Application Of High Strain Testing For Determining Of The Pile Bearing Capacity

Although pile foundation is the main form of the building foundations, on the researchof the pile foundation design, which determining pile bearing capacity is the key issue. Todetermine the vertical ultimate bearing capacity of a single pile, the high strain dynamictesting has unique advantages. For instance, don’t need static load testing of the anchor pileor goods, but short time, low cost, high efficiency and test pile foundation of the bigtonnage, etc. In the current application, calculation model of the parameter which is greatregional and subjectivity, the causes are changeable; In addition, on the actual operationprocess, hammer of the weight and whereabouts of the distance selection, all factors thattesting precision cause the influence of different level. In the high strain testing, the valueof pile-soil parameters and hammer of the weight selection are carried out in-depthanalysis and research, Hence, they have important theoretical significance and engineeringpractical value.Through introducing basic principle and method of the high strain dynamic testing, thedamping parameters selection of deficiencies are pointed out in this paper. The dampingparameterJ cneed artificial judgement and has a certain degree of subjectivity, but also itis related to soil indicator and has a certain degree of regionalism. Affect the test accuracyif damping parameter is selected improperly. This article based on the mass of monitor datawhich the pile engineering of Tangshan-caofeidian coastal regions. Contrast and analysebetween the testing results of static loading and dynamic high strain, under different soilconditions, give the experience values that damping parameter of high dynamic testing inthis region. In this region, as a reliable basis for the similar projects which determining thepile of bearing capacity.In the desert, Shanxi-Yanchang Petroleum Group subordinate Jingbian-chemicalindustry park of geological conditions, under the condition of different hammer weightwhich high strain testing, With the help of MIDAS/GTS software, the model of high straindynamic is established, under the condition of different heavy hammer, conducting highstrain testing, and analyse reinforced concrete filling pile which the relative displacementbetween pile-soil and friction force distribution rules of pile side, for the pile foundationdetection of high dynamic refer to the selection of reasonable hammer weight in desertareas.By the pile of bearing capacity of the contrast between the testing results of staticloading and dynamic high strain, and combining with the high strain dynamic of numerical analysis, discusses the reliability and surveying precision of CASE method and analysesthe error sources and reason and sums up the several measures to reduce dynamic testingerror, determine bearing capacity in pile foundation being a certain guiding significance tothe promotion and application of high stain dynamic testing.