發(fā)布時間：2018-01-25 04:30

  本文關(guān)鍵詞： 基坑支護 變形 彈性抗力 地下連續(xù)墻　出處：《吉林大學(xué)》2013年碩士論文　論文類型：學(xué)位論文

【摘要】：隨著我國城市軌道交通建設(shè)的快速發(fā)展，臨近地鐵隧道的基坑工程越來越多。這類在地鐵隧道附近開挖的基坑工程對地鐵隧道的影響表現(xiàn)在三個方面。第一，由于開挖的卸載，引起隧道結(jié)構(gòu)的位移；第二，，圍護結(jié)構(gòu)在施工期間，尚未發(fā)揮作用時也會引起隧道結(jié)構(gòu)的位移；第三，龐大體量的建筑荷載在加載后會再次引起隧道結(jié)構(gòu)的位移。上述三個方面嚴(yán)重地影響著地鐵的運營安全。因此，在基坑支護結(jié)構(gòu)設(shè)計時，起決定性因素的是支護結(jié)構(gòu)的變形控制。由于基坑開挖引起的變形影響因素眾多，迄今為止尚難得出較為準(zhǔn)確的定量結(jié)論，基坑支護墻后土體的位移場在一般的分析軟件中均未涉及，大型三維數(shù)值分析軟件的建模又比較復(fù)雜，難以在所有工程中應(yīng)用。因此，如何在一般的工程項目中耦合支護結(jié)構(gòu)的變形與周邊土體的位移場十分重要。 本文結(jié)合北京外交公寓基坑工程，從基坑支護結(jié)構(gòu)的設(shè)計計算原理出發(fā)，基于同濟啟明星深基坑支護分析軟件FRWS7，按照平面應(yīng)變問題采用彈性抗力有限單元法進行支護結(jié)構(gòu)的設(shè)計，再根據(jù)支護結(jié)構(gòu)的位移，利用土體位移場的簡單解析法求解基坑周邊任意點的位移。以臨近基坑的隧道底部控制位移作為設(shè)計輸入條件進行基坑支護結(jié)構(gòu)的設(shè)計，同時運用基于FLAC3D的數(shù)值分析方法進行應(yīng)力應(yīng)變分析。運用上述兩種分析方法對本基坑工程進行了分析，繼而得出根據(jù)變形控制為原則的基坑支護設(shè)計方案—采用復(fù)合土釘墻+地下連續(xù)墻的方案進行基坑支護。監(jiān)測數(shù)據(jù)表明彈性抗力有限元法計算得到的支護結(jié)構(gòu)變形與實際監(jiān)測數(shù)據(jù)相當(dāng)，按照基坑周圍土體位移場的簡單解析法計算得到的隧道結(jié)構(gòu)位移與實際監(jiān)測的數(shù)據(jù)相吻合，說明了簡單解析法基本適用于北京地區(qū)的土體位移場計算�；贔LAC3D的連續(xù)介質(zhì)數(shù)值分析方法在模擬基坑工程等巖土體材料方面的位移場與實際監(jiān)測數(shù)據(jù)符合性較好，對于復(fù)雜環(huán)境條件下的基坑分析設(shè)計有獨特的優(yōu)勢。 地下連續(xù)墻在施工中成槽是關(guān)鍵，該工程對地下連續(xù)墻與隧道間分布的易于坍塌的粉土及砂類土進行了水泥土攪拌樁的加固，減小了地下連續(xù)墻對隧道的影響。土方開挖充分考慮邊坡的時空效應(yīng)，分時分段采取抽條式開挖，有效地控制了基坑變形。通過分析監(jiān)測數(shù)據(jù)的平面分布特征可以發(fā)現(xiàn)，支護結(jié)構(gòu)的變形和內(nèi)力最大值均出現(xiàn)在基坑剖面中部，是邊坡空間效應(yīng)的具體表現(xiàn)，基坑陰角處的位移及內(nèi)力均較小，角隅作用明顯。
[Abstract]:With the rapid development of urban rail transit construction in China, there are more and more foundation pit projects near the subway tunnel. The displacement of tunnel structure is caused by the unloading of excavation. Second, the surrounding structure will also cause the displacement of the tunnel structure when it has not played a role during the construction period; Third, the large volume of building load will cause the displacement of tunnel structure again after loading. The above three aspects seriously affect the safety of subway operation. Therefore, in the foundation pit support structure design. The decisive factor is the deformation control of the supporting structure. Because there are many factors affecting the deformation caused by the excavation of foundation pit, it is difficult to get a more accurate quantitative conclusion so far. The displacement field of soil behind the retaining wall of foundation pit is not involved in the general analysis software, and the modeling of large-scale three-dimensional numerical analysis software is complex, so it is difficult to be applied in all projects. It is very important to analyze the deformation of coupling support structure and the displacement field of surrounding soil in general engineering projects. In this paper, based on the design and calculation principle of foundation pit support structure, based on Tongji Qi-star deep foundation pit support analysis software FRWS7, combined with Beijing diplomatic apartment foundation pit project. According to the plane strain problem, the elastic resistance finite element method is used to design the supporting structure, and then according to the displacement of the supporting structure. The displacement of any point around the foundation pit is solved by the simple analytical method of the displacement field of soil, and the control displacement of the tunnel bottom near the foundation pit is taken as the design input condition to design the supporting structure of the foundation pit. At the same time, the stress and strain analysis is carried out by using the numerical analysis method based on FLAC3D, and the foundation pit engineering is analyzed by the above two analysis methods. Then, according to the principle of deformation control, the design scheme of foundation pit support is obtained, which is based on composite soil nailing wall. The monitoring data show that the deformation of the supporting structure calculated by the finite element method of elastic resistance is equivalent to the actual monitoring data. The displacement of tunnel structure calculated by simple analytical method according to the displacement field of soil around foundation pit coincides with the actual monitoring data. It is shown that the simple analytical method is suitable for the calculation of soil displacement field in Beijing area. The displacement field and actual monitoring number of continuous medium numerical analysis method based on FLAC3D in simulating rock and soil materials such as foundation pit engineering are discussed. According to good conformity. It has a unique advantage for foundation pit analysis and design under complex environment. Grooving is the key in the construction of underground continuous wall. The cement soil mixing pile is used to reinforce the silt and sand soil which is easy to collapse between underground continuous wall and tunnel. The influence of underground continuous wall on tunnel is reduced. The time and space effect of slope is fully considered in earthwork excavation. By analyzing the plane distribution characteristics of the monitoring data, it can be found that the maximum deformation and internal force of the supporting structure appear in the middle of the foundation pit section, which is the concrete manifestation of the slope spatial effect. The displacement and internal force at the bottom corner of foundation pit are smaller, and the corner effect is obvious.
【學(xué)位授予單位】：吉林大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2013
【分類號】：TU753

