In order to achieve advanced technology, economic rationality, safety and applicability, and quality assurance in the design and construction of grid structures, this code is specially formulated. This code is applicable to flat grid structures of industrial and civil building roofs and floors. The span of other roofs should not be greater than 120m, and the span of floors should not be greater than 40m. JGJ 7-1991 Grid Structure Design and Construction Code JGJ7-1991 Standard download decompression password: www.bzxz.net

Information System
Standard of the State Administration of Construction Engineering
Box Foundation of High-Rise Building
Design and Construction Specifications
JGJ7—91
1991 Beijing
Engineering Construction Standard Full-text Information System
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Standard of the State Administration of Construction Engineering
Design and Construction Specifications of Box Foundation of High-Rise Building 6—80
Editor Department: China Academy of Building Research Approval Department:
Approved by the State Administration of Construction Engineering
Report to the State Recorded with the National Capital Construction Committee
Trial date: July 1, 1981
Engineering Construction Standards Full Text Information System
Engineering Construction Standards Full Text Information System
(80)Jiangongkezi No. 825
According to the arrangement of the "1978 National Construction Science and Technology Development Plan" of the National Construction Committee, in order to meet the needs of the development of high-rise buildings in my country, the "Design and Construction Code for Box Foundations of High-Rise Buildings" compiled by the China Academy of Building Research in conjunction with relevant units has been reviewed and approved as a ministerial standard with the code number JGJ680, which will be implemented on a trial basis from July 1, 1981. In view of the fact that the box foundation of high-rise buildings in my country is still in the development stage, it is hoped that all units will pay attention to summarizing experience, put forward amendments and supplementary opinions when implementing this code on a trial basis, and inform the China Academy of Building Research in writing at any time for future revisions. State Administration of Construction Engineering
November 15, 1980
Engineering Construction Standards Full-text Information System
Engineering Construction Standards Full-text Information System
Preparation Instructions
According to the requirements of the "National Construction Science and Technology Development Plan for 1978" of the State Construction Commission on the design and calculation methods of high-rise building structures and the arrangements of Item 58 of the "National Construction Science and Technology Development Plan for 1979", in order to summarize the practical experience and scientific research results in the investigation, design and construction of box foundations of high-rise buildings in my country, the Construction Science and Technology Bureau of the State Construction Commission entrusted our institute to form a compilation team together with Beijing Architectural Design Institute, Beijing Survey Office, Beijing University of Technology, Shanghai Industrial Architectural Design Institute, Tongji University, Shanghai Civil Architectural Design Institute, Shanghai Geological Bureau, Shaanxi Provincial Architectural Design Institute and Fujian Provincial Industrial and Civil Architectural Design Institute to compile the "Design and Construction Code for Box Foundations of High-rise Buildings" to meet the needs of the growing development of high-rise buildings in my country. In November 1978, the outline of this code was passed at the "Technical Experience Exchange Meeting on Box Foundation Design of High-Rise Buildings". The draft for soliciting opinions of this code was completed in April 1979. In September 1979, based on the opinions of relevant scientific research, design, construction units and colleges and universities across the country, the draft for review was revised and completed. In November 1979, the Foundation Academic Committee of the Architectural Society of China discussed the draft for review, and a review group composed of some experts and professors reviewed it. Based on the review opinions, it was revised and supplemented to complete this draft. In view of the fact that the box foundation of high-rise buildings in my country is still developing, it is necessary to continue to summarize experience in practice. When using this code, if any unit finds that there is a need for modification or supplementation, please send your opinions and relevant information to our institute at any time for future revisions.
China Academy of Building Research
September 1980
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Chapter 1
Chapter 2
Chapter 3
Chapter 4
Chapter 5
Appendix - 1
Appendix 2
Appendix 3
Appendix 4
Appendix 5
Survey requirements·
Foundation calculation.
