The Difference Of Dianchi Kunming Shear Wave Velocity Test Results And It Impact On Classification Of Site

The shear wave velocity is one of the important indexes of soil dynamic mechanics, and it is a basic dynamic parameters for the seismic assessment of building field, and shear wave velocity of rock and soil can only be measured in field, so in China Code for investigation of geotechnical engineering, which clear require to test soil shear wave velocity, and provided specific test methods. But engineering practice shows that the same method was used for multiple shear wave velocity test which have some differences results. Although shear wave velocity value is uncertain, but it will fluctuate within a certain range, so uncertainty of the test results of the shear wave velocity will certainly affect the seismic evaluation results. First of all this research is preliminary discussion on the uncertain results of shear wave velocity test, especially the change range. and to explore the influence of site classification.This paper is to study the uncertainty of shear wave velocity from engineering significance,in the research using single hole method to collecte sample.Ragard Dianchi Yunnan as research object,On the basis of Complying with the relevant test operation requirements strictly. Through testing a pilot hole that use the instrument of same type and the instrument of same type of different testing company do many tests.According to analysis the measured shear wave velocity which get the following conclusions(1) The shear wave velocity of different test points is different that present obvious uncertainty features. The shear wave velocity of each test point can be classified into two categories, they are Normal distribution type and Skewness distribution type that checked by chi square distribution. This phenomenon shows that the value of shear wave velocity is discrete, but it also has relatively stable characteristic.(2) The change ranges of the relative average that 95% 85% 75% reference ranges of shear wave velocity of each point were calculated by using percentile method, and getting probabilities of different reference intervals.(3) The uncertainty of the shear wave velocity for the classification of the site categories, The equivalent shear wave velocity of each test in this research field has little change and There is no obvious effect on the classification of the site, but the influence depends on the difference between the average value of the shear wave velocity and the value of the division of the field. The equivalent shear wave velocity difference is large that impact on the site classification is obviously.