基于排水法砂土地基抗液化评估方法对比

传统的抗液化措施以密实法为主,对于细粒含量高的砂性土,由于密实效果有限,需要采用基于排水法的抗液化措施,而目前国内标准中尚无以排水法为主的抗液化设计方法。针对国内外常用的排水法抗液化设计方法,通过选取的工程案例进行计算,对不同方法的差异性进行分析。结果表明,等应变模型方法与自由应变模型方法相比,计算公式简单,方便工程推广应用;不考虑井阻的方法计算得到的孔压比仅为考虑井阻时的10%~24%;等应变模型王四根法计算的超孔压比随深度增加而增加,与实际液化调查规律相符,但计算的最大值和平均值均比Onoue法和吴世明法偏大。

Comparison of different assessment methods against liquefaction for sand foundation based on drainage method

The main traditional remedial measure against liquefaction is the compaction method,but it has a limited compaction effect for silty sand soil layer with high fines content.The measure based on drainage method is needed,however,there is no relevant assessment method providing in nation standard for reference.Based on the different assessment methods for drainage criterion against liquefaction from domestic and international researchers,we carry out the calculation for selected engineering and analyze the differences of methods.The results show that the equal strain method is simpler when comparing with the free strain model method,thus it is more convenient for engineering application.The computational excess pore pressure ratio based on the method without considering well resistance is only 10%to 24%than the method with considering well resistance.The computational excess pore pressure ratio from Wang Sigen's method of equal strain model increases with depth,which is consistent with the site liquefaction survey.Further,the average and maximum value from Wang Sigen's method is higher than Onoue's and Wu Shiming's methods.