【摘要】：由于樁基沉降量小、抗震性能好及承載能力高等優(yōu)點(diǎn)而被廣泛應(yīng)用于橋梁工程、高層建筑和海洋平臺(tái)等眾多工程領(lǐng)域。在動(dòng)荷載作用下,樁基礎(chǔ)的穩(wěn)定性取決于樁的工作性能,而樁基的工作性能是樁與其周?chē)林g的動(dòng)力相互作用的結(jié)果,目前,部分埋入樁的振動(dòng)和完全埋入樁基的瞬態(tài)響應(yīng)研究還僅限于單相介質(zhì),然而土又是由固液氣組成的三相介質(zhì),研究飽和兩相介質(zhì)無(wú)疑更接近客觀(guān)實(shí)際、更具有工程實(shí)際價(jià)值。因此,本文在博士學(xué)科點(diǎn)專(zhuān)項(xiàng)科研項(xiàng)目等項(xiàng)目基金的資助下,對(duì)飽和土中部分埋入樁基的水平振動(dòng)特性和飽和土中完全埋入樁基的瞬態(tài)響應(yīng)進(jìn)行展開(kāi)研究。 本文將土體視為飽和兩相多孔介質(zhì),運(yùn)用Biot固結(jié)理論來(lái)描述飽和土的力學(xué)性能,利用Novak薄層法,引入勢(shì)函數(shù)解耦,求得層狀飽和土半空間位移和應(yīng)力基本解,利用樁-土變形協(xié)調(diào)條件和樁單元間位移、轉(zhuǎn)角、彎矩和剪力的連續(xù)性條件建立了樁身剛度矩陣方程,導(dǎo)出了水平穩(wěn)態(tài)諧振下部分埋入單樁阻抗函數(shù)的封閉形式解答。利用層狀飽和土半空間位移建立衰減函數(shù),構(gòu)筑被動(dòng)樁的控制方程,同樣采用矩陣傳遞法求得到相互動(dòng)力作用因子,采用迭代法原則建立群樁矩陣方程,最后求解高承臺(tái)群樁矩陣方程得到群樁的動(dòng)力阻抗。并以雙層飽和土中部分埋入單樁和3x3高承臺(tái)群樁基礎(chǔ)為例,分析了埋入比、樁間距、滲透系數(shù)和土層模量比等參數(shù)對(duì)群樁阻抗的影響。 通過(guò)對(duì)Biot動(dòng)力固結(jié)方程無(wú)量綱化和Laplace變換,先引入勢(shì)函數(shù)進(jìn)行解耦,通過(guò)算子分解和分離變量法,得到均質(zhì)飽和土Laplace域內(nèi)的位移,并以此建立Laplace域內(nèi)的衰減函數(shù),基于Winkler模型,聯(lián)立振動(dòng)微分方程,推導(dǎo)了Laplace變換域內(nèi)單樁和群樁位移函數(shù)及單樁內(nèi)力表達(dá)式。最后采用Laplace逆變換的優(yōu)化模型求得了時(shí)域內(nèi)瞬態(tài)響應(yīng)的封閉解。參數(shù)分析結(jié)果表明：樁土模量比、長(zhǎng)徑比、滲透系數(shù)對(duì)單樁水平位移均影響顯著,而長(zhǎng)徑比超過(guò)一定值后則影響較小,且樁土模量比是影響樁身彎矩和剪力大小及其分布的重要參數(shù)。 圖36幅,表2個(gè),參考文獻(xiàn)145篇
[Abstract]:Because of the advantages of small settlement, good seismic performance and high bearing capacity, pile foundation has been widely used in many engineering fields, such as bridge engineering, high-rise building and offshore platform. Under the dynamic load, the stability of the pile foundation depends on the working performance of the pile, and the working performance of the pile foundation is the result of the dynamic interaction between the pile and the surrounding soil. The study of the vibration of partially buried pile and the transient response of completely buried pile foundation is limited to single-phase medium, but the soil is a three-phase medium composed of solid, liquid and gas, so the study of saturated two-phase medium is undoubtedly closer to the objective reality and has practical engineering value. Therefore, the horizontal vibration characteristics of partially embedded pile foundation and the transient response of fully embedded pile foundation in saturated soil are studied in this paper, supported by the special scientific research project of doctorate. In this paper, the soil is regarded as a saturated two-phase porous medium, the mechanical properties of saturated soil are described by Biot consolidation theory, and the basic solution of displacement and stress in half-space of layered saturated soil is obtained by introducing potential function decoupling by Novak thin-layer method. In this paper, the stiffness matrix equation of pile body is established by using the compatibility condition of pile and soil deformation and the continuity conditions of displacement, rotation angle, bending moment and shear force between pile elements, and the closed form solution of impedance function of partially embedded single pile under horizontal steady state resonance is derived. The attenuation function is established by using the half-space displacement of layered saturated soil, and the governing equation of passive pile is constructed. In the same way, the interaction factor is obtained by matrix transfer method, and the matrix equation of pile group is established by iterative principle. Finally, the dynamic impedance of pile group is obtained by solving the matrix equation of pile group with high cap. The effects of embedding ratio, pile spacing, permeability coefficient and soil modulus ratio on pile group impedance are analyzed with the example of partially embedded single pile and 3x3 high cap pile group foundation in double-layer saturated soil. Through dimensionless and Laplace transformation of Biot dynamic consolidation equation, the potential function is introduced to decouple, and the displacement in Laplace domain of homogeneous saturated soil is obtained by operator decomposition and separation variable method, and the attenuation function in Laplace domain is established based on Winkler model. The displacement function of single pile and group pile and the expression of internal force of single pile in Laplace transform domain are derived by simultaneous vibration differential equation. Finally, the closed solution of transient response in time domain is obtained by using the optimization model of Laplace inverse transformation. The results of parameter analysis show that the pile-soil modulus ratio, the ratio of length to diameter and permeability coefficient have significant effects on the horizontal displacement of single pile, but when the ratio of length to diameter exceeds a certain value, the influence is small. The pile-soil modulus ratio is an important parameter that affects the bending moment, shear force and distribution of pile. 36 figures, 2 tables, 145 references
【學(xué)位授予單位】：中南大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2013
【分類(lèi)號(hào)】：TU473.1

