The Chinese method for calculating the liquefaction probability of gravelly soils based on shear wave velocity

Assessing the risk of earthquake-induced liquefaction in gravelly soils is a new challenge faced by earthquake prevention and disaster reduction efforts in China's engineering sector. In situ shear wave velocity testing is a universally applicable technical method; however, existing methods are not suitable for China. This study establishes a new method for calculating the liquefaction probability of gravelly soils based on shear wave velocity under the Chinese model, and compared it with the CYY (Cao, Youd and Yuan) method, which is based on the CSR (cyclic stress ratio) theory. The comparative analysis using measured data as well as different probability liquefaction threshold models indicates that the proposed Chinese model for calculating the liquefaction probability of gravelly soils based on shear wave velocity can solve the problem of CYY method unsuitable for China and is more advanced than the CYY method. It overcomes the shortcomings of the CYY method, which struggles to simultaneously consider different burial depths of gravelly soil layers and the effects of varying seismic intensities. Both in the deterministic discrimination with a probability of 0.5 and in the reliability of liquefaction probability calculation under measured data, the method proposed in this paper outperforms the CYY method. The proposed formula in this paper has been adopted in the revised version of the General Rules for Performance-Based Seismic Design of Buildings, serving as a model for China, and can provide guidance and technical support for related specifications and engineering applications.