JGJ 79-1991 Technical Specification for Building Foundation Treatment JGJ79-91
Some standard content:
Industry Standard of the People's Republic of China
Technical Specification for Construction Foundation Treatment
JGJ 79-91
Editor: China Academy of Building ResearchApproval Department: Ministry of Construction of the People's Republic of ChinaEffective Date: September 1, 19992
Announcement on Partial Revision of Engineering Construction Standards
No. 16
Industry Standard "Technical Specification for Construction Foundation Treatment" JGJ79-91 has been partially revised by China Academy of Building Research together with relevant units. It has been reviewed by relevant departments and the partially revised provisions are now approved for implementation from January 15, 1999. The corresponding provisions in the standard are abolished at the same time. This is hereby announced.
Ministry of Construction of the People's Republic of China
December 23, 1998
Notice on the Release of the Industry Standard "Technical Specifications for Building Foundation Treatment"
No. 19927116 of Jianbiao
According to the requirements of the former State Planning Commission's Letter of Bidding (1987) No. 3, the "Technical Specifications for Building Foundation Treatment" edited by the China Academy of Building Research has been reviewed and approved as an industry standard, numbered JGJ79--91, and will be implemented from September 1, 1992. This standard is managed by the China Academy of Building Research, the unit responsible for building engineering standards and technology of the Ministry of Construction, interpreted by the Foundation Institute of the China Academy of Building Research, and published and distributed by the Standard and Quota Research Institute of the Ministry of Construction. Www.bzxZ.net
Ministry of Construction of the People's Republic of China
March 7, 1992
A----foundation bottom area;
A—1The treatment area borne by the pile;
A,—the cross-sectional area of the pile;
b——the width of the bottom surface of the foundation;
D,—--relative density of sand;
d-pile body diameter;
d.—equivalent influence circle diameter;
d.——relative density of soil particles;
porosity ratio;
fk——standard value of foundation bearing capacity;
f..standard value of bearing capacity per unit cross-sectional area of the pile; fstandard value of bearing capacity of soil between piles,
composite Standard value of foundation bearing capacity;
Plasticity index;
1 Length of foundation bottom surface, pile length,
Area replacement rate,
Foundation bottom surface pressure,
Self-weight pressure of soil at foundation bottom surface,
Main symbols
Standard value of bearing capacity of natural foundation soil at pile end; Standard value of friction of soil around pile;
R——Standard value of vertical bearing capacity of single pile;
s-—pile spacing;
U—consolidation degree,
Wop—optimum water content;
Z————Thickness of cushion layer under foundation bottom surface;-Pressure diffusion angle;
Into compaction coefficient
Pa—dry density.
Chapter 1 General
Article 1.0.1 This specification is formulated to implement the national technical and economic policies in the design and construction of foundation treatment, to achieve advanced technology, economic rationality, safety and applicability, and to ensure quality. Article 1.0.2 This specification applies to the design and construction of foundation treatment for industrial and civil buildings (including structures). Article 1.0.3 In addition to meeting the requirements of engineering design, foundation treatment should also be adapted to local conditions, use local materials, protect the environment and save resources.
Article 1.0.4 In addition to implementing this specification, building foundation treatment should also comply with the relevant current national standards. The design of the foundation after foundation treatment shall be carried out in accordance with the relevant provisions of the national standard "Code for Design of Building Foundations" GBJ7-89. Chapter 2 Basic Provisions
Article 2.0.1 Before selecting a foundation treatment plan, the following work should be completed: 1. Collect detailed engineering geology, hydrogeology and foundation design data; 2. According to the design requirements of the project and the main problems of using natural foundations, determine the purpose of foundation treatment, treatment scope and various technical and economic indicators required to be achieved after treatment; 3. Combined with the project situation, understand the foundation treatment experience and construction conditions in the region and the foundation treatment experience and use of similar projects on similar sites in other regions.
Article 2.0.2 When selecting a foundation treatment plan, the co-effects of the superstructure, foundation and foundation should be considered, and after technical and economic comparisons, a foundation treatment plan or a plan combining strengthening the superstructure and treating the foundation should be selected. Article 2.0.3 The determination of the foundation treatment method should be carried out in the following steps: 1. According to the structure type, load size and use requirements, combined with factors such as topography, stratum structure, soil conditions, groundwater characteristics, environmental conditions and impact on adjacent buildings, preliminarily select several foundation treatment schemes for consideration: 2. For the various foundation treatment schemes preliminarily selected, conduct technical and economic analysis and comparison from the aspects of reinforcement principle, scope of application, expected treatment effect, material source and consumption of machinery and equipment conditions, construction progress and impact on the environment, and select the best foundation treatment method. If necessary, a comprehensive treatment method consisting of two or more foundation treatment measures can also be selected: 3. For the selected foundation treatment method, it is advisable to conduct corresponding on-site tests or experimental construction on representative sites according to the safety level of the building and the complexity of the site, and carry out necessary tests to verify the design parameters and treatment effects. If the design requirements are not met, the reasons should be found and measures should be taken or the design should be modified. Article 2.0.4 For the treated foundation, when the foundation bottom area and burial depth are determined according to the foundation bearing capacity and the standard value of the foundation bearing capacity determined in this code needs to be corrected, the foundation bearing capacity correction coefficient for the foundation width should be zero, and the foundation bearing capacity correction coefficient for the foundation burial depth should be 1.0.
Article 2.0.5 Foundation treatment technicians should master the purpose of foundation treatment, reinforcement principles, technical requirements and quality standards of the project they undertake. During construction, there should be a dedicated person responsible for quality control and monitoring, and construction records should be kept. When abnormal situations occur, they must be properly resolved in a timely manner in conjunction with relevant departments.
Article 2.0.6 During the construction process, there should be a dedicated person or a dedicated organization responsible for quality supervision. After the construction is completed, the project quality inspection and acceptance should be carried out in accordance with relevant national regulations.
Article 2.0.7 For buildings with treated foundations, settlement observations should be carried out during construction. For important buildings or buildings with strict settlement restrictions, settlement observations should continue to be carried out during use. Chapter 3 Replacement method
Section 1 General provisions
Article 3.1.1 The replacement method is applicable to shallow treatment of silt, silty soil, collapsible loess, plain fill, miscellaneous fill foundation, and culverts, ponds, etc.
When the replacement method is used to eliminate the collapsibility of loess, in addition to being implemented in accordance with the provisions of this code, it shall also comply with the relevant provisions of the national standard "Building Code for Collapsible Loess Areas" GBJ25-89. The use of large-area fill as a building foundation shall comply with the relevant provisions of the national standard "Code for Design of Building Foundations" GBJ7-89. Article 3.1.2 The design of the replacement cushion layer, the selection of replacement materials and the tamping construction method shall be carried out based on the building size, structural characteristics, load properties and geological conditions, combined with a comprehensive analysis of construction machinery and equipment and local material sources. Section 2
Article 3.2.1 The thickness of the cushion layer shall be determined according to the bearing capacity of the underlying soil layer and shall meet the following requirements: p.+p.
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