本文關(guān)鍵詞： 基坑 樁錨支護(hù) 數(shù)值模擬 監(jiān)測(cè)　出處：《東華理工大學(xué)》2014年碩士論文　論文類型：學(xué)位論文

【摘要】：近幾年,隨著我國(guó)經(jīng)濟(jì)的快速發(fā)展,城市化水平的不斷提高,城市土地資源緊缺日趨凸顯。房地產(chǎn)、市政工程以及隧道工程的迅速崛起,加之城市地上空間使用范圍的限制,使得更多的工程向著地下空間發(fā)展,便出現(xiàn)了地下商場(chǎng)、地下停車場(chǎng)、地鐵站臺(tái)、地下隧道等一系列的地下工程的興建,基坑數(shù)目日趨增加,涉及領(lǐng)域不斷擴(kuò)大,基坑復(fù)雜性和難度也隨之加大�；庸こ淌墙ㄔO(shè)工程中數(shù)量多、投入大、困難多、高風(fēng)險(xiǎn)的關(guān)鍵性工程項(xiàng)目。在基坑中,設(shè)計(jì)與施工既要確保支護(hù)系統(tǒng)在施工過(guò)程當(dāng)中的安全,還要控制結(jié)構(gòu)及其周圍土體的變形,以保證周圍環(huán)境的安全。樁錨支護(hù)結(jié)構(gòu)是在20世紀(jì)80年代開(kāi)始應(yīng)用并快速發(fā)展起來(lái)的,現(xiàn)已經(jīng)成為一種比較成熟,也是我們目前常用的基坑支護(hù)形式。隨著基坑開(kāi)挖深度加深、開(kāi)挖環(huán)境日益復(fù)雜以及基坑坍塌事故的頻發(fā),這樣不僅僅影響了工程工期同時(shí)也會(huì)增加施工的成本代價(jià),因此為了使基坑在建(構(gòu))筑物達(dá)到安全有效的目的,挽回不必要的經(jīng)濟(jì)損失以及可能到來(lái)的不良的社會(huì)影響,需要對(duì)基坑工程進(jìn)行實(shí)時(shí)監(jiān)測(cè)。通過(guò)實(shí)際的監(jiān)測(cè)數(shù)據(jù)來(lái)反饋基坑在實(shí)際的施工中的變化狀態(tài),確�；拥陌踩ｋS著科學(xué)技術(shù)的發(fā)展,計(jì)算機(jī)現(xiàn)在已經(jīng)應(yīng)用到各個(gè)領(lǐng)域,數(shù)值分析和數(shù)值模擬在基坑工程也得到了廣泛應(yīng)用。利用數(shù)值模擬方法對(duì)支護(hù)結(jié)構(gòu)進(jìn)行分析,可以更好的歸納影響基坑開(kāi)挖、支護(hù)的因素。本文結(jié)合具體工程實(shí)例-江西國(guó)光安福城市綜合體基坑,對(duì)基坑進(jìn)行樁錨支護(hù)體系設(shè)計(jì)、模擬分析和現(xiàn)場(chǎng)監(jiān)測(cè)。結(jié)合工程概況、工程地質(zhì)條件、周圍的環(huán)境因素以及各個(gè)方案的工程造價(jià),對(duì)比不同的支護(hù)方案,優(yōu)選出最佳的支護(hù)方案為支護(hù)樁+錨索+高壓旋噴樁聯(lián)合的支護(hù)形式。利用FLAC3D軟件,通過(guò)設(shè)定模型尺寸和邊界條件,確定初始應(yīng)力條件和選擇本構(gòu)模型,建立數(shù)值模擬分析的模型。通過(guò)對(duì)基坑開(kāi)挖前后的最大不平衡力模擬得出,計(jì)算最終收斂。通過(guò)對(duì)樁身內(nèi)力的模擬得到最大軸力、剪力、彎矩分別為2.649×105N、2.956×105N、9.058×105N.m,理論計(jì)算結(jié)果為2.62×105N、2.59×105N、8.78×105N.m,兩者計(jì)算結(jié)果相差不大,基本一致。模擬錨索軸力得到的最大軸力值為3.851×105N,理論結(jié)算結(jié)果為3.6×105N,兩者基本相等。通過(guò)對(duì)樁頂位移模擬得出樁頂?shù)目偝两滴灰浦禐?7.7mm,水平位移為35mm,兩者都符合規(guī)范要求。通過(guò)模擬基坑在有支護(hù)和無(wú)支護(hù)條件下,每步開(kāi)挖過(guò)程中的土體位移、內(nèi)力,的對(duì)比可知,基坑在開(kāi)挖較淺的情況下,土體的內(nèi)力和位移變化基本一致。但是隨著深度的增加,在無(wú)支護(hù)條件下,土體將會(huì)產(chǎn)生很大的內(nèi)力、位移,造成基坑的滑塌,而在有支護(hù)時(shí)變化較小,說(shuō)明樁錨支護(hù)體系保證了本基坑的安全。根據(jù)工程實(shí)際情況,制定了具體的監(jiān)測(cè)方案,分別監(jiān)測(cè)基坑四周的樁頂沉降位移、建筑物沉降位移、水位變化以及深層土體位移。通過(guò)監(jiān)測(cè)可知,在基坑四側(cè)的樁頂最大沉降量為10.39mm,最大沉降速度為0.65mm/d。建筑物最大沉降量為14.61mm,最大沉降速度為0.63 mm/d。基坑四周的水位基本維持在高程81~82m之間。最大深層土體位移為14.36mm。以上數(shù)據(jù)均在預(yù)警值范圍之內(nèi),基坑處于安全狀態(tài)。最后通過(guò)對(duì)樁頂沉降的監(jiān)測(cè)位移值和模擬位移值進(jìn)行比較得知,兩者的變化基本一致,數(shù)值相差不大。
[Abstract]:In recent years, with the rapid development of China's economy, the continuous improvement of the level of city, city land resources shortage is becoming increasingly prominent. Real estate, municipal engineering and the rapid rise of tunnel engineering, and the city space restrictions on the use range, more and more engineering toward the development of underground space, appeared the underground shopping malls, underground parking lot, subway stations, underground engineering, a series of underground tunnel construction, the foundation pit number increasing, relates to the field of expanding excavation, complexity and difficulty increased. The foundation pit engineering construction project quantity, large investment, more difficult, the key project of high risk. In the foundation, design and the construction is to ensure the safety in the construction process of the supporting system, but also control the structure and deformation of surrounding soil, in order to ensure the safety of the surrounding environment. Pile anchor retaining structure in 1980s Start the application and rapid development, now has become a relatively mature, but also our common form of excavation. With the deepening of the depth of excavation, excavation and foundation pit environment increasingly complex frequent collapse accident, this not only affect the construction period and also will increase the construction cost, so in order to make the foundation pit in the building built (structure) is a safe and effective to save unnecessary economic losses and possible adverse social impact, the need for real-time monitoring of foundation pit engineering. Through the actual monitoring data feedback to change state of foundation pit in actual construction, ensure the safety of the foundation pit. With the development of science and technology, computer now it has been applied to various fields, the simulation has been widely used in foundation pit engineering numerical analysis and numerical. The supporting structure is divided by the method of numerical simulation Analysis can better induction effects of pit excavation, supporting factors. Combining with the specific engineering example - Jiangxi Guoguang Anfu city complex foundation, the design of supporting system of foundation pit anchor pile, simulation analysis and field monitoring. Combined with practical engineering, the engineering geological conditions, environmental factors around and each project cost, comparison different support schemes, the best supporting scheme for supporting pile + anchor + jet grouting pile retaining structure. Using FLAC3D software, by setting the model size and boundary conditions, to determine the initial stress conditions and the selection of constitutive model, numerical simulation model was established. Through the analysis of the maximum pit before and after the excavation of the unbalanced force is simulated, calculating the final convergence. The maximum axial force, through the simulation of the internal forces of the pile shear, bending moment are 2.649 * 105N, 2.956 * 105N, 9.058 * 105N.m, theoretical calculation The result is 2.62 * 105N, 2.59 * 105N, 8.78 * 105N.m, the two results are similar, basically the same. The simulated maximum axial force axial force of cable is 3.851 * 105N, the theoretical results is 3.6 * 105N, which is basically the same. The simulation results show the total pile top displacement value is 27.7mm to drop the pile top displacement, horizontal displacement is 35mm, both meet the standard requirements. Through the simulation of foundation pit in supporting and supporting conditions, internal force of soil displacement, each step in the process of excavation, the comparison shows that the shallow foundation pit in excavation case, internal force and displacement of soil with depth but basically the same. The increase in non support conditions, the soil will have a lot of internal forces, displacement, caused by the collapse of the foundation pit, and there is a little change in support, that the pile anchor support system ensures the safety of the foundation pit. According to the actual situation, formulate specific monitoring Solutions were monitored around the pit settlement of the pile top displacement, displacement and settlement of buildings, the change of water level and the displacement of deep soil. By monitoring the four side of the top of the pile foundation in the maximum settlement is 10.39mm, the maximum settlement rate of 0.65mm/d. building the maximum settlement is 14.61mm, the maximum settlement rate of 0.63 mm/d. water level maintained around the pit at the altitude of 81~82m. The maximum displacement of deep soil is more than 14.36mm. data are in the warning value within the scope of excavation in a safe state. The values were compared and simulated that the displacement monitoring displacement of pile top settlement, the change is basically the same numerical difference.

