砂土—混凝土接触面剪切力学性状试验研究
发布时间：2018-08-18 17:38
【摘要】：土与结构物相互作用普遍存在于桩与桩侧土、挡土墙与墙后填土、隧道地下结构与周围土之间，土与结构物接触面相互作用的模拟对于分析结构物在荷载作用下的反应具有重要的意义。 本文首先利用Shear Trac-Ⅲ大型直剪仪研究了砂土-混凝土接触面在常法向应力/变法向应力作用下的剪切力学性状。在常法向应力作用下单调剪切过程中，松砂-混凝土接触面上剪应力-剪切位移关系曲线表现出应变硬化特征，而密砂-混凝土接触面上剪应力-剪切位移关系曲线表现出应变软化的特征。在常法向应力作用下循环剪切过程中，卸载时，松/密砂-混凝土接触面上剪应力-剪切位移之间呈现出线性关系；卸载后反向剪切，松/密砂-混凝土接触面上剪应力-剪切位移关系曲线均表现出应变硬化的特征。在变法向应力作用下单调剪切过程中，在第二级法向应力作用下，松/密砂-混凝土接触面上剪应力-剪切位移关系曲线均表现出应变硬化的特征。 然后，对试验结果进行拟合分析，建立了砂土-混凝土接触面剪应力-剪切位移关系数学模型。在常法向应力作用下单调剪切时，松砂-混凝土接触面剪应力-剪切位移关系可用双曲线表示，密砂-粗糙/光滑混凝土接触面剪应力-剪切位移关系可分别用三折线和双折线表示；在常法向应力作用下循环剪切时，松/密砂-混凝土接触面剪应力-剪切位移关系均可用双曲线与直线分段表示。在变法向应力作用下单调剪切时，松砂-混凝土接触面剪应力-剪切位移关系可用分段双曲线表示，，密砂-混凝土接触面剪应力-剪切位移关系可用折线和双曲线分段表示。 最后，根据松砂-粗糙混凝土接触面数学模型编写了FRIC子程序，并基于该模型分析了单桩在软基固结过程中桩身摩阻力、桩身中性点的发展变化规律。
[Abstract]:The interaction between soil and structure exists generally between pile and pile side soil, retaining wall and backfill, tunnel underground structure and surrounding soil, and the simulation of soil-structure interface interaction is of great significance for analyzing the response of structure under load.
In this paper, Shear Trac-III large-scale direct shear apparatus is used to study the shear mechanical behavior of sand-concrete interface under the action of normal stress and variable normal stress. The curve of shear stress-shear displacement relationship on the concrete contact surface shows the characteristic of strain softening. In the cyclic shear process under normal stress, there is a linear relationship between shear stress-shear displacement on the loose/dense sand-concrete contact surface during unloading; after unloading, the shear stress-shear displacement on the loose/dense sand-concrete contact surface presents a linear relationship. In the monotonic shear process under variable normal stress and under the second normal stress, the shear stress-shear displacement curves on the loose/dense sand-concrete interface show the characteristics of strain hardening.
Then, a mathematical model of the shear stress-shear displacement relationship of sand-concrete interface is established by fitting and analyzing the test results. Under monotonic shear under normal stress, the shear stress-shear displacement relationship of loose sand-concrete interface can be expressed by hyperbola, and the shear stress-shear displacement relationship of sand-rough/smooth concrete interface is closed. The shear stress-shear displacement relationship of loose/dense sand-concrete contact surface can be expressed by hyperbola and straight line segments under cyclic shear under normal stress. The shear stress-shear displacement relationship of loose sand-concrete contact surface can be expressed by piecewise hyperbola under monotonic shear under variable normal stress. The line shows that the relationship between shear stress and shear displacement of dense sand concrete interface can be represented by broken line and hyperbola.
Finally, the FRIC subroutine is compiled according to the mathematical model of loose sand-rough concrete contact surface. Based on the FRIC subroutine, the development and variation of the skin friction and the neutral point of a single pile during the consolidation of soft foundation are analyzed.
【学位授予单位】：西安建筑科技大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TU473.1
本文编号：2190196
[Abstract]:The interaction between soil and structure exists generally between pile and pile side soil, retaining wall and backfill, tunnel underground structure and surrounding soil, and the simulation of soil-structure interface interaction is of great significance for analyzing the response of structure under load.
In this paper, Shear Trac-III large-scale direct shear apparatus is used to study the shear mechanical behavior of sand-concrete interface under the action of normal stress and variable normal stress. The curve of shear stress-shear displacement relationship on the concrete contact surface shows the characteristic of strain softening. In the cyclic shear process under normal stress, there is a linear relationship between shear stress-shear displacement on the loose/dense sand-concrete contact surface during unloading; after unloading, the shear stress-shear displacement on the loose/dense sand-concrete contact surface presents a linear relationship. In the monotonic shear process under variable normal stress and under the second normal stress, the shear stress-shear displacement curves on the loose/dense sand-concrete interface show the characteristics of strain hardening.
Then, a mathematical model of the shear stress-shear displacement relationship of sand-concrete interface is established by fitting and analyzing the test results. Under monotonic shear under normal stress, the shear stress-shear displacement relationship of loose sand-concrete interface can be expressed by hyperbola, and the shear stress-shear displacement relationship of sand-rough/smooth concrete interface is closed. The shear stress-shear displacement relationship of loose/dense sand-concrete contact surface can be expressed by hyperbola and straight line segments under cyclic shear under normal stress. The shear stress-shear displacement relationship of loose sand-concrete contact surface can be expressed by piecewise hyperbola under monotonic shear under variable normal stress. The line shows that the relationship between shear stress and shear displacement of dense sand concrete interface can be represented by broken line and hyperbola.
Finally, the FRIC subroutine is compiled according to the mathematical model of loose sand-rough concrete contact surface. Based on the FRIC subroutine, the development and variation of the skin friction and the neutral point of a single pile during the consolidation of soft foundation are analyzed.
【学位授予单位】：西安建筑科技大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TU473.1
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1 梁鹏;砂土—混凝土接触面剪切力学性状试验研究[D];西安建筑科技大学;2014年
本文编号：2190196
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