According to the requirements of Document JianBiao ［2008］ No.102 issued by the Ministry of Housing and Urban-Rural Development—"Notice on Printing and Publishing of ‘Development and Revision Plan of National Engineering Construction Standards in 2008 (first batch)’",this Code is revised from the former GB 50007—2002Code for Design of Building Foundationby China Academy of Building Research together with other relevant organizations.

During theperiod of revision,the drafting group finalized this code through reviewing based on extensive investigation and study,earnestly summarizing the practical experience,making reference to the foreign advanced standards,coordinating with relevant national standards and extensively soliciting for opinions.

This Code comprises 10 chapters and 22 appendixes.The main technical contents include general provisions,terms and symbols,basic requirements,classification of rocks and soils and their engineering properties,foundation design calculation,foundation in mountain area,soft ground,foundation,excavation engineering,inspection and monitoring.

The main technical contents revised in this Code are:

1.Add the relevant content of excavation engineering in the design grade of foundation;

2.The design working life of foundation shall not be less than that of building structure;

3.Add the engineering definitions of peat and peaty soil;

4.Add rebounding and recompression deformation calculation method;

5.Add building anti-buoyancy stability calculation method;

6.Add the design principles of soil-rock composite ground with rock face gradient greater than 10%and soil thickness greater than 1.5m when the underlying rock surface beneath foundation is inclining in single direction;

7.Add the design content of rock foundation;

8.Add the principle of foundation design according to the karst development degree in karst region;

9.Add the deformation calculation method for composite ground;

10.Add the design requirements that the minimum ratio of reinforcement of spread foundation shall not be less than 0.15%;

11.Add the requirements for the shear load-capacity calculation of oblique section when the short-side dimension of the spread foundation bottom is less than or equal to the column width plus 2 times the foundation effective height;

12.Adjust the settlement empirical coefficient for pile foundation settlement calculation method through statistical analysis;

13.Add the requirements of specific design for underground water control in Grade-A excavation engineering featured by complex hydrogeologic conditions on site,high protection requirement for surrounding environment of foundation pit in high underground water level area;

14.Add the inspection requirements for ground treatment engineering;

15.Add the key points for lateral load test of single pile and key points for vertical uplift test of single pile.

In this Code,the provisions printed in bold type are compulsory ones and must be enforced strictly.

The Ministry of Housing and Urban-Rural Development is in charge of the administration of this Code and the explanation of the mandatory clauses;the China Academy of Building Research is responsible for the explanation of specific technical contents.During the process of implementing this code,the relevant opinions or advice,whenever necessary,can be posted or passed on to the Administrative Group of national standard "Code for Design of Building Foundation" China Academy of Building Research (Address:No.30,North Third Ring East Road,Beijing,100013,China,Email:tyjcabr@sina.com.cn).

Chief Development Organization:

China Academy of Building Research

Participating Development Organizations: CIGIS

Beijing Geotechnical Institute

China Southwest Geotechnical Investigation and Architecture Design Institute

Guiyang Architectural Design&Surveying Prospecting Co.,Ltd.

Beijing Institute of Architectural Design

China Architecture Design and Research Group

Shanghai Xiandai Architectural Design Group Co.,Ltd.

China Northeast Architectural Design&Research Institute

Liaoning Provincial Building Design&Research Institute

Yunnan Yicheng Architectural Design Company

Central-South Architectural Design Institute

Hubei Provincial Academy of Building Research

Guangzhou Academy of Building Research

Heilongjiang Province Academy of Cold Area Building Research

Heilongjiang Province Building Engineering Quality Supervision Station

Northern Engineering&Technology Corporation,MCC

China State Construction Engineering Corp.

