本文選題：土工加筋路基 + 沉降��； 參考：《湘潭大學(xué)》2014年碩士論文

【摘要】：土工合成材料作為一種新型的巖土工程材料，已廣泛應(yīng)用于各個(gè)工程領(lǐng)域。目前對(duì)于土工合成材料加筋路基的理論研究與工程實(shí)踐比相對(duì)滯后，如對(duì)加筋路基的沉降變形分析中，荷載在路基和地基中的傳遞擴(kuò)散作用常常被忽略，且較少考慮筋材抗彎剛度及筋土界面軟化-位移方面性質(zhì)，導(dǎo)致理論計(jì)算結(jié)果與工程實(shí)際相差較大，限制了土工合成加筋材料的應(yīng)用。 本文主要研究內(nèi)容和結(jié)論如下： （1）利用Ansys軟件，建立了多層加筋路基平面應(yīng)變模型，研究了路基的沉降變形。 （2）采用Yin的基本假設(shè)和變形協(xié)調(diào)關(guān)系，并將軟土地基簡化為winkler彈簧，建立了一維加筋路基沉降變形微分方程。利用Mathematica符號(hào)解法，對(duì)方程進(jìn)行了求解。 （3）通過算例，將Mathematica符號(hào)解法計(jì)算結(jié)果與退化至單層加筋的有限元解進(jìn)行對(duì)比，驗(yàn)證了符號(hào)解與有限元解的一致性。在有限元模擬中，研究了路基沉降變形特性，并進(jìn)行了參數(shù)分析，結(jié)果表明，當(dāng)路基填料彈性模量小于40MPa，筋材彈性模量小于20MPa時(shí)，兩者對(duì)路基沉降的影響相對(duì)顯著；而大于上述值時(shí)，影響會(huì)變得越來越有限。在實(shí)際工程運(yùn)用中，可根據(jù)需要，應(yīng)控制路基彈性模量和筋材模量在上述合理范圍內(nèi)，以實(shí)現(xiàn)最優(yōu)的經(jīng)濟(jì)效果。在軟土地基上，鋪設(shè)土工合成加筋材料，加筋效果更為明顯。 （4）以模型實(shí)驗(yàn)數(shù)據(jù)為基礎(chǔ)，利用Ansys軟件，分別建立了樁承式加筋路基的平面應(yīng)變模型和軸對(duì)稱三維模型。平面模型中，樁體和樁間土采用不同彈性常數(shù)的彈簧單元模擬，大大減少了計(jì)算單元的數(shù)量；軸對(duì)稱模型選取了中心樁及相鄰樁間土四分之一部分建模。計(jì)算結(jié)果與實(shí)驗(yàn)數(shù)據(jù)的對(duì)比表明，兩者之間具有良好的一致性。 （5）基于兩種樁承式加筋路基模型，，考察了路基頂面和樁頂平面位置沉降變形特性，并分析了各參數(shù)對(duì)路基沉降的影響，為樁承式加筋路基的優(yōu)化設(shè)計(jì)提供了參考。參數(shù)分析表明，加筋層數(shù)對(duì)路基沉降變形影響不足1%，不建議采用增加層數(shù)的方法來控制路基沉降；樁反力系數(shù)在100kN/m3左右時(shí)可以取得最好的加筋效果；筋材的高度對(duì)路基沉降變形也有較大的影響。
[Abstract]:As a new geotechnical engineering material, geosynthetics have been widely used in various engineering fields. At present, the theoretical research of geo-composite material reinforced roadbed is lagging behind the engineering practice. For example, in the analysis of settlement and deformation of reinforced subgrade, the transfer and diffusion of load in subgrade and foundation are often neglected. Less consideration is given to the flexural stiffness of reinforced materials and the properties of softening and displacement of the interface between reinforcement and soil, which leads to a big difference between the theoretical calculation results and the engineering practice, which limits the application of geosynthetic reinforced materials. The main contents and conclusions of this paper are as follows: 1) using Ansys software, the plane strain model of multi-layer reinforced roadbed is established, and the settlement deformation of roadbed is studied. (2) based on the basic assumption of Yin and the compatibility of deformation, the differential equation of settlement and deformation of one-dimensional reinforced roadbed is established by simplifying the soft soil foundation to winkler spring. The equation is solved by Mathematica symbolic method. 3) the results of Mathematica symbolic solution are compared with the finite element solution which degenerates to single-layer reinforcement, and the consistency between the symbolic solution and the finite element solution is verified. In the finite element simulation, the characteristics of subgrade settlement and deformation are studied, and the results show that when the elastic modulus of subgrade filler is less than 40 MPA and the elastic modulus of reinforcement is less than 20MPa, the influence of them on subgrade settlement is relatively significant. And above the above value, the impact will become more and more limited. In practical engineering application, the elastic modulus of roadbed and the modulus of steel bar should be controlled within the above reasonable range according to the need, so as to realize the optimal economic effect. On the soft soil foundation, the reinforcement effect is more obvious when the geo-composite reinforcement material is laid. Based on the model experimental data, the plane strain model and axisymmetric three-dimensional model of pile-supported reinforced roadbed are established by using Ansys software. In the plane model, the spring element with different elastic constants is used to simulate the pile and the soil between the piles, which greatly reduces the number of calculation elements, and the axisymmetric model selects a quarter of the soil between the central pile and the adjacent pile to model the model. The comparison between the calculated results and the experimental data shows that there is a good agreement between the two. Based on two kinds of pile-supported reinforced roadbed models, the settlement and deformation characteristics of the top surface of the roadbed and the plane position of the pile-top are investigated, and the influence of various parameters on the settlement of the roadbed is analyzed, which provides a reference for the optimization design of the pile-supported reinforced roadbed. Parameter analysis shows that the effect of reinforcement layer number on subgrade settlement is less than 1, the method of increasing the number of layers is not recommended to control the subgrade settlement, the pile reaction coefficient can obtain the best reinforcement effect when the 100kN/m3 is about or so. The height of reinforcement also has great influence on subgrade settlement and deformation.
【學(xué)位授予單位】：湘潭大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2014
【分類號(hào)】：U416.1

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相關(guān)期刊論文 前3條

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本文編號(hào)：1989189