發(fā)布時間：2018-02-23 16:19

  本文關(guān)鍵詞： 飽和軟土 深基坑 圍護結(jié)構(gòu) 變形　出處：《石家莊鐵道大學》2015年碩士論文　論文類型：學位論文

【摘要】：隨著經(jīng)濟的發(fā)展,城市建(構(gòu))筑物的高度、密度都在持續(xù)增加,同時因為城市地下軌道交通發(fā)展的需要,大量地鐵車站深基坑工程不可避免設(shè)計建造于密集既有建(構(gòu))筑物附近,因此基坑的施工受到了越來越嚴格的環(huán)境制約。本文以寧波市軌道交通1號線一期工程TJ-VII標海晏北路站西延段為工程研究對象,針對寧波富水軟土地區(qū)地鐵深基坑施工工程地質(zhì)、水文地質(zhì)條件差的現(xiàn)實情況,通過縝密理論分析、計算及對監(jiān)測數(shù)據(jù)的整理,分析了寧波富水軟土地區(qū)地鐵深基坑施工過程中基坑內(nèi)外水土變化特點和圍護結(jié)構(gòu)的變形特征,提出了該地質(zhì)條件下深基坑施工中基坑變形控制的技術(shù)措施。論文從土力學基本原理出發(fā),采用深基坑支擋結(jié)構(gòu)分析計算軟件(FRWS)進行基坑圍護結(jié)構(gòu)內(nèi)力及變形計算分析,施工全過程的跟蹤監(jiān)測、數(shù)據(jù)采集、變形分析,得出了寧波富水軟土地區(qū)基坑開挖所引起的圍護變形多呈現(xiàn)為弧線形,即凸鼓形或凹槽形。圍護結(jié)構(gòu)最大變形位置隨著開挖面的加深而逐步下移,并基本穩(wěn)定處于開挖面以下3~5 m范圍�？油獾乇碜冃吻妗o結(jié)構(gòu)變形曲面、坑外墻邊地層水平位移曲面均為不規(guī)則弧線形,具有相似性�？觾�(nèi)土體的回彈隆起及塑性變形應(yīng)由基坑開挖卸載、圍護結(jié)構(gòu)變形和擠壓、深部承壓含水層水壓及墻趾下部或圍護結(jié)構(gòu)地下連續(xù)墻薄弱部分外部地層水土的流入等四方面主要因素引起�；邮┕r,圍護結(jié)構(gòu)的變形規(guī)律由設(shè)計方案、基坑開挖方案、支撐架設(shè)質(zhì)量、施工過程控制水平、工程地質(zhì)和水文地質(zhì)條件等綜合決定,拐角效應(yīng)所影響的范圍很小,圍護結(jié)構(gòu)變形長邊效應(yīng)不明顯。軟土地區(qū)地鐵深基坑施工變形控制是一項系統(tǒng)工程,它是一個與時間、空間賽跑的過程,一項集加固、降水、開挖、支撐架設(shè)、結(jié)構(gòu)施作等分項作業(yè)綜合控制的系統(tǒng)作業(yè)。所有的基坑變形控制措施都要以過程控制為重中之重,施工過程控制的規(guī)范程度決定了措施的效果。因此,對于寧波富水軟土深基坑工程施工過程中時間、空間的控制和把握是精神,過程控制是關(guān)鍵。
[Abstract]:With the development of economy, the height and density of urban buildings are increasing continuously, and at the same time, because of the need of the development of urban underground rail transit, A large number of subway station deep foundation pit projects are inevitably designed and built near dense existing structures. Therefore, the construction of foundation pit is more and more strictly restricted by the environment. This paper takes the west extension section of Haiyan North Road Station as the research object of the first phase project of Ningbo Rail Transit Line 1. In view of the fact that the construction engineering geology and hydrogeological conditions of deep foundation pit of subway in Ningbo water-rich soft soil area are poor, through careful theoretical analysis, calculation and collation of monitoring data, The characteristics of soil and water change inside and outside the foundation pit and the deformation characteristics of the retaining structure during the construction of deep foundation pit of subway in Ningbo water-rich soft soil area are analyzed. Based on the basic principles of soil mechanics, the internal force and deformation of the retaining structure of deep foundation pit are calculated and analyzed by using the software of FRWS, which is based on the basic principle of soil mechanics, and puts forward the technical measures to control the deformation of the foundation pit in the construction of the deep foundation pit under this geological condition. Tracking and monitoring, data acquisition and deformation analysis during the whole process of construction, it is concluded that the surrounding deformation caused by excavation of foundation pit in rich water soft soil area of Ningbo is mostly arcuate. That is, convex drum or groove shape. The maximum deformation position of the retaining structure gradually moves down with the deepening of the excavating surface, and is basically stable in the range of 3 ~ 5 m below the excavating surface. The horizontal displacement surfaces along the outer wall of the pit are all irregular arcs, which are similar. The springback and plastic deformation of the soil in the pit should be unloaded by the excavation of foundation pit, and the deformation and extrusion of the surrounding structure should be carried out. The water pressure of the deep confined aquifer and the inflow of soil and water from the weak part of the underground continuous wall are mainly caused by the water pressure of the deep confined aquifer and the water and soil inflow of the weak part of the underground continuous wall. During the construction of the foundation pit, the deformation law of the retaining structure is caused by the design scheme and the excavation scheme of the foundation pit. The influence of corner effect on the quality of support erection, construction process control level, engineering geology and hydrogeological conditions is very small. Deformation long side effect of retaining structure is not obvious. Deformation control of deep foundation pit construction in soft soil area is a systematic engineering, it is a race with time and space process, a consolidation, precipitation, excavation, support erection, All the deformation control measures of foundation pit should take process control as the most important one, and the standard degree of construction process control determines the effect of the measures. Space control is the spirit and process control is the key to the construction of deep foundation pit with rich water and soft soil in Ningbo.
【學位授予單位】：石家莊鐵道大學
【學位級別】：碩士
【學位授予年份】：2015
【分類號】：TU753

【引證文獻】

相關(guān)碩士學位論文 前1條

1 王大軍;某地鐵車站深基坑有限元模擬及現(xiàn)場監(jiān)測分析[D];長安大學;2017年

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本文編號：1526832