Requirements for foundation design and construction
Construction requirements
Empirical coefficient for settlement calculation mz
Base reaction coefficient
Approximate calculation method for shear force of wall section
Specialized business
Example of overall bending moment calculation…
Terms used in this code
Engineering Construction Standard Full-text Information System
Engineering Construction Standard Full-text Information System
Main symbols
A——vertical cross-sectional area of ​​wall,
Ai——calculated cross-sectional area of ​​upper lintel;
A2——calculated cross-sectional area of ​​lower lintel;
Area of ​​additional vertical reinforcement on each side of an opening; A
Area of ​​additional inclined reinforcement at the opening;|| tt||Width of box foundation;
-thickness of wall or width of slab taken in calculation; elastic modulus of concrete of beams and columns;
elastic modulus of concrete of box foundation;
-elastic modulus of concrete of continuous reinforced concrete wall connected to box foundation in bending direction;
bottom area of ​​foundation;
height of building;
height of wall;
height of upper column of ith floor;
height of lower column of ith floor;
effective height of slab;
h1——height of section of upper lintel;
height of section of lower lintel;
section moment of inertia of ith beam,
section moment of inertia of ith column;
Jth Sectional moment of inertia of the column below the layer
J.—Sectional moment of inertia of the continuous reinforced concrete wall connected to the box foundation in the bending direction;
Engineering Construction Standard Full-text Information System
Engineering Construction Standard Full-text Information System
K——Safety factor;
K——Linear stiffness of the beam of the ith layer;
—Linear stiffness of the column on the ith layer;
—Linear stiffness of the column below the ith layer;
—Total length of the upper structure in the bending direction,—Column distance or opening width in the bending direction of the upper structure; Bending moment caused by overall bending;
—Bending moment at the end of the upper lintel;
M2——Bending moment at the end of the lower lintel;
Number of intervals in the bending direction;
Sinking Empirical coefficient for drop calculation;
Number of floors of the building,
Average pressure at the bottom of the foundation
Maximum pressure at the edge of the bottom of the foundation;
Minimum pressure at the edge of the bottom of the foundation;
Shear force of the vertical section of the wall or the shear force at the center of the opening; The shear force borne by the slab minus the load within the rigid angle range;-Allowable bearing capacity of foundation soil;
Corrected allowable bearing capacity of foundation soil;
Design axial compressive strength of concrete;
Design tensile strength of concrete;
The circumference at the place where the foundation is located;bZxz.net
The resistance moment of the foundation bottom at the distance from the load edge
,
α——the calculated value of the overall inclination;
r——opening coefficient.
Engineering Construction Standard Full Text Information System
Engineering Construction Standard Full Text Information System
Chapter 1 General
Article 1-0-1 This code is applicable to the box foundation of high-rise civil buildings with reinforced concrete frame structures and cast-in-place shear wall structures with eight to twenty floors on natural foundations or a building height not exceeding 60 meters. When the conditions of frame-shear wall structures and multi-story industrial buildings are equivalent to the requirements of this code, they can also be used as a reference.
Note: The building height refers to the height from the outdoor floor to the roof (excluding local auxiliary buildings such as elevator rooms and water tank rooms protruding from the roof).
Article 1-0-2 The box foundation referred to in this code mainly refers to a reinforced concrete box structure with good overall rigidity composed of a bottom plate, a top plate, side walls and a certain number of internal partition walls.
Article 1-0-3 The design of the box foundation shall comprehensively consider the geological conditions, construction methods and use requirements of the entire construction site, and appropriately consider the interaction between the foundation and the superstructure and the mutual influence with the adjacent buildings. Article 1-0-4 The depth of the box foundation must meet the requirements of foundation strength and stability, so as to reduce the overall tilt of the building, prevent overturning and sliding, and the burial depth in the earthquake zone should not be less than one tenth of the building height. Article 1-0-5 High-rise buildings with earthquake resistance, civil air defense and basement requirements should adopt box foundations.
Article 1-0-6 For high-rise buildings of major or scientific research value, in addition to settlement observation, it is advisable to conduct tests such as foundation pit rebound, base reaction force and foundation internal force.
