本文選題：堆載　切入點(diǎn)：橋梁樁基　出處：《中南大學(xué)》2014年碩士論文

【摘要】：摘要：為實(shí)現(xiàn)高速、安全的運(yùn)營(yíng)目標(biāo),新建高速鐵路普遍采用無砟軌道,如何保證其平順性是高速鐵路建設(shè)和運(yùn)營(yíng)過程中的關(guān)鍵技術(shù)。深厚軟土地區(qū)高速鐵路橋梁普遍采用樁基礎(chǔ),沿線區(qū)域經(jīng)濟(jì)發(fā)展過程中,不可避免地會(huì)遭遇到鄰近堆載的作用,導(dǎo)致地基中附加應(yīng)力增加,引起影響線路的平順性。 本文采用理論分析、現(xiàn)場(chǎng)調(diào)研和數(shù)值模擬相結(jié)合的方法,針對(duì)鄰近堆載對(duì)高速鐵路橋梁樁基內(nèi)力與變位的影響開展研究,主要工作和成果如下： (1)通過對(duì)國(guó)內(nèi)外相關(guān)研究現(xiàn)狀的綜合分析,制定了本文的研究?jī)?nèi)容和技術(shù)路線； (2)基于彈性半空間理論,編制了用于計(jì)算堆載引起的樁側(cè)應(yīng)力的計(jì)算程序。將堆載引起的側(cè)應(yīng)力分段簡(jiǎn)化為集中荷載作用于基樁上,對(duì)不同土層施加不同的彈簧勁度系數(shù),改進(jìn)了有限差分求解彈性地基梁的計(jì)算程序,并用于實(shí)際工程,效果較好； (3)將平面剛架靜力分析程序中的水平桿件視為彈性支撐,用于計(jì)算側(cè)向力對(duì)基樁內(nèi)力的影響,并與有限差分法求解彈性地基梁的結(jié)果進(jìn)行對(duì)比分析,驗(yàn)證了該方法的可行性； (4)采用控制變量法,分析了堆載寬度、堆載間距、堆載高度等變化的情況下樁身彎矩與墩頂位移的變化規(guī)律； (5)采用FLAC有限差分軟件,分析了鄰近堆載對(duì)深厚軟土地區(qū)橋梁樁基變位的影響,獲得了一些對(duì)設(shè)計(jì)和施工有參考價(jià)值的結(jié)果。
[Abstract]:Abstract: in order to realize the goal of high-speed and safe operation, ballastless track is widely used in newly built high-speed railway. How to ensure its smoothness is the key technology in the construction and operation of high-speed railway.Pile foundation is widely used in high speed railway bridges in deep soft soil area. In the process of regional economic development, it will inevitably encounter the effect of adjacent surcharge, which will lead to the increase of additional stress in the foundation, which will affect the smoothness of the line.In this paper, theoretical analysis, field investigation and numerical simulation are used to study the influence of adjacent surcharge on the internal force and displacement of pile foundation of high-speed railway bridge. The main work and results are as follows:1) based on the comprehensive analysis of the current research situation at home and abroad, the research content and technical route of this paper are worked out.Based on the elastic half-space theory, a program for calculating the lateral stress of piles caused by heaps is developed.The lateral stress caused by surcharge is simplified as a concentrated load acting on the foundation pile, different spring stiffness coefficient is applied to different soil layers, the calculation program for solving elastic foundation beam by finite difference method is improved, and it is used in practical engineering with good results.(3) the horizontal member in the static analysis program of plane rigid frame is regarded as elastic support, which is used to calculate the influence of lateral force on the internal force of foundation pile, and compared with the result of solving elastic foundation beam by finite difference method, the feasibility of this method is verified.(4) the variation law of pile bending moment and pier top displacement is analyzed under the condition of the variation of the surcharge width, the distance between the piles and the height of the pile load by using the control variable method.Using FLAC finite difference software, the influence of adjacent surcharge on displacement of bridge pile foundation in deep soft soil area is analyzed, and some results of reference value for design and construction are obtained.
【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】：2014
【分類號(hào)】：U443.15

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本文編號(hào)：1712723