- 摘 要
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（1安徽建筑大學(xué)土木工程學(xué)院， 合肥 230601；2 建筑健康監(jiān)測與災(zāi)害預(yù)防技術(shù)國家地方聯(lián)合工程實驗室， 合肥 230601）
［摘要］以合肥城市軌道交通工程建設(shè)過程中某緊鄰既有高速公路高填方路基偏壓深基坑為背景，通過現(xiàn)場監(jiān)測資料，分析該深基坑在偏壓作用下圍護(hù)樁的樁體深層水平位移和樁頂水平位移、支撐軸力、基坑周圍地表沉降以及基坑開挖對鄰近高速公路的影響。結(jié)果表明：偏壓作用下，基坑兩側(cè)圍護(hù)結(jié)構(gòu)變形特性以及基坑開挖對周圍環(huán)境的影響與對稱荷載條件下存在很大差異，基坑同一斷面內(nèi)高荷載一側(cè)的各項變形均大于低荷載一側(cè)；高荷載一側(cè)基坑長邊方向中部位置的各項變形大于其兩邊變形，是整個基坑最薄弱區(qū)域；基坑開挖過程中，鋼支撐軸力與其架設(shè)以后所在平面的圍護(hù)結(jié)構(gòu)水平位移增量有關(guān)，圍護(hù)結(jié)構(gòu)水平位移增量越大，鋼支撐軸力越大；基坑開挖所引起的鄰近高速公路路基不均勻沉降主要位于靠近基坑一側(cè)；受端部效應(yīng)影響，基坑短邊方向左右兩端的各項變形明顯小于其長邊方向上下兩側(cè)變形。最后，結(jié)合上述規(guī)律給出了一些工程建議。
［關(guān)鍵詞］偏壓； 深基坑； 高速公路； 圍護(hù)結(jié)構(gòu)； 受力； 變形； 現(xiàn)場監(jiān)測
中圖分類號：TU921,TU46+3 文獻(xiàn)標(biāo)識碼：A 文章編號：1002-848X(2015)06-0093-06
Study on excavation effect of an unsymmetrical loaded deep foundation pit
adjacent to existed expressway
Liu Bo1,2, Xi Peisheng1,2
(1 School of Civil Engineering, Anhui Jianzhu University, Hefei 230601, China;
2 State and Local Joint Engineering Laboratory of Structure Health Monitoring and Disaster Prevention, Hefei 230601, China)
Abstract:The studied deep foundation pit under the eccentric compression is in Hefei Metro project and adjacent to the existed expressway high fill subgrade. The deep horizontal displacements of retaining piles, the horizontal displacements of pile tops, the axial forces of supports, the ground surface settlement around the foundation pit and the influence of the excavation of foundation pit on adjacent expressway were analyzed through field monitoring data. The results indicate that under the eccentric compression, the deformation characteristics of retaining structures and the influence on the surrounding environment induced by excavation are quite different from that under the symmetrical load condition. The deformations on the side under higher loading are larger than corresponding values under the lower loading side. The deformations of central position along the long side of deep foundation pit is larger than those of two sides, central position along the long side of deep foundation pit is the weakest area in the whole foundation pit. The axial force of steel support is related to the horizontal displacement increment of retaining structure in the same plane, and the bigger the horizontal displacement increment, the bigger the axial force. Differential settlement of expressway subgrade induced by excavation mainly lies on the side close to deep foundation pit. Influenced by end effect, the deformations of two sides along the short size are smaller than those of two sides along the long size of deep foundation pit obviously. Lastly, some engineering suggestions were provided for similar projects based on studies.
Keywords:eccentric compression; deep foundation pit; expressway; retaining structure; stress; deformation; field monitoring
作者簡介：劉波，碩士，Email：aualiubo@163.com。
參考文獻(xiàn)
［1］姚愛軍, 張新東.偏壓對深基坑圍護(hù)變形的影響［J］. 巖土力學(xué), 2011, 32(S2): 378382.
［2］呂小軍, 楊琪, 錢德玲,等.非對稱超載條件下深基坑支護(hù)結(jié)構(gòu)的變形分析［J］. 合肥工業(yè)大學(xué)學(xué)報:自然科學(xué)版,2012, 35(6): 809813.
［3］林剛, 徐長節(jié), 蔡袁強. 不平衡堆載作用下深基坑開挖支護(hù)結(jié)構(gòu)性狀研究［J］. 巖土力學(xué), 2010, 31(8): 25922598.
［4］楊震偉. 基坑工程開挖支護(hù)的數(shù)值計算分析［J］. 鐵道建筑, 2012（5）: 116119.
［5］李志高, 吳小將. 差異環(huán)境保護(hù)等級下基坑變形計算方法探討［J］. 巖石力學(xué)與工程學(xué)報, 2008, 27(5): 10741080.
［6］熊健.兩種模型在偏壓基坑有限元分析中的應(yīng)用與對比［J］.建筑結(jié)構(gòu),2012，42(1):129132.
［7］石鈺鋒, 陽軍生, 白偉, 等.緊鄰鐵路偏壓基坑圍護(hù)結(jié)構(gòu)變形與內(nèi)力測試分析［J］.巖石力學(xué)與工程學(xué)報, 2011, 30(4): 826833.
［8］ZHANG H, ZHANG G, YANG J. A case history of the excavation of deep foundation pit adjacent to railway［C］//Tunnel Management, Emerging Technologies, and Innovation. Changsha, 2011: 1016.
［9］JGJ 120—2012 建筑基坑支護(hù)技術(shù)規(guī)程［S］. 北京: 中國建筑工業(yè)出版社, 2012.