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Article 1-0-7 When adopting this code, it shall also comply with the requirements of the current relevant standards and specifications of my country.
Chapter II Survey Requirements
Article 2-0-1 The survey of the foundation shall clarify the suitability of the box foundation through the following work and provide relevant information. 1. Find out whether there are adverse engineering geological phenomena, ancient river channels or artificial caves near the building that affect the stability of the project. In the earthquake zone, it shall be found out whether there are liquefiable strata and provide relevant parameters required for seismic design. 2. Find out the uniformity of the stratum soil and groundwater conditions within the influence range of the building, and evaluate the strength and deformation indicators of the foundation soil. 3. When necessary, relevant information on foundation pit excavation and artificial lowering of groundwater levels required for design and construction shall be provided.
Article 2-0-2 The arrangement of the boreholes shall be sufficient to evaluate the uniformity of the stratum soil in both the vertical and horizontal directions of the building. The number of boreholes for each individual high-rise building shall not be less than four, of which no less than two shall be control boreholes. The spacing between boreholes shall be determined according to the complexity of stratum changes and the specific requirements of buildings, in accordance with the provisions of the spacing between exploration points for Class I buildings in the Code for Geological Survey for Industrial and Civil Construction Engineering (TJ21-77), but the maximum spacing shall not exceed 35 meters. Article 2-0-3 The depth of the controlled borehole is generally 1.0 to 2.0 times the width of the box foundation from the bottom surface of the foundation. If bedrock, solid soil or soft strata are encountered within this depth range, Article 30 of the Code for Geological Survey for Industrial and Civil Construction Engineering Construction (TJ21-77) shall be followed. Article 2-0-4 The quality of drilling sampling shall be guaranteed. If necessary, in-situ tests such as static and dynamic penetration, wave velocity test, cross plate shear test and static load test can be carried out in areas with conditions. For dynamic penetration test, the standard penetration depth of the borehole may not be limited to 21 meters. Article 2-0-5 In geotechnical tests, a certain number of shear tests and consolidation tests should be included.
For major projects or projects with scientific research value, the following or other tests should be carried out to make a comprehensive evaluation of the strength and deformation of the foundation. 1. Consolidation test of initial consolidation pressure and repeated loading and unloading; 2. Triaxial compression test.
Chapter 3 Foundation Calculation
Article 3-0-1 The foundation of the box foundation should be subjected to strength and deformation calculations, and the stability of the foundation should be verified when necessary.
Article 3-0-2 The base pressure P, Pmax, and Pmn of the box foundation shall be calculated according to formulas (13), (14), and (15) in the Code for Design of Foundations for Industrial and Civil Buildings (TJ7-74) (the buoyancy of groundwater shall be deducted from the foundation part below the groundwater level), and shall meet the requirements of the following formulas: 1. Non-seismic area
Pmax<1.2R
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(3-0-2-1)
(3-0-2-1)
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Pmin>0||tt| |III. Earthquake Zone
(3-0-2—3)
The load combination shall be implemented in accordance with the Code for Seismic Design of Industrial and Civil Buildings (TJ11-78). In addition to meeting the requirements of formulas (3-0-2-1) and (3-0-2-2), the foundation strength shall also meet the requirements of the following formula: Pmaxy[R]
(3-0-2—4)
In the formula, R and [R] shall be determined in accordance with the Code for Seismic Design of Industrial and Civil Buildings (TJ7-74) or according to regional experience (tons/m2);
Ya shall be determined in accordance with the Code for Seismic Design of Industrial and Civil Buildings (TJ11-78).
Article 3-0-3 The final settlement of the box foundation is obtained by multiplying the foundation deformation value calculated by the layered summation method by the empirical coefficient m. The empirical coefficient m can be determined according to regional experience or by referring to Appendix 1. Article 3-0-4 The overall inclination of the box foundation can be calculated based on the eccentricity of the load, the unevenness of the foundation, the influence of adjacent loads and regional experience.
