上海中心大廈裙房深大基坑變形特性及盆式開挖技術(shù)研究
發(fā)布時間：2019-05-18 10:26
【摘要】：上海中心大廈基坑工程為近年來上海軟土地區(qū)罕見的超大、超深基坑工程。其周邊環(huán)境復(fù)雜，變形控制要求高；且因該地區(qū)隔水性好的第⑧粘性土層的缺失，導(dǎo)致第⑦和第⑨砂土承壓含水層貫通，地下連續(xù)墻未能隔斷坑內(nèi)外承壓水層的水力聯(lián)系，且水頭降深大、降水時間長，從而導(dǎo)致承壓降水對基坑變形影響顯著。該基坑工程采用“主樓順作+裙房逆作”的總體施工方案，采用圓形地墻將主樓區(qū)和裙房區(qū)臨時隔開，先行施工主樓區(qū)基坑，后再逆作施工裙房區(qū)基坑。由于工程的特殊性，針對此類裙房基坑變形特性的研究甚少。同時，現(xiàn)采用逆作法施工的深大基坑工程普遍采用盆式土方開挖技術(shù)；但在實(shí)際施工過程中，相關(guān)施工參數(shù)通常只根據(jù)施工經(jīng)驗確定，甚至有時較為隨意，從而容易導(dǎo)致基坑變形過大。另外，基坑工程總體施工方案合理與否，對工程施工的安全性和經(jīng)濟(jì)性起到關(guān)鍵作用。由此，本文通過理論分析、數(shù)值模擬和實(shí)測數(shù)據(jù)分析等手段，對基坑降水對基坑變形的影響、本裙房基坑工程的變形特性、深大基坑的盆式土方開挖技術(shù)、及本工程的總體施工方案合理性驗證等方面內(nèi)容，作了較深入的研究。主要內(nèi)容包括以下幾個方面： （1）基于FLAC滲流分析模塊對不同土層分布的孔壓場進(jìn)行了研究，定性把握了不同土層及滲流邊界條件下的孔壓分布規(guī)律；并依此規(guī)律，針對上海軟土地區(qū)常見三類深基坑降水情況，給出了相應(yīng)的考慮滲流作用的水壓分布計算簡化方法，且對此合理性作了相應(yīng)論證；同時結(jié)合本裙房基坑工程實(shí)例，對給出的水壓分布簡化計算方法的合理性給予了驗證。 （2）依據(jù)實(shí)測數(shù)據(jù)詳細(xì)分析了圍護(hù)墻側(cè)移的整體變形性狀、最大側(cè)移值及發(fā)生位置和三維空間效應(yīng)，并分析了基坑開挖寬度和出入口進(jìn)出施工車輛對圍護(hù)墻側(cè)移的影響；同時著重分析了混凝土墊層的設(shè)置和水平梁板及大底板的混凝土結(jié)構(gòu)收縮對圍護(hù)墻側(cè)移的影響，指出混凝土墊層對圍護(hù)墻具有較好的支撐作用，及超長水平混凝土結(jié)構(gòu)的收縮對圍護(hù)墻變形影響顯著。另外，圍護(hù)墻頂豎向位移、立柱的隆沉、墻柱之間的差異沉降、墻后地表沉降及基坑周邊歷時建筑和臨近管線沉降作了詳細(xì)分析。突出說明了承壓降水對基坑變形的顯著影響。 （3）基于FLAC有限差分軟件對基坑變形特性進(jìn)行了研究。在模擬中，結(jié)合水土分算原則，土體物理參數(shù)采用有效應(yīng)力指標(biāo)，并根據(jù)實(shí)際施工過程降水情況，及前面考慮滲流作用的水壓分布研究成果，考慮了土中孔壓變化對基坑變形的影響。在分析過程中，，首先討論了主樓區(qū)與裙房區(qū)之間的臨時隔斷圓形地墻的簡化方式、是否考慮地下水和工程樁的作用等因素對計算結(jié)果的影響；分析了基坑開挖寬度及水平支撐剛度對基坑變形的影響；并對裙房基坑中間部位的變形特性做了較全面的計算分析，且比較了計算值和實(shí)測值之間的關(guān)系，特別說明了基坑北側(cè)部分地表測點(diǎn)有所隆起的原因；同時采用不同計算方法對作用在圍護(hù)墻上的水土壓力大小進(jìn)行了分析，并與實(shí)測值進(jìn)行了對比，說明了采用前面提出的考慮滲流作用的水壓分布計算方法用于水土壓力計算的合理性。 （4）為合理確定逆作法深大基坑工程的盆式土方開挖方案，依據(jù)懸臂和帶撐兩種不同條件的特點(diǎn)，對土方開挖的分塊大小、盆邊開挖深度、盆中開挖深度、盆邊留土寬度和坡度及分塊開挖順序等施工參數(shù)的確定進(jìn)行了較為詳細(xì)的分析說明。并提出了盆邊開挖路徑向相關(guān)區(qū)和盆中開挖路徑非相關(guān)區(qū)的概念及劃分。且對盆式開挖盆邊留土寬度的對基坑變形影響作較深入的研究，并給出了合理確定的方法和建議。 （5）為論證背景基坑工程現(xiàn)行總體施工方案的合理性，首先詳細(xì)分析了該基坑工程的特點(diǎn)；在此基礎(chǔ)上，提出了四個比選方案：中間大開口全順作、中間大開口全逆作、主樓區(qū)順作+裙房區(qū)順作、主樓區(qū)順作+裙房區(qū)逆作等方案；接著從工期、經(jīng)濟(jì)成本、周邊環(huán)境影響、技術(shù)方法等方面進(jìn)行方案了比較分析。同時對現(xiàn)行所采用方案的優(yōu)點(diǎn)作了進(jìn)一步說明。
[Abstract]:The foundation pit project of Shanghai Center Building is a rare and super-deep foundation pit project in Shanghai soft soil area in recent years. The surrounding environment is complex, and the deformation control requirement is high; and due to the absence of the second sticky soil layer in the area, the first and the second sandy soil pressure-bearing water-bearing layers are communicated, the underground continuous wall can not block the hydraulic connection of the inner and outer bearing water layers of the pit, the water head is deep in depth and the precipitation time is long, So that the pressure-bearing precipitation greatly influences the deformation of the foundation pit. The general construction scheme of the "The main building is in the direction of the + skirt." is adopted for the foundation pit engineering, and the main building area and the skirt building area are temporarily separated by a circular floor wall, and the foundation pit of the main building area is firstly constructed, and then the foundation pit of the construction apron area is inverted. Due to the particularity of the project, there is little research on the deformation characteristics of the foundation pit of this kind of skirt. At the same time, the deep foundation pit works which are constructed by using the reverse construction method are generally adopted in the basin-type earth excavation technology, but in the actual construction process, the relevant construction parameters are usually determined according to the construction experience, and even at random, so that the deformation of the foundation pit is easily caused to be too large. In addition, the overall construction scheme of the foundation pit works is reasonable or not, and plays a key role in the safety and economy of the construction. In this paper, by means of theoretical analysis, numerical simulation and actual data analysis, the influence of the foundation pit dewatering on the deformation of the foundation pit, the deformation characteristics of the foundation pit engineering of the present skirt, the basin-type earth excavation technology of the deep foundation pit and the rationality verification of the overall construction scheme of the project