水泥土-混凝土界面特性试验研究

Experimental Research on Interfacial Performance between Cement Treated Soil and Concrete

水泥土-混凝土的界面特性是控制劲性复合桩竖向承载力和沉降特性的关键参数。文章设计了水泥土-混凝土制样方法,通过直剪试验研究了水泥土-混凝土界面特性,并分析了水泥土中水泥掺入量、混凝土强度等对界面特性的影响规律。试验结果表明,混凝土-水泥土破坏面位于两者交界面上;水泥土强度较低时,界面破坏模式为塑性破坏,随着水泥土强度的提高,脆性特征逐渐显现,破坏模式由塑性破坏转为脆性破坏;界面剪切强度与法向应力符合库伦定律;在一定的水泥土无侧限抗压强度范围内,界面黏聚力与水泥土无侧限抗压强度符合近似线性函数,但界面摩擦角与水泥土强度之间的相关度不密切;界面剪切强度约为水泥土无侧限抗压强度0.188倍。

The interfacial feature between cement treated soil and concrete is a key parameter to control the vertical bearing capacity and settlement characteristics of the composite pile. The interracial feature was analyzed by direct shear tests and a sample preparation method for cement treated soil-concrete is developed, and the influence of cement treated soil strength and concrete strength on the interface characteristics were also investigated. Tests results show that the destruction always occurs on the interface. The failure mode changes from plastic failure to brittle fracture with the increasing of cement treated soil unconfined compressive strength. The interface shear strength and normal stress are in line with Coulomb＇ s law. There is a linear relationship between interface cohesion and unconfined compressive strength of cement treated soil within a certain range. However, the angle of friction is independent of strength of cement treated soil. The interracial shear strength of about O. 188 times the unconfined compressive strength of cement treated soil.