砂泥岩配合比对钢-土界面剪切特性影响的试验研究

Test Researches on Shearing Characteristics of Steel-soil Interface Considering Sandstone Mudstone Particle Ratio

通过控制试样级配、含水率及密实度,研究不同砂泥岩配合比对钢-土接触界面剪切特性的影响。试验设计砂泥岩配合比分别为0∶10、2∶8、4∶6、6∶4、8∶2、10∶0,在法向应力分别为100 kPa、200 kPa、300 kPa、400 kPa条件下观测不同砂泥岩配合比试样的水平位移和竖向位移的变化情况。通过引入含泥量m及摩尔-库伦准则,分析不同含泥量条件下,剪应力与水平位移的关系、抗剪强度以及水平位移与法向位移的关系,得出剪应力随水平位移的增加而增大并趋于稳定,且变化过程主要分为三个阶段:弹性阶段、塑性阶段和破坏阶段;钢-土接触界面的抗剪强度符合摩尔-库伦准则,通过摩尔-库伦准则反算出内摩擦角和界面黏结力,发现随着含泥量逐渐增大,黏结力呈线性增大而内摩擦角呈抛物线递减;法向位移随着含泥量的增加而增大。

Shear properties of contact interface between steel and soil which were influenced by different mud- stone sandstone particle ratio were studied under fixed gradation, moisture content and dry density. The sandstone mudstone particle ratio was designed from 10： 0, 8： 2, 6： 4, 4： 6, 2：8 to 0：10 in tests. The change of horizontal displacement and vertical displacement was observed with different sandstone mudstone particle ratio under normal stress from 100 kPa, 200 kPa, 300 kPa to 400 kPa. Relations between shear stress and horizontal displacement, changes of shear strength＇ and relations between horizontal displacement and vertical displacement were analysed by the introduction of mud content and Mohr-Coulomb Failure Criterion. Some results are gotten ： ①The shear stress is increased to a stable value with the increasing horizontal displacement and the process is consisted by elastic stage, plastic stage and failure stage. ②Shear strength of interface between steel and soil is accord with Mohr-Coulomb Failure Criterion and the cohesive force is increased linearly with the increasing mud content and the internal fric- tion angle is decreased parabolically. ③Vertical displacement is increased with the increasing mud content.