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In accordance with the requirements of Notice on printing and distributing the development and revision plan on engineering construction standards and codes in 2012 (JIANBIAO [2012] No. 5) issued by the Ministry of Housing and Urban-Rural Development, the drafting group of this standard has revised GB 50202-2002 Code for acceptance of construction quality of building foundation through the extensive investigation and study, careful summarization of practical experience and reference to relevant international and foreign advanced standards and on the basis of widely soliciting for opinions.
The newly revised standard is divided into 10 clauses and 1 annex, with main technical contents covering: general provisions, terms, basic requirements, ground engineering, foundation engineering, special soil foundation engineering, excavation protection engineering, groundwater control, earthwork, slope engineering, etc.
The main technical contents revised in this standard are: 1. the arrangement of clauses is adjusted; 2. terms of specific foundation names in the former standard are deleted while terms concerned with acceptance are added; 3. the basic requirements for acceptance are improved; the information submitted for acceptance and the procedures, contents and evaluation criteria of acceptance are added; 4. the vibro-replacement foundation and sand pile foundation are combined into stone column composite foundation; 5. acceptance requirements for non-reinforced spread foundation, reinforced concrete spread foundation, raft and box foundations, anchor foundation, etc. are added; 6. acceptance requirements for foundation pit supporting combining secant pile wall, soil reinforcement and main structure are added; 7. acceptance requirements for special foundation engineering are added; 8. acceptance requirements for groundwater control and slope engineering are added; 9. requirements for ground inspecting points are added; 10. requirements inconsistent with specific acceptance contents in the former standard are deleted.
The provisions printed in bold type in this standard are compulsory and must be enforced strictly.
Ministry of Housing and Urban-Rural Development is in charge of the administration of this standard and the explanation of the compulsory provisions; Shanghai Foundation Engineering Group Co., Ltd. is responsible for the explanation of specific technical contents. Any comment or suggestion, during the process of implementing this standard, shall be posted to Shanghai Foundation Engineering Group Co., Ltd. (Address: No. 406, Middle Jiangxi Road, Shanghai; 200002).
Contents
Foreword i
1 General provisions 1
2 Terms 1
3 Basic requirements 2
4 Ground engineering 3
4.1 General requirements 3
4.2 Soil and lime-soil foundation 4
4.3 Sand and sandstone foundation 5
4.4 Geosynthetics foundation 6
4.5 Flyash foundation 7
4.6 Dynamic consolidation foundation 8
4.7 Grouting consolidated foundation 9
4.8 Preloading ground 10
4.9 Stone column composite foundation 11
4.10 Jet grouting composite foundation 13
4.11 Cement-soil mixing pile composite foundation 14
4.12 Soil-lime compacted pile composite foundation 15
4.13 Cement flyash and gravel pile composite foundation 17
4.14 Tamping soil-cement pile composite foundation 18
5 Foundation engineering 19
5.1 General requirements 19
5.2 Non-reinforced spread foundation 21
5.3 Reinforced concrete spread foundation 22
5.4 Raft and box foundations 23
5.5 Reinforced concrete precast pile 24
5.6 Cast-in-situ pile with mud protection wall 26
5.7 Dry drilling cast-in-situ pile 28
5.8 Long spiral drill hole grouting pile 31
5.9 Driven cast-in-situ pile 31
5.10 Steel pile 32
5.11 Static press anchored pile 34
5.12 Foundation on rock-anchor system 36
5.13 Sunk well and caisson 36
6 Special soil foundation engineering 39
6.1 General requirements 39
6.2 Collapsible loess 39
6.3 Frozen soil 43
6.4 Expansive soil 47
6.5 Saline soil 48
7 Foundation pit supporting engineering 49
7.1 General requirements 49
7.2 Contiguous bored pile wall 50
7.3 Sheet pile wall 56
7.4 Secant pile wall 58
7.5 Soil mixed wall 59
7.6 Soil nailing wall 60
7.7 Diaphragm wall 62
7.8 Gravity cement-soil wall 66
7.9 Soil reinforcement 67
7.10 Strut 68
7.11 Anchor 70
7.12 Foundation pit support combined with main structure 71
8 Groundwater control 72
8.1 General requirements 72
8.2 Dewatering and drainage galleries 73
8.3 Recharge 78
9 Earthwork 79
9.1 General requirements 79
9.2 Excavation of earthwork 80
9.3 Excavation of rock foundation pit 82
9.4 Earthwork stacking and transport 84
9.5 Backfilling of earthwork 86
10 Slope engineering 88
10.1 General requirements 88
10.2 Bolt-shotcrete support 88
10.3 Retaining walls 90
10.4 Slope excavation 91
Annex A Ground inspecting of foundation 93
Explanation of wording in this standard 97
List of quoted standards 98
Standard for acceptance of construction quality of building foundation
1 General provisions
1.0.1 This standard is formulated with a view to strengthening the construction quality management, unifying the acceptance of construction quality and ensuring the construction quality of building foundation.
