【摘要】：隨著高層建筑以及各類大型跨江和跨海橋梁工程的不斷建設(shè),群樁基礎(chǔ)的規(guī)模越來越大,樁徑越來越大,樁長也越來越長,荷載作用下樁基礎(chǔ)和土體共同作用的工作機(jī)理是一個(gè)很復(fù)雜問題,針對后壓漿單樁基礎(chǔ)的承載力計(jì)算方法較多,但這些方法有各自的優(yōu)缺點(diǎn)及其適用范圍、計(jì)算準(zhǔn)確性不一,對于群樁基礎(chǔ)與土體相互作用則更加復(fù)雜,一直未能得到有效的解答。 本文首先系統(tǒng)分析了后壓漿技術(shù)的國內(nèi)外研究現(xiàn)狀、巖土注漿理論、施工工藝及后壓漿對于樁基礎(chǔ)承載特性的作用機(jī)理等；然后以巖土注漿理論為指導(dǎo),基于國內(nèi)某超大群樁基礎(chǔ)建設(shè)工程,運(yùn)用大型非線性有限元分析軟件ADINA建立了深厚軟土層中九樁高承臺(tái)群樁基礎(chǔ)樁端注漿與未注漿兩種情況下的樁-土相互作用的三維模型,通過計(jì)算對后注漿群樁基礎(chǔ)的承載性能進(jìn)行分析,具體開展了以下方面的工作： (1)計(jì)算并分析了群樁基礎(chǔ)樁端采用注漿加固后樁端阻力的分布規(guī)律,群樁中角樁端部反力最大,邊樁和中間樁均小于角樁,最大反力值達(dá)到9727934kN;工況六下最大反力達(dá)到3.064×107kN,后壓漿能起到改善和平衡群樁基礎(chǔ)中各單樁的不均勻受力的作用。 (2)計(jì)算了樁側(cè)阻力的分布,樁側(cè)阻力是從樁端以上一定高度開始逐漸向上發(fā)揮,這是由于高樁承臺(tái)群樁基礎(chǔ)受力后上段樁體首先產(chǎn)生彈性壓縮,然后逐漸向下傳遞；由于樁端加固體的作用,樁端的位移受到限制,樁端以上一定范圍內(nèi)的樁側(cè)阻力沒有充分發(fā)揮,并且由于角樁和邊樁的相對位移比中樁要大,其摩擦阻力的發(fā)揮先于中樁。 (3)計(jì)算得到群樁基礎(chǔ)壓漿前在豎向荷載作用下最大沉降達(dá)51.45cm,采用樁端注漿加固條件下的沉降22.58cm,可以減少沉降量43.8%,加固效果比較顯著；承臺(tái)施工階段,最大沉降均發(fā)生在各角樁位置處,隨著荷載的逐步施加,樁端壓漿加固體對于群樁中各單樁的沉降起到了很好的協(xié)調(diào)作用,荷載加載完成階段,群樁基礎(chǔ)的沉降分布己趨于均勻； (4)壓漿后群樁基礎(chǔ)中處于同一深度位置處的樁身軸力分布規(guī)律與壓漿前的相類似,群樁中角樁A的軸力最大、邊樁B的軸力小于角樁A、中心樁C的軸力小于角樁和邊樁。此外,群樁中各單樁的軸力分布在-45m以上比較均勻,-45m以下軸力依次減小。 (5)樁頂反力與樁頂沉降大致呈線性變化,相同沉降量A樁所承受的豎向荷載最大,因此在群樁樁位布置時(shí)應(yīng)盡量增加角樁和邊樁的比例,可以充分發(fā)揮群樁基礎(chǔ)的整體承載性能。
[Abstract]:With the continuous construction of high-rise buildings and all kinds of large cross-river and sea-crossing bridge projects, the scale of pile group foundation is getting larger and larger, the pile diameter is getting larger and larger, and the pile length is getting longer and longer. The working mechanism of pile foundation and soil under load is a very complex problem. There are many methods for calculating the bearing capacity of post-grouting single pile foundation, but these methods have their own advantages and disadvantages and their applicable scope, and the calculation accuracy is different. The interaction between pile group foundation and soil mass is more complicated and can not be solved effectively. In this paper, the research status of post-grouting technology at home and abroad, geotechnical grouting theory, construction technology and the mechanism of post-grouting on the bearing characteristics of pile foundation are systematically analyzed. Then, guided by the theory of geotechnical grouting, based on the construction of a super-large pile group in China, A three-dimensional model of pile-soil interaction at the end of nine high cap pile groups in deep soft soil layer is established by using the large nonlinear finite element analysis software ADINA. Through the calculation and analysis of the bearing capacity of the post-grouting pile group foundation, the following aspects are carried out: (1) the distribution law of the resistance at the pile end strengthened by grouting is calculated and analyzed. The reaction force at the end of the corner pile group is the largest, the side pile and the middle pile are smaller than the angle pile, and the maximum reaction force is 9727934kN. Under the working condition, the maximum reaction force is 3.064 脳 107kN, and the post-grouting can improve and balance the uneven force of each single pile in the pile group foundation. (2) the distribution of pile side resistance is calculated, and the pile side resistance is gradually brought into play from a certain height above the pile end, which is due to the elastic compression of the upper section of the pile group foundation of the high pile cap and then the gradual downward transmission. Due to the effect of adding solid at the end of the pile, the displacement of the end of the pile is limited, the resistance of the side of the pile in a certain range above the end of the pile is not brought into full play, and because the relative displacement of the angular pile and the side pile is larger than that of the middle pile, the friction resistance is brought into full play before the middle pile. (3) the maximum settlement of pile group foundation under vertical load is 51.45 cm before grouting, and 22.58 cm of settlement under grouting at pile end can reduce settlement by 43.8%, and the reinforcement effect is remarkable. In the stage of cap construction, the maximum settlement occurs at the position of each angle pile. With the gradual application of load, grouting and solid at the end of the pile play a very good role in coordinating the settlement of each single pile in the pile group, and the completion stage of load loading. The settlement distribution of pile group foundation tends to be uniform. (4) the distribution of axial force of pile body at the same depth in pile group foundation after grouting is similar to that before grouting. The axial force of angle pile A is the largest, and the axial force of side pile B is smaller than that of angle pile A. The axial force of central pile C is smaller than that of corner pile and side pile. In addition, the axial force distribution of each single pile in the pile group is more uniform than-45m, and the axial force below-45m decreases in turn. (5) the reaction force of pile top and the settlement of pile top change linearly, and the vertical load of pile A with the same settlement is the largest, so the ratio of angle pile to side pile should be increased as much as possible when the pile group is arranged. It can give full play to the overall bearing performance of pile group foundation.
【學(xué)位授予單位】：湖北工業(yè)大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2013
【分類號(hào)】：TU473.1

