GB 50202-2018Standard for acceptance of construction quality of building foundation (English PDF)

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.

2.0.1 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

3.0.1

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.

4.1 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.

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.