【作者】 张远荣；

【导师】 赵有明； 刘国楠；

【作者基本信息】 中国铁道科学研究院 ， 岩土工程， 2011， 博士

【摘要】 城市隧道的施工会影响周边环境,导致地面下沉、管线损坏、建构筑物变形等,严重时会影响社会稳定。盾构施工是一种公认对环境影响较小的施工方法,但是由于施工过程控制缺乏经验,造成环境影响的工程实例很多。盾构施工对环境影响的因素很多,在饱和强透水砂层中施工引起的地面沉降、孔压变化及其对周围环境影响的问题十分复杂,深入研究该问题对于盾构隧道设计、施工和城市环境保护具有重要的意义。本文在盾构力学模型的基础上,考虑水土流-固耦合相互作用,建立了盾构施工计算模型,模拟盾构掘进施工过程;采用FLAC3D非线性有限差分程序,模拟计算盾构的实际工作性状和对环境的影响,与实际检测数据对比具有合理性;进一步利用上述计算模型和方法研究了不同施工条件与施工参数对环境影响的规律,取得了一些十分有意义的结论,对实际工程具有指导意义。本文的主要研究工作包括:1、回顾总结了盾构施工技术的发展历程及其在国内的应用情况,分析了盾构施工对周围土体的扰动机理及其对地层沉降的影响范围,归纳了盾构施工对隧道周边土体扰动的研究方法。2、介绍了FLAC3D非线性有限差分程序的特点,以及饱和土体流-固耦合数值模拟方法、计算原理及其计算流程。3、通过分析盾构施工过程和受力特征,建立了综合反映各种因素影响的盾构施工计算模型。4、以深圳地铁2号线一段90米长富水砂层为例,考虑水土的流-固耦合相互作用,采用有效应力法,模拟计算了盾构通过该段地层产生地表沉降与孔压变化的规律,通过模拟计算结果与实测值的对比分析,验证了计算模型建立与计算参数选取的合理性。5、采用上述计算模型和计算方法,进一步研究了不同施工条件与施工参数对环境影响的变化规律。通过数值模拟计算结果分析,取得了一些新的认识和具有指导施工意义的研究成果。更多还原

【Abstract】 The problems of environment in urban would be caused by tunnel construction, such as ground subsidence, pipe line damage, building deformation etc.,even the confusion of the society may be aroused. As well as we known the shield tunneling technology is a method which environment influence less than others, but for the lack of construction control experience, the environment accidents occurs at times. They were many factors by which environment were affected during shield tunneling construction. It is a particularly complicated problem to analyze the ground subsidence and prop pressure change when shield tunneling pass through Saturated Sandy Stratum. Furthermore the influence on environment by the ground subsidence and prop pressure change is another problem. So the in-depth study on this problem have important significance for the design and construction of shield tunnel and protection of urban environmental. Based on the shield tunneling mathematical model, a model was erected to simulate the process of shield tunneling work in consideration of Fluid-Solid coupling interaction. The behavior and the environment influence of a metro construction site was simulated by FLAC3D Program Compared with the measured result, it was shown that the calculation results is reasonable.With the above calculation method and model, the law of the influence on environment by shield tunneling construction with different parameters and conditions was studied. Some valuable conclusion was achieved and those conclusion have the significance for the guidance to the shield tunneling construction. The main research work of this paper is as follow:1. The development of shield construction technology and its application in China was described. The mechanism of soil-disturbing and the range of the ground subsidence were analyzed resulting from the tunnel construction. Also the research methods about disturbance of surrounding soil caused by shield tunneling were generalized.2. The characteristic of FLAC3D program was introduced. And the method of fluid-saturated solid coupling numerical simulation and the principles and process of the simulation was illustrated.3. A shield model which combined with every kind of impact factors was established based on the analysis of characteristic of construction and mechanical behavior of shield tunnel. 4. According to the shield drivage process of a 90 meters long tunnel with Saturated Sandy Stratum conditions in Line 2 Shenzhen Metro project, the law of prop pressure changes and ground subsidence which caused by excavation was calculated with principle of effictive stress in consideration of Fluid-solid Coupling interaction. Compared the calculated result and the measurement results, the value were similar and tendency got good agreement. So it was confirmed that the numerical simulation method and the parameter which was used in the model was rational.5. With the calculation model and method above, the law of impaction on the environment from the difference construction conditions and driving parameters was simulated. According to the above study, some new conclusion was drawn and the new achievement of this study can be used as guide to the construction of shield tunneling in similar stratum.更多还原