Research on the Promotion and Application of Self-balanced Loading Test in Guangdong Province

The self-balanced loading test method has the advantages of strong field adaptability, simplicity, high efficiency and safety. Due to the large number of deep foundation pits, tight construction period and large tonnage of test piles in Guangdong, the self-balanced loading test method has been fully developed and applied in Guangdong. Several typical engineering examples of the self-balanced loading test method were introduced in detail, the application of this method in vertical compression/withdrawal static load test on piles, rock foundation load test on pile bottom bearing layer, deep plate loading test were briefly summarized, and the following conclusions were obtained through comparative analysis: The pile body concrete at the test pile load box is directly affected by the rational design of the load box. All excessively long hole-forming time, excessively thick mud skin, and excessively high pull-out coefficient may cause the actual measured value of the upper friction resistance of the cast-in-place pile to be lower than the theoretical calculated value. The extubation time and extubation speed should be controlled, and effective hole cleaning should be performed according to the specifications. When determining the pull-out coefficient, it is necessary to take values based on local experience or the field test results of the test pile.