發(fā)布時間：2018-08-18 17:38

【摘要】：土與結(jié)構(gòu)物相互作用普遍存在于樁與樁側(cè)土、擋土墻與墻后填土、隧道地下結(jié)構(gòu)與周圍土之間，土與結(jié)構(gòu)物接觸面相互作用的模擬對于分析結(jié)構(gòu)物在荷載作用下的反應具有重要的意義。 本文首先利用Shear Trac-Ⅲ大型直剪儀研究了砂土-混凝土接觸面在常法向應力/變法向應力作用下的剪切力學性狀。在常法向應力作用下單調(diào)剪切過程中，松砂-混凝土接觸面上剪應力-剪切位移關(guān)系曲線表現(xiàn)出應變硬化特征，而密砂-混凝土接觸面上剪應力-剪切位移關(guān)系曲線表現(xiàn)出應變軟化的特征。在常法向應力作用下循環(huán)剪切過程中，卸載時，松/密砂-混凝土接觸面上剪應力-剪切位移之間呈現(xiàn)出線性關(guān)系；卸載后反向剪切，松/密砂-混凝土接觸面上剪應力-剪切位移關(guān)系曲線均表現(xiàn)出應變硬化的特征。在變法向應力作用下單調(diào)剪切過程中，在第二級法向應力作用下，松/密砂-混凝土接觸面上剪應力-剪切位移關(guān)系曲線均表現(xiàn)出應變硬化的特征。 然后，對試驗結(jié)果進行擬合分析，建立了砂土-混凝土接觸面剪應力-剪切位移關(guān)系數(shù)學模型。在常法向應力作用下單調(diào)剪切時，松砂-混凝土接觸面剪應力-剪切位移關(guān)系可用雙曲線表示，密砂-粗糙/光滑混凝土接觸面剪應力-剪切位移關(guān)系可分別用三折線和雙折線表示；在常法向應力作用下循環(huán)剪切時，松/密砂-混凝土接觸面剪應力-剪切位移關(guān)系均可用雙曲線與直線分段表示。在變法向應力作用下單調(diào)剪切時，松砂-混凝土接觸面剪應力-剪切位移關(guān)系可用分段雙曲線表示，，密砂-混凝土接觸面剪應力-剪切位移關(guān)系可用折線和雙曲線分段表示。 最后，根據(jù)松砂-粗糙混凝土接觸面數(shù)學模型編寫了FRIC子程序，并基于該模型分析了單樁在軟基固結(jié)過程中樁身摩阻力、樁身中性點的發(fā)展變化規(guī)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.
【學位授予單位】：西安建筑科技大學
【學位級別】：碩士
【學位授予年份】：2014
【分類號】：TU473.1

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1 梁鵬;砂土—混凝土接觸面剪切力學性狀試驗研究[D];西安建筑科技大學;2014年

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