深基坑开挖与临近既有城际铁路的相互影响研究

发布时间：2018-08-31 11:45

【摘要】：随着我国高速城际铁路建造的快速发展以及基坑工程大规模的建设,在工程建设中,必然遇到基坑开挖与临近既有城际铁路线相互影响的问题。本文以临近沪宁城际的小红山汽车客运站基坑工程为项目背景,运用大型有限元软件ABAQUS,建立静力分析和动力分析模型,对深基坑开挖与城际铁路的相互影响进行了研究,主要的研究内容和成果如下： (1)依据小红山客运站基坑工程的实际条件,建立了有限元模型,分析了基坑开挖和动荷载作用下双排桩支护结构的特点及路基的动力响应特征,并将计算结果与基坑工程实测数据进行了对比,验证了模型的有效性。 (2)对比分析了150km/h、200km/h、250km/h、300km/h、350km/h等五种不同列车时速下支护结构的内力、水平位移及地表变形,结果表明,列车时速的增加,双排桩弯矩值有明显的增加,双排桩水平位移及地表沉降和隆起略有增加。 (3)通过对城际铁路与基坑不同距离下,基坑双排桩弯矩、水平位移、地表隆起的分析,认为两者距离4倍基坑深度以内时,在支护结构设计中,应考虑城际铁路对基坑支护结构的影响。 (4)对比分析了双排桩及被动区土体加固与仅采用双排桩支护下,路基x方向、y方向的动响应特征,结果表明采用双排桩支护及被动区土体加固,相比仅采用双排桩支护,能显著降低基坑开挖引起的路基侧移、沉降等不利影响。 (5)对比分析了不同基坑开挖深度下,路基变形、振动及动应力特征,结果表明,基坑开挖深度对路基的影响主要体现在增大路基的水平侧移,竖向沉降,路基的差异沉降以及增大基床表层x方向拉应力。
[Abstract]:With the rapid development of high-speed inter-city railway construction in China and the large-scale construction of foundation pit engineering, the problem of interaction between excavation and adjacent intercity railway lines is inevitable in the engineering construction. In this paper, based on the foundation pit project of Xiaohong Mountain passenger Station near the city of Shanghai and Nanjing, the static and dynamic analysis models are established by using the large-scale finite element software ABAQUS, and the interaction between the excavation of deep foundation pit and the inter-city railway is studied. The main research contents and results are as follows: (1) according to the actual conditions of foundation pit engineering in Xiaohong Mountain passenger Station, the finite element model is established. The characteristics of double-row pile supporting structure under excavation and dynamic load of foundation pit and the dynamic response of roadbed are analyzed, and the calculated results are compared with the measured data of foundation pit engineering. The validity of the model is verified. (2) the internal force, horizontal displacement and surface deformation of the support structure under different train speeds are compared and analyzed. (2) the internal force, horizontal displacement and surface deformation of the support structure with the speed of 150 km / h are compared and analyzed. The results show that the bending moment of the double-row pile increases obviously with the increase of the speed of the train, and the value of the bending moment of the double-row pile is obviously increased with the increase of the speed of the train. The horizontal displacement, ground subsidence and uplift of double-row piles are slightly increased. (3) through the analysis of bending moment, horizontal displacement and surface uplift of double-row piles at different distances between inter-city railway and foundation pit, When the distance between them is within 4 times of the depth of foundation pit, the influence of inter-city railway on the supporting structure of foundation pit should be considered in the design of supporting structure. The dynamic response characteristics of roadbed in x direction and y direction show that using double row pile support and soil reinforcement in passive zone can significantly reduce the lateral displacement of subgrade caused by excavation of foundation pit, compared with only adopting double row pile support. (5) the characteristics of subgrade deformation, vibration and dynamic stress under different excavation depth are compared and analyzed. The results show that the influence of excavation depth on subgrade is mainly reflected in increasing the horizontal lateral displacement of subgrade. Vertical settlement, differential settlement of subgrade and increase of tensile stress in X direction of the surface layer of foundation bed.
【学位授予单位】：南京大学
【学位级别】：硕士
【学位授予年份】：2013
【分类号】：TU473.2;U212.22

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