【參考文獻(xiàn)】

相關(guān)期刊論文 前10條

1 虞煥新;;基于Novak薄層法的部分埋入式單樁的扭轉(zhuǎn)振動(dòng)[J];四川建筑科學(xué)研究;2012年03期

2 熊輝;呂西林;;豎向力下各型群樁-層狀土體的水平阻抗效應(yīng)[J];地下空間與工程學(xué)報(bào);2006年02期

3 張玉紅,黃義;二相介質(zhì)飽和土中群樁動(dòng)力阻抗分析[J];地震工程與工程振動(dòng);2001年03期

4 張翠紅;楊先健;;群樁的回轉(zhuǎn)及水平動(dòng)力剛度和阻尼[J];地震工程與工程振動(dòng);2010年06期

5 徐國(guó)林;張令心;孫景江;柏亞雙;;基于Timoshenko梁理論纖維模型巨型鋼框架結(jié)構(gòu)非線(xiàn)性地震反應(yīng)分析方法[J];地震工程與工程振動(dòng);2011年04期

6 花羽超;朱媛媛;程昌鈞;;非線(xiàn)性樁基的動(dòng)力響應(yīng)分析[J];動(dòng)力學(xué)與控制學(xué)報(bào);2007年03期

7 劉東甲,王建國(guó);均勻土中有限長(zhǎng)樁瞬態(tài)橫向動(dòng)力響應(yīng)[J];工程力學(xué);2003年06期

8 雷文軍,魏德敏;分層土中單樁和群樁的水平動(dòng)力阻抗計(jì)算[J];工程力學(xué);2004年05期

9 文學(xué)章;尚守平;;層狀地基中樁筏基礎(chǔ)的動(dòng)力阻抗研究[J];工程力學(xué);2009年08期

10 劉林超;楊驍;;基于嚴(yán)格平面應(yīng)變模型的土中群樁水平振動(dòng)研究[J];工程力學(xué);2010年07期

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