强震作用下不同处理方式黄土地基抗震陷性能评价

Evaluation of Aseismic Subsidence of Loess Foundation with Different Ground Treatments under Strong Earthquake

由于黄土高原区抗震设防标准长期偏低,无法承受强震带来的严重灾害链后果,因此为了提高地基及公路路基的抗强震能力,以强震动荷载为试验输入条件,以强夯、粉煤灰、水泥土等三种地基改性处理试样为研究对象,对其进行室内动三轴试验,寻找针对震陷性黄土工程场地更加经济、科学的抗震陷地基处理方法,研究不同地基改性处理方法在强震动荷载下的残余应变特性,得到强震作用与残余应变的定量关系,并从变形特征和动载振次两个角度对比三类方法的适用性。在此基础上,估算场地不同地基处理方式下的震陷量,给出强震荷载下不同工程场地有效的抗震陷处理方法与评价办法,为黄土场地抗震设计和地基处理提供参考依据。

In the search for more scientifically-sound and economical foundations for seismic subsidence loess sites experiencing strong earthquakes,indoor dynamic triaxial tests were carried out on samples of three types of foundation.The samples were modified through treatment with fly ash,cement soil,and dynamic compaction.The residual strain characteristics of the different foundation modification treatments under strong earthquake conditions were analyzed,and the quantitative relationship between strong earthquakes and residual strain were obtained.The applicability of the three treatment methods were compared from two perspectives:that of deformation characteristics,and that of cyclic number of dynamic load.Based on these tests,the amount of seismic subsidence in the loess site under different methods was estimated,and the proven effective treatment and evaluation methods for different engineering sites under strong earthquake load are given.The study can provide some reference for seismic design and foundation treatment of loess sites.