Technical standard for steel structure inspection

1.structure

1.1 Determination and calculation of slenderness ratio of steel structure bar can be measured according to the provisions of Section 6.4 of this chapter bar size, the actual size should be calculated rod length ratio.

1.2 The connection of the steel structure support system shall be carried out in accordance with the provisions of 6.3 of this Chapter; the dimensions of the support system components shall be determined in accordance with the provisions of Section 6.4 of this Chapter and shall be verified or assessed in accordance with the design drawings or corresponding design specifications.

1.3 The width ratio of the cross section of the steel structure shall be measured in accordance with the provisions of Section 6.4 of this Chapter and shall be evaluated in accordance with the design drawings and relevant specifications.

2.painting

2.1 The quality of steel structure protective coating, should be the current national product standards related to the provisions of the quality of paint testing.

2.2 steel surface rust level, available the current national standard "before the steel surface corrosion grade and rust level" GB8923 specified by the control observation to determine.

2.3 different types of coating thickness of the coating should be used to detect the following methods:

1 film thickness, can be measured with the film thickness gauge, the number of sampling components should not be less than the standard Table 3.3.13 in the A class of test samples of the minimum capacity, nor should not be less than 3; Each value is 3 points away from the 50mm measuring point dry film thickness of the average.

2 on the thin layer of fire retardant coating thickness, coating thickness tester can be used to detect the measurement method should be consistent with "steel structure fire retardant coating application technical regulations" CECS24 requirements.

3 on the thickness of the thick fire retardant coating coating, should be used needle and steel ruler detection, measurement methods should be consistent with "steel structure fire retardant coating application technical regulations" CECS24 requirements.

The thickness value and the deviation value of the coating shall be evaluated according to the provisions of GB50205 of "Specification for Construction Quality Acceptance of Steel Structure Engineering".

6.7.4 The appearance quality of the coating can be tested and evaluated according to the requirements of GB50205 according to the specification of "steel structure construction quality acceptance standard" according to different materials.

3.steel grid frame

3.1 steel grid detection can be divided into node bearing capacity, weld, size and deviation, bar unevenness and steel frame deflection and other projects.

3.2 steel grid welding ball joints and bolts ball node bearing capacity of the test, should be "grid structure engineering quality inspection and evaluation standards" JGJ78 requirements. For the existing bolt ball node grid, the node can be removed from the structure to carry out the ultimate bearing capacity of the node test. When taking the bolt ball node, take measures to ensure the safety of the structure.

3.3 steel grid in the weld, can be detected by ultrasonic testing methods, testing operations and assessment should be "welding ball joints steel mesh welding seam ultrasonic testing and quality grading method" JG / T3034.1 or "bolt ball node steel mesh Weld seam ultrasonic testing and quality grading method "JG / T3034.2 requirements.

3.4 steel grid in the appearance of the weld quality, should be "steel structure construction quality acceptance norms" GB50205 requirements for testing.

3.5 welding ball, bolt ball, high strength bolts and rod deviation detection, detection methods and deviation allowable value should be "grid structure engineering quality inspection and evaluation standards" JGJ78 provisions of the implementation.

3.6 steel frame steel pipe wall thickness, can be detected by ultrasonic thickness gauge, inspection should be removed before the decorative layer.

3.7 steel frame in the bar of the uneven plate, the cable can be used to detect the method, its unevenness shall not exceed one thousandth of the length of the bar.

3.8 steel frame deflection, can be used laser range finder or level of detection, every half-span range of measuring points should not be less than 3, and there should be a measuring point, the end of the distance from the end of the seat should not be greater than 1m.

4.structural performance test and dynamic test

4.1 For large-scale complex steel structure system can be in situ non-destructive load test, direct inspection of structural performance. Structural performance

Shall be carried out in accordance with the provisions of Appendix H of this Standard. The coefficient of loading and the principle of determination may be determined in accordance with the provisions of Appendix H.2, or may be adjusted as appropriate.

4.2 If there is any doubt as to the carrying capacity of the structure or components, a prototype or full-scale model load test may be carried out. The trial should be commissioned by a specialized agency with sufficient equipment capacity. A detailed test plan shall be developed before the test, including the purpose of the test, the selection or production of the test piece, the loading device, the measuring point arrangement and the test instrument, the loading step and the evaluation method of the test result. The test plan may be formulated in accordance with Appendix H and shall be subject to the consent of the parties concerned prior to the test.

4.3 For large-scale important and new steel structure system, it is advisable to carry out the actual structural dynamic test to determine the dynamic parameters such as the vibration period of the structure. Structural testing should conform to the provisions of Appendix E of this standard.

4.4 steel structure of the stress, according to the actual conditions selected resistance strain gauge or other effective method for testing.