Tianjin University

Tongji University

Taiyuan University of Technology

Guangzhou University

Zhengzhou University

Southeast University

Chongqing University

Chief Drafting Staff:

Teng Yanjing Huang Xiling Wang Shuguang Gong Jianfei Wang Weidong Wang Xiaonan Wang Gongshan Bai Xiaohong Ren Qingying Liu Songyu Zhu Lei Shen Xiaoke Zhang Bingji Zhang Chengjin Zhang Jichao Chen Xiangfu Yang Min Lin Liyan Zheng Gang Zhou Tonghe Wei Wu Hao Jiangnan Hou Guangyu Hu Daiwen Yuan Neizhen Gu Baohe Tang Mengxiong Gu Xiaolu Liang Zhirong Kang Jingwen Pei Jie Pan Kaiyun Xue Huili

Chief Examiners:

Xu Zhengzhong Huang Shaoming Wu Xuemin Gu Guorong Hua Jianxin Wang Changqing Xiao Ziqiang Song Zhaohuang Xu Tianping Xu Zhangjian Mei Quanting Huang Zhihong Dou Nanhua

Announcement of the Ministry of Housing and Urban-Rural Development of the Peoples Republic of China

No.1096

Announcement of Publishing the National Standard of Code for Design of Building Foundation

Code for Design of Building Foundation has been approved as a national standard with a serial number of GB 50007-2011,and shall be implemented on August 1,2012.Therein,Articles 3.0.2, 3.0.5, 5.1.3, 5.3.1, 5.3.4, 6.1.1, 6.3.1, 6.4.1, 7.2.7, 7.2.8, 8.2.7, 8.4.6, 8.4.9, 8.4.11, 8.4.18, 8.5.10, 8.5.13, 8.5.20, 8.5.22, 9.1.3, 9.1.9, 9.5.3, 10.2.1, 10.2.10, 10.2.13, 10.2.14, 10.3.2 and 10.3.8 are compulsory provisions and must be enforced strictly.The original GB 50007-2002 Code for Design of Building Foundation shall be abolished simultaneously.

Organized by the Research Institute of Standards and Norms of the Ministry of Housing and Urban-Rural Development of the Peoples Republic of China,this code is published and distributed by China Architecture&Building Press.

Ministry of Housing and Urban-Rural Development of the Peoples Republic of China

July 26，2011

目录

Announcement of the Ministry of Housing and Urban-Rural Development of the Peoples Republic of China

Foreword

1 General Provisions

2 Terms and Symbols

2.1 Terms

2.2 Symbols

3 Basic Requirements

4 Classification of Rocks and Soils and Their Engineering Properties

4.1 Classification of Rocks and Soils

4.2 Indexes of Engineering Properties

5 Foundation Design Calculation

5.1 Embedment Depth of Foundation

5.2 Calculation of Bearing Capacity

5.3 Calculation of Deformation

5.4 Calculation of Stability

6 Foundation in Mountain Area

6.1 General Requirements

6.2 Soil-rock Composite Ground

6.3 Foundation on Compacted Fill

6.4 Landslide Prevention

6.5 Foundation on Rock

6.6 Karst and Sinkhole

6.7 Soil Slope and Gravity Retaining Wall

6.8 Rock Slope and Retaining Wall with Rock Anchor

7 Soft Ground

7.1 General Requirements

7.2 Utilization and Treatment

7.3 Architectural Measures

7.4 Structural Measures

7.5 Large Area Ground Surcharge

8 Foundation

8.1 Non-reinforced Spread Foundation

8.2 Spread Foundation

8.3 Strip Foundation under Columns

8.4 Raft Foundation of High-rise Buildings

8.5 Pile Foundation

8.6 Rock Anchor Foundation

9 Excavation Engineering

9.1 General Requirements

9.2 Geotechnical Investigation and Environmental Investigation for Excavation Engineering

9.3 Earth Pressure and Water Pressure

9.4 Design Calculation

9.5 Internal Bracing of Retaining Structure

9.6 Soil Anchor

9.7 Top-down Construction of Excavation Engineering

9.8 Rock Excavation Engineering

9.9 Underground Water Control

10 Inspection and Monitoring

10.1 General Requirements

10.2 Inspection

10.3 Monitoring

Appendix A Division of Rock Hardness Degree and Rock Mass Integrity Degree

Appendix B Field Identification of Gravel Soil

Appendix C Key Points for Shallow Plate Load Test

Appendix D Key Points for Deep Plate Load Test

Appendix E Standardized Value of Shear Strength Index c and φ

Appendix F Contour of Standard Frost Penetration of Seasonally Frozn Soil in China

