本文選題：深基坑 + 深層土體��； 參考：《天津大學(xué)》2014年博士論文

【摘要】：本文通過對某深基坑開挖全過程中圍護(hù)樁的水平位移進(jìn)行實測，發(fā)現(xiàn)由于水平支撐提供的支撐剛度不同，并受到基坑非對稱性的影響，不同位置處的圍護(hù)樁可產(chǎn)生不同的水平位移分布模式，，且最大水平位移值也存在明顯差別。 通過建立精細(xì)化有限元模型，針對4種典型圍護(hù)結(jié)構(gòu)變形模式引起的坑外深層土體位移場變化特點進(jìn)行分析，結(jié)果表明，即使圍護(hù)結(jié)構(gòu)最大水平位移相同，由于側(cè)移分布模式不同，基坑外深層土體的位移場可存在較大差別，從而可能對環(huán)境產(chǎn)生不同程度的影響。 圍護(hù)結(jié)構(gòu)在內(nèi)凸型和復(fù)合型模式下，坑外深層土體豎向變形可分為凹槽形沉降區(qū)、三角形過渡區(qū)和隆起區(qū)，懸臂型模式則只存在三角形變形區(qū)和隆起區(qū)，而踢腳型模式下凹槽形沉降區(qū)影響范圍更深；對于內(nèi)凸型和復(fù)合型模式，坑外深層土體水平位移場可分為弓形變形區(qū)、變形過渡區(qū)以及懸臂形變形區(qū)，懸臂型模式導(dǎo)致坑外水平位移全部呈懸臂形，踢腳型模式下影響區(qū)的范圍更深且更廣。 進(jìn)而探討了不同圍護(hù)結(jié)構(gòu)變形模式引起坑外既有隧道變形及受力的變化特性，并結(jié)合隧道位移的控制標(biāo)準(zhǔn)，分析4種模式下隧道產(chǎn)生過大位移的坑外范圍，并將不同模式下的位移影響范圍進(jìn)行了對比。 根據(jù)拱頂拱底的豎向變形特點，可將隧道變形按深度分為沉降區(qū)、變形過渡區(qū)及隆起區(qū)。復(fù)合型與內(nèi)凸型模式下各區(qū)域的范圍及特點基本相同；懸臂型模式對坑外隧道豎向位移影響較弱，沉降區(qū)范圍明顯減小；踢腳型模式中坑外的沉降區(qū)域增大，變形過渡區(qū)及隆起區(qū)范圍被顯著壓縮。 懸臂型模式對坑外隧道的位移影響范圍最小，內(nèi)凸型與復(fù)合型模式下范圍基本相同，分布大于懸臂型，而踢腳型模式下范圍最大。 在實際工程中除控制圍護(hù)結(jié)構(gòu)最大變形值外，尚應(yīng)根據(jù)周圍環(huán)境特點合理控制圍護(hù)結(jié)構(gòu)變形模式，并盡可能避免出現(xiàn)踢腳模式變形。
[Abstract]:By measuring the horizontal displacement of the retaining pile during the excavation of a deep foundation pit, it is found that the stiffness of the support provided by the horizontal bracing is different and affected by the asymmetry of the foundation pit. Different horizontal displacement distribution patterns can be produced in different positions of retaining piles, and the maximum horizontal displacement values are obviously different. By establishing a fine finite element model, the variation characteristics of the displacement field of deep soil in the deep layer outside the pit caused by the deformation modes of four typical enclosure structures are analyzed. The results show that the maximum horizontal displacement of the enclosure structure is the same, even if the maximum horizontal displacement of the enclosure structure is the same. Because of the different lateral distribution patterns, the displacement field of the deep soil outside the foundation pit can be greatly different, which may have a different degree of impact on the environment. The vertical deformation of deep soil outside the pit can be divided into concave settlement zone, triangular transition zone and uplift zone, while the cantilever model only exists triangular deformation zone and uplift zone. For the convex and composite models, the horizontal displacement field of deep soil can be divided into the arch deformation zone, the deformation transition zone and the cantilever deformation zone. The cantilever mode causes the horizontal displacement of the pit to be all cantilever, and the area of influence is deeper and wider under the kick-foot mode. Furthermore, the characteristics of deformation and force change of existing tunnel outside the pit caused by different deformation modes of enclosure structure are discussed. Combined with the control standard of tunnel displacement, the out-of-pit range of excessive displacement of tunnel under four modes is analyzed. The influence range of displacement in different modes is compared. According to the vertical deformation characteristics of arch bottom, tunnel deformation can be divided into settlement zone, deformation transition area and uplift area according to depth. The range and characteristics of each region are basically the same in the composite and convex mode, the influence of cantilever mode on the vertical displacement of the tunnel outside the pit is weak, and the settlement area is obviously reduced, while the settlement area outside the pit increases in the kick foot mode. The range of the deformation transition zone and the uplift area is significantly reduced. The cantilever mode has the smallest influence range on the displacement of the tunnel outside the pit. The range of the convex type is basically the same as that of the compound mode, and the distribution is larger than that of the cantilever type, while the range of the kicking mode is the largest. Besides controlling the maximum deformation value of the enclosure structure, the deformation mode of the surrounding structure should be reasonably controlled according to the characteristics of the surrounding environment, and the deformation of the kick foot mode should be avoided as far as possible in the actual engineering.
【學(xué)位授予單位】：天津大學(xué)
【學(xué)位級別】：博士
【學(xué)位授予年份】：2014
【分類號】：TU753;U452.1

【參考文獻(xiàn)】

相關(guān)期刊論文 前10條

1 楊德春;劉建國;;地鐵隧道附近軟土深基坑設(shè)計與施工關(guān)鍵技術(shù)分析[J];建筑結(jié)構(gòu);2012年07期

2 梅傳書,嚴(yán)馳,陸紅,徐海東;高層建筑基坑開挖的數(shù)值分析研究及工程應(yīng)用分析[J];建筑結(jié)構(gòu)學(xué)報;2001年03期

3 唐孟雄，趙錫宏;深基坑周圍地表沉降及變形分析[J];建筑科學(xué);1996年04期

4 姜兆華;張永興;;基坑開挖對鄰近隧道縱向位移影響的計算方法[J];土木建筑與環(huán)境工程;2013年01期

5 戚科駿;王旭東;蔣剛;常銀生;陳亞東;;臨近地鐵隧道的深基坑開挖分析[J];巖石力學(xué)與工程學(xué)報;2005年S2期

6 徐方京,譚敬慧;地下連續(xù)墻深基坑開挖綜合特性研究[J];巖土工程學(xué)報;1993年06期

7 劉興旺,施祖元,益德清,吳世明;軟土地區(qū)基坑開挖變形性狀研究[J];巖土工程學(xué)報;1999年04期

8 況龍川;深基坑施工對地鐵隧道的影響[J];巖土工程學(xué)報;2000年03期

9 黃宏偉;徐凌;嚴(yán)佳梁;余占奎;;盾構(gòu)隧道橫向剛度有效率研究[J];巖土工程學(xué)報;2006年01期

10 王衛(wèi)東;沈健;翁其平;吳江斌;;基坑工程對鄰近地鐵隧道影響的分析與對策[J];巖土工程學(xué)報;2006年S1期

本文編號：1824651