1.0.2 This standard is applicable to the acceptance of construction quality of building foundation.
1.0.3 The acceptance of construction quality of building foundation shall meet the requirements stipulated in this standard and those in relevant current national standards.
2 Terms
2.0.1 inspection
activity in which the characteristics and performance of an item are measured, inspected and tested, and the results are compared with the requirements of the design and standard so as to determine the conformity of each performance
activity in which the building materials, components, equipment and appliances, after entering the construction site, shall be sampled from the construction site for laboratory inspection according to relevant requirements, provided that they meet the requirements of appearance quality inspection and quality certification document verification
2.0.2 acceptance
activity of confirming the conformity of engineering quality in written form according to the design document and relevant standards, upon passing the self-inspection by the construction organization
2.0.3 dominant item
inspection item dominating the quality, safety, energy conservation, environmental protection and main use functions of building engineering
2.0.4 general item
inspection item other than the dominant item
2.0.5 ground inspecting
activity of inspecting the conformity of ground after the foundation pit or foundation trench is excavated to the design bottom elevation
3 Basic requirements
3.3.1 Acceptance of construction quality of building foundation shall meet the following requirements:
1 Construction quality of foundation shall meet the acceptance requirements;
2 Quality acceptance procedures shall meet the acceptance requirements;
3 Engineering quality acceptance shall be conducted upon passing the self-inspection by the construction organization;
4 Quality acceptance shall be carried out for sub-section and sub-item works;
5 Quality acceptance shall be carried out for dominant items and general items.
3.0.2 The following information shall be submitted during the acceptance of foundation work:
1 Geotechnical engineering investigation report;
2 Design documents, joint review records of drawings and technical disclosure materials;
3 Engineering survey, positioning and setting-out records;
4 Construction organization’s design and special construction scheme;
5 Construction records and construction organization’s self-inspection assessment report;
6 Monitoring data;
7 Acceptance data of concealed work;
8 Testing and inspection report;
9 As-built drawings.
3.0.3 Inspection items implemented before and during construction shall be tabulated, and then recorded, checked and filed accordingly.
3.0.4 The foundation work must be subjected to ground inspecting, of which, the inspecting points shall meet the requirements of Annex A.
3.0.5 All quality inspection results of dominant items must comply with inspection criteria, while the acceptance rate of general items shall not be less than 80%.
3.0.6 The inspection quantity shall be subjected to sampling by inspection batches in accordance with corresponding clause (if any) in this standard while subjected to sampling inspection by inspection batches where there are no corresponding clauses in this standard. Division and sampling inspection quantity of inspection batches may be implemented in accordance with the requirements of GB 50300 Unified standard for constructional quality acceptance of building engineering.
3.0.7 Where the strength assessment of standard test piece of foundation does not meet relevant requirements, or the representativeness of the test piece is doubtful, such test piece shall be subjected to strength testing, and may be accepted if the testing result conforms to design requirements.
3.0.8 Quality inspection for raw materials shall meet the following requirements:
1 Quality inspection of raw materials such as steel bar and concrete shall meet the requirements of design and GB 50204 Code for acceptance of constructional quality of concrete structures;
2 The approaching, welding or connection testing of raw materials and finished products such as steels, welding materials and connecting pieces shall meet the requirements of design and GB 50205 Code for acceptance of construction quality of steel structures.
3 The quality, inspection items, batches and inspection methods of raw materials such as admixtures and additives like sand, stone, cement, lime, flyash and ore (steel) slag powder shall comply with the relevant current national standard.
4 Ground engineering
4.1 General requirements
4.1.1 Quality acceptance of ground engineering should be carried out upon completion and after the interim period of construction; wherein, the interim period shall meet the requirements of design and the relevant current national standard.
4.1.2 The dimension of plate adopted for flat plate static load test shall be determined according to the requirements of design and relevant standard. The area of plate adopted for static load test on soil and lime-soil foundation, sand and sandstone foundation, geosynthetics foundation, flyash foundation, grouting consolidated foundation and preloading foundation should not be less than 1.0m2, while that adopted for static load test on dynamic consolidation foundation should not be less than 2.0m2. The dimension of plate adopted for static load test on composite foundation shall be determined according to the design replacement rate.
4.1.3 Upon the bearing capacity inspection of foundation, the maximum loading capacity for static load test shall not be less than twice the characteristic value required by the design.
4.1.4 The bearing capacity of soil and lime-soil foundation, sand and sandstone foundation, geosynthetics foundation, flyash foundation, dynamic consolidation foundation, grouting consolidated foundation and preloading foundation must meet the design requirements. For bearing capacity inspection of foundation, at least 1 point shall be inspected per 300m2, and at least 1 point shall be inspected per 500m2 in the area beyond 3000m2. At least 3 points shall be inspected for each unit work.
