水泥土搅拌桩复合地基承载特性现场试验
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摘要
为探究水泥土搅拌桩及水泥土搅拌桩复合地基的承载性能,对青岛某厂区的6根水泥土搅拌桩单桩及2组3桩水泥土搅拌桩复合地基进行竖向抗压静载荷试验,并采用修正双曲线模型预测单桩和复合地基的极限承载力。试验结果表明:6根单桩及2组复合地基均未加载到破坏,其Q-s曲线均为缓变形,桩端持力层为全风化花岗岩的水泥土桩桩顶回弹量较大,弹性工作特征明显;桩端持力层为中砂层的水泥土桩桩身弹性工作特征不显著。经推算水泥土搅拌桩单桩承载力发挥系数为0. 88,符合《建筑地基处理技术规范》(JGJ 79—2012)中水泥土桩承载力发挥系数的取值范围。经工程实例验证,修正双曲线函数能够精准预测水泥土单桩和复合地基的极限承载力,对于确定本试验中水泥土单桩和复合地基的极限承载力可信度较高。研究成果可为类似的复合地基的设计、施工与检测提供借鉴和参考。
In order to investigate the bearing behavior of composite foundation of cement-soil mixing pile and cement-soil mixing pile,vertical compression static load test of 6 cement-soil mixing pile single pile and 2 sets of 3 pile cement-soil mixing pile composite foundation in a factory area in Qingdao,and used the modified hyperbolic model to pretest the ultimate bearing capacity of the pile. The test results show that the 6 single piles and the 2 sets of composite foundations were not loaded with damage,which the Q-s curves were all slowly deformed,and the cement piles with fully weathered granite at the pile end had a large amount of spring-back and strong elastic working characteristics; the elastic working characteristics of the test pile body with the pile end bearing layer being the middle sand layer is not obvious. It is estimated that the bearing capacity of the single pile of cement-soil mixing pile is 0. 88,which is in line with the value range of the bearing capacity of the cement-soil pile in the technical specification for building foundation treatment( JGJ 79—2012). It is verified by engineering examples that the modified hyperbolic function can accurately predict the ultimate bearing capacity of cement-soil single pile and composite foundation. The reliability of ultimate bearing capacity of cement-soil single pile and composite foundation is higher in this test. The research results can provide reference and reference for the design,construction and testing of similar composite foundations.
In order to investigate the bearing behavior of composite foundation of cement-soil mixing pile and cement-soil mixing pile,vertical compression static load test of 6 cement-soil mixing pile single pile and 2 sets of 3 pile cement-soil mixing pile composite foundation in a factory area in Qingdao,and used the modified hyperbolic model to pretest the ultimate bearing capacity of the pile. The test results show that the 6 single piles and the 2 sets of composite foundations were not loaded with damage,which the Q-s curves were all slowly deformed,and the cement piles with fully weathered granite at the pile end had a large amount of spring-back and strong elastic working characteristics; the elastic working characteristics of the test pile body with the pile end bearing layer being the middle sand layer is not obvious. It is estimated that the bearing capacity of the single pile of cement-soil mixing pile is 0. 88,which is in line with the value range of the bearing capacity of the cement-soil pile in the technical specification for building foundation treatment( JGJ 79—2012). It is verified by engineering examples that the modified hyperbolic function can accurately predict the ultimate bearing capacity of cement-soil single pile and composite foundation. The reliability of ultimate bearing capacity of cement-soil single pile and composite foundation is higher in this test. The research results can provide reference and reference for the design,construction and testing of similar composite foundations.
