1970年制订《工业与民用建筑抗震设计规范》(TJ11-74)时,根据解放后几次大地震,特别是1966年邢台地震的砂土液化现场勘察资料,首先定出砂土埋深为3米,地下水位深度为2米时的砂土液化临界标准贯入试验N值(基本临界N值),然后,以它为准,以砂土和地下水位埋深为变量进行开拓,取到线性项,即:N′=(?)[1+0.125(d_s-3)-0.05×(d_w-2)](1) When the “Code for the Seismic Design of Industrial and Civil Buildings” (TJ11-74) was drafted in 1970, based on several large earthquakes after the liberation, especially the site survey data of sand liquefaction in the 1966 Xingtai earthquake, the sand depth was first determined to be 3 m, the critical pebble penetration test N value (basic critical N value) when the depth of the ground water table is 2 meters, and then, subject to it, the sand and groundwater depth is used as a variable to develop, and linear Items, namely: N’=(?)[1+0.125(d_s-3)-0.05x(d_w-2)](1)