复合地基沉降及按沉降控制的优化设计研究
详细信息    本馆镜像全文|  推荐本文 |  |   获取CNKI官网全文
摘要
复合地基是指在地基处理过程中,部分土体得到增强或被置换,或在地基中设置加筋材料,加固区是由基体和增强体两个部分组成的人工地基。其本质是在荷载作用下,基体和增强体共同直接承担上部荷载。复合地基在工程中得到越来越广泛的应用,但其沉降计算方法研究还相对落后于工程实践。在处理深厚软弱地基时沉降控制显得格外重要,因此对复合地基及按沉降控制的复合地基优化设计进行研究十分必要。本文在前人研究成果的基础上结合实际情况对刚性基础下复合地基沉降及按沉降控制的优化设计进行了较系统的研究:
     根据散体材料桩复合地基荷载传递及变形机理,分析了散体材料桩与桩间土之间的应力应变关系。根据散体材料桩复合地基在荷载作用下的变形形式将压缩层分为鼓胀段、非鼓胀段和下卧层三部分,并分别采用不同方法进行沉降计算,改进了散体材料桩复合地基的沉降计算方法。文中还对影响散体材料桩复合地基沉降的主要因素进行分析。
     引入剪切位移法并考虑了桩长和端阻效应对复合模量的影响,对面积加权复合模量公式进行了修正,并分析了各影响因素对复合模量的影响。
     柔性桩在荷载作用下存在有效桩长。文中根据桩侧摩阻力分布形式,推导了复合地基中柔性桩的有效桩长计算公式。考虑有效桩长的影响将复合地基压缩层分为三层,即桩顶至有效桩长范围、有效桩长至桩端范围和下卧层,分别计算沉降并最终求得总沉降,改进了柔性桩复合地基沉降计算方法。
     刚性桩复合地基为改善受力性状常在桩顶设置褥挚层以保证桩体有一定上刺。由于刚性桩刚度较大,桩身变形很小常可忽略不计,整个复合地基沉降主要由上下刺入量和下卧层沉降组成。根据加固区桩土单元体桩与桩间土的静力平衡,推导了考虑上下刺入量的沉降计算公式。
     当采用复合地基主要要求减小沉降量时,按沉降控制的复合地基优化设计显得更为重要。影响复合地基沉降的两个主要因素为桩长和置换率,结合上述对不同类型复合地基沉降计算方法的研究,将桩长和置换率作为优化参数,沉降量作为约束条件,用桩量最省作为目标函数,结合具体工程实例,对复合地基进行优化设计,以期达到更好的经济效益。
Composite foundation is an artificial foundation composed of basal body and reinforced body, in which some soil is reinforced or replaced, or some reinforced materials are set in the progress of foundation treatment. The essence of composite foundation is that the superimposed loading is shared by the basal body and the reinforced body jointly and directly. Composite foundation has been widely applied in the civil engineering, but its study on settlement is relatively fall behind the engineering practice. Settlement of composite foundation is especially important when treating deep soft foundation, so it is quite necessary to study on settlement calculation and optimum design according to settlement. Based on the known research findings, research on settlement and optimum design according to settlement of composite foundation under rigid foundation has been systematically carried out in this paper.
    Based on the mechanism of load transfer and deformation of discrete material piles, the relationship between stress and strain of pile and soil is analyzed. Compression layer is divided into 3 different sections: expanding, un-expanding and substratum according to deformation forms, and each section is calculated by different method. By this method, the settlement calculation of discrete material piles composite foundation has been improved. And factors influencing the settlement are analyzed in this paper.
    Modified formula of composite modulus is deduced in which shear deformation method is introduced and the influence of pile length and tip resistance on composite modulus is considered. Then factors influencing the composite modulus are analyzed.
    There exists an effective length in the flexible pile under loading. The calculation formula of effective length of pile is deduced by assuming skin friction form. Considering the influence of effective length of piles, compression layer is divided into 3 different sections: top to effective length, effective length to bottom of pile and substratum. The settlement of composite foundation is the sum of these three sections. By this method, the settlement calculation of flexible piles composite foundation has been improved.
    In order to improve the stress distributions, it should have the upper penetration into the cushion. The deformation of pile can be ignored because of its large rigidity. So the total settlement of rigid pile composite foundation is chiefly composed of the upper and lower penetration and substratum. According to the equilibrium equation,
引文
A.Asnoka, T.Kodaka, and M.Nozu. Improvement of Deep Soft Clay with Sand. Science Press, Beijing, China, 1993,628-633
    