are discussed in this paper. A more in-depth study was made. The main contents include the following aspects: (1) Based on the FLAC seepage analysis module, the pore pressure distribution of different soil layers is studied, and the distribution of pore pressure in different soil layers and seepage boundary conditions is determined qualitatively. In view of the three types of deep foundation pit dewatering in the soft soil area in Shanghai, the paper gives a simplified method for calculating the water pressure distribution of the seepage, and proves the rationality. At the same time, the foundation pit engineering of this skirt is combined. In this paper, the rationality of the simplified calculation method of the water pressure distribution is given. (2) According to the measured data, the whole deformation character, the maximum lateral displacement value and the position and the three-dimensional space effect of the side-shift of the enclosure wall are analyzed in detail, and the excavation width of the foundation pit and the access and exit of the access and exit construction vehicle to the side of the enclosure wall are analyzed. The effect of the shrinkage of the concrete cushion on the side of the enclosure wall is analyzed, and the effect of the shrinkage of the concrete structure on the side of the enclosure wall is analyzed. It is pointed out that the concrete cushion has a good supporting effect on the enclosure wall, and the shrinkage of the super-long horizontal concrete structure can be used for the deformation of the enclosure wall. In addition, the vertical displacement of the top of the enclosure, the uplift of the column, the differential settlement between the wall columns, the settlement of the ground surface after the wall and the settlement of the surrounding of the foundation pit and the settlement of the adjacent pipelines Fine analysis. The effect of pressure-bearing precipitation on the deformation of foundation pit is highlighted. The Influence of (3) on the Deformation of the Foundation Pit Based on the Finite Difference Software of FLAC In the simulation, the effective stress index is used in the physical parameters of the soil, and according to the actual construction process and the water pressure distribution of the seepage, the change of the pore pressure in the soil to the foundation pit is considered. In the process of the analysis, the paper first discusses the simplified way of the temporary partition of the circular floor between the main building area and the skirt building area, and whether the influence of the factors such as the role of the ground water and the engineering pile on the calculation results is considered, and the excavation width and the horizontal support stiffness of the foundation pit are analyzed to the foundation pit. The influence of deformation is made, and the deformation characteristic of the middle part of the foundation pit of the skirt is calculated and analyzed, and the relation between the calculated value and the measured value is compared. The reason of the bump is that the water and soil pressure on the wall of the enclosure is analyzed by different calculation methods, and compared with the measured value, the water pressure distribution calculation method considering the seepage effect is used in the water and soil pressure gauge. The rationality of calculation is as follows: (4) In order to reasonably determine the basin-type earth excavation scheme of the deep foundation pit project of the reverse practice, the block size of the earth excavation and the depth of the basin edge are excavated according to the characteristics of the two different conditions of the cantilever and the belt support. The determination of the construction parameters such as the depth of the excavation in the basin, the width of the retaining soil at the side of the basin, the sequence of the excavation of the block and the like is carried out. The detailed analysis shows that the excavation path of the basin edge is not related to the excavation path in the relevant area and the basin The concept and division of the area are studied, and the effect of the soil width on the deformation of the foundation pit is studied. (5) In order to prove the rationality of the current general construction scheme of the background foundation pit engineering, the characteristics of the foundation pit project are analyzed in detail. On the basis of the above, four selection schemes are proposed: the middle large opening is the whole and the middle large opening is the whole and the main building The area is in the direction of the + skirt building, the main building area is in the reverse direction of the + skirt building area, and then the construction period, the economic cost, the surrounding environment impact, the technical method and the like are followed. The comparison and analysis of the scheme are carried out. At the same time, the current scheme is adopted.