【參考文獻(xiàn)】

相關(guān)期刊論文 前10條

1 劉影;姚勇;彭陸;肖軍;;砂卵石地層中灌注樁后壓漿模型試驗(yàn)設(shè)計(jì)與分析[J];四川建筑科學(xué)研究;2009年05期

2 傅文洵，王清友;壓力注漿樁模型試驗(yàn)研究[J];北京水利;1996年06期

3 傅文洵,王清友;壓力注漿樁現(xiàn)場荷載試驗(yàn)研究[J];北京水利;1997年03期

4 安愛軍;李亮;鄒金鋒;肖華溪;羅恒;;長鉆孔灌注樁后注漿深度及數(shù)值模擬研究[J];鐵道科學(xué)與工程學(xué)報(bào);2011年02期

5 陸培毅;于勇;韓麗君;;考慮注漿過程的后壓漿樁有限元分析[J];低溫建筑技術(shù);2007年01期

6 黃生根,王輝,張曉煒,龔維明,慕紅勛;超長大直徑橋樁的壓漿效果研究[J];公路交通科技;2004年05期

7 沈保漢;后注漿樁技術(shù)(1)——后注漿樁技術(shù)的產(chǎn)生與發(fā)展[J];工業(yè)建筑;2001年05期

8 祝經(jīng)成;灌注樁樁端壓漿結(jié)合超聲波檢測新技術(shù)[J];施工技術(shù);1995年09期

9 郭琦;李春軒;劉慧林;;應(yīng)用后壓漿技術(shù)的鉆孔灌注樁承載力計(jì)算方法[J];水運(yùn)工程;2010年03期

10 俞縉;;群樁基礎(chǔ)豎向承載變形三維彈塑性數(shù)值模擬分析[J];蘇州科技學(xué)院學(xué)報(bào)(工程技術(shù)版);2009年04期

相關(guān)碩士學(xué)位論文 前7條

1 呂旭東;鉆孔灌注樁樁底后壓漿技術(shù)的工程應(yīng)用[D];西安建筑科技大學(xué);2004年

2 張寒;后壓漿鉆孔灌注樁承載性狀分析[D];浙江大學(xué);2006年

3 韓學(xué)偉;超大型鉆孔灌注樁基礎(chǔ)樁底后壓漿機(jī)理及效果的實(shí)測研究[D];河海大學(xué);2007年

4 紀(jì)小彬;灌注樁后壓漿作用機(jī)理研究[D];北京交通大學(xué);2008年

5 于勇;考慮注漿過程的后壓漿樁有限元模擬與分析[D];天津大學(xué);2007年

6 劉渤;超高層建筑樁基礎(chǔ)承載性能研究[D];中國地質(zhì)大學(xué)（北京）;2010年

7 孫立黨;鉆孔灌注樁后壓漿施工工藝研究及工程實(shí)例[D];長安大學(xué);2010年

，

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