Settlement of buildings with shallow foundations induced by excavation in soft soils
LIU Nian-wu1, 2, GONG Xiao-nan1, 2, YU Feng3, TANG Heng-si4
1. Research Center of Coastal and Urban Geotechnical Engineering, Zhejiang University, Hangzhou 310058, China; 2 Key Laboratory of Soft Soils and Geoenvironmental Engineering, Zhejiang University, Hangzhou 310058, China; 3. School of Civil Engineering and Architecture, Zhejiang Sci-Tech University, Hangzhou 310018, China; 4. China Construction Fifth Engineering Division Corp. Ltd., Hangzhou 310058, China
Abstract:Excavation will cause additional stress and deformations to the surrounding buildings. A series of field monitoring exercise of a deep foundation pit are conducted, including lateral wall deflections, soil settlements and building settlements. Field data indicate that the maximum wall deflections increase as the excavation depth increases, and the maximum wall deflection occurs near the excavation face. The wall deflection is accounted for 91.8% of the final wall displacement when the slab is cast in place. The settlement increases firstly and decreases sharply as the value of x/He increases (x, the distance from the wall in the horizontal direction; He, excavation depth). The soil settlement is relatively large, while the differential settlement is small when x<16 m, however, the soil settlement is relatively small, while the differential settlement is large when 10 m< x <28 m. The building settlements at the time the slab is cast in place is accounted for 76.6%, 71.5%, 56.8% of the final building settlements with the value of x being 9.6 m, 27.6 m, 45.2 m, respectively. The settlement profile of the five-storey building varies with x and is different from that of soil settlement. However, the settlement profile of the two or three-storey building varies when x is similar to that of soil settlement. The building settlement is relatively large, while the differential settlement is large when y<30 m (y, the distance from the excavation corner in the longitudinal direction), however, the building settlements are relatively small, while the differential settlement is small when y>30 m.
刘念武, 龚晓南, 俞峰, 汤恒思. 软土地区基坑开挖引起的浅基础建筑沉降分析[J]. 岩土工程学报, 2014, 36(zk2): 325-329.
LIU Nian-wu, GONG Xiao-nan, YU Feng, TANG Heng-si. Settlement of buildings with shallow foundations induced by excavation in soft soils. Chinese J. Geot. Eng., 2014, 36(zk2): 325-329.
[1] BOSCARDIN D, CORDING E J. Buliding resopnse to excavation-induced stettlement[J]. Journal of Geotechnical Engineering, 1989, 115(1): 1-21. [2] BOONE S J. Ground-movement-related building damage[J]. Journal of Geotechnical Engineering, 1996, 122(11): 886-896. [3] SON M, COORDING E J. Estimation of building damage due to excavation-induced ground movements[J]. Journal of Geotechnical and Geoenvironmental Engineering, 2005, 131(2): 162-177. [4] FINNO R J, VOSS F T, ROSSOW E, et al. Evaluating damage potential in buildings affected by excavations[J]. Journal of Geotechnical and Geoenvironmental Engineering, 2005, 131(10): 1199-1210. [5] SCHUSTER M, KUNG T C JUANG C H, et al. Simplified model for evaluating damage potential of buildings adjacent to a braced excavation[J]. Journal of Geotechnical and Geoenvironmental Engineering, 2009, 135(12): 1823-1835. [6] 李进军, 王卫东, 邸国恩, 等. 基坑工程对邻近建筑物附加变形影响的分析[J]. 岩土力学, 2007, 28(增刊1): 623-629. (LI Jin-jun, WANG Wei-dong, DI Guo-en, et al. Analysis of the influence of excavation engineering on additional deformation of adjacent buildings[J]. Rock and Soil Mechanics, 2007, 28(S1): 623-629. (in Chinese)) [7] 王浩然, 王卫东, 徐中华. 基坑开挖对邻近建筑物影响的三维有限元分析[J]. 地下空间与工程学报, 2009, 5(增刊 2): 1512-1517. (WANG Hao-ran, WANG Wei-dong, XU Zhong-hua. Three dimensional analysis of the influence of deep excavation on adjacent building[J]. Chinese Journal of Underground Space and Engineering, 2009, 5(S2): 1512-1517. (in Chinese)) [8] 潘军刚, 李大勇, 赵少飞. 风载作用下深基坑开挖对邻近高层建筑物的变形影响[J]. 岩土工程学报, 2006, 28(增刊): 1870-1873. (PAN Jun-gang, LI Da-yong, ZHAO Shao-fei. Effect of excavation of deep foundation pits on adjacent tall buildings influnced by wind loads[J]. Chinese Journal of Geotechnical Engineering, 2006, 28(S0): 1870-1873. (in Chinese)) [9] 郑 刚, 李志伟. 基坑开挖对邻近任意角度建筑物影响的有限元分析[J]. 岩土工程学报, 2012, 34(4): 615-625. (ZHENG Gang, LI Zhi-wei. Finite element analysis of response of buildings with arbitrary angle adjacent to excavations[J]. Chinese Journal of Geotechnical Engineering, 2012, 34(4): 615-625. (in Chinese)) [10] 徐中华. 上海地区支护结构与主体地下结构相结合的深基坑变形性状研究[D]. 上海:上海交通大学, 2007. (XU Zhong-hua. Deformation behavior of deep excavations supported by permanent structure in shanghai soft deposit[D]. Shanghai: Shanghai Jiaotong University, 2007. (in Chinese)) [11] WANG Z W, NG C W W, LIU G B. Characteristics of wall deflections and ground surface settlements in Shanghai[J]. Canadian Geotechnical Journal, 2005, 42(5): 1243-1254. [12] MANA A I, CLOUGH G W. Prediction of movements for braced cut in clay[J]. Journal of Geotechnical Engineering Division, 1981, 107(6): 759-777. [13] CLOUGH G W, O’Rourke T D. Construction induced movements of in situ walls[C]// Proceedings ASCE Conference on Design and Performance of Earth Retaining Structures, Geotechnical Special Publication No.25. New York: ASCE, 1990: 439-470. [14] HSIEH P G, OU C Y. Shape of ground surface settlement profiles caused by excavation[J]. Canadian Geotechnical Journal, 1998, 35(6): 1004-1017. [15] OU C Y, LIAO J T, CHENG W L. Building response and ground movements induced by a deep excavation[J]. Géotechnique, 2000, 50(3): 209-220.