本文選題：高速公路 + 拓寬工程�。� 參考：《河北工業(yè)大學(xué)》2014年碩士論文

【摘要】：在軟土地基高速公路拓寬工程中，普遍存在新、老路堤差異沉降的問題。而這個(gè)問題也成為高速公路改擴(kuò)建工程中的重要問題。為解決差異沉降給工程帶來的不利影響，國內(nèi)外的工程技術(shù)人員都進(jìn)行了大量的工程實(shí)踐，雖然在已完成的拓寬工程中取得了一些寶貴的經(jīng)驗(yàn)，但相關(guān)的理論成果較少，沒有系統(tǒng)性的規(guī)范，對(duì)新老路基的沉降特性了解的也不是很全面，需要作進(jìn)一步的研究。 本文以北方某高速公路的拓寬工程為背景，從軟土地基上實(shí)際出現(xiàn)的問題出發(fā)，基于ABAQUS有限元分析，通過數(shù)值模擬對(duì)新老路堤的沉降特性進(jìn)行了系統(tǒng)的研究，主要內(nèi)容如下： 1.介紹了有限元法和ABAQUS的基本概況，建立了路基拓寬的有限元模型，分別分析了無處理措施時(shí)路基的沉降、附加應(yīng)力以及超孔壓變形。結(jié)果表明：新路基以附加荷載形式作用于老路基，，從而引起了新老路基的不均勻沉降變形；路基頂面豎向沉降沿路基橫斷面方向由路中心向兩側(cè)呈勺型分布；新路基水平位移的最大值出現(xiàn)在新路基的形心位置；新路堤填土處出現(xiàn)了附加剪應(yīng)力集中。 2.建立水泥攪拌樁復(fù)合地基模型，分析填土與樁體參數(shù)的改變對(duì)拓寬路基沉降變形的影響。結(jié)果表明：路基的變形情況會(huì)隨填土和樁體設(shè)計(jì)參數(shù)的變化而改變，路堤填土和樁基對(duì)路基的穩(wěn)定都有著至關(guān)重要的影響，選擇有效的工藝參數(shù)才能最有效的控制路基的變形。 3.闡述了PTC管樁在地基處理時(shí)的作用機(jī)理，分析了PTC管樁復(fù)合地基對(duì)路基沉降變形的影響。結(jié)果表明：PTC管樁復(fù)合地基處理措施增加了軟土路基的總體剛度，整個(gè)地基變形向深部傳遞。在樁土的相互作用中，PTC管樁內(nèi)、外側(cè)摩阻力異步發(fā)揮，土芯和樁壁之間產(chǎn)生比較大的摩阻力，使得土芯和樁壁一起下沉，樁呈類似閉口樁的破壞形式。
[Abstract]:The problem of differential settlement between old and new embankments is common in the widening project of expressway with soft soil foundation. And this question also becomes the important question in the highway reconstruction and extension project. In order to solve the adverse effects of differential settlement on the project, many engineers and technicians at home and abroad have carried out a large number of engineering practices. Although some valuable experience has been obtained in the completed widening project, there are few related theoretical achievements. Without systematic specification, the settlement characteristics of new and old subgrade are not fully understood, and need to be further studied. In this paper, the settlement characteristics of new and old embankment are systematically studied by numerical simulation based on ABAQUS finite element analysis and based on the actual problems on soft soil foundation based on the widening project of a highway in the north. The main contents are as follows: 1. This paper introduces the basic situation of finite element method and ABAQUS, establishes the finite element model of roadbed widening, and analyzes the settlement, additional stress and superpore pressure deformation of roadbed without treatment measures respectively. The results show that the new roadbed acts on the old roadbed in the form of additional load, which causes the uneven settlement of the new and old roadbed, and the vertical settlement of the top surface of the roadbed distributes along the cross-section of the roadbed from the center of the road to the two sides of the roadbed. The maximum horizontal displacement of the new embankment appears in the center of the new roadbed and the additional shear stress concentration appears at the new embankment fill. 2. The model of cement mixing pile composite foundation is established, and the influence of the change of filling and pile parameters on the settlement deformation of widening roadbed is analyzed. The results show that the deformation of embankment will change with the change of the design parameters of embankment and pile. The embankment filling and pile foundation have an important influence on the stability of roadbed. The most effective control of subgrade deformation can be achieved by selecting effective technological parameters. 3. This paper expounds the action mechanism of PTC pipe pile in foundation treatment, and analyzes the influence of PTC pipe pile composite foundation on subgrade settlement and deformation. The results show that the total stiffness of soft soil subgrade is increased and the deformation of the whole foundation is transmitted to the deep. In the pile-soil interaction, the lateral frictional resistance of PTC pipe pile plays asynchronously, and the friction between the soil core and the pile wall causes the soil core to sink together with the pile wall, and the pile is similar to the closed pile.
【學(xué)位授予單位】：河北工業(yè)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

【參考文獻(xiàn)】

相關(guān)期刊論文 前1條

1 張軍輝;黃曉明;彭嫻;;軟土地基上高速公路雙側(cè)加寬工程的數(shù)值分析[J];公路交通科技;2007年03期

本文編號(hào)：1869465