Appendix G Classification of Frost Heaving of Ground Soil and Allowable Maximum Thickness of Frozen Soil under Building Foundation

Appendix H Key Points for Load Test on Rock

Appendix J Key Points for Saturated Uni-axial Compressive Strength Test of Rock

Appendix K Coefficient of Additional Stress α and Coefficient of Average Additional Stress α

Appendix L Coefficient of Active Earth Pressure k_a for Retaining Wall

Appendix M Key Points for Pullout Test of Rock Anchor

Appendix N Calculation of Additional Ground Settlement under the Action of Large Area Ground Surcharge

Appendix P Calculation Formulae for Perimeter and Polar Moment of Inertia of Critical Punching Shear Section

Appendix Q Key Points for Vertical Static Load Test on a Single Pile

Appendix R Calculation for Final Settlement of Pile Foundation

Appendix S Key Points for Lateral Load Test on a Single Pile

Appendix T Key Points for Uplift Load Test on a Single Pile

Appendix U Sectional Width for Shear Oblique Section of Stepped and Conical Pilecap

Appendix V Calculation of Stability for Retaining Structures

Appendix W Calculation for Anti-seepage Stability of Excavation

Appendix Y Key Points for Test of Anchor in Soil

Explanation of Wording in This Code

List of Quoted Standards

3.0.2 According to the design grade of foundation and the degree of influence on superstructure dueto ground deformation under the effect of long-term loading, the design of foundation shall conform to the following stipulations:

1 The foundation design calculation of all the buildings shall meet the relevant requirements for calculation of bearing capacity;

2 The buildings with a design grade of Grade A or Grade B shall be designed according to subsoil deformation control;

3 The buildings with a design grade of Grade C shall be subjected to deformation checking under one of the following conditions:

1)Buildings with characteristic value of subsoil bearing capacity less than 130kPa, and with complicated shape;

2)Excessive differential settlement may be caused due to surface loading on the foundation and surrounding or load difference on adjacent foundations is large;

3)Building under eccentric load on soft ground;

4)When the adjacent buildings are close and may have inclination;

5)When there is relatively thick or uneven fill in ground and its deadweight consolidation has not been completed.

4 For high-rise buildings, tall structure, retaining wall, etc.frequently subjected to horizontal load, as well as buildings and structures built on or near slope, their stability shall also be checked;

5 Stability shall be checked for excavation engineering;

6 When building basement or underground structure has floating problem, anti-buoyancy stability shall also be checked.

3.0.5 In design of foundation, the adopted action effect and corresponding resistance limit valueshall meet the following requirements:

1 When determining foundation base area and embedment depth according to subsoil bearing capacity or determining pile number according to single pile bearing capacity, the action effect transmitted to foundation base or pilecap shall accord with the characteristic combination of action effects under serviceability limit state, and the corresponding resistance shall adopt characteristic value of subsoil bearing capacity or characteristic value of single pile capacity;

2 When calculating ground deformation, the action effect transmitted to foundation base shall accord with the quasi-permanent combination of action effects under serviceability limit state, meanwhile wind load and seismic action shall not be counted into; corresponding limit value shall be the allowable deformation of foundation;

3 When calculating retaining wall, stability of ground or slope and foundation anti-buoyancy stability, the action effect shall accord with the fundamental combination of action effects under ultimate limit state, but the partial coefficient shall be 1.0;

4 When determining the height of foundation or pile cap, the section of retaining structure, calculating the internal force of foundation or retaining structure, determining reinforcement and checking material strength, the action effect transmitted from superstructure and corresponding base reaction, earth pressure on retaining wall and landslide thrust force shall accord with the fundamental combination of action effects under ultimate limit state, and adopting the corresponding partial coefficient; when it is necessary to check the crack width of foundation, it shall accord with thecharacteristic combination of action effects under serviceability limit state;

5 The safety class for foundation design, the design working life of structure and the coefficient for structure importance shall be adopted according to the stipulations of relevant Codes, but the coefficient for structure importanceγshall not be less than 1.0.