【學(xué)位授予單位】：同濟(jì)大學(xué)
【學(xué)位級別】：博士
【學(xué)位授予年份】：2014
【分類號】：TU753
本文編號：2479917
[Abstract]:The foundation pit project of Shanghai Center Building is a rare and super-deep foundation pit project in Shanghai soft soil area in recent years. The surrounding environment is complex, and the deformation control requirement is high; and due to the absence of the second sticky soil layer in the area, the first and the second sandy soil pressure-bearing water-bearing layers are communicated, the underground continuous wall can not block the hydraulic connection of the inner and outer bearing water layers of the pit, the water head is deep in depth and the precipitation time is long, So that the pressure-bearing precipitation greatly influences the deformation of the foundation pit. The general construction scheme of the "The main building is in the direction of the + skirt." is adopted for the foundation pit engineering, and the main building area and the skirt building area are temporarily separated by a circular floor wall, and the foundation pit of the main building area is firstly constructed, and then the foundation pit of the construction apron area is inverted. Due to the particularity of the project, there is little research on the deformation characteristics of the foundation pit of this kind of skirt. At the same time, the deep foundation pit works which are constructed by using the reverse construction method are generally adopted in the basin-type earth excavation technology, but in the actual construction process, the relevant construction parameters are usually determined according to the construction experience, and even at random, so that the deformation of the foundation pit is easily caused to be too large. In addition, the overall construction scheme of the foundation pit works is reasonable or not, and plays a key role in the safety and economy of the construction. In this paper, by means of theoretical analysis, numerical simulation and actual data analysis, the influence of the foundation pit dewatering on the deformation of the foundation pit, the deformation characteristics of the foundation pit engineering of the present skirt, the basin-type earth excavation technology of the deep foundation pit and the rationality verification of the overall construction scheme of the project are discussed in this paper. A more in-depth study was made. The main contents include the following aspects: (1) Based on the FLAC seepage analysis module, the pore pressure distribution of different soil layers is studied, and the distribution of pore pressure in different soil layers and seepage boundary conditions is determined qualitatively. In view of the three types of deep foundation pit dewatering in the soft soil area in Shanghai, the paper gives a simplified method for calculating the water pressure distribution of the seepage, and proves the rationality. At the same time, the foundation pit engineering of this skirt is combined. In this paper, the rationality of the simplified calculation method of the water pressure distribution is given. (2) According to the measured data, the whole deformation character, the maximum lateral displacement value and the position and the three-dimensional space effect of the side-shift of the enclosure wall are analyzed in detail, and the excavation width of the foundation pit and the access and exit of the access and exit construction vehicle to the side of the enclosure wall are analyzed. The effect of the shrinkage of the concrete cushion on the side of the enclosure wall is analyzed, and the effect of the shrinkage of the concrete structure on the side of the enclosure wall is analyzed. It is pointed out that the concrete cushion has a good supporting