【摘要】：中國西部地區(qū)經(jīng)濟(jì)的快速發(fā)展促進(jìn)交通運輸向更方便、更安全、更環(huán)保的方向發(fā)展，考慮到保護(hù)山區(qū)生態(tài)環(huán)境，目前山區(qū)高等級公路大多采用隧道或高架橋的形式穿越，橋梁樁基則建設(shè)在微坡、緩坡、陡坡、極陡坡的不同形式邊坡上。因此，除了承受上部傳來的軸向荷載和水平荷載以外，還將承受坡體給予的側(cè)向土壓力，邊坡段的橋梁樁基處于復(fù)雜的地質(zhì)環(huán)境中，，目前針對該類樁基的研究還相對較少，沒有一套完整的理論體系，也不能用常規(guī)的計算方式來設(shè)計和指導(dǎo)。為此，本文采用大型非線性有限元軟件ABAQUS模擬，分析不同形式的荷載作用下以及不同荷載的不同組合作用下該類樁基的內(nèi)力變化和位移變形，并對影響該類樁基受力變形的相關(guān)因素進(jìn)行綜合對比分析。 ①首先結(jié)合邊坡段橋梁樁基特點綜合分析其承載機理和受力特性。研究了荷載傳遞過程，建立了樁基不同特征段的受力微分方程式，并用冪級數(shù)解答，得到樁基繞曲變形的求解方法。 ②將邊坡根據(jù)坡度大小進(jìn)行分類，引入邊坡介質(zhì)載體這一概念，總結(jié)歸納為邊坡滑移的鏈?zhǔn)椒磻?yīng)是介質(zhì)載體的物質(zhì)體現(xiàn)，用介質(zhì)載體的鏈?zhǔn)窖莼枋龌掳l(fā)生過程的滑移特征，基于此，分析滑坡推力及抗力分布形式和計算方法。 ③通過本工程案例中樁土相互作用的三維數(shù)值模型計算得到：荷載對樁基的影響程度順序為：坡頂均布荷載＞樁頂豎向荷載＞樁頂橫向荷載。組合荷載作用下，樁身發(fā)生撓曲變形，隨著樁徑的增大，樁身水平位移減小。 ④本案例中陡坡段樁基的變形大于緩坡段樁基的變形，且陡坡段的樁基承載力小于緩坡段樁基的承載力。在斜坡段樁基設(shè)計時，其設(shè)計樁徑或者配筋范圍應(yīng)取決于坡度的急緩程度。 ⑤本案例中巖土彈性模量的增加明顯的限制了樁基的變形和減小了樁土的水平應(yīng)力值。另外，樁周巖體在有橋梁樁基情況下的應(yīng)力值在規(guī)定地基容許范圍內(nèi)。故此，不需要為邊坡增加抗滑措施。
[Abstract]:The rapid economic development in the western region of China has promoted the development of transportation in the direction of more convenient, safer and more environmentally friendly. Considering the protection of the ecological environment in mountain areas, most of the high-grade highways in mountain areas now traverse in the form of tunnels or viaducts. The pile foundation of bridge is built on the different slope of micro-slope, gentle slope, steep slope and extremely steep slope. Therefore, in addition to bearing the axial load and horizontal load from the upper part, it will also bear the lateral earth pressure from the slope body. The bridge pile foundation in the slope section is in a complex geological environment, and the research on this kind of pile foundation is still relatively rare at present. There is no complete theoretical system, nor can conventional calculation be used to design and guide. In this paper, the large-scale nonlinear finite element software ABAQUS is used to simulate the internal force and displacement of this kind of pile foundation under different loads and different combinations of different loads. The relative factors affecting the deformation of this kind of pile foundation are comprehensively compared and analyzed. The main contents of this paper are as follows: 1. Firstly, the bearing mechanism and mechanical characteristics of bridge pile foundation in slope section are analyzed comprehensively. In this paper, the load transfer process is studied, and the differential equations of force in different characteristic segments of pile foundation are established, and the method of solving the winding deformation of pile foundation is obtained by using the solution of power series. (2) the slope is classified according to the size of slope, and the concept of medium carrier is introduced. It is concluded that the chain reaction of slope slip is the material embodiment of medium carrier, and the chain evolution of medium carrier is used to describe the slip characteristics of landslide. Based on this, the distribution form and calculation method of landslide thrust and resistance are analyzed. 3 through the calculation of three-dimensional numerical model of pile-soil interaction in this project case, it is found that the order of influence of load on pile foundation is as follows: slope top distributed load > pile top vertical load > pile top transverse load. With the increase of pile diameter, the horizontal displacement of pile body decreases. 4in this case, the deformation of the steep section pile foundation is larger than that of the gentle slope section pile foundation, and the pile foundation bearing capacity of the steep slope section is smaller than that of the gentle slope section pile foundation. In the design of slope section pile foundation, the designed pile diameter or reinforcement range should depend on the degree of rapidity of slope. 5 in this case, the increase of elastic modulus of rock and soil obviously limits the deformation of pile foundation and reduces the horizontal stress value of pile-soil. In addition, the stress value of the surrounding rock mass under the condition of bridge pile foundation is within the allowable range of the specified foundation. Therefore, there is no need to add anti-slip measures for the slope.
【學(xué)位授予單位】：重慶交通大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2014
【分類號】：U443.15

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