5.1.3 The foundation embedment depth of high-rise building shall satisfy the requirements for theground bearing capacity, deformation and stability.The embedment depth of foundation of high-rise building, while located on rock, shall satisfy the requirements of stability against sliding.

5.3.1 The calculation value of deformation of building ground shall not be greater than the allowablevalue of ground deformation.

5.3.4 The allowable ground deformation of the building shall be adopted in accordance with Table5.3.4.For the buildings uncovered in this table, the allowable ground deformation shall be determined according to the adaptive capacity of the superstructure to ground deformation and the requirement of building serviceability.

6.1.1 For the design of foundation in mountain area(including hilly ground),the following designconditions shall be analyzed and identified:

1 Whether there is landslide phenomenon or fault and fracture zone influencing the site stability under natural conditions in the construction site;

2 Whether there is unstable slope around the construction site;

3 The influence of excavation, filling, stacking, unloading, etc.on hillside stability in construction process;

4 Rock thickness and space distribution condition in foundation, fluctuation condition of rock bed, and open face influencing the foundation stability or not;

5 Non-uniformity of building foundation;

6 Development degree of karst and sinkhole, mined-out section or not;

7 Possibility of adverse geological phenomena such as dangerous rock collapse and debris flow;

8 Influence of surface water and underground water on building foundation and construction site.

6.3.1 When the compacted fill is used as the bearing stratum of the building foundation, before thesite leveling, quality requirements shall be proposed for the fill to be compacted according to structure type, properties of fill material, site condition, etc..The compacted fill, not subjected to inspection and inconformity to quality requirements, shall not be used as the bearing stratum of the building foundation.

6.4.1 In the area of construction site, for the section where landslide may occur due to the influenceof construction or other factors, reliable preventive measures must be taken.For the landslide with developing trend and threatening the buildings safety and serviceability, comprehensive treatment measures shall be taken as soon as possible to prevent landslide from developing continuously.

7.2.7 The design of composite ground shall meet the requirements of bearing capacity and deformation ofbuilding.When the ground is special soils such as underconsolidated soil, expansive soil, collapsible loess and liquefiable soil etc., the reinforcement and construction technology adopted for design shall meet the technical requirements of jointly undertaking of loading by reinforcement and ground soil after treatment.

7.2.8 Characteristic value of bearing capacity of composite ground shall be determined by in-situload test of composite ground, or be determined by adopting result of load test on reinforcement and characteristic value of bearing capacity of surrounding soil, in combination with experience.

8.2.7 The calculation of spread foundation shall meet the following requirements:

1 For the isolated foundation under columns, when the punching shear failure cone falls within the foundation base, the punching shear capacity shall be checked at the joints of column and foundation and at the step of foundation;

2 For the isolated foundation under columns with the shorter side dimension of foundation base less than or equal to column width plus twice the effective height of foundation and the strip foundation under walls, the shear capacity shall be checked at the joints of column(wall)and foundation;

3 The foundation slab reinforcement shall be determined in accordance with the flexural calculation;

4 When the concrete strength grade of the foundation is less than that of the column, the local bearing capacity at the top surface of foundation under columns shall also be checked.

8.4.6 The slab thickness of plain slab raft foundation shall meet the requirements for punching shearcapacity.

8.4.9 For the plain slab raft foundation, the shear capacity of the section at apart from both theinner tube and column edge shall be checked.When the raft slab is in variable thickness, then the shear capacity of the raft slab at the thickness variation shall still be checked.

8.4.11 For the base slab of the beam-and-slab raft foundation, the flexural capacity at normalsection shall be calculated and the slab thickness shall meet the requirements for both punching shear capacity and shear capacity.

