Abstract: Although the sandy soil liquefaction under a seismic event is one of the major hazards in the geotechnical engineering, the soil liquefaction evaluation and prediction of the potential are difficult, and the in-situ testing evaluation methods are usually used. This paper presents various sandy soil seismic liquefaction evaluation methods by using in-situ testing methods. Earthquake damage of sands liquefaction is one of the most serious engineering disasters in geotechnical engineering. In situ test methods are often used to evaluate liquefaction because of the liquefaction evaluation and prediction is difficulty. Relying on the Chibi Yangtze River Highway Bridge Project, we analysis the domestic code methods and Seed simplified methods, and the engineering characteristics of each sands, then liquefaction evaluation of each sand layer is carried out by using shear wave test and standard penetration test respectively. The research results show that: the discrimination depth of “code for Investigation of Geotechnical Engineering” and “Code For Seismic Design Of Building” is relatively shallow, within the range of 20m, and the former is conservative for the use of SPT blow to discriminate sands liquefaction; compared with the code methods, seed simplified methods provide various calculation formulas, and can provide further discrimination for deep sands liquefaction, the discrimination results can be used as a supplement to the cod methods; the comprehensive comparison and analysis of various insitu testing methods are helpful to improve the accuracy of sand liquefaction identification.

Key words: shear waves velocity, standard penetration test, liquefaction of sandy soils, code methods, seed simplified methods