【參考文獻】

相關(guān)期刊論文 前10條

1 王建華,徐中華,陳錦劍,王衛(wèi)東;上海軟土地區(qū)深基坑連續(xù)墻的變形特性淺析[J];地下空間與工程學(xué)報;2005年04期

2 陳有亮;李林;劉井學(xué);;某深基坑地下連續(xù)墻開挖變形有限元分析[J];地下空間與工程學(xué)報;2008年02期

3 肖同剛;;基坑開挖施工監(jiān)控對臨近地鐵隧道影響分析[J];地下空間與工程學(xué)報;2011年05期

4 秦四清;基坑支護設(shè)計的彈性抗力法[J];工程地質(zhì)學(xué)報;2000年04期

5 韓雪峰;崔青玉;;地鐵基坑開挖對臨近隧道的影響及措施分析[J];工程建設(shè)與設(shè)計;2012年05期

6 蔣洪勝,侯學(xué)淵;基坑開挖對臨近軟土地鐵隧道的影響[J];工業(yè)建筑;2002年05期

7 李宇升;喻衛(wèi)華;;深基坑施工對緊鄰地鐵區(qū)間隧道結(jié)構(gòu)影響分析[J];地下空間與工程學(xué)報;2013年02期

8 馮龍飛;楊小平;劉庭金;;緊鄰地鐵隧道深基坑支護技術(shù)及監(jiān)測分析[J];隧道建設(shè);2013年06期

9 唐孟雄，趙錫宏;深基坑周圍地表任意點移動變形計算及應(yīng)用[J];同濟大學(xué)學(xué)報(自然科學(xué)版);1996年03期

10 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

本文編號：1461987