    C.F.Leung and T.S.Tang. Load Distribution in Soft Clay Reinforced by Sand Columns. Proceedings of the international conference on soft soil engineering. Science Press, Beijing, China, 1993,779-784
    
    C.F.Leung. Observation of the Foundation Loading and Excess Pore Pressure Filed Around a Closed-ended Pile. J.Geotech, ASCE, 2002,128(1): 1-12
    
    D.T.Bergardo and F.L.Lam. Full Scale Load Test of Granular Piles with Different Densities and Different Proportions of Gravel and Sand on Soft Bangkok Clay. Soils and Foundations, 1987,27(1): 86-93
    
    G.Canetta and R.Nova. A numerical method for the analysis of ground improved by columnar inclusion. Computers and Geotechnics, 1989,7:99-114
    
    Geddes J.D.. Stresses in Foundation Soils Due to Vertical Subsurface Load[J], Geotechnique, 1966,Vol.l6: 231-255
    
    H.Aboshi, E.Ichimoto, M.Enoki and K.Harada. The composer-a method to improved characteristics of soft clay by inclusion of large diameter san columns. Proc. of International Conference on Soil Reinfrecements, 1979,1:211-216
    
    H.B.Poorooshasb, M.Alamgir and N.Miura. Negative skin fricion on rigid and deformable piles. Computers and Geotechnics, 1996,18(2):109-126
    
    H.F.Schweiger and G.N.Pande. Modelling stone column reinforced soft-a modified Voigt approach. Proc. 3~(rd) Num.Models in Geomech., 1989:204-214
    
    H.G.Poulos. Piled Raft Foundation: Design and Applications.Geotechnique,2001,151(2):95-l 13
    
    H.Priebe. Estimation settlement in a gravel column consolidated soil. Die Bautechnik,1976:160-162
    
    I.Juran and A.Guernazi. Settlement Response of Soft Soil Reinforced by Compacted Sand Columns, Journal of Geotechnical Engineering, ASCE, 1988,114,930-943
    
    J.G.Wang, C.F.Leung and Y.Ichikawa. A simplified homogenization method for composite soils. Computers and Geotechnics, 2002,29:477-500
    
    M.Alamgir, N.Miura, H.B.Proorooshasb and M.R.Madhav. Deformation anslysis of soft ground reinforced by columnar inclusion. Computers and Geotechnice, 1996, 18(4):267-289
    
