京沪高速铁路凤阳试验段CFG桩复合地基承载力的研究
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摘要
本文采用慢速维持荷载法对京沪高速铁路凤阳试验段的天然土、桩间土、CFG单桩以及不同布置形式的CFG桩复合地基进行大量的现场载荷试验,通过对试验数据的对比分析,深入研究A、B、C、D四区不同布置形式的CFG桩复合地基承载力、桩土应力比以及荷载分担随荷载及其设计参数变化而变化的规律,以便为CFG桩复合地基在高速铁路建设中的应用提供科学的建议与依据。
本文的主要结论如下:
1.通过对该试验段天然土及CFG桩复合地基桩间土静载试验的数据分析,得出处理后桩间土的极限承载力及模量提高系数。
2.通过CFG桩单桩竖向承载力及侧摩阻力的测定,得出A、B、C、D四区不同布置形式的CFG桩复合地基中单桩承载力的极限值。
3.通过对该试验段CFG桩复合地基载荷试验的数据分析,得出不同布置形式CFG桩复合地基的承载力,并结合该试验段的地质条件,分析桩长、桩间距及桩径对CFG桩复合地基承载力的影响。
4.通过对该试验段CFG桩复合地基桩、土分担数据的比较分析,得出不同布置形式的CFG桩复合地基的桩应力、土应力、桩土应力比及桩荷载分担比均随荷载的增加而增加,并进一步分析了在同一荷载作用下,各量随CFG桩复合地基桩长、桩径、桩间距的变化而变化的趋势。
5.利用桩土应力比及桩荷载分担比平均增幅转向点个数的多少,从一定程度上来描述在共同承担上部荷载时桩土应力及桩土荷载分担相互协调程度的高与低,桩、土共同作用的充分与否,并依此判断出:该试验段C区布置形式的CFG桩复合地基中,桩、土在共同承担上部荷载作用时,桩、土应力及荷载分担协调较高,桩、土共同作用较充分。
6.利用CFG桩承载能力的发挥系数γp及桩间土承载能力的发挥系数在s的大小,在一定程度上来描述复合地基中桩、土的承载能力发挥的大小,并依此判断出凤阳段C区布置形式的CFG桩复合地基在承受上部荷载作用时桩、土的承载能力发挥最大。
With load method of low maintenance, a lot of local static loading tests on natural soil, soil between piles, CFG single piles and CFG Pile Composite Foundation are made in the Fengyang experimental section of Beijing-Shanghai High-Speed Railway. From the experimental date in this paper, variation regularities of the bearing capacity, the pile-soil stress ratio and load sharing in CFG Pile Composite Foundation of different arrangement forms in A、B、C、D sections are analyzesd, as well as their changes with load and design parameters,which can provide scientific suggestion for practical railroading.
The main conclusions are as follows:
1. The the limit bearing capacity and the modulus improvement of inter-pile soil are obtained by the analyses on the date of local static loading tests on natural soil and soil between piles.
2. With vertical bearing capacity and side friction determination of CFG single pile, the limit bearing capacities of CFG single piles are calculated in CFG pile composite foundation of different arrangement forms in A、B、C、D sections.
3. By the analyses on the date of local static loading tests on CFG pile composite foundation in different arrangement forms, pile length, pile diameter and spacing between adjacent piles have influenced on the bearing capacity of CFG Composite Foundation. Their influences are analysed respectively.
4. By the analyses on the date of local static loading share tests on CFG pile composite foundation in different arrangement forms, Pile Stress, soil Stress, the pile-soil stress ratio and the ratio of load share of CFG pile are increased with the load on composite foundation of all sections. Their change trends with different pile length, pile diameter and spacing between adjacent piles at the same load are further analysisd.
5. The larger number of turning points on the graphs of average increasing amplitude that are on the pile-soil stress ratio and the ratio of loading share of CFG pile reflects higher mutual coordination in stress and load share between pile and soil and the better interaction between soil and pile to some extent. And according to that, both the highest mutual coordination in stress and load share between pile and soil and the best interaction between soil and pile are both in composite foundation in C section arrangement forms, when the pile and soil share the up load together.