引文
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4 Ye G,Cai Y,Zhang Z. Numerical study on load transfer effect of stiffened deep mixed column-supported embankment over soft soil[J]. KSCE Journal of Civil Engineering,2017,21(3):703-714
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11 龚晓南.广义复合地基理论及工程应用[J].岩土工程学报,2007,29(1):1-13Gong Xiaonan. Generalized composite foundation theory and engineering application[J]. Chinese Journal of Geotechnical Engineering,2007,29(1):1-13
12 张石友,孙海建,赵自文.混凝土芯水泥土搅拌桩复合地基现场试验研究[J].地下空间与工程学报,2016,12(6):1702-1709Zhang Shiyou,Sun Haijian,Zhao Ziwen. Field test of concretecored DCM pile composite foundation[J]. Chinese Journal of Underground Space and Engineering,2016,12(6):1702-1709
13 Phutthananon C,Jongpradist P,Yensri P,et al. Dependence of ultimate bearing capacity and failure behavior of T-shaped deep cement mixing piles on enlarged cap shape and pile strength[J]. Computers and Geotechnics,2018,97:27-41
14 中国建筑科学研究院.建筑地基处理技术规范:JGJ 79—2012[S].北京:中国建筑工业出版社,2012China Academy of Building Research. Technical specifications for building foundation treatment:JGJ 79—2012[S]. Beijing:China Building Industry Press,2012
15 何杰,刘杰,张可能,等.夯实水泥土楔形桩复合地基承载特性试验研究[J].岩石力学与工程学报,2012,31(7):1506-1512He Jie,Liu Jie,Zhang Keneng et al. Experimental study of bearing behaviour of composite foundation with rammed soil-cement tapered piles[J]. Chinese Journal of Rock Mechanics and Engineering,2012,31(7):1506-1512
16 罗战友,董清华,龚晓南.未达到破坏的单桩极限承载力的灰色预测[J].岩土力学,2004,25(2):304-307Luo Zhanyou,Dong Qinghua,Gong Xiaonan. Application of gray system theory to determining ultimate bearing capacity of a single pile[J]. Rock and Soil Mechanics,2004,25(2):304-307
17 党发宁,刘娜,何文安.西安地区单桩荷载传递双曲线模型与工程应用[J].岩土工程学报,2007,29(9):1428-1432Dang Faning,Liu Na,He We'nan. Hyperbolic model of load transfer method for single pile in Xi'an area and its engineering application[J]. Chinese Journal of Geotechnical Engineering,2007,29(9):1428-1432
18 俞宗卫,许魁,李祯.几种单桩极限承载力预测模型的验证分析[J].工业建筑,2007,37(8):64-67Yu Zongwei,Xu Kui,Li Zhen. Validating analysis of several kinds of prediction models of single-pile ultimate bearing capacity[J]. Industrial Construction,2007,38(8):64-67
19 俞峰,张忠苗.混凝土开口管桩竖向承载力的经验参数法设计模型[J].土木工程学报,2011,44(7):100-110Yu Feng,Zhang Zhongmiao. A design framework for evaluating the vertical bearing capacity of open-ended concrete pipe pile from empirical correlations[J]. China Civil Engineering Journal,2011,44(7):100-110
20 刘胜利,赵文光,尚林,等.基于Boltzmann函数的桩基极限承载力预测[J].土木工程与管理学报,2011,28(4):30-33,57Liu Shengli,Zhao Wenguang,Shang Lin,et al. Prediction on ultimate bearing capacity of pile based on Boltzmann function[J]. Journal of Civil Engineering and Management,2011,28(4):30-33
21 唐小松,李典庆,周创兵,等.基于Copula函数的基桩荷载-位移双曲线概率分析[J].岩土力学,2012,33(1):171-178Tang Xiaosong,Li Dianqing,Zhou Chuangbing,et al. Probabilistic analysis of load-displacement hyperbolic curves of single pile using copula[J]. Rock and Soil Mechanics,2012,33(1):171-178
22 李安勇,陈苏.水泥土搅拌桩复合地基承载力试验分析[J].建筑技术,2004,35(3):211-221Li Anyong,Chen Su. Analysis of bearing capacity test for composite foundation of cement mixing piles[J]. Architecture Technology,2004,35(3):211-221
23 易耀林,刘松玉,杜延军,等.变径水泥土搅拌桩单桩承载力试验研究[J].东南大学学报(自然科学版),2010,40(2):352-356Yi Yaolin,Liu Songyu,Du Yanjun,et al. Field tests on bearing capacity of single diameter-varied soil-cement deep mixed column[J].Journal of Southeast University(Nature Science Edition),2010,40(2):352-356
2 闫楠,杨俊杰,刘强,等.海水环境下水泥土强度衰减过程室内试验研究[J].土木工程学报,2017,50(11):115-124Yan Nan,Yang Junjie,Liu Qiang,et al. Laboratory test on strength deterioration process of soil cement in seawater environment[J]. China Civil Engineer Journal,2017,50(11):115-124
3 Ho L S,Nakarai K,Ogawa Y,et al. Strength development of cement-treated soils:effects of water content,carbonation,and pozzolanic reaction under drying curing condition[J]. Construction and Building Materials,2017,134:703-712
4 Ye G,Cai Y,Zhang Z. Numerical study on load transfer effect of stiffened deep mixed column-supported embankment over soft soil[J]. KSCE Journal of Civil Engineering,2017,21(3):703-714
5 闫楠,杨俊杰.海相软土场地形成的水泥土劣化深度预测[J].中国海洋大学学报(自然科学版),2015,45(11):92-99Yan Nan,Yang Junjie. Prediction of deterioration depth of cement soil formed by marine soft soil site[J]. Periodical of Ocean University of China,2015,45(11):92-99
