真空预压法在某软基加固工程中对邻近地基的影响
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摘要
真空预压法是加固软土和超软土地基的常用方法之一,尤其是在加固吹填土地基时具有不可替代的优势。由于吹填土具有含水率高、渗透性差等特点,经真空预压加固后,地基随着土孔隙水的排出会产生较大的沉降量。对周边已成熟使用的地基会产生一定的影响,甚至可能造成已使用的地基出现地表开裂和不均匀沉降的现象,从而影响成熟地基的正常使用,因此需重点关注真空预压加固吹填土过程中对临近地基的影响。以实际工程为依托,采用数值模拟方法,对真空预压法处理过程中对周边环境的影响进行了分析、评估,研究结果表明,采用打设水泥搅拌桩密封墙的措施,可有效减小邻近地基因真空预压引起的竖向沉降和侧向变形大小。
Vacuum preloading method is one of the common methods to reinforce soft soil and ultra-soft soil foundation,especially when it is used to reinforce dredger fill foundation, it has irreplaceable advantages. Due to the high water content and poor permeability, there is much settlement of foundation with the discharge of pore water reinforced by vacuum preloading. It will have a certain impact on the nearby mature used foundation, and may even cause surface cracking and uneven settlement of the used foundation, thus affecting the normal use of the mature foundation. Therefore, it is necessary to focus on the influence of vacuum preloading on the nearby foundation in the process of reinforcing the dredger fill. Based on practical engineering, the influence of vacuum preloading on surrounding environment was analyzed and evaluated by numerical simulation. The results show that the vertical settlement and lateral deformation of nearby foundation caused by vacuum preloading can be effectively reduced by setting up cement mixing pile sealing wall.
Vacuum preloading method is one of the common methods to reinforce soft soil and ultra-soft soil foundation,especially when it is used to reinforce dredger fill foundation, it has irreplaceable advantages. Due to the high water content and poor permeability, there is much settlement of foundation with the discharge of pore water reinforced by vacuum preloading. It will have a certain impact on the nearby mature used foundation, and may even cause surface cracking and uneven settlement of the used foundation, thus affecting the normal use of the mature foundation. Therefore, it is necessary to focus on the influence of vacuum preloading on the nearby foundation in the process of reinforcing the dredger fill. Based on practical engineering, the influence of vacuum preloading on surrounding environment was analyzed and evaluated by numerical simulation. The results show that the vertical settlement and lateral deformation of nearby foundation caused by vacuum preloading can be effectively reduced by setting up cement mixing pile sealing wall.
引文
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[7] INDRARATNA B, RUJIKIATKAMJORN C, AMERATUNGA J, et al. Performance and prediction of vacuum combined surcharge consolidation at port of Brisbane[J]. Journal of Geotechnical and Geoenvironmental Engineering, 2011, 137(11):1 009-1 018.
[8] INDRARATNA B, RUJIKIATKAMJORN C, BALASUBRAMANIAM A, et al. Soft ground improvement via vertical drains and vacuum assisted preloading[J]. Geotextiles and Geomembranes, 2012, 30(4):16-23.
[2]陈兰云,朱建才.真空预压影响区安全措施有限元分析[J].岩石力学与工程学报,2005,24(S2):5 712-5 715.CHEN Lan-yun, ZHU Jian-cai. Finite element analysis of safety measures for affected soft ground area by vacuum preloading[J].Chinese Journal of Rock Mechanics and Engineering, 2005, 24(S2):5 712-5 715.
[3]艾英钵.真空预压对周围环境影响的试验研究及计算分析[D].南京:河海大学,2006.AI Ying-bo. Experimental study and calculation analysis of the influence of vacuum preloading on the surrounding environment[D].Nanjing:Hohai University, 2006.
[4]艾英钵,蔡南树,柯朝辉.减小真空预压区外土体侧向变形的措施[J].河海大学学报:自然科学版,2007,35(6):686-689.AI Ying-bo, CAI Nan-shu, KE Chao-hui. Measures for reducing lateral deformation of soil outside vacuum preloading area[J]. Journal of Hohai University:Natural Sciences, 2007, 35(6):686-689.
[5]金小荣,俞建霖,龚晓南.真空预压的环境效应及其防治方法的试验研究[J].岩土力学,2008(4):1 093-1 096.JIN Xiao-rong, YU Jian-lin, GONG Xiao-nan. Study on environmental effect induced by vacuum preloading and its control method[J]. Rock and Soil Mechanics, 2008(4):1 093-1 096.
[6]蔡南树,董志良,张功新,等.真空预压加固吹填土地基对周边环境的影响[J].中国港湾建设,2008(6):20-23.CAI Nan-shu, DONG Zhi-liang, ZHANG Gong-xin, et al. Influence of improvement of hydraulically reclaimed land by vacuum preloading technique upon surrounding environment[J]. China Harbour Engineering, 2008(6):20-23.
[7] INDRARATNA B, RUJIKIATKAMJORN C, AMERATUNGA J, et al. Performance and prediction of vacuum combined surcharge consolidation at port of Brisbane[J]. Journal of Geotechnical and Geoenvironmental Engineering, 2011, 137(11):1 009-1 018.
[8] INDRARATNA B, RUJIKIATKAMJORN C, BALASUBRAMANIAM A, et al. Soft ground improvement via vertical drains and vacuum assisted preloading[J]. Geotextiles and Geomembranes, 2012, 30(4):16-23.