论文部分内容阅读
通过黏性土与不同表面粗糙度混凝土板的室内直剪试验,模拟预制桩的界面受力性态。利用微型硅压阻式传感器测定桩-土界面孔隙水压力和土压力的变化,定量分析表面粗糙度对界面抗剪强度参数、界面阻力-剪切位移曲线的影响。试验结果表明:桩-土界面孔隙水压力约占法向应力的10%,实际工程中应考虑;提出桩-土界面阻力的概念,界面阻力由黏性土与混凝土之间黏着力和摩擦力两部分构成,其中摩擦力为界面法向有效土压力与界面摩擦系数的乘积。随着混凝土表面粗糙度的增加,界面黏着力增大且逐渐接近黏土自身黏聚力。表面粗糙度对界面摩擦系数影响较小,但对界面阻力有一定影响,桩-土界面峰值阻力和剪切位移均随粗糙度的增加而增大。试验结果能够为桩基工程的设计、施工与检测提供参考依据。
Through the direct shear test of clay with different surface roughness concrete slabs, the interface behavior of precast piles was simulated. The micro-silicon piezoresistive sensor was used to measure the changes of pore-water interface pore pressure and earth pressure, and the influence of surface roughness on interface shear strength parameters and interfacial resistance-shear displacement curves was quantitatively analyzed. The experimental results show that the pore-water pressure at the pile-soil interface accounts for about 10% of the normal stress and should be considered in practical engineering. The concept of pile-soil interfacial resistance is proposed. The interfacial resistance is determined by the cohesion and friction between cohesive soil and concrete Two parts constitute, among them the frictional force is the product of the normal effective earth pressure of the interface and the interface friction coefficient. As the surface roughness of concrete increases, the interfacial adhesion increases and gradually approaches the cohesion of the clay itself. The surface roughness has little effect on the friction coefficient of the interface, but it has some influence on the interface resistance. The peak resistance and the shear displacement of the pile-soil interface increase with the increase of the roughness. The test results can provide reference for the design, construction and testing of pile foundation engineering.