    M.Enoki, N.Yagi, R.Yatabe and E.Echimoto, Shearing Characteristic of Composite Ground and It's Application to Stability Analysis[J]. Deep Foundation Improvement: Design, Construction and Testing, ASTM, 1991
    M. Enoki, N. Yagi, R. Yatabe and E. Ichimoto, Shearing Characteristic of Composite Ground and It's Application to Stability Analysis[J]. Deep Foundation Improvement: Design, Construction and Testing, ASTM, 1991
    M. F. Randolph and C. P. Wroth. An analytical solution for the consolidation around a driven pile. Int. J. Numer. Anal. Methods in Geomech., 1979, Vol. 3: 217-229
    Mine K. and Ohno S. Deformation analysis of composite ground by homogenization method. Preceedings of the 4th International Conference on Soil Mechanics and Foundation Engineering, 1997: 719-722
    N. Balaam and H. Poulos. The behaviour of foundations supported by clay stablilized by stone columns. Proc. 8th European Conference on Soil Mechanics and Foundation Engineering, 1983, Vol. 1: 199-204
    N. Balaam and J. Booker. Analysis of rigid rafts supported by granular piles. I. J. Num. Anal. Meth. Geomech., 1981, 5: 379-403
    N. Balaam and J. Booker. Effect of stone column yield on settlement of rigid foundation in stabilized clay. I. J. Num. Anal. Meth. Geomech., 198, 93: 331-351
    R. R. Goughnour. Settlement of vertically loaded stone columns in soft ground. Proc. 8th European Conference on Soil Mechanics and Foundation Engineering. 1983, 1: 235-240
    R. W. Cooke. Axially Loaded Piles and Pile Groups Embedded in a Cross-anisotropic Soil. Geotechnical, Div, ASCE, 1977, 119, 230-242
    Y. K. Chow. Settlement analysis of sand compaction pile. Soils and Foundations, 1996, 36(1): 111-113
    陈强,黄志义,左人宇等.组合型复合地基的特性及其FEM模拟研究[J].土木工程学报,2001,34(1):50-55
    陈艳平.土工格室碎石垫层+碎石桩复合地基碎石桩复合地基模型试验研究[D].湖南大学硕士学位论文,2003
    陈善雄.复合地基桩型的合理选择[J].土工基础,1995,9(1):1-7
    陈善雄.柔性桩荷载传递特性与有效桩长分析[J].岩土工程师,1995,7(3):1-8
    陈振建等.满堂加固碎石桩地基的强度与变形[J].第五届土力学及基础工程学术会议论文集.北京:中国建筑工业出版社,1990:444-454
    陈志芳.高速公路PTC疏桩复合地基试验研究和优化设计方法[D].河海大学硕学位论文,2005
