Calculation Of Vertical Pile Bearing Capacity By CPTU Method

The Cone Penetration Test(CPT)has become the mostly used and accepted test methods for determining geotechnical soil properties.The methods for the assessment of pile capacity in terms of its sleeve friction(fs)and tip resistance(qc)have followed a constant evolution over the past many decades.The force measurements collected during testing include cone tip resistance(qc)and the sleeve friction(fs)along the shaft(sleeve)of the penetrometer.This paper will focus on the use of Cone Penetration Test(CPT)data for the computation of bearing capacity for axially loaded pile in YIZHENG windmill power project site.Project objectives are to conduct literature review on existing methods of direct vertical pile bearing capacity prediction using CPT data.To collect information on in-service foundation piles and soil characteristics in YIZHENG Wind power Engineering Construction site and analyse load test data/installation records to determine accurate bearing capacity.Conduct calculations of vertical pile capacity by different CPT/CPTU based methods and to compare different methods to load test results and give suggestion to the application of CPTU based method for estimating vertical pile capacity in practice.Eight CPT tests were conducted on the site to classify soil.In this study the CPT/CPTU based methods were used to estimate and compare the results of static load test and CPT predictions.The study showed that Eslami and Fellenius(1997),Takesue et al.(1998)have showed very close results to the static load test and stood First among all the methods to estimate the ultimate bearing capacity of bored piles.Chinese CPT Method for calculating the vertical pile bearing capacity has also shown close prediction with the above mentioned methods.The research will be significant and beneficial to the application of CPT/CPTU-based methods in the estimation of vertical pile capacity in pile foundation design.