软土场地双线隧道土压盾构施工地表沉降规律研究

发布时间：2018-05-13 00:05

本文选题：土压盾构 + 双线隧道　；参考：《哈尔滨工业大学》2017年硕士论文

【摘要】：随着地铁工程的逐渐发展,地铁设计建造过程中所受的制约因素也越来越多。传统的单线隧道已经不能满足社会发展的需要,而双线隧道较好地兼顾了成本与交通量两方面的因素,因而得到了越来越多的应用。现有研究成果中,涉及双线隧道盾构施工引起的地表沉降方面的研究较少,工程中通常做法是采用两条单线隧道沉降曲线进行叠加。但由于两条隧道施工过程中的相互影响,沉降曲线的简单叠加并不能准确地反映地表沉降的发展。因此有必要对双线隧道盾构施工引起的地表沉降规律进行研究。常州轨道交通一号线工程采用典型的双线隧道断面形式,且工程位于长江中下游,隧道所处地区属于软土场地。因此,本文结合常州轨道交通一号线,通过现场监测、有限元分析对软土场地双线隧道土压盾构施工引起的地表沉降规律进行研究。主要研究工作如下:(1)根据工程中6个监测断面现场监测数据,结合地质条件、施工参数等因素,对常州市轨道交通一号线盾构施工引起的地表变形特性进行分析,研究了单线、双线隧道地表沉降发展历程和横向分布规律。另外,分析搜集到的国内外双线隧道工程地表沉降槽曲线,研究双线隧道土压盾构施工引起的地表沉降槽分布规律,发现双线隧道地表沉降槽曲线形态呈现出多样化、复杂化的特点。(2)根据工程勘察资料以及设计文件,利用有限元软件ABAQUS,采用摩尔库伦弹塑性屈服准则,对双线隧道土压盾构施工过程按照施工工序进行三维数值模拟。针对注浆过程难以模拟的难题,引入注浆压力计算公式,完善了弱化注浆层直接施加注浆压力的方法。结合模拟结果,从地表沉降横向分布和地表沉降发展历程两个方面验证模型的正确性。在验证模型的同时,对监测数据所反映的规律进行补充,得到完整的地表沉降曲线。(3)基于已有模型,研究隧道间距、注浆压力、土仓压力三个因素对双线隧道盾构施工地表沉降横向分布和沉降发展较过程的影响。结合地铁设计规范以及现有研究成果,从控制沉降的角度给出双线隧道土压盾构施工过程中注浆压力、土仓压力、隧道间距的参考值,以求为下一阶段设计施工提供参考和建议。
[Abstract]:With the development of subway engineering, there are more and more restricted factors in the course of subway design and construction. The traditional single-line tunnel can not meet the needs of social development, while the dual-line tunnel has been applied more and more because of the cost and traffic volume. Among the existing research results, there are few researches on the surface settlement caused by the shield tunneling construction of two-line tunnel. In the engineering, the settlement curve of two single-line tunnels is usually used to superposition. However, because of the interaction between the two tunnels, the simple superposition of the settlement curve can not accurately reflect the development of surface subsidence. Therefore, it is necessary to study the law of ground subsidence caused by shield tunneling. Changzhou Rail Transit Line 1 works in the form of a typical double-track tunnel section, and the project is located in the middle and lower reaches of the Yangtze River, where the tunnel is located in the soft soil site. Therefore, combined with Changzhou Rail Transit Line 1, through field monitoring and finite element analysis, this paper studies the law of ground subsidence caused by earth pressure shield construction of double-line tunnel in soft soil site. The main research work is as follows: (1) based on the field monitoring data of 6 monitoring sections, combined with geological conditions, construction parameters and other factors, the characteristics of surface deformation caused by shield tunneling on Line 1 of Changzhou Rail Transit are analyzed, and a single line is studied. The development history and transverse distribution law of surface settlement of double-track tunnel. In addition, the surface subsidence trough curves collected at home and abroad are analyzed, and the distribution law of surface settlement trough caused by earth pressure shield tunneling construction is studied. It is found that the surface settlement trough curve of double-line tunnel is diversified. According to the engineering survey data and design documents, using finite element software Abaqus, using the Mohr Coulomb elastoplastic yield criterion, the construction process of double-line tunnel earth pressure shield is simulated according to the construction procedure. In view of the difficult problem of grouting process simulation, the calculation formula of grouting pressure is introduced, and the method of weakening grouting layer directly exerting grouting pressure is improved. Based on the simulation results, the correctness of the model is verified from two aspects: the lateral distribution of surface subsidence and the development of surface subsidence. At the same time, the model is verified, the law reflected by the monitoring data is supplemented, and the complete surface subsidence curve is obtained. Based on the existing model, the tunnel spacing and grouting pressure are studied. The influence of three factors of soil silo pressure on the lateral distribution of ground surface settlement and the process of settlement development in shield tunneling construction of double-line tunnel. Combined with the design code of subway and the existing research results, the reference values of grouting pressure, soil chamber pressure and tunnel spacing during the construction of double-line tunnel earth pressure shield are given from the point of view of controlling settlement. In order to provide reference and suggestions for the next stage of design and construction.
【学位授予单位】：哈尔滨工业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：U455.43;P642.26

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