Article 3-0-5 The allowable settlement and overall inclination value of the box foundation should be determined according to the regional building experience, taking into account the use requirements of the building and the influence on adjacent buildings. However, the calculated value of the lateral overall inclination α should meet the requirements of the following formula in non-seismic areas:
W—the width of the box foundation (meters);
H—the height of the building (meters).
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(3-0-5)
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Chapter 4 Foundation Design and Construction Requirements
Article 4-0-1 The plane dimensions of the box foundation should be determined based on the foundation strength, the layout of the superstructure, and the load distribution. For a single building, under the condition of uniform foundation, the centroid of the base plane should coincide with the centroid of the vertical static load of the structure, and the eccentricity should not be greater than 0.10.1p. p is calculated as follows: W
W is the moment of resistance of the bottom surface of the foundation (m); F
is the area of ​​the bottom of the foundation (m).
(4-0-1)
Article 4-0-2 The height of the box foundation
is generally taken as 1/
8~1/12 of the building height, and should not be less than 1/18 of the length of the box foundation. Note: The length of the box foundation does not include the cantilevered part of the bottom plate. Article 4-0-3 In the same unit of a high-rise building, the box foundation should not be used locally. Continuous windows shall not be set on the outer wall of the box foundation. When continuous window wells must be set, the openings shall meet the requirements of Article 4-0-13. Article 4-0-4 The outer walls of the box foundation are arranged along the four sides of the building, and the inner walls are generally arranged evenly along the upper structure column grid and shear wall. The average wall length per square meter of foundation area shall not be less than 40 cm or the horizontal cross-sectional area of ​​the wall shall not be less than 1/10 of the foundation area. The longitudinal wall configuration shall not be less than 3/5 of the total wall configuration.
Note: 1. The foundation area does not include the cantilevered part of the bottom plate; 2. When calculating the wall length or horizontal cross-sectional area, the opening part is not deducted. Engineering Construction Standard Full Text Information System
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Pmin>0
3. Earthquake Zone
(3-0-2—3)
The load combination shall be implemented in accordance with the "Code for Seismic Design of Industrial and Civil Buildings" (TJ11-78). In addition to meeting the requirements of formulas (3-0-2-1) and (3-0-2-2), the foundation strength shall also meet the requirements of the following formula: Pmaxy[R]
(3-0-2—4)
Wherein, R and [R] shall be determined in accordance with the "Code for Seismic Design of Foundations for Industrial and Civil Buildings" (TJ7-74) or according to regional experience (tons/m2);
Ya shall be determined in accordance with the "Code for Seismic Design of Industrial and Civil Buildings" (TJ11-78).
Article 3-0-3 The final settlement of the box foundation is obtained by multiplying the foundation deformation value calculated by the layered summation method by the empirical coefficient m. The empirical coefficient m can be determined according to regional experience or in reference to Appendix 1. Article 3-0-4 The overall inclination of the box foundation can be calculated based on the eccentricity of the load, the unevenness of the foundation, the influence of adjacent loads and regional experience.
Article 3-0-5 The allowable settlement and overall inclination value of the box foundation should be determined according to regional building experience, taking into account the use requirements of the building and the impact on adjacent buildings. However, the calculated value of the lateral overall inclination α should meet the requirements of the following formula in non-seismic areas:
Where B is the width of the box foundation (meters);
H is the height of the building (meters).
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(3-0-5)
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Chapter 4 Foundation Design and Construction Requirements
Article 4-0-1 The plane dimensions of the box foundation shall be determined based on the foundation strength, the layout of the superstructure, and the load distribution. For a single building, under the condition of uniform foundation, the centroid of the base plane should coincide with the centroid of the vertical static load of the structure, and the eccentricity should not be greater than 0.10.1p. p is calculated as follows: W
W is the resistance moment of the foundation bottom surface (m); F
is the foundation bottom area (m).