4.1.5 The bearing capacity of composite foundation such as stone column, jet grouting pile, cement-soil mixing pile, soil and lime-soil compacted pile, cement, flyash and gravel pile and rammed soil-cement pile must meet the design requirements. For the bearing capacity inspection of composite foundation, at least 0.5% of the total number of piles (not less than 3 points) shall be inspected. In case of any inspection requirement for single pile bearing capacity or pile shaft strength, at least 0.5% of the total number of piles (not less than 3 pieces) shall be inspected.
4.1.6 Items other than those specified in 4.1.4 and 4.1.5 shall be sampled by inspection batches. For the reinforcement of composite foundation, at least 20% of the total number shall be inspected.
4.1.7 For acceptance of foundation treatment work, where the result obtained by one inspection method is uncertain, other inspection methods shall also be adopted for comprehensive judgment.
4.2 Soil and lime-soil foundation
4.2.1 Prior to construction, the mix ratio of soil, lime-soil, lime or cement and the mixing uniformity of lime-soil shall be inspected.
4.2.2 During construction, the thickness of paved layer, the water quantity added for compaction, the compaction passes and the compaction coefficient shall be inspected.
4.2.3 On completion of construction, bearing capacity inspection shall be carried out for foundation.
4.2.4 The quality inspection criteria for soil and lime-soil foundation shall meet the requirements of Table 4.2.4.
Table 4.2.4 Quality inspection criteria for soil and lime-soil foundation
Item S.N. Inspection item Permissible value or permissible deviation Inspection method
Unit Value
Dominant item 1 Foundation bearing capacity ≥ design value Static load test
2 Mix ratio Design value Checking the volume ratio during mixing
3 Compaction coefficient ≥ design value Cutting ring method
General item 1 Lime particle size mm ≤5 Sieving analysis method
2 Organic content in soil % ≤5 Ignition loss method
3 Soil particle size mm ≤15 Sieving analysis method
4 Moisture content Optimum moisture content ± 2% Oven drying method
5 Layer thickness mm ±50 Measuring with a level gauge
4.3 Sand and sandstone foundation
4.3.1 Prior to construction, the quality, mix ratio and uniformity of raw materials such as sand and stone shall be inspected.
4.3.2 During construction, the layer thickness as well as the compaction condition, water quantity added, compaction passes and compaction coefficient of the overlapped part in section construction shall be inspected.
4.3.3 On completion of construction, bearing capacity inspection shall be carried out for ground.
4.3.4 The quality inspection criteria for sand and sandstone foundation shall meet the requirements of Table 4.3.4.
Foreword i
1 General provisions
2 Terms
3 Basic requirements
4 Ground engineering
4.1 General requirements
4.2 Soil and lime-soil foundation
4.3 Sand and sandstone foundation
4.4 Geosynthetics foundation
4.5 Flyash foundation
4.6 Dynamic consolidation foundation
4.7 Grouting consolidated foundation
4.8 Preloading ground
4.9 Stone column composite foundation
4.10 Jet grouting composite foundation
4.11 Cement-soil mixing pile composite foundation
4.12 Soil-lime compacted column composite foundation
4.13 Cement flyash and gravel pile composite foundation
4.14 Tamping soil-cement pile composite foundation
5 Foundation engineering
5.1 General requirements
5.2 Non-reinforced spread foundation
5.3 Reinforced concrete spread foundation
5.4 Raft and box foundations
5.5 Reinforced concrete precast pile
5.6 Cast-in-situ pile with mud protection wall
5.7 Dry drilling cast-in-situ pile
5.8 Long spiral drill hole grouting pile
5.9 Driven cast-in-situ pile
5.10 Steel pile
5.11 Anchor pile
5.12 Foundation on rock-anchor system
5.13 Sunk well and caisson
6 Special soil foundation engineering
6.1 General requirements
6.2 Collapsible loess
6.3 Frozen soil
6.4 Expansive soil
6.5 Saline soil
7 Foundation pit supporting engineering
7.1 General requirements
7.2 Contiguous bored pile wall
7.3 Sheet pile wall
7.4 Secant pile wall
7.5 Soil mixed wall
7.6 Soil nailing wall
7.7 Diaphragm wall
7.8 Gravity cement-soil wall
7.9 Soil reinforcement
7.10 Strut
7.11 Anchor
7.12 Foundation pit support combined with main structure
8 Groundwater control
8.1 General requirements
8.2 Dewatering and drainage galleries
8.3 Recharge
9 Earthwork
9.1 General requirements
9.2 Excavation of earthwork
9.3 Excavation of rock foundation pit
9.4 Earthwork stacking and transport
9.5 Backfilling of earthwork
10 Slope engineering
10.1 General requirements
10.2 Bolt-shotcrete support
10.3 Retaining walls
10.4 Slope excavation
Annex A Ground inspecting of foundation
Explanation of wording in this standard
List of quoted standards
