吉图珲高铁深路堑膨胀土工程特性的试验研究

以新建吉图珲高速铁路GDK275+470~GDK276+432段深路堑工程为依托，对边坡膨胀土进行了物理特性、胀缩特性、强度特性、冻融特性等试验。研究结果表明:膨胀土具有高含水率、低密度的特征；膨胀土的膨胀率与含水率及上部垂直荷载呈负相关，与压实度呈正相关，压实越紧密，其膨胀率越高；在临界含水率以内时，膨胀土含水率与抗剪强度参数之间存在线性相关关系；土体黏聚力随着冻融循环次数的增加，降低至初始值的80%左右，但冻融循环次数对内摩擦角的影响较小。

Experimental Research on Engineering Characteristics of Deep Cut Expansive Soil for Jituhui High-speed Rail

Relying on deep cut project of GDK275+470~GDK276+432 section of newly built Jituhui High-speed Rail, the physical property, expansion and shrinkage characteristics, strength characteristics, freezing and thawing behavior test were carried out for the slope expansive soil. The research results show that the expansive soil has high water content and low density; the expansion rate and moisture content of expansive soil are negatively related to upper vertical load and positively related to the compaction degree. The closer the compaction is, the higher the expansion rate is. Within the critical water content, the water content has linear correlation with shear strength parameters; the soil cohesion will be decreased to about 80% of initial value with the increase of freezing and thawing cycle, but the freezing and thawing cycle has minor influence on the internal frictional angle.