(4-0-1)
Article 4-0-2 The height of the box foundation
is generally 1/
8~1/12 of the building height, and should not be less than 1/18 of the length of the box foundation. Note: The length of the box foundation does not include the cantilevered part of the bottom plate. Article 4-0-3 In the same unit of a high-rise building, the box foundation should not be used locally. Continuous windows shall not be set on the outer wall of the box foundation. When continuous window wells must be set, the openings shall meet the requirements of Article 4-0-13. Article 4-0-4 The outer walls of the box foundation are arranged along the four sides of the building, and the inner walls are generally arranged evenly along the upper structure column grid and shear wall. The average wall length per square meter of the foundation area shall not be less than 40 cm or the horizontal cross-sectional area of ​​the wall shall not be less than 1/10 of the foundation area. The longitudinal wall configuration shall not be less than 3/5 of the total wall configuration.
Note: 1. The foundation area does not include the cantilevered part of the bottom plate; 2. When calculating the length or horizontal cross-sectional area of ​​the wall, the opening part is not deducted. Engineering Construction Standard Full Text Information System
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Pmin>0
3. Earthquake Zone
(3-0-2—3)
The load combination shall be implemented in accordance with the "Code for Seismic Design of Industrial and Civil Buildings" (TJ11-78). In addition to meeting the requirements of formulas (3-0-2-1) and (3-0-2-2), the foundation strength shall also meet the requirements of the following formula: Pmaxy[R]
(3-0-2—4)
Wherein, R and [R] shall be determined in accordance with the "Code for Seismic Design of Foundations for Industrial and Civil Buildings" (TJ7-74) or according to regional experience (tons/m2);
Ya shall be determined in accordance with the "Code for Seismic Design of Industrial and Civil Buildings" (TJ11-78).
Article 3-0-3 The final settlement of the box foundation is obtained by multiplying the foundation deformation value calculated by the layered summation method by the empirical coefficient m. The empirical coefficient m can be determined according to regional experience or in reference to Appendix 1. Article 3-0-4 The overall inclination of the box foundation can be calculated based on the eccentricity of the load, the unevenness of the foundation, the influence of adjacent loads and regional experience.
Article 3-0-5 The allowable settlement and overall inclination value of the box foundation should be determined according to regional building experience, taking into account the use requirements of the building and the impact on adjacent buildings. However, the calculated value of the lateral overall inclination α should meet the requirements of the following formula in non-seismic areas:
Where B is the width of the box foundation (meters);
H is the height of the building (meters).
Engineering Construction Standard Full Text Information System
(3-0-5)
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Chapter 4 Foundation Design and Construction Requirements
Article 4-0-1 The plane dimensions of the box foundation shall be determined based on the foundation strength, the layout of the superstructure, and the load distribution. For a single building, under the condition of uniform foundation, the centroid of the base plane should coincide with the centroid of the vertical static load of the structure, and the eccentricity should not be greater than 0.10.1p. p is calculated as follows: W
W is the resistance moment of the foundation bottom surface (m); F
is the foundation bottom area (m).
(4-0-1)
Article 4-0-2 The height of the box foundation
is generally 1/
8~1/12 of the building height, and should not be less than 1/18 of the length of the box foundation. Note: The length of the box foundation does not include the cantilevered part of the bottom plate. Article 4-0-3 In the same unit of a high-rise building, the box foundation should not be used locally. Continuous windows shall not be set on the outer wall of the box foundation. When continuous window wells must be set, the openings shall meet the requirements of Article 4-0-13. Article 4-0-4 The outer walls of the box foundation are arranged along the four sides of the building, and the inner walls are generally arranged evenly along the upper structure column grid and shear wall. The average wall length per square meter of the foundation area shall not be less than 40 cm or the horizontal cross-sectional area of ​​the wall shall not be less than 1/10 of the foundation area. The longitudinal wall configuration shall not be less than 3/5 of the total wall configuration.
Note: 1. The foundation area does not include the cantilevered part of the bottom plate; 2. When calculating the length or horizontal cross-sectional area of ​​the wall, the opening part is not deducted. Engineering Construction Standard Full Text Information System
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