杭州软土地区浅埋大断面隧道施工对地层竖向变形的影响分析

发布时间：2018-01-09 03:25

本文关键词：杭州软土地区浅埋大断面隧道施工对地层竖向变形的影响分析　出处：《浙江工业大学》2015年硕士论文　论文类型：学位论文

【摘要】：本文在前人研究工作的基础上,采用理论研究、数值模拟和现场试验相结合的方法初步分析了杭州市软土地区浅埋大断面隧道施工的地层竖向变形规律,主要的内容和结论如下:1、利用有限元软件ABAQUS分析了CRD工法施工时不同开挖步对地层变形的影响,得出在CRD工法中,第一部开挖地表沉降最大值就远超30mm;其次,对CRD工法、CD工法、台阶工法的竖向变形进行研究,得出地表沉降最大值的大小关系为:台阶工法CD工法CRD工法;最后,分析CRD工法的三种施工工况下的竖向变形,得到错开开挖将有利于控制地层变形。2、模拟不同轴线埋深、不同间距情况下的双线隧道开挖,得出地表沉降规律;利用水平距离系数C值判断地表变形曲线形态是单峰还是双峰;其次,通过分析沉降槽宽度,得出在大断面隧道中,地表沉降槽宽度可以利用分段函数进行表示。同时,通过对地表最大值的修正,得出双线地表沉降公式。将预测公式计算值与有限元值对比,发现两者接近。3、对双线隧道的深层沉降进行分析,得出深层沉降规律。其次,结合Mair公式对深层沉降槽宽度、深层最大值进行修正,并结合Peck的双线叠加公式的方法得出双线深层沉降公式。最后,将预测公式计算值与有限元值对比,发现两者接近。4、分析双线浅埋大断面隧道地表纵向变形,得出纵向地表沉降规律,并得出在z/D(轴线埋深/等效直径)不同的情况下的浅埋暗挖纵向地表沉降公式。5、利用监测数据分析地表沉降、深层沉降、拱顶沉降规律,并将监测数据与有限元值及预测公式进行对比分析;预测公式在总体趋势和规律上与监测数据相似,且数值差距在20%以内;预测公式可以初步应用于隧道的地层竖向变形预测。
[Abstract]:On the basis of previous research work, the vertical deformation law of shallow buried large section tunnel in soft soil area of Hangzhou is analyzed preliminarily by the method of theoretical study, numerical simulation and field test. The main contents and conclusions are as follows: 1. By using the finite element software ABAQUS, the influence of different excavation steps on the formation deformation during the construction of CRD construction method is analyzed, and the result is obtained in the CRD construction method. In the first part, the maximum value of surface subsidence is far more than 30mm; Secondly, the vertical deformation of CRD method and step method are studied, and the relation of the maximum value of surface subsidence is obtained as follows: step method, CD method, CRD method; Finally, the vertical deformation under three construction conditions of CRD method is analyzed, and it is found that staggered excavation will be beneficial to control the formation deformation of 0.2 and simulate the excavation of double-line tunnel with different axis depth and different spacing. The law of surface subsidence is obtained. The horizontal distance coefficient C value is used to judge whether the shape of surface deformation curve is single peak or double peak. Secondly, by analyzing the width of settlement trough, it is concluded that in large section tunnel, the width of surface settlement trough can be expressed by subsection function. At the same time, through the correction of the maximum value of surface. The calculation value of the prediction formula is compared with the finite element value, and it is found that both of them are close to .3. the deep settlement of the double-line tunnel is analyzed, and the law of deep settlement is obtained. Combined with Mair formula, the width and maximum value of deep settlement trough are modified, and combined with Peck's double-line superposition formula, the double-line deep settlement formula is obtained. Finally. By comparing the calculated value of prediction formula with the value of finite element, it is found that the two values are close to .4. the longitudinal deformation of tunnel surface with shallow and large section is analyzed, and the law of longitudinal surface subsidence is obtained. And under the condition of different z / D (axis buried depth / equivalent diameter), the vertical surface subsidence formula. 5. The law of surface subsidence, deep settlement and dome settlement are analyzed by monitoring data. The monitoring data are compared with the finite element value and the prediction formula. The prediction formula is similar to the monitoring data in general trend and law, and the numerical difference is less than 20%; The prediction formula can be applied to the vertical deformation prediction of the tunnel.
【学位授予单位】：浙江工业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：U455

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