本文選題：筒樁 + 荷載傳遞��； 參考：《浙江工業(yè)大學(xué)》2014年碩士論文

【摘要】：筒樁具有施工方便、成樁質(zhì)量好、承載能力高、經(jīng)濟(jì)性好等的特點(diǎn),因此其在軟土地基中的基坑工程、道路工程、海洋工程等領(lǐng)域有著廣泛的應(yīng)用。筒樁作為一種新型樁,其設(shè)計(jì)理論研究落后于工程實(shí)踐,筒樁在軟土地基中的承載能力評(píng)價(jià)方面還缺乏較為合理且簡(jiǎn)便的計(jì)算方法,有待進(jìn)一步的研究。筒樁在海堤結(jié)構(gòu)中的運(yùn)用是時(shí)下熱點(diǎn)之一,但是在波浪荷載作用下,筒樁結(jié)構(gòu)海堤的設(shè)計(jì)理論目前尚無(wú)規(guī)范或標(biāo)準(zhǔn)可循。為此,本文將結(jié)合實(shí)際工程,對(duì)軟土地基上的筒樁的承載性能進(jìn)行相關(guān)研究工作,主要的內(nèi)容和結(jié)論如下： 1.利用荷載傳遞函數(shù)法研究筒樁的單樁豎向承載力。在考慮樁土軟化、土芯分擔(dān)荷載及筒樁內(nèi)摩阻力發(fā)揮情況下,通過(guò)對(duì)筒樁內(nèi)、外側(cè)土選取彈塑性荷載傳遞函數(shù),而對(duì)樁底土選取三折線荷載傳遞函數(shù),建立微分方程,并推導(dǎo)出一套樁體任意截面的樁身軸力以及樁周摩阻力公式。最后,通過(guò)一個(gè)實(shí)際工程來(lái)驗(yàn)證公式的正確性,把現(xiàn)場(chǎng)試驗(yàn)得到的P-S曲線與公式計(jì)算所得到的曲線比較,發(fā)現(xiàn)曲線較吻合。因此,該套公式有很好的工程使用價(jià)值。 2.利用有限元軟件ABAQUS分別分析了筒樁基礎(chǔ)在豎向荷載和水平荷載下的受力過(guò)程。在豎向荷載下,通過(guò)與工程實(shí)例的現(xiàn)場(chǎng)試驗(yàn)結(jié)果比較,兩者荷載-沉降曲線較為吻合,驗(yàn)證了采用有限元方法研究筒樁的承載性能是切實(shí)可行的,同時(shí)還得到了筒樁內(nèi)外側(cè)摩阻力的分布圖；在水平向荷載下,通過(guò)與等截面面積的實(shí)心樁比較,發(fā)現(xiàn)筒樁在抵抗水平荷載作用中有較大優(yōu)勢(shì)；最后,分析了三種典型杭州地區(qū)的筒樁基礎(chǔ)分別在豎向荷載和水平向荷載作用下的承載性狀,得到了一些較為實(shí)用的結(jié)論。 3.在實(shí)際工程的基礎(chǔ)上,利用等效剛度原理,將雙排筒樁結(jié)構(gòu)海堤受力問(wèn)題由三維問(wèn)題轉(zhuǎn)換為平面應(yīng)變問(wèn)題,采用有限元分析手段研究其在波浪荷載作用下,排樁剛度、系梁剛度、系梁位置、樁間距、排距等筒樁海堤的主要設(shè)計(jì)參數(shù)對(duì)該結(jié)構(gòu)水平位移的影響,得到的結(jié)論有助于筒樁結(jié)構(gòu)海堤的設(shè)計(jì)與推廣。
[Abstract]:Barrel pile has the characteristics of convenient construction, good pile quality, high bearing capacity and good economy. Therefore, it is widely used in the field of foundation pit engineering, road engineering, ocean engineering and so on. As a new type of pile, the design theory of cylindrical pile falls behind the engineering practice, and there is still a lack of reasonable and simple calculation method in evaluating the bearing capacity of tubular pile in soft soil foundation, which needs further study. The application of tubular pile in seawall structure is one of the hotspots at present, but under the action of wave load, there is no criterion or standard for the design theory of tubular pile structure seawall. Therefore, combined with practical engineering, this paper will study the bearing capacity of cylindrical pile on soft soil foundation. The main contents and conclusions are as follows: 1. The load transfer function method is used to study the vertical bearing capacity of single pile. Considering the softening of pile and soil, the load sharing of soil core and the exertion of friction in the cylinder pile, the differential equation is established by selecting the elastic-plastic load transfer function for the inner and outer soil of the pile, and selecting the three-fold line load transfer function for the bottom soil of the pile. A set of formulas for axial force of pile body and friction around pile are derived. Finally, a practical project is used to verify the correctness of the formula. Comparing the P-S curve obtained from the field test with the curve obtained by the formula calculation, it is found that the curve is in good agreement with that obtained by the formula calculation. Therefore, the formula has good engineering value. 2. 2. The finite element software Abaqus is used to analyze the stress process of cylindrical pile foundation under vertical and horizontal loads respectively. Under vertical load, the load-settlement curves are in good agreement with the field test results of engineering examples, which verifies the feasibility of using finite element method to study the bearing capacity of cylindrical piles. At the same time, the distribution map of the friction resistance inside and outside the cylinder pile is obtained. By comparing with the solid pile with equal cross-section area under horizontal load, it is found that the cylinder pile has a great advantage in resisting horizontal load. The bearing behavior of three typical cylindrical pile foundations in Hangzhou under vertical and horizontal loads is analyzed, and some practical conclusions are obtained. On the basis of practical engineering, using the principle of equivalent stiffness, the stress problem of double-row cylindrical pile structure is transformed from three-dimensional problem to plane strain problem, and the stiffness of row pile under wave load is studied by finite element method. The influence of the main design parameters on the horizontal displacement of the seawall, such as the stiffness of the tie beam, the position of the tie beam, the distance between the piles and the distance between the piles, is obtained. The conclusions obtained are helpful to the design and popularization of the seawall of the tubular pile structure.
【學(xué)位授予單位】：浙江工業(yè)大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2014
【分類(lèi)號(hào)】：U656.314

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相關(guān)期刊論文 前1條

1 楊樺;楊敏;;荷載傳遞法研究單樁荷載-沉降關(guān)系進(jìn)展綜述[J];地下空間與工程學(xué)報(bào);2006年01期

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本文編號(hào)：2048687