矩形人工挖孔桩断面尺寸对护壁土压力的影响研究
发布时间：2018-11-20 21:39
【摘要】：人工挖孔桩由于施工速度快、施工简单、无噪声、无环境污染等特点,被广泛应用于地质灾害防治和边坡工程等工程领域。目前大多数的人工挖孔桩理论研究是针对圆形截面,对矩形人工挖孔桩的相关理论研究较少,且现行设计规范对人工挖孔桩护壁的设计没有统一的规定,护壁土压力是按照经典土压力理论进行计算,实际工程中护壁土压力受开挖过程的影响比较大,土体的开挖改变了原来土体的应力状态,产生新的应力分布,导致护壁结构产生相应的变形,反之护壁结构上的变形也会对土体产生影响,这样一种相互作用的过程,使得经典土压力理论在护壁设计中存在一些缺陷。本文重点研究了矩形人工挖孔桩断面尺寸对护壁土压力的影响。研究内容以及成果有：(1)采用ANSYS有限元分析软件,选用五种不同的矩形人工挖孔桩断面尺寸,针对粘性土以及无粘性土,建立矩形人工挖孔桩护壁与土相互作用的有限元模型,并通过生死单元来模拟其实际施工过程。(2)对矩形人工挖孔桩护壁与土相互作用进行数值分析,结果表明：护壁土压力随着开挖深度增加而增加,但护壁土压力增加到一定程度时,随着开挖深度增加,护壁土压力基本趋于稳定,也就是说存在一个临界开挖深度。(3)矩形人工挖孔桩断面尺寸的大小,不仅对护壁土压力增加的速率存在一定的影响,而且对护壁土压力达到稳定时的临界开挖深度存在一定的影响,当桩的断面尺寸增加时,不仅护壁土压力增长的速率增加,而且临界开挖深度也相应的增加。(4)针对粘性土和无粘性土分析了断面尺寸对护壁土压力的影响,得到了护壁土压力在两种土中临界开挖深度的大致范围。
[Abstract]:Manual excavated pile is widely used in geological hazard prevention and slope engineering because of its rapid construction, simple construction, no noise, no environmental pollution and so on. At present, most of the theoretical research of manual excavated pile is aimed at circular section, but there is little theoretical research on rectangular manual excavated pile, and the current design code has no unified regulation on the design of artificial excavated pile wall. The earth pressure of wall protection is calculated according to the classical earth pressure theory. In actual engineering, the earth pressure of wall protection is greatly affected by the excavation process, and the excavation of soil changes the stress state of the original soil mass and produces a new stress distribution. As a result of the corresponding deformation of the wall protection structure, on the contrary, the deformation of the wall protection structure will also have an impact on the soil mass. Such an interaction process makes the classical earth pressure theory have some defects in the design of the wall protection. In this paper, the influence of cross section size of rectangular artificial excavated pile on earth pressure of retaining wall is studied. The research contents and results are as follows: (1) using ANSYS finite element analysis software, five different rectangular artificial excavated pile section sizes are selected, aiming at cohesive soil and non-cohesive soil. The finite element model of the interaction between the retaining wall and soil of the rectangular artificial excavated pile is established, and the actual construction process is simulated by the birth and death element. (2) the interaction between the retaining wall of the rectangular manual excavated pile and the soil is analyzed numerically. The results show that the earth pressure increases with the increase of excavation depth, but when the earth pressure increases to a certain extent, with the increase of excavation depth, the earth pressure of wall protection tends to be stable. That is to say, there is a critical excavation depth. (3) the cross section size of rectangular manual digging pile not only has a certain influence on the increasing rate of earth pressure, Moreover, there is some influence on the critical excavation depth when the earth pressure of the retaining wall reaches the stability. When the section size of the pile increases, not only the growth rate of the soil pressure of the retaining wall increases, but also the soil pressure increases. And the critical excavation depth also increases correspondingly. (4) the influence of section size on the soil pressure of wall protection is analyzed for cohesive soil and non-cohesive soil. The approximate range of critical excavation depth of soil pressure for wall protection in the two soils is obtained.
【学位授予单位】：长沙理工大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TU473.1
本文编号：2346115
[Abstract]:Manual excavated pile is widely used in geological hazard prevention and slope engineering because of its rapid construction, simple construction, no noise, no environmental pollution and so on. At present, most of the theoretical research of manual excavated pile is aimed at circular section, but there is little theoretical research on rectangular manual excavated pile, and the current design code has no unified regulation on the design of artificial excavated pile wall. The earth pressure of wall protection is calculated according to the classical earth pressure theory. In actual engineering, the earth pressure of wall protection is greatly affected by the excavation process, and the excavation of soil changes the stress state of the original soil mass and produces a new stress distribution. As a result of the corresponding deformation of the wall protection structure, on the contrary, the deformation of the wall protection structure will also have an impact on the soil mass. Such an interaction process makes the classical earth pressure theory have some defects in the design of the wall protection. In this paper, the influence of cross section size of rectangular artificial excavated pile on earth pressure of retaining wall is studied. The research contents and results are as follows: (1) using ANSYS finite element analysis software, five different rectangular artificial excavated pile section sizes are selected, aiming at cohesive soil and non-cohesive soil. The finite element model of the interaction between the retaining wall and soil of the rectangular artificial excavated pile is established, and the actual construction process is simulated by the birth and death element. (2) the interaction between the retaining wall of the rectangular manual excavated pile and the soil is analyzed numerically. The results show that the earth pressure increases with the increase of excavation depth, but when the earth pressure increases to a certain extent, with the increase of excavation depth, the earth pressure of wall protection tends to be stable. That is to say, there is a critical excavation depth. (3) the cross section size of rectangular manual digging pile not only has a certain influence on the increasing rate of earth pressure, Moreover, there is some influence on the critical excavation depth when the earth pressure of the retaining wall reaches the stability. When the section size of the pile increases, not only the growth rate of the soil pressure of the retaining wall increases, but also the soil pressure increases. And the critical excavation depth also increases correspondingly. (4) the influence of section size on the soil pressure of wall protection is analyzed for cohesive soil and non-cohesive soil. The approximate range of critical excavation depth of soil pressure for wall protection in the two soils is obtained.
【学位授予单位】：长沙理工大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TU473.1
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