effect on the enclosure wall, and the shrinkage of the super-long horizontal concrete structure can be used for the deformation of the enclosure wall. In addition, the vertical displacement of the top of the enclosure, the uplift of the column, the differential settlement between the wall columns, the settlement of the ground surface after the wall and the settlement of the surrounding of the foundation pit and the settlement of the adjacent pipelines Fine analysis. The effect of pressure-bearing precipitation on the deformation of foundation pit is highlighted. The Influence of (3) on the Deformation of the Foundation Pit Based on the Finite Difference Software of FLAC In the simulation, the effective stress index is used in the physical parameters of the soil, and according to the actual construction process and the water pressure distribution of the seepage, the change of the pore pressure in the soil to the foundation pit is considered. In the process of the analysis, the paper first discusses the simplified way of the temporary partition of the circular floor between the main building area and the skirt building area, and whether the influence of the factors such as the role of the ground water and the engineering pile on the calculation results is considered, and the excavation width and the horizontal support stiffness of the foundation pit are analyzed to the foundation pit. The influence of deformation is made, and the deformation characteristic of the middle part of the foundation pit of the skirt is calculated and analyzed, and the relation between the calculated value and the measured value is compared. The reason of the bump is that the water and soil pressure on the wall of the enclosure is analyzed by different calculation methods, and compared with the measured value, the water pressure distribution calculation method considering the seepage effect is used in the water and soil pressure gauge. The rationality of calculation is as follows: (4) In order to reasonably determine the basin-type earth excavation scheme of the deep foundation pit project of the reverse practice, the block size of the earth excavation and the depth of the basin edge are excavated according to the characteristics of the two different conditions of the cantilever and the belt support. The determination of the construction parameters such as the depth of the excavation in the basin, the width of the retaining soil at the side of the basin, the sequence of the excavation of the block and the like is carried out. The detailed analysis shows that the excavation path of the basin edge is not related to the excavation path in the relevant area and the basin The concept and division of the area are studied, and the effect of the soil width on the deformation of the foundation pit is studied. (5) In order to prove the rationality of the current general construction scheme of the background foundation pit engineering, the characteristics of the foundation pit project are analyzed in detail. On the basis of the above, four selection schemes are proposed: the middle large opening is the whole and the middle large opening is the whole and the main building The area is in the direction of the + skirt building, the main building area is in the reverse direction of the + skirt building area, and then the construction period, the economic cost, the surrounding environment impact, the technical method and the like are followed. The comparison and analysis of the scheme are carried out. At the same time, the current scheme is adopted.
【學(xué)位授予單位】：同濟(jì)大學(xué)
【學(xué)位級別】：博士
【學(xué)位授予年份】：2014
【分類號】：TU753
【參考文獻(xiàn)】
相關(guān)期刊論文 前10條
1 盧禮順,劉建航,劉國彬;基坑底混凝土墊層的支撐效應(yīng)分析[J];地下空間;2004年02期
2 褚偉洪,黃永進(jìn),張曉滬;上海環(huán)球金融中心塔樓深基坑施工監(jiān)測實(shí)錄[J];地下空間與工程學(xué)報;2005年04期
3 孫洋波;袁聚云;趙錫宏;;逆作法施工盆式開挖預(yù)留土體坡肩寬度的研究[J];地下空間與工程學(xué)報;2006年05期
4 劉建航;;地下墻深基坑周圍地層移動的預(yù)測和治理之二——基坑周圍地層移動的預(yù)測[J];地下工程與隧道;1993年02期
5 劉建航,劉國彬,范益群;軟土基坑工程中時空效應(yīng)理論與實(shí)踐(上)[J];地下工程與隧道;1999年03期
6 劉建航,劉國彬,范益群;軟土基坑工程中時空效應(yīng)理論與實(shí)踐(下)[J];地下工程與隧道;1999年04期
7 張飛;李鏡培;;考慮流—固耦合效應(yīng)的基坑水土壓力計算[J];工程勘察;2011年02期
8 鄧指軍;賈堅;;地鐵車站深基坑卸荷回彈影響深度的試驗[J];城市軌道交通研究;2008年03期
9 戴標(biāo)兵,范慶國,趙錫宏;深基坑工程逆作法的實(shí)測研究[J];工業(yè)建筑;2005年09期
10 李寅華;林文明;唐軍;俞順國;梁永明;;上海廖創(chuàng)興金融中心大廈深基坑工程逆作法的實(shí)測與研究[J];工業(yè)建筑;2006年12期
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