铁路路基砂土地震液化及其加固措施

Considerations on the Liquefaction of Soils for Railway Subgrade the Mitigations

砂土在地震力的作用下变形及稳定与其物理力学性质和结构组成密切相关,且地震对地下结构的破坏,是随其埋深的增加而减轻的,对铁路路基工程而言,在路基本体及周围特定的地质环境条件以及运营过程中列车振动及冲击力的反复作用下,部分改变了原地基的物理力学性质,地基土抗震液化强度也随之改变,使问题变得更为复杂。因此,依据铁路路基工程的实际情况,进行砂土物理力学性质及抗液化强度试验,划分液化区与非液化区对路基工程的设计及加固是十分必要的。

Since the Niigata Earthquake in Japan and Alaska Earthquake in the United States in 1964, Xingtai Earthquake in 1966 and Wenehuan Earthquake in 2008 in China, soil liquefaction has been paid much attention than ever before. In China, in addition to the detailed site seismic investigation and surveying, research work has been conducted on the test equipment such as dynamic triaxial apparatus, laboratory research on the seismic properties of sand, research on liquefaction evaluation method of sandy soils. Research results indicate that, the deformation and the stability of sandy soils under the action of seismic force are closely related to their physical and mechanical properties, the structural compositions. The seismic damage to the under- ground structures decreases with the increase of their embedment depths. For the rail.way subgrades, under cyclic impacts from the train and the other vibration sources, the soil properties have changed from their initial conditions and result in more com plicated conditions for the seismic liquefaction evaluation. Therefore, the testing on the subgrade soils has a significant impor tance on the liquefaction evaluation.