6. Exerting coefficient of bearing capacity of pile and soil,which symbol areγ_p andγ_S, reflects higher exerting degree of bearing capacity of pile and soil in some extent. And according to that, the highest exerting coefficient of bearing capacity of pile and soil are both in composite foundation in C section arrangement forms, when the pile and soil share the up load together.
本文的主要结论如下:
1.通过对该试验段天然土及CFG桩复合地基桩间土静载试验的数据分析,得出处理后桩间土的极限承载力及模量提高系数。
2.通过CFG桩单桩竖向承载力及侧摩阻力的测定,得出A、B、C、D四区不同布置形式的CFG桩复合地基中单桩承载力的极限值。
3.通过对该试验段CFG桩复合地基载荷试验的数据分析,得出不同布置形式CFG桩复合地基的承载力,并结合该试验段的地质条件,分析桩长、桩间距及桩径对CFG桩复合地基承载力的影响。
4.通过对该试验段CFG桩复合地基桩、土分担数据的比较分析,得出不同布置形式的CFG桩复合地基的桩应力、土应力、桩土应力比及桩荷载分担比均随荷载的增加而增加,并进一步分析了在同一荷载作用下,各量随CFG桩复合地基桩长、桩径、桩间距的变化而变化的趋势。
5.利用桩土应力比及桩荷载分担比平均增幅转向点个数的多少,从一定程度上来描述在共同承担上部荷载时桩土应力及桩土荷载分担相互协调程度的高与低,桩、土共同作用的充分与否,并依此判断出:该试验段C区布置形式的CFG桩复合地基中,桩、土在共同承担上部荷载作用时,桩、土应力及荷载分担协调较高,桩、土共同作用较充分。
6.利用CFG桩承载能力的发挥系数γp及桩间土承载能力的发挥系数在s的大小,在一定程度上来描述复合地基中桩、土的承载能力发挥的大小,并依此判断出凤阳段C区布置形式的CFG桩复合地基在承受上部荷载作用时桩、土的承载能力发挥最大。
With load method of low maintenance, a lot of local static loading tests on natural soil, soil between piles, CFG single piles and CFG Pile Composite Foundation are made in the Fengyang experimental section of Beijing-Shanghai High-Speed Railway. From the experimental date in this paper, variation regularities of the bearing capacity, the pile-soil stress ratio and load sharing in CFG Pile Composite Foundation of different arrangement forms in A、B、C、D sections are analyzesd, as well as their changes with load and design parameters,which can provide scientific suggestion for practical railroading.
The main conclusions are as follows:
1. The the limit bearing capacity and the modulus improvement of inter-pile soil are obtained by the analyses on the date of local static loading tests on natural soil and soil between piles.
2. With vertical bearing capacity and side friction determination of CFG single pile, the limit bearing capacities of CFG single piles are calculated in CFG pile composite foundation of different arrangement forms in A、B、C、D sections.
3. By the analyses on the date of local static loading tests on CFG pile composite foundation in different arrangement forms, pile length, pile diameter and spacing between adjacent piles have influenced on the bearing capacity of CFG Composite Foundation. Their influences are analysed respectively.
4. By the analyses on the date of local static loading share tests on CFG pile composite foundation in different arrangement forms, Pile Stress, soil Stress, the pile-soil stress ratio and the ratio of load share of CFG pile are increased with the load on composite foundation of all sections. Their change trends with different pile length, pile diameter and spacing between adjacent piles at the same load are further analysisd.
5. The larger number of turning points on the graphs of average increasing amplitude that are on the pile-soil stress ratio and the ratio of loading share of CFG pile reflects higher mutual coordination in stress and load share between pile and soil and the better interaction between soil and pile to some extent. And according to that, both the highest mutual coordination in stress and load share between pile and soil and the best interaction between soil and pile are both in composite foundation in C section arrangement forms, when the pile and soil share the up load together.
6. Exerting coefficient of bearing capacity of pile and soil,which symbol areγ_p andγ_S, reflects higher exerting degree of bearing capacity of pile and soil in some extent. And according to that, the highest exerting coefficient of bearing capacity of pile and soil are both in composite foundation in C section arrangement forms, when the pile and soil share the up load together.
