粗糙度对粘性土—混凝土结构接触面力学特性的影响

发布时间：2018-05-07 11:46

  本文选题：粗糙度 + 接触面　； 参考：《中南大学》2014年硕士论文

【摘要】：土体与混凝土结构接触面的粗糙度是岩土工程界研究的重要课题之一。本文以红粘土与混凝土结构接触面为研究对象,通过大型直剪试验,重点研究粗糙度对粘性土与混凝土结构接触面力学特性的影响,分析影响规律并探究影响机理。主要取得以下成果： 1.对常用的混凝土表面粗糙度评定方法进行了对比分析,研究结果表明灌砂法是目前工程实际中比较合理的方法。但是灌砂法评定表面规则变化的混凝土结构的粗糙度时存在明显不足,本文对灌砂法引入了两个修正系数,修正后的灌砂法能够很好地评定表面规则变化的混凝土结构的粗糙度。 2.粘性土与混凝土结构光滑接触面是一种特殊界面,本文对光滑接触面的力学特性进行了重点研究。总结了接触面剪应力-切向位移关系曲线、破坏强度、破坏面发生位置和法向变形的规律。对剪应力-切向位移关系曲线进行了分段描述,峰值前,满足指数关系,峰值后,满足双曲线关系,并提出了确定双曲线参数的试验方法。在一定法向应力范围内,法向变形-法向应力满足指数关系。 3.总结了粗糙度对粘性土与混凝土结构接触面力学特性的影响规律。研究结果表明,随着粗糙度增大,接触面剪应力-切向位移关系曲线由峰值型变为折线型,进而变为双曲线型。指出粘性土与混凝土结构接触面的粗糙度y的最大值是粘性土的影响深度dmax,并且对于接触面粘聚力,存在一个临界粗糙度y。,当0≤yyncr时,接触面粘聚力随粗糙度的增大而增大,近似呈指数关系。当yncr≤ymax。时,接触面粘聚力在土体粘聚力附近波动。接触面摩擦角随粗糙度变化是波动的。 4.粗糙度对粘性土与混凝土结构接触面的力学特性产生影响,主要是由于混凝土表面粘性土的错动和断裂产生的抗力。随着法向应力的增大,粗糙度的影响程度降低。在实际工程中,法向应力一般在600kPa以下,粗糙度的影响是不能忽略的。
[Abstract]:The roughness of the interface between soil and concrete structure is one of the important research topics in geotechnical engineering field. In this paper, the interface between red clay and concrete structure is taken as the object of study. Through large-scale direct shear test, the influence of roughness on the mechanical properties of the interface between clay and concrete structure is studied, the influence law is analyzed and the influence mechanism is explored. The following results have been achieved: 1. The common methods for evaluating the surface roughness of concrete are compared and analyzed. The results show that the sand filling method is a reasonable method in engineering practice at present. However, the roughness of concrete structures with regular surface changes is obviously inadequate in the sand filling method. In this paper, two correction coefficients are introduced to the sand filling method. The modified sand filling method can evaluate the roughness of concrete structure with regular surface. 2. The smooth interface between clay and concrete structure is a special interface. In this paper, the mechanical properties of smooth interface are studied. The relationship curve between shear stress and tangential displacement, the failure strength, the position of failure surface and the rule of normal deformation are summarized. The shear stress-tangential displacement curve is described in sections. Before the peak value, the exponential relation is satisfied, and after the peak value, the hyperbolic relation is satisfied, and the test method for determining the hyperbolic parameters is put forward. In a certain range of normal stress, the normal deformation-normal stress satisfies the exponential relationship. 3. The influence of roughness on the mechanical properties of clay-concrete interface is summarized. The results show that with the increase of roughness, the shear stress-tangential displacement curve of contact surface changes from peak to broken line, and then to hyperbolic. It is pointed out that the maximum value of the roughness y of the interface between clay and concrete is the influence depth d _ max of the cohesive soil, and there exists a critical roughness y.for the cohesive force of the contact surface, when 0 鈮，

本文编号：1856794