开挖地下通道对上部文物建筑结构影响的研究

发布时间：2018-03-27 11:40

本文选题：桩基托换　切入点：文物建筑　出处：《东北大学》2013年硕士论文

【摘要】：对重要的既有建筑物下进行施工开挖,经常需要对桩基进行托换。特别针对保护历史文物建筑,托换技术非常有效。由于托换工程的复杂性和历史文物建筑的重要性,因此,在开挖地下通道中,对上部结构影响进行研究是非常重要的。首先,论文在研究桩基托换理论和计算方法的基础上,以上部有保护建筑、下部有盾构隧道的沈阳站地下通道工程为背景,建立东站房框架结构的ANSYS三维模型,对其在施工中可能出现的整体纵向倾斜式、整体横向倾斜式和“盆式”沉降的结构响应进行数值分析。验算在正常使用状态下结构的内力和变形,得出各构件在三种沉降方式下的受力状况和变形规律。研究结果表明,在三种沉降形式下,框架柱主要受轴力,且边柱普遍小于内柱；框架梁主要受剪力与弯矩,且二层梁普遍大于一层梁约15%。纵式沉降对横梁影响较大,横式沉降对纵梁影响较大,“盆式”沉降则对纵横梁都产生较大内力。纵、横式沉降下,梁、柱的变形均为线性,“盆式”则呈现非线性。同时,研究发现结构的极限沉降差与柱距大小有关,近似呈正比例关系。最终得出,结构在横式、纵式和“盆式”沉降下的极限沉降差分别为118mm、69mm和23.5mm,均为受压破坏。另外,对沉降数据进行分析,得出结构沉降的变化规律,实践证明在通道开挖中利用桩基托换对文物建筑进行保护是可行、合理的。分析数据表明,施工第一阶段(破除原地表和柱承台)、第二阶段(东侧基坑开挖)、第三阶段(站房下暗挖)和第四阶段(截断支撑桩)的沉降值分别占总沉降的35%、30%、25%和10%左右。破除原地表和柱承台对结构扰动最大,在通道结构封闭成环后,截桩截断支撑桩对结构的扰动并不大。最后,依据实测数据对框架结构进行内力分析,得出结构的内力变化规律,并对施工过程中结构的安全性做出评判。计算结果表明,各施工阶段均满足相关规范的要求,结构内力最大的部位位于沉降最大柱的相邻框架柱及其对应的框架梁。在施工的四个施工阶段中,该柱的轴力增幅约为8.2%、17.7%、38.9%和52.8%,该梁剪力分别约为自重下的1.6、3.6、6.9和9倍,弯矩分别约为自重下的1.5、4.2、6.6、9.8倍。
[Abstract]:In order to carry out construction and excavation under important existing buildings, pile foundations are often required to be underpinned. Especially for the protection of historical heritage buildings, the underpinning technology is very effective. Because of the complexity of the underpinning project and the importance of historical heritage buildings, therefore, In the excavation of underground passage, it is very important to study the influence of superstructure. Firstly, based on the research of pile foundation underpinning theory and calculation method, the above part has protected building. In the background of the underground passage project of Shenyang Station with shield tunneling in the lower part, the ANSYS three-dimensional model of the frame structure of the East Station House is established, and the overall longitudinal tilt type that may appear in the construction is analyzed. The structural response of the integral transverse inclined and "basin" settlement is numerically analyzed. The internal force and deformation of the structure under normal working conditions are checked, and the stress and deformation laws of each member under three settlement modes are obtained. The results show that, Under the three kinds of settlement forms, the frame column is mainly subjected to axial force, and the side column is generally smaller than the inner column, and the frame beam is mainly subjected to shear force and bending moment, and the two-story beam is generally larger than the one-story beam about 15. The horizontal settlement has a great influence on the longitudinal beam, while the "basin type" settlement has a greater internal force on the longitudinal and horizontal beam. Under the longitudinal and horizontal settlement, the deformation of the beam and column is linear, while the "basin type" is nonlinear. It is found that the ultimate settlement difference of the structure is related to the size of the column distance and is approximately proportional. Finally, the ultimate settlement difference of the structure under horizontal, longitudinal and "basin" settlement is 118mm / 69mm and 23.5mm respectively, which are all under compression damage. By analyzing the settlement data, the variation law of structural settlement is obtained, and the practice proves that it is feasible and reasonable to use pile foundation underpinning to protect the cultural relic building during the tunnel excavation. The settlement value of the first stage of construction (removing the surface and column cap, the second stage (excavation of foundation pit on the east side), the third stage (underground excavation of the station room) and the fourth stage (truncated supporting pile) accounted for about 3530% and 10% of the total settlement, respectively. Except in situ table and column cap, the disturbance to the structure is the biggest, After the tunnel structure is closed into a ring, the disturbance to the structure caused by the truncated pile supporting pile is not great. Finally, according to the measured data, the internal force of the frame structure is analyzed, and the law of the internal force variation of the structure is obtained. The calculation results show that each construction stage meets the requirements of relevant codes. The maximum internal force of the structure is located in the adjacent frame column with the largest settlement column and its corresponding frame beam. In the four construction stages of construction, the axial force increase of the column is about 8.2% and 52.8% respectively, and the shear force of the beam is about 1.63.66.9 and 9 times that of the deadweight, respectively. The bending moment is about 1.5U 4.2U 6.69.8times as high as that under deadweight.
【学位授予单位】：东北大学
【学位级别】：硕士
【学位授予年份】：2013
【分类号】：TU94;TU433

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