8.4.18 The top surface of both foundation beam of beam-and-slab raft foundation and plain slab raftfoundation shall meet the requirements of local bearing capacity under columns of base storey.For high-rise buildings with seismic precautionary intensity 9, in checking local bearing capacity of foundation beam and raft slab under columns, the influence of vertical earthquake action to column axial forces shall be counted in.

8.5.10 The concrete strength of pile shaft shall meet the design requirements for bearing capacity ofpile.

8.5.13 The settlement calculation of pile foundation shall meet the following requirements:

1 The settlement shall be checked for the pile foundations of the following buildings:

1)The pile foundation of building with Grade-A design grade of foundation;

2)The pile foundation of building with Grade-B design grade of foundation, in case of complicated building shape and configuration, nonuniform loading or with soft soil stratum available below the pile tip;

3)Friction pile foundation.

2 The settlement of pile foundation shall not exceed allowable value of building settlement and shall meet the requirements of Table 5.3.4 of this code.

8.5.20 For the isolated cap of pile foundation undercolumns, the shear calculation shall be carried out respectively for the oblique sections formed by the connecting lines between the column side and the edge of pile, as well as, between the step and the edge of pile.When multiple shear oblique sections are formed by multirow piles available at outside the column side, each oblique section shall be checked.

8.5.22 When the concrete strength grade of the cap is lower than that of the column or piles, thelocal bearing capacity of the cap under the column or on the pile shall also be checked.

9.1.3 The design of excavation engineering shall include the following contents:

1 Planning of retaining structure system with technical and economical comparison;

2 Stability checking of retaining system for excavation;

3 Calculation of bearing capacity, stability and deformation of retaining structure;

4 Design of underground water control;

5 Design of control on influence on surrounding environment;

6 Planning of earthwork of excavation;

7 Monitoring requirements for excavation engineering.

9.1.9 Earth excavation of foundation pit shall be in strict accordance with the design requirements,and overexcavation is not allowed.The surcharge at the periphery of the foundation pit shall not exceed the design stipulation.After the completion of earth excavation, the cushion shall be constructed immediately and make the foundation pit closed to prevent water immersion and exposure, and the underground structure construction shall be carried out timely.

9.5.3 The order of installation and demolition of the bracing structure shall be consistent with thedesigned working conditions of bracing structure, and must comply with the principle of excavation only after bracing.

10.2.1 Foundation trench(pit)inspection shall be carried out after it is excavated to the bottom.When the discovered geological conditions are inconsistent with the investigation report and design document, or abnormal condition is encountered, treatment suggestion shall be proposed in combination with geological conditions.

10.2.10 Composite ground shall be subjected to inspection of pile shaft integrity and vertical loadcapacity of single pile as well as load test of single pile or multi-pile composite ground, if the construction process has an effect on bearing capacity of inter-pile soil, inspection on the bearing capacity of inter-pile soil shall be carried out.

10.2.13 When the hand-dug pile is excavated to the bottom, inspection on piletip bearing stratumshall be carried out.For the larger-diameter rock-socketed pile using as one pile for one column, adverse geologic conditions like soil hole, karst cave, broken zone or weak intercalated layer within 3 times the pile shaft diameter or 5m depth shall be inspected according the properties of underlying rock.

10.2.14 Engineering piles after construction shall be subjected to pile shaft integrity inspection andvertical bearing capacity inspection.The pile bearing larger horizontal load shall be subjected to horizontal bearing capacity inspection, and the uplift pile shall be subjected to pullout capacity inspection.

10.3.2 Monitoring for excavation shall be carried out according to the design requirements, thus toachieve dynamic design and informational construction.

10.3.8 Settlement and deformation observation shall be carried out during both construction periodand serviceability period for the following buildings:.

1 Buildings with Grade-A design grade of foundation;

2 Buildings with Grade-B design grade of foundation on soft ground;

3 Buildings on treated ground;

4 Extra-storey and expanded building;

5 Buildings influenced by adjacent deep excavation or by the variation of environmental factorlike underground water change;

6 Buildings adopting new foundation type or new structure type.