引文
[1]邬雷勇.CFG桩复合地基承载性状研究[硕士学位论文].合肥.合肥工业大学.2007.3-4
[2]牛志蓉.地基处理技术及工程应用.北京:中国建材工业出版社.2004
[3]龚晓南主编.复合地基理论及工程应用.中国建筑工业出版社,2002
[4]龚晓南主编.地基处理技术发展与展望(第一版).中国水利水电出版社,2004。
[5]阎明礼,张东刚.CFG装复合地基技术及工程实践.北京:中国水利水电出版社.2001
[6]罗朝基.CFG桩加固京津高速铁路软基施工技术.路基工程,2006,3:89.
[7]Jiang Kong.CFG pile strengthening technology of soft ground.Journal of Traffic and Transportation Engineering,v4,n3,September,2004.
[8]娄国充,卜建清,王树栋.CFG桩复合地基工程特性分析.中南公路工程.2001,26(1):24-26
[9]张尚东,娄国充,刘俊彦.CFG桩复合地基特性分析及承载力计算.石家庄铁道学院学报.2000,13.0(增刊):15-18
[10]贾瑞杰.CFG桩复合地基的设计研究与应用[D].中国学位论文全文数据库,中南大学,2006。
[11]沈旦申.粉煤灰混凝土.北京:中国铁道出版社.1989
[12]周兴华,CFG桩复合地基在郑州市区地基中的应用,河南科学,2003.21(5):543-545.
[13]段继伟,龚晓南等,水泥搅拌桩的荷载传递规律.岩土工程学报,1994.16(4):1-7
[14]杨顺安,刘志欣等.粉喷桩加固软土地基的认识.地质科技情报,1999.18(3):75-78.
[15]问建学,黄慧明.CFG桩复合地基常见施工病害及其处治.公路.2003.6:94-96.
[16]赵秀绍.CFC桩施工引起工程环境问题的试验研究与有限元分析[博士论文].中国地质人学,2006.5.
[17]范云,汪英珍.CFG复合地基桩材特性的试验分析.地质与勘探.2002.38(4):94-96
[18]阎明礼,杨军,吴春林等.CFG桩复合地基的褥垫技术.地基处理.1996.7(3)
[19]阎明礼,杨军等.CFG桩复合地基试验研究.北京:中国建筑科学研究院研究报告,1992
[20]吴春林,阎明礼等.CFG桩及其复合地基水平荷载作用下的性状.工程勘察.1996(4)
[21]韩云山,白晓红,梁仁旺.垫层对CFG桩复合地基承载力评价的影响研究.岩石力学与工程学报,2004.23(2):3498-3503
[22]王瑞永,李建光.滑移线场理论在CFG桩复合地基桩土应力比研究中的应用.岩土工程技术,2003.(6):368-371
[23]赵其华,李建光等,CFG桩复合地基设计的最优化理论模型及应用.地基处理,2002,13.0(2)
[24]娄国充.CFG桩复合地基设计及现场试验分析.铁道标准设计.2002.2:43-44
[25]张东刚,CFG桩复合地基变形计算分析.建筑科学.1993.4:35-40.
[26]张小敏,郑俊杰.CFG桩复合地基承载力可靠度分析.岩土力学,2002.23(6):810-8I2
[27]阎明礼,李春灵.有边载条件下CFG桩复合地基性状.地基处理.2000.11(3)
[28]李宁,韩煊.褥垫层对复合地基承载机理的影响.土木工程学报,2001.34(2):68-73.
[29]李坛,赵其华,梁璋彬,何文秀,姚巍.利用FLAC3D软件对夯扩CFG桩复合地基承载性能的研究.岩土工程届2007.0(12):24-26
[30]刘胜群,吴建奇,陈玉平.Ansys有限元软件在CFG桩复合地基中的应用.铁道建 筑.2006(12):66-69
[31]刘胜群,陈玉平.CFG桩复合地基工程应用实例及非线性有限元分析.铁道建筑,2006,9:52-54
[32]《建筑地基处理技术规范》(JGJ79-2002).北京:中国建筑工业出版社,2002
[33]《建筑地基基础设计规范》(GB50007-2002).北京:中国建筑工业出版社,2002
[2]牛志蓉.地基处理技术及工程应用.北京:中国建材工业出版社.2004
[3]龚晓南主编.复合地基理论及工程应用.中国建筑工业出版社,2002
[4]龚晓南主编.地基处理技术发展与展望(第一版).中国水利水电出版社,2004。
[5]阎明礼,张东刚.CFG装复合地基技术及工程实践.北京:中国水利水电出版社.2001
[6]罗朝基.CFG桩加固京津高速铁路软基施工技术.路基工程,2006,3:89.
