鉴于1976年唐山大地震后液化调查手段及液化评价方法研究的局限性，开展液化和非液化区的现场再调查是非常有用的。采用符合国际标准的多功能地震波孔压静力触探(SCPTu)在唐山及其邻近地区进行调查试验，为场地液化再调查提供近似连续的锥尖阻力、侧壁摩阻力、孔压及剪切波速数据。通过18个试验点的SCPTu、室内试验及历史震害调查资料的综合比较，对各场地现今的液化可能性进行分析，并对国内外常用的几种液化判别方法进行分析研究。国内规范法、国际常用的Robertson确定性方法及Moss概率方法的分析结果均表明，曾经发生过液化的场地现今仍然容易发生液化；基于CPTu的Robertson确定性方法及基于贝叶斯理论的Moss概率方法各有优缺点，均有完善的计算流程，前者在液化后场地沉陷及侧向大变形预测方面具有优势，后者可以给出各试验点的液化概率，进而服务于基于概率的工程抗震评估与设计；由于 SCPTu 试验技术在国内发展缓慢，现今基于 SCPTu的几种国际常用液化评价方法在国内应用较少，也是今后在技术手段突破后急需加深研究的方向。%Due to the limitations of investigating instruments and liquefaction evaluation methods after the 1976 Tangshan earthquake,it is very useful to perform the re-investigations at liquefaction and non-liquefaction sites nowadays. The multifunctional seismic piezocone penetration test(SCPTu) method was used for this work. The nearly continuous profiles of tip resistance,sleeve friction,pore water pressure,and shear wave velocity were obtained. The liquefaction potential of testing sites was evaluated by comparing the SCPTu measurements,the indoor experiments and historical investigation data. Several popular CPTu-based liquefaction evaluation methods at home and abroad were analyzed particularly. Results from Chinese Standard method,Robertson deterministic method and Moss probabilistic method indicate that most of the testing sites that liquefied during the 1976 Tangshan earthquake will liquefy again. The CPTu-based Robertson deterministic method and the Moss probabilistic method based on Bayesian theory show respective advantages and disadvantages. Both of them have reasonably comprehensive calculation procedures. The Robertson deterministic method has special advantage in predicting vertical settlement and lateral large deformation,while the Moss probabilistic method can present the liquefaction probability for every site and serve for the seismic evaluation and engineering design. However,due to the slow development of SCPTu technique in China,kinds of current international CPTu-based liquefaction evaluation methods are seldom used,which require further study after technology have been breakthrough in future.
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