夯实水泥土桩-土界面摩擦特性试验研究

Interface Friction Characteristics of Soil and Compacted Soil-Cement-Mixed Columns

夯实水泥土桩属于典型摩擦型桩,常用于处理大面积软土。为探究其桩土界面摩擦产生的原因及影响因素,通过一系列直剪试验,模拟了桩-土界面工作性状,探讨了夯实水泥土桩-土界面的接触特性,研究了水泥掺量、土的含水量、法向应力、养护龄期等因素对桩-土接触面摩阻力的影响规律。研究发现存在最优水泥配比,剪切带的影响范围与法向应力和摩擦角有关,龄期通过分阶段影响粘聚力和摩擦角提高接触面抗剪强度,研究结果对工程实践具指导意义。

The compacted soil-cement mixed column is a typical friction type of column and is commonly used in the treatment of large area of soft soils. To investigate factors that might impact the interface contact characteristics of the column-soil, a se- ries of direct shear tests were conducted. These factors are： cement content, soil moisture content, normal stress on the side of the column and curing age. The test results indicate that there is an optimum cement-soil ratio for the side friction behavior. The interface shear influence zone correlates with the normal stress and the international friction angle. The curing age will af- fect the cohesion and the internal friction angle and therefore, improves the shear strength of the interface.