6 Yang J J,Yan N,Liu Q,et al. Laboratory test on long-term deterioration of cement soil in seawater environment[J]. Transactions of Tianjin University,2016,22(2):132-138
7 Jayasinghe C,Fonseka W,Abeygunawardhene Y M. Load bearing properties of composite masonry constructed with recycled building demolition waste and cement stabilized rammed earth[J]. Construction and Building Materials,2016,102(1):471-477
8 Wonglert A,Jongpradist P,Jamsawang P,et al. Bearing capacity and failure behaviors of floating stiffened deep cement mixing columns under axial load[J]. Soils and Foundations,2018,58(2):446-461
9 张伟丽,蔡健,林奕禧,等.水泥土搅拌桩复合地基荷载传递机理的试验研究[J].土木工程学报,2010,43(6):116-121Zhang Weili,Cai Jian,Lin Yixi,et al. Experimental study of the load transfer mechanism of cement-soil pile composite foundation[J].China Civil Engineering Journal,2010,43(6):116-121
10 徐超,叶观宝.水泥土搅拌桩复合地基的变形特性与承载力[J].岩土工程学报,2005,27(5):600-603Xu Chao,Ye Guanbao. Deformation and bearing capacity of composite foundation with cement-soil mixed piles[J]. Chinese Journal of Geotechnical Engineering,2005,27(5):600-603
11 龚晓南.广义复合地基理论及工程应用[J].岩土工程学报,2007,29(1):1-13Gong Xiaonan. Generalized composite foundation theory and engineering application[J]. Chinese Journal of Geotechnical Engineering,2007,29(1):1-13
12 张石友,孙海建,赵自文.混凝土芯水泥土搅拌桩复合地基现场试验研究[J].地下空间与工程学报,2016,12(6):1702-1709Zhang Shiyou,Sun Haijian,Zhao Ziwen. Field test of concretecored DCM pile composite foundation[J]. Chinese Journal of Underground Space and Engineering,2016,12(6):1702-1709
13 Phutthananon C,Jongpradist P,Yensri P,et al. Dependence of ultimate bearing capacity and failure behavior of T-shaped deep cement mixing piles on enlarged cap shape and pile strength[J]. Computers and Geotechnics,2018,97:27-41
14 中国建筑科学研究院.建筑地基处理技术规范:JGJ 79—2012[S].北京:中国建筑工业出版社,2012China Academy of Building Research. Technical specifications for building foundation treatment:JGJ 79—2012[S]. Beijing:China Building Industry Press,2012
15 何杰,刘杰,张可能,等.夯实水泥土楔形桩复合地基承载特性试验研究[J].岩石力学与工程学报,2012,31(7):1506-1512He Jie,Liu Jie,Zhang Keneng et al. Experimental study of bearing behaviour of composite foundation with rammed soil-cement tapered piles[J]. Chinese Journal of Rock Mechanics and Engineering,2012,31(7):1506-1512
16 罗战友,董清华,龚晓南.未达到破坏的单桩极限承载力的灰色预测[J].岩土力学,2004,25(2):304-307Luo Zhanyou,Dong Qinghua,Gong Xiaonan. Application of gray system theory to determining ultimate bearing capacity of a single pile[J]. Rock and Soil Mechanics,2004,25(2):304-307
17 党发宁,刘娜,何文安.西安地区单桩荷载传递双曲线模型与工程应用[J].岩土工程学报,2007,29(9):1428-1432Dang Faning,Liu Na,He We'nan. Hyperbolic model of load transfer method for single pile in Xi'an area and its engineering application[J]. Chinese Journal of Geotechnical Engineering,2007,29(9):1428-1432
18 俞宗卫,许魁,李祯.几种单桩极限承载力预测模型的验证分析[J].工业建筑,2007,37(8):64-67Yu Zongwei,Xu Kui,Li Zhen. Validating analysis of several kinds of prediction models of single-pile ultimate bearing capacity[J]. Industrial Construction,2007,38(8):64-67
19 俞峰,张忠苗.混凝土开口管桩竖向承载力的经验参数法设计模型[J].土木工程学报,2011,44(7):100-110Yu Feng,Zhang Zhongmiao. A design framework for evaluating the vertical bearing capacity of open-ended concrete pipe pile from empirical correlations[J]. China Civil Engineering Journal,2011,44(7):100-110
20 刘胜利,赵文光,尚林,等.基于Boltzmann函数的桩基极限承载力预测[J].土木工程与管理学报,2011,28(4):30-33,57Liu Shengli,Zhao Wenguang,Shang Lin,et al. Prediction on ultimate bearing capacity of pile based on Boltzmann function[J]. Journal of Civil Engineering and Management,2011,28(4):30-33
21 唐小松,李典庆,周创兵,等.基于Copula函数的基桩荷载-位移双曲线概率分析[J].岩土力学,2012,33(1):171-178Tang Xiaosong,Li Dianqing,Zhou Chuangbing,et al. Probabilistic analysis of load-displacement hyperbolic curves of single pile using copula[J]. Rock and Soil Mechanics,2012,33(1):171-178
22 李安勇,陈苏.水泥土搅拌桩复合地基承载力试验分析[J].建筑技术,2004,35(3):211-221Li Anyong,Chen Su. Analysis of bearing capacity test for composite foundation of cement mixing piles[J]. Architecture Technology,2004,35(3):211-221
23 易耀林,刘松玉,杜延军,等.变径水泥土搅拌桩单桩承载力试验研究[J].东南大学学报(自然科学版),2010,40(2):352-356Yi Yaolin,Liu Songyu,Du Yanjun,et al. Field tests on bearing capacity of single diameter-varied soil-cement deep mixed column[J].Journal of Southeast University(Nature Science Edition),2010,40(2):352-356