使用的特点确定其代表值。
３．１．３永久荷载标准值，对结构自重，可按结构构件的设计尺寸与材料单位体积的自重计算确定。对于自重变异较大的材料和构件（如现场制作的保温材料、混凝土薄壁构件等），自重的标准值应根据对结构的不利状态，取上限值或下限值。
注：对常用材料和构件可参考本规范附录Ａ采用。
３．１．４可变荷载的标准值，应按本规范各章中的规定采用。
３．１．５承载能力极限状态设计或正常使用极限状态按标准组合设计时，对可变荷载应按组合规定采用标准值或组合值作为代表值。可变荷载组合值，应为可变荷载标准值乘以荷载组合值系数。


３．１．６正常使用极限状态按频遇组合设计时，应采用频遇值、准永久值作为可变荷载的代表值；按准永久组合设计时，应采用准永久值作为可变荷载的代表值。
可变荷载频遇值应取可变荷载标准值乘以荷载频遇值系数。
可变荷载准永久值应取可变荷载标准值乘以荷载准永久值系
数。


３．２荷载组合
３．２．１建筑结构设计应根据使用过程中在结构上可能同时出现的荷载，按承载能力极限状态和正常使用极限状态分别进行荷载（效应）组合，并应取各自的最不利的效应组合进行设计。
３．２．２对于承载能力极限状态，应按荷载效应的基本组合或偶然组合进行荷载（效应）组合，并应采用下列设计表达式进行设计：



３．２．４对于一般排架、框架结构，基本组合可采用简化规则，并应按下列组合值中取最不利值确定：
1) 由可变荷载效应控制的组合：

２）由永久荷载效应控制的组合仍按公式（３．２．３／２）式采用。

３．２．５基本组合的荷载分项系数，应按下列规定采用：
１永久荷载的分项系数：
１）当其效应对结构不利时
—对由可变荷载效应控制的组合，应取１．２；
—对由永久荷载效应控制的组合，应取１．３５；
２）当其效应对结构有利时
—一般情况下应取１．０；
—对结构的倾覆、滑移或漂浮验算，应取０．９。
２可变荷载的分项系数：
—一般情况下应取１．４；
—对标准值大于４ｋＮ／ｍ２的工业房屋楼面结构的活荷载应取１．３。
注：对于某些特殊情况，可按建筑结构有关设计规范的规定确定。
３．２．６对于偶然组合，荷载效应组合的设计值宜按下列规定确定：偶然荷载的代表值不乘分项系数；与偶然荷载同时出现的其他荷载可根据观测资料和工程经验采用适当的代表值。各种情况下荷载效应的设计值公式，可由有关规范另行规定。
３．２．７对于正常使用极限状态，应根据不同的设计要求，采用荷载的标准组合、频遇组合或准永久组合，并应按下列设计表达式进行设计：

Ｓ≤Ｃ （３．２．７）

式中Ｃ———结构或结构构件达到正常使用要求的规定限值，例如变形、裂缝、振幅、加速度、应力等的限值，应按各有关建筑结构设计规范的规定采用。

３．２．８对于标准组合，荷载效应组合的设计值Ｓ应按下式采用：

３．２．９对于频遇组合，荷载效应组合的设计值Ｓ应按下式采用：

３．２．１０对于准永久组合，荷载效应组合的设计值Ｓ可按下式采用：







４ 楼面和屋面活荷载
４．１民用建筑楼面均布活荷载

４．１．１民用建筑楼面均布活荷载的标准值及其组合值、频遇值和准永久值系数，应按表４．１．１的规定采用。


４．１．２设计楼面梁、墙、柱及基础时，表４．１．１中的楼面活荷载标准值在下列情况下应乘以规定的折减系数。
１ 设计楼面梁时的折减系数：
１）第１（１）项当楼面梁从属面积超过２５ 时，应取０．９；
２）第１（２）～７项当楼面梁从属面积超过５０ 时应取０．９；
３）第８项对单向板楼盖的次梁和槽形板的纵肋应取０．８；对单向板楼盖的主梁应取０．６；对双向板楼盖的梁应取０．８；
４）第９～１２项应采用与所属房屋类别相同的折减系数。
２ 设计墙、柱和基础时的折减系数
１）第１（１）项应按表４．１．２规定采用；
２）第１（２）～７项应采用与其楼面梁相同的折减系数；
３）第８项对单向板楼盖应取０．５；对双向板楼盖和无梁楼盖应取０．８
４）第９～１２项应采用与所属房屋类别相同的折减系数。
注：楼面梁的从属面积应按梁两侧各延伸二分之一梁间距的范围内的实际面积确定。