    池跃君,沈伟,宋二祥.桩体复合地基桩、土相互作用的解析法[J].岩土力学,2002,23(5):546-550
    池跃君,宋二祥,陈肇元.刚性桩复合地基沉降计算方法的探讨及应用[J].土木工程学报, 2003,36(11):19-23
    池跃君,宋二祥,陈肇元.刚性桩复合地基竖向承载特性分析[J].工程力学,2003,20(4):9-14
    池跃君,宋二祥等.刚性桩复合地基应力场分布的试验研究[J].岩土力学,2003,24(3):339-343
    党昱敬.CFG桩和沉管挤密碎石桩组合型复合地基的承载力[J].工业建筑,1997,27(3):13-18
    邓修甫,刘新华,张琳.碎石桩复合地基沉降计算方法[J].湘潭矿业学院学报,2003,18(4):55-57
    邓修甫,王祥秋.干振碎石桩复合地基沉降计算方法探讨[J].水文地基工程地质,2003,3:92-94
    邓永锋,刘松玉等.水泥土搅拌桩复合地基变形模量确定的一种新方法[J].公路交通科技,2005,22(3):13-16
    段继伟,龚晓南,曾国熙.水泥搅拌桩的荷载传递规律[J].岩土工程学报,1994,16(4):1-8
    段继伟.柔性桩复合地基的数值分析[D].浙江大学博士学位论文,1993
    方永凯,周芝英.双向复合地基加固码头堆场的现场试验[J].水利水运科学研究,1994,16(4):359-366
    何思明,卢国胜等.群桩沉降计算理论分析[J].岩土力学,2003,24(3):435-441
    何思明.复合地基压缩模量计算新方法[J].四川科学建筑研究,1997,3:38-40
    傅景辉,宋二祥.刚性桩复合地基工作特性分析[J].岩土力学,2000,21(4):335-339
    高英.复合桩基的变形控制设计理论研究[D].武汉理工大学硕士学位论文,2006
    龚晓南.复合地基[M].杭州:浙江大学出版社,1992
    龚晓南.复合地基理论及工程应用[M].北京:中国建筑工业出版社,2002
    龚晓南.复合地基理论与实践[M].杭州:浙江大学出版社,1996
    龚晓南.复合地基引论(一)[J].地基处理,1991,2(3):36-42
    龚晓南.复合地基引论(二)[J].地基处理,1991,2(4):1-11
    韩杰,叶书麟.复合地基应力特性分析[J].工程勘察,1993,5:1-5
    韩杰,叶书麟.国外碎石桩加固技术发展的新认识[J].地基处理,1991,2(2):15-24
    韩杰,叶书麟.碎石桩复合地基的有限元分析[J].岩土工程学报,1992(增刊),13-19
    韩煊,李宁.复合地基中群桩相互作用机理数值试验研究[J].土木工程学报,1999,32(4):75-80
    侯学渊,杨敏.软土地区变形控制设计理论和工程实践[M].上海:同济大学出版社,1996
    姜前.计算碎石桩复合地基变形模量的新方法[J].岩土工程学报,1992,14(4):53-58
    康景俊.拉格都堆石坝基回填松砂和软土层振冲加固处理[J].水利学报,1983,No.10
    雷金波.带帽控沉疏桩复合地基试验研究及作用机理分析[D].河海大学博士学位论文,2005
    李洪文.CFG桩复合地基工作性状研究[D].吉林大学硕士学位论文,2004
    李建光.组合桩复合地基沉降变形研究及优化设计探讨[D].武汉理工大学硕士学位论文,2002
    李宁,韩煊.单桩复合地基加固机理数值试验研究[J].岩土力学,1999,20(4):42-49
    李仁民,方磊,刘松玉.采用联合求解法分析复合地基附加应力和沉降[J].中南公路工程,2002,27(4):9-12
    李小青,潘鸿宝.复合地基柔性垫层作用分析[J].探矿工程,2001,3:6-8
    梁晓东.复合地基等效实体法研究[D].浙江大学硕士学位论文,2005
    林孔锱.碎石桩地基的承载力与沉降计算[J].1983年振冲加固法经验交流学术讨论会论文选编.水利电力出版社,1984
    刘杰,张可能.复合地基中垫层作用机理[J].中南工业大学学报,2001,32(6):568-572
    刘杰,张可能.散体材料桩复合地基极限承载力计算[J].岩土力学,2002,23(2):204-207
    刘杰,张可能.碎石桩复合地基若干问题的理论分析[J].力学与实践.2003,25(5):44-46
    刘丽萍,黄义,李向阳.复合地基沉降影响因素的半解析元分析[J].西安建筑科技大学学报(自然科学版),2005,37(3):360-365
    刘利民,程庆阳,张洪文.以沉降控制为标准的水泥土搅拌桩设计方法的研究[J].工业建筑,1997,27(3):9-12
