IN-SITU TESTS OF PILE FOUNDATION AT POWER PLANT IN SOUTHWEST OF SHANDONG PROVINCE

the foundation of a 2300MW pithead's power plant in southwest of Shandong province is located in alluvial layers of the Yellow River. The engineering properties of the strata are poor. The low foundation strength can't meet the needs of the key structures and buildings of the power plant. According to the geological conditions, foundation treatment has been conducted by high-strength pre-stressed concrete pipe. In the case study, we test the pile body with low strain integrity testing methods, determine the vertical ultimate bearing capacity of single pile using two methods such as high strain tests and static load tests, and contrast the advantages/disadvantages and affecting factors. Then we conclude the following three results.(1)Testing results by high strain CAPWAP method after fitting agree well with that by the vertical static load of a single pile. So it is likely to enhance the accuracy and reliability of high strain test results by optimizing the pile and soil parameters.(2)When it is not allowed for in-situ static load test, high strain tests can be used as a supplement means to the load test for pile foundation.(3)When we get more reliable high strain test results, some adjustments can be made for the design scheme according to standard method based on rigorous calculation.