【學(xué)位授予單位】：東華理工大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2014
【分類號(hào)】：TU753

【參考文獻(xiàn)】

相關(guān)期刊論文 前10條

1 楊春發(fā);張括;;多支點(diǎn)錨樁支護(hù)結(jié)構(gòu)計(jì)算方法及錨點(diǎn)位置優(yōu)化的探討[J];水利與建筑工程學(xué)報(bào);2008年02期

2 張強(qiáng)勇;彈性地基梁桿系有限元法在深大基坑工程支護(hù)設(shè)計(jì)中的應(yīng)用[J];建筑結(jié)構(gòu)學(xué)報(bào);2005年03期

3 余巍偉;管曉琴;于韻;;基坑樁錨結(jié)構(gòu)支護(hù)的開(kāi)挖響應(yīng)分析[J];礦業(yè)研究與開(kāi)發(fā);2012年03期

4 李志偉;;軟土基坑放坡開(kāi)挖對(duì)坑內(nèi)工程樁的影響分析[J];城市建筑;2013年10期

5 季聰;田作印;劉錄君;張大龍;鄭以寶;;FLAC3D對(duì)基坑開(kāi)挖數(shù)值模擬分析[J];資源環(huán)境與工程;2013年04期

6 劉岸軍;屠忠堯;;排樁錨桿聯(lián)合支護(hù)在淤泥質(zhì)黏土基坑中的應(yīng)用[J];建筑結(jié)構(gòu);2014年01期

7 吳朝陽(yáng);李正農(nóng);鐘e，

本文編號(hào)：1507497