【摘要】：人工挖孔樁由于施工速度快、施工簡單、無噪聲、無環(huán)境污染等特點,被廣泛應(yīng)用于地質(zhì)災(zāi)害防治和邊坡工程等工程領(lǐng)域。目前大多數(shù)的人工挖孔樁理論研究是針對圓形截面,對矩形人工挖孔樁的相關(guān)理論研究較少,且現(xiàn)行設(shè)計規(guī)范對人工挖孔樁護壁的設(shè)計沒有統(tǒng)一的規(guī)定,護壁土壓力是按照經(jīng)典土壓力理論進行計算,實際工程中護壁土壓力受開挖過程的影響比較大,土體的開挖改變了原來土體的應(yīng)力狀態(tài),產(chǎn)生新的應(yīng)力分布,導(dǎo)致護壁結(jié)構(gòu)產(chǎn)生相應(yīng)的變形,反之護壁結(jié)構(gòu)上的變形也會對土體產(chǎn)生影響,這樣一種相互作用的過程,使得經(jīng)典土壓力理論在護壁設(shè)計中存在一些缺陷。本文重點研究了矩形人工挖孔樁斷面尺寸對護壁土壓力的影響。研究內(nèi)容以及成果有：(1)采用ANSYS有限元分析軟件,選用五種不同的矩形人工挖孔樁斷面尺寸,針對粘性土以及無粘性土,建立矩形人工挖孔樁護壁與土相互作用的有限元模型,并通過生死單元來模擬其實際施工過程。(2)對矩形人工挖孔樁護壁與土相互作用進行數(shù)值分析,結(jié)果表明：護壁土壓力隨著開挖深度增加而增加,但護壁土壓力增加到一定程度時,隨著開挖深度增加,護壁土壓力基本趨于穩(wěn)定,也就是說存在一個臨界開挖深度。(3)矩形人工挖孔樁斷面尺寸的大小,不僅對護壁土壓力增加的速率存在一定的影響,而且對護壁土壓力達到穩(wěn)定時的臨界開挖深度存在一定的影響,當樁的斷面尺寸增加時,不僅護壁土壓力增長的速率增加,而且臨界開挖深度也相應(yīng)的增加。(4)針對粘性土和無粘性土分析了斷面尺寸對護壁土壓力的影響,得到了護壁土壓力在兩種土中臨界開挖深度的大致范圍。
[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.
【學位授予單位】：長沙理工大學
【學位級別】：碩士
【學位授予年份】：2014
【分類號】：TU473.1

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本文編號：2346115