利用动三轴试验系统,对兰州、固原、潼关地区饱和原状黄土进行了液化试验。通过对饱和黄土液化的动应力、动应变和动孔压发展特点等问题的对比和分析,研究了我国不同地区饱和原状黄土的液化特性。研究表明:(1)黄土液化有其自身的特点,一旦发生液化,抗液化强度将迅速丧失;(2)黄土的区域性结构特性对黄土液化的影响非常明显,表现为不同地区、不同结构的黄土,其液化强度是不同的。而不同地区间黄土的干密度等物性指标对黄土液化的影响远小于区域性结构特性的影响;(3)基于黄土的结构破坏特性和液化特性,给出了饱和黄土的液化破坏应变标准。
With the dynamic triaxial apparatus,the liquefaction test is studied of saturated undisturbed loess sampled from Lanzhou,Guyuan,and Tongguan regions.Through comparing and analyzing the dynamic stress,dynamic strain,dynamic pore pressure,and other problems in saturated loess liquefaction,the liquefaction characteristics of saturated undisturbed loess is examined among different regions in China.The results indicate that,firstly,the liquefaction of loess has its own characteristics: once suffering liquefaction,the anti-liquefaction intensity will lose immediately.Secondly,the affection of regional loess structure is obvious to liquefaction,indicating that the liquefaction intensity of loess varies among different areas and structures,and the affection caused by dry density and other physical indexes of loess in different regions is much less than by regional structure.Thirdly,based on the speciality of structure break,the strain criterion about liquefaction break of saturated loess is put forward.