[7]Jiang Kong.CFG pile strengthening technology of soft ground.Journal of Traffic and Transportation Engineering,v4,n3,September,2004.
[8]娄国充,卜建清,王树栋.CFG桩复合地基工程特性分析.中南公路工程.2001,26(1):24-26
[9]张尚东,娄国充,刘俊彦.CFG桩复合地基特性分析及承载力计算.石家庄铁道学院学报.2000,13.0(增刊):15-18
[10]贾瑞杰.CFG桩复合地基的设计研究与应用[D].中国学位论文全文数据库,中南大学,2006。
[11]沈旦申.粉煤灰混凝土.北京:中国铁道出版社.1989
[12]周兴华,CFG桩复合地基在郑州市区地基中的应用,河南科学,2003.21(5):543-545.
[13]段继伟,龚晓南等,水泥搅拌桩的荷载传递规律.岩土工程学报,1994.16(4):1-7
[14]杨顺安,刘志欣等.粉喷桩加固软土地基的认识.地质科技情报,1999.18(3):75-78.
[15]问建学,黄慧明.CFG桩复合地基常见施工病害及其处治.公路.2003.6:94-96.
[16]赵秀绍.CFC桩施工引起工程环境问题的试验研究与有限元分析[博士论文].中国地质人学,2006.5.
[17]范云,汪英珍.CFG复合地基桩材特性的试验分析.地质与勘探.2002.38(4):94-96
[18]阎明礼,杨军,吴春林等.CFG桩复合地基的褥垫技术.地基处理.1996.7(3)
[19]阎明礼,杨军等.CFG桩复合地基试验研究.北京:中国建筑科学研究院研究报告,1992
[20]吴春林,阎明礼等.CFG桩及其复合地基水平荷载作用下的性状.工程勘察.1996(4)
[21]韩云山,白晓红,梁仁旺.垫层对CFG桩复合地基承载力评价的影响研究.岩石力学与工程学报,2004.23(2):3498-3503
[22]王瑞永,李建光.滑移线场理论在CFG桩复合地基桩土应力比研究中的应用.岩土工程技术,2003.(6):368-371
[23]赵其华,李建光等,CFG桩复合地基设计的最优化理论模型及应用.地基处理,2002,13.0(2)
[24]娄国充.CFG桩复合地基设计及现场试验分析.铁道标准设计.2002.2:43-44
[25]张东刚,CFG桩复合地基变形计算分析.建筑科学.1993.4:35-40.
[26]张小敏,郑俊杰.CFG桩复合地基承载力可靠度分析.岩土力学,2002.23(6):810-8I2
[27]阎明礼,李春灵.有边载条件下CFG桩复合地基性状.地基处理.2000.11(3)
[28]李宁,韩煊.褥垫层对复合地基承载机理的影响.土木工程学报,2001.34(2):68-73.
[29]李坛,赵其华,梁璋彬,何文秀,姚巍.利用FLAC3D软件对夯扩CFG桩复合地基承载性能的研究.岩土工程届2007.0(12):24-26
[30]刘胜群,吴建奇,陈玉平.Ansys有限元软件在CFG桩复合地基中的应用.铁道建 筑.2006(12):66-69
[31]刘胜群,陈玉平.CFG桩复合地基工程应用实例及非线性有限元分析.铁道建筑,2006,9:52-54
[32]《建筑地基处理技术规范》(JGJ79-2002).北京:中国建筑工业出版社,2002
[33]《建筑地基基础设计规范》(GB50007-2002).北京:中国建筑工业出版社,2002