郑西客运专线黄土路基震陷研究

以郑（州）—西（安）高速铁路为例，选择潼关段为研究区，采集大量原状黄土样品，将合成的人工地震动输入到动三轴，进行了固结不排水的动三轴实验，估算了黄土路基的震陷量。建立了高速铁路黄土路基动力学数值模型，研究了50年10%和2%的超越概率水平的地震作用下黄土路基的永久变形，以及地基处理后黄土地基的永久变形。结果显示, 沉降主要发生在Q3黄土中，强夯、DDC桩等地基处理措施可以有效的减少地基黄土的沉降变形，但是当处理深度不够时，在强地震作用下仍然可以产生较大沉降。研究成果为地基抗震处理提供了依据。

LABORATORY AND NUMERICAL STUDIES ON SEISMIC SUBSIDENCE OF LOESS SUBGRADE |ALONG ZHENGZHOU—XI′AN HIGH-SPEED RAILWAY

This paper is about the Zhengzhou-Xi'an high-speed railway, in particular, the  Tongguan section about their potential seismic subsidence.   A large number of undisturbed loess samples were collected  at Tongguan section.  By inputting artificial synthetic seismic wave to the dynamic triaxial testing of the samples, the seismic subsidence experiments were carried out. Based  the laboratory tests,  the paper obtains  the following results.  Firstly, the seismic subsidence of loess foundation  was estimated and the foundation dynamic numerical model  was established. Secondly, It further examined the permanent deformation of the sub-grade loess at the levels of 10% and 2% exceedance probability in 50 years under the earthquake effect and the sub-grade loess after soil treatment.  The results showed that, the settlement occurred mainly in Q3 loess. The foundation treatment measures such as dynamic compaction, down-hole dynamic consolidation can effectively reduce the settlement of the loess foundation.  However, larger settlement can still be generated under strong earthquakes  if the soil treatment depth is not deep enough. The  results presented in the paper can provide  a basis for the foundation seismic treatment.