人工冻结黏土承载力模型试验及数值模拟分析
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摘要
在天然冻土地区进行工程建设需研究冻土地基承载力。在人工冻结黏土蠕变试验的基础上建立广义开尔文模型,通过改造人工冻土大型冻结试验平台,进行人工冻结黏土地基承载力试验,发现载荷–沉降曲线可以分为3个阶段,基础呈局部剪切破坏。在ANSYS中将考虑相变的温度场转化为温度载荷施加在三维实体模型上,并将广义开尔文模型应用于软件中,采用增量加载方式分级加载。对比数值模拟与模型试验结果,发现地基载荷–沉降曲线规律一致,极限承载力大小基本相等,基础破坏模式相同。结果表明ANSYS软件可以分析复杂边界、初始条件下冻土材料的性质,且能得到不同载荷下冻土材料的应力、位移、塑性区发展状况。
This paper studies the bearing capacity of the frozen soil foundation of engineering constructions in permafrost areas. Based on the creep tests of the arti?cial frozen clay, a generalized Kelvin model is established. The large-scale arti?cial frozen soil freezing test platform is used to test the bearing capacity of the arti?cial frozen clay. It is found that the load-settlement curve could be divided into three stages, and the foundation sees a local shear failure. For the use of the ANSYS, the temperature ?eld with consideration of the phase transition is transformed into a temperature load and a three-dimensional solid model and a generalized Kelvin model are built, with a step loading. By comparing the numerical simulation results and the model test results, it is found that the load-settlement curve is consistent, the ultimate bearing capacity is basically the same, and the basic failure mode is the local shear failure. The results show that the ANSYS could analyze the properties of the frozen soil under complex boundary and initial conditions, and the stress and displacement of the frozen soil under different loads could be obtained.
This paper studies the bearing capacity of the frozen soil foundation of engineering constructions in permafrost areas. Based on the creep tests of the arti?cial frozen clay, a generalized Kelvin model is established. The large-scale arti?cial frozen soil freezing test platform is used to test the bearing capacity of the arti?cial frozen clay. It is found that the load-settlement curve could be divided into three stages, and the foundation sees a local shear failure. For the use of the ANSYS, the temperature ?eld with consideration of the phase transition is transformed into a temperature load and a three-dimensional solid model and a generalized Kelvin model are built, with a step loading. By comparing the numerical simulation results and the model test results, it is found that the load-settlement curve is consistent, the ultimate bearing capacity is basically the same, and the basic failure mode is the local shear failure. The results show that the ANSYS could analyze the properties of the frozen soil under complex boundary and initial conditions, and the stress and displacement of the frozen soil under different loads could be obtained.
引文
1徐学祖,王家澄,张立新.冻土物理学.北京:科学出版社,2001Xu Xuezu,Wang Jiacheng,Zhang Lixin.Permafrost Physics.Beijing:Science Press,2001(in Chinese)
2汪仁和,王伟,陈永锋.冻土中单桩抗压承载力模型试验研究.冰川冻土,2002,24(5):188-193Wang Renhe,Wang Wei,Chen Yongfeng.Model experimental study on compressive bearing capacity of single pile in frozen soil.Journal of Glaciology&Geocryology,2002,24(5):188-193(in Chinese)
3李栋伟,汪仁和,胡璞等.冻土中锥型桩模型试验研究及有限元分析.岩土工程学报,2006,28(增):1529-1533Li Dongwei,Wang Renhe,Hu Pu,et al.Model tests on cone-shaped piles in frozen soils and finite element analysis.Chinese Journal of Geotechnical Engineering,2006,28(S):1529-1533(in Chinese)
4张军伟,马巍,王大雁等.青藏高原多年冻土区钻孔灌注桩承载特性试验研究.冰川冻土,2008,30(3):482-487Zhang Junwei,Ma Wei,Wang Dayan,et al.In-situ experimental study of the bearing characteristics of cast-in-place bored pile in permafrost regions of the Tibetan Plateau.Journal of Glaciology&Geocryology,2008,30(3):482-487(in Chinese)
5 Zhang H,Zhang JM,Zhang KQ,et al.Long-term plate load tests in permafrost region on the Qinghai-Tibetan Plateau.Cold Regions Science and Technology,2017,143:105-111
6贾艳敏,郭红雨,郭启臣.多年冻土区灌注桩-冻土相互作用有限元分析.岩石力学与工程学报,2007,26(增1):3134-3140Jia Yanmin,Guo Hongyu,Guo Qichen.Finite element analysis of bored pile-frozen soil interactions in permafrost.Chinese Journal of Rock Mechanics&Engineering,2007,26(S1):3134-3140(in Chinese)
7原喜忠,李宁,赵秀云等.东北多年冻土地区地基承载力对气候变化敏感性分析.岩土力学,2010(10):3265-3272Yuan Xizhong,Li Ning,Zhao Xiuyun,et al.Analysis of sensitivity of frozen ground bearing capacity to climate change in Northeast China permafrost regions.Rock and Soil Mechanics,2010(10):3265-3272(in Chinese)
