滨海软土地区近接高铁顶进铁路立交桥综合施工技术

发布时间：2018-05-20 01:38

本文选题：全封闭止水 + 地下水位　；参考：《石家庄铁道大学》2015年硕士论文

【摘要】：本文研究了滨海软土地区近接高铁顶进铁路立交桥综合施工技术,具体来说,可以分为以下几个方面:(1)全封闭止水方案设计。本工程地层软弱,地下水位较高,工程止水方案设计为:框构工作坑及U型槽基坑开挖后不渗不漏,实现无水施工;顶桥降水顶进期间,线间止水帷幕渗透系数控制在1×108 m/s以下,从而避免由于地下水位下降引起的地层有效应力增加造成的路基下沉。(2)全封闭止水施工技术研究。本工程止水帷幕桩长最大21 m,距离既有京津城际最近2.5 m,本文通过城际刚构桥下止水帷幕及封底旋喷桩试验确定了施工工艺参数,为工程顺利进行提供了保证。(3)基坑开挖技术研究。本工程基坑开挖深度虽然最大只有6 m,但是由于地层软弱、地下水位较高,提高了施工难度。本文应用PLAXIS有限元软件模拟基坑开挖对既有线的影响程度,从而确定了合理的基坑开挖步序。(4)施工监测技术研究。运营中的京津城际附加差异沉降不得大于1 mm,为达到控制标准要求,本文采用SMAIS(自动化管理与分析系统),研究制定了合理的监测手段及监测方法。
[Abstract]:This paper studies the comprehensive construction technology of the overpass of the railway with high speed and entering the railway near the seaside soft soil area. Specifically, it can be divided into the following aspects: 1) the design of the completely closed watertight scheme. In this project, the stratum is weak and the underground water level is high. The design of the watertight project is as follows: no seepage and leakage after excavation of the frame working pit and U-groove foundation pit, and no water construction during the dewatering of the top bridge, The permeability coefficient of the interline waterproof curtain is controlled below 1 脳 10 ~ 8 m / s, so as to avoid the subgrade subsidence caused by the increase of effective stress in the formation caused by the decrease of groundwater level. The maximum length of the waterproof curtain pile in this project is 21 m, and the nearest 2.5 m from the existing Beijing-Tianjin city. This paper determines the construction technical parameters through the test of the waterproof curtain under the inter-city rigid frame bridge and the bottom rotating grouting pile. The research on excavation technology of foundation pit is provided to ensure the smooth progress of the project. Although the excavation depth of foundation pit of this project is only 6 m, it is difficult to construct because of weak stratum and high groundwater level. In this paper, PLAXIS finite element software is used to simulate the influence of foundation pit excavation on existing railway lines, so as to determine the reasonable construction monitoring technology. The additional differential settlement between Beijing and Tianjin should not be greater than 1 mm in operation. In order to meet the requirements of control standard, this paper adopts SMAIS (automatic Management and Analysis system) to study and establish reasonable monitoring means and methods.
【学位授予单位】：石家庄铁道大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：U445.4

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