桩-土接触面剪切性质室内单剪试验研究

土与混凝土桩的接触面力学行为随土的含水量变化.进行了17%、2O%、24%共3组含水量的土与混凝土桩接触面室内单剪试验,每组试验考虑5个法向应力.试验结果表明,在含水量一定时,接触面强度破坏仍遵循摩尔一库仑破坏准则;接触面的抗剪强度、摩擦角随含水量的增大非线性单调减小,粘聚力则先增大后减小.随着含水量和法向应力的增大,接触面的破坏位置逐渐由几何接触界面向土体内部过渡.法向应力较小时,含水量对接触面应力应变曲线的初始段影响不大.试验结果可供相关工程数值分析参考.

A Study on Laboratory Simple Shearing Test of Pile-Soil Interface

Water content of soil plays an important role in mechanism behavior of pile-soil interface.Experiments by using laboratory simple shear tests are performed on soil-concrete interfaces with 17%,20%,24%,three water contents,where five normal stresses are taken into account in each water content.The experimental data show that while water content is fixed,failure of interface still satisfies the Mohr-Coulomb criterion.With higher water content,shearing strength,friction angle of the interface all decrease monotonously and nonlinearly,but cohesion force of the interface first increases and then decreases after reaching a peak value.With water content increasing,failure position of the interface moves from concrete surface to soil inner part.The initial piece of stress-strain curve of interface is not sensitive to water content of soil.This experimental results put the good foundation for relative engineering numerical simulation.