8 You YH,Wang JC,Wu QB,et al.Causes of pile foundation failure in permafrost regions:the case study of a dry bridge of the Qinghai-Tibet Railway.Engineering Geology,2017,230:95-103
9美启航,于晖,陈继.冻土蠕变特性研究现状及展望.灾害学,2018,33(增):47-56Mei Qihang,Yu Hui,Chen Ji.Research status and prospect of permafrost creep characteristics.Journal of Catastrophology,2018,33(S):47-56(in Chinese)
10彭世龙,荣传新,程桦.基于广义开尔文模型的冻结壁和井壁共同作用下冻结压力解析解.长江科学院院报,2017,34(11):84-88Peng Shilong,Rong Chuanxin,Cheng Hua.Analytical solution of freezing pressure under the interaction of freezing wall and shaft lining based on generalized Kelvin model.Journal of Yangtze River Scientific Research Institute,2017,34(11):84-88(in Chinese)
11商玉娇.人工冻土地基承载力模型试验及数值模拟分析.[硕士论文].淮南:安徽理工大学,2018Shang Yujiao.Model test and numerical simulation analysis of bearing capacity of artificial frozen soil foundation.[Master Thesis].Huainan:AnHui University of Science and Technology,2018(in Chinese)
12中华人民共和国住房和城乡建设部.JGJ118国住房和城冻土地区建筑地基基础设计规范.北京:中国建筑工业出版社,2011Ministry of Housing and Urban-Rural Development of the People’s Republic of China.JGJ118-2011 Code for design of foundations for buildings in frozen soil areas.Beijing:China Building Industry Press,2011(in Chinese)
13邓楚键,孔位学,郑颖人.极限分析有限元法讲座III--增量加载有限元法求解地基极限承载力.岩土力学,2005,26(3):500-504Deng Chujian,Kong Weixue,Zheng Yingren.Analysis of ultimate bearing capacity of foundations by elastoplastic FEMthrough step loading.Rock and Soil Mechanics,2005,26(3):500-504(in Chinese)
2汪仁和,王伟,陈永锋.冻土中单桩抗压承载力模型试验研究.冰川冻土,2002,24(5):188-193Wang Renhe,Wang Wei,Chen Yongfeng.Model experimental study on compressive bearing capacity of single pile in frozen soil.Journal of Glaciology&Geocryology,2002,24(5):188-193(in Chinese)
3李栋伟,汪仁和,胡璞等.冻土中锥型桩模型试验研究及有限元分析.岩土工程学报,2006,28(增):1529-1533Li Dongwei,Wang Renhe,Hu Pu,et al.Model tests on cone-shaped piles in frozen soils and finite element analysis.Chinese Journal of Geotechnical Engineering,2006,28(S):1529-1533(in Chinese)
4张军伟,马巍,王大雁等.青藏高原多年冻土区钻孔灌注桩承载特性试验研究.冰川冻土,2008,30(3):482-487Zhang Junwei,Ma Wei,Wang Dayan,et al.In-situ experimental study of the bearing characteristics of cast-in-place bored pile in permafrost regions of the Tibetan Plateau.Journal of Glaciology&Geocryology,2008,30(3):482-487(in Chinese)
5 Zhang H,Zhang JM,Zhang KQ,et al.Long-term plate load tests in permafrost region on the Qinghai-Tibetan Plateau.Cold Regions Science and Technology,2017,143:105-111
6贾艳敏,郭红雨,郭启臣.多年冻土区灌注桩-冻土相互作用有限元分析.岩石力学与工程学报,2007,26(增1):3134-3140Jia Yanmin,Guo Hongyu,Guo Qichen.Finite element analysis of bored pile-frozen soil interactions in permafrost.Chinese Journal of Rock Mechanics&Engineering,2007,26(S1):3134-3140(in Chinese)
7原喜忠,李宁,赵秀云等.东北多年冻土地区地基承载力对气候变化敏感性分析.岩土力学,2010(10):3265-3272Yuan Xizhong,Li Ning,Zhao Xiuyun,et al.Analysis of sensitivity of frozen ground bearing capacity to climate change in Northeast China permafrost regions.Rock and Soil Mechanics,2010(10):3265-3272(in Chinese)
8 You YH,Wang JC,Wu QB,et al.Causes of pile foundation failure in permafrost regions:the case study of a dry bridge of the Qinghai-Tibet Railway.Engineering Geology,2017,230:95-103
9美启航,于晖,陈继.冻土蠕变特性研究现状及展望.灾害学,2018,33(增):47-56Mei Qihang,Yu Hui,Chen Ji.Research status and prospect of permafrost creep characteristics.Journal of Catastrophology,2018,33(S):47-56(in Chinese)
10彭世龙,荣传新,程桦.基于广义开尔文模型的冻结壁和井壁共同作用下冻结压力解析解.长江科学院院报,2017,34(11):84-88Peng Shilong,Rong Chuanxin,Cheng Hua.Analytical solution of freezing pressure under the interaction of freezing wall and shaft lining based on generalized Kelvin model.Journal of Yangtze River Scientific Research Institute,2017,34(11):84-88(in Chinese)
11商玉娇.人工冻土地基承载力模型试验及数值模拟分析.[硕士论文].淮南:安徽理工大学,2018Shang Yujiao.Model test and numerical simulation analysis of bearing capacity of artificial frozen soil foundation.[Master Thesis].Huainan:AnHui University of Science and Technology,2018(in Chinese)
12中华人民共和国住房和城乡建设部.JGJ118国住房和城冻土地区建筑地基基础设计规范.北京:中国建筑工业出版社,2011Ministry of Housing and Urban-Rural Development of the People’s Republic of China.JGJ118-2011 Code for design of foundations for buildings in frozen soil areas.Beijing:China Building Industry Press,2011(in Chinese)
13邓楚键,孔位学,郑颖人.极限分析有限元法讲座III--增量加载有限元法求解地基极限承载力.岩土力学,2005,26(3):500-504Deng Chujian,Kong Weixue,Zheng Yingren.Analysis of ultimate bearing capacity of foundations by elastoplastic FEMthrough step loading.Rock and Soil Mechanics,2005,26(3):500-504(in Chinese)