    刘利民,张建新.用位移协调法计算柔性桩的沉降[J].工业建筑,1997,27(3):1-5
    刘绪普,龚晓南等.用弹性理论法和传递函数法联合求解单桩的沉降[J].第四届全国地基处理学术讨论会论文集,1995:484-488
    刘一林,谢康和,潘秋元等.水泥搅拌桩复合地基试验研究[J].复合地基,1990,265-269
    陆贻杰,周国钧.搅拌桩复合地基模型及三维有限元分析[J].岩土工程学报,1989,11(5):86-91
    罗惟德.单桩承载机理分析与荷载—沉降曲线的理论推导[J].岩土工程学报,1990,12(1):35-44
    毛前,龚晓南.桩体复合地基柔性垫层的效用研究[J].岩土力学,1998,19(2):67-73
    明珉,王蔚.南京南湖地区适用深层水泥搅拌桩加固软土地基的一点体会[J].复合地基理论与实践.杭州:浙江大学出版社,1996
    聂福霞.CFG桩复合地基设计与应用研究[D].中国海洋大学硕士学位论文,2005
    亓乐.搅拌桩复合地基沉降计算方法研究[D].山东大学硕士学位论文,2005
    齐伟军,杨海涛等.复合地基有效桩长的计算方法[J].黑龙江科技学院学报,2003,12(4):50-51
    沈伟,池跃君,宋二祥.考虑桩、土、垫层协同作用的刚性桩复合地基沉降计算方法[J].工程力学,2003,20(2):36-42
    盛崇文.碎石桩复合地基的沉降计算[J].土木工程学报,1986,19(1):72-80
    施建勇,邹坚.深层搅拌桩复合地基沉降计算理论研究[J].岩士力学,2002,23(3):309-320
    王步云,赵秀芹.砂石桩与低强度混凝土桩组合型复合地基在软土地基中的应刚(二)[J]. 岩土工程技术,1997,11(2):3-5
    王步云,赵秀芹.砂石桩与低强度混凝土桩组合型复合地基在软土地基中的应用(一)[J].岩土工程技术,1997,11(1):8-14
    王凤池,朱浮声,王晓初.复合地基复合模量的理论修正[J].东北大学学报(自然科学版),2003,24(5):491-494
    王启铜.柔性桩的沉降(位移)特性及荷载传递规律[D].浙江大学博士学位论文,1991
    吴慧明,龚晓南.刚性基础与柔性基础下复合地基模型试验对比研究[J].土木工程学报,2001,34(5):81-84
    吴廷杰,杨志红.干振碎石桩的特性和设计计算研究[J].岩土工程学报,1996,18(1):29-38
    吴廷杰,杨志红.碎石桩复合地基应力传递的研究[J].地基处理,1994,5(4):7-12
    熊辉.基于沉降控制理论的水泥搅拌桩复合地基设计[J].岩土工程技术,2001,3:169-172
    徐洋,卢廷浩,董海洲等.考虑沉桩及群桩间相互影响的复合模量计算方法[J].岩土力学,2001,22(4):486-489
    徐洋,谢康和,胡茂刚.考虑变形协调的刚性基础复合地基沉降计算[J].浙江大学学报(工学版),2003,37(5):551-555
    徐洋,谢康和.复合地基的平面应力扩散效应[J].土木工程学报,2002,35(2):57-60
    徐洋,谢康和.影响复合地基应力扩散的因素[J].工业建筑,2003,33(1):36-38
    徐芝纶.弹性力学简明教程[M].北京:高等教育出版社,2001
    闫明礼,曲秀莉,刘伟等.复合地基的复合模量分析[J].建筑科学,2004,20(4):27-32
    闫明礼,王明山,闫雪峰等.多桩型复合地基设计计算方法探讨[J].岩土工程学报,2003,25(3):352-355
    闫明礼.地基处理技术[M].北京:中国环境科学出版社,1996
    阎明礼,吴春林,杨军.水泥粉煤灰碎石桩复合地基试验研究[J].岩土工程学报,1996,18(2):55-62
    杨慧.双层地基和复合地基压力扩散角比较分析[D].浙江大学硕士学位论文,2000
    叶彬.CFG桩复合地基性状及设计计算研究[D].浙江大学硕士学位论文,2005
    叶观宝,司明强.半刚性复合地基沉降使用计算方法的探讨[J].水文地质工程地质,2001,4:12-14
    叶观宝,叶书麟,章关福.深层搅拌桩桩身荷载传递量测与分析[J].第三届全国地基处理学术讨论会论文集,杭州:浙江大学出版社,1992,136-139
    袁聚云,赵锡宏.竖向均布荷载作用在地基内部时的土中应力公式[J].上海力学,1995,16(2):213-222
    曾国熙,叶正青,冯国栋等.桩基工程手册[M].北京:中国建筑工业出版社,1995
    曾磊.以沉降为控制指标对粉喷桩复合地基的优化设计研究[J].广东交通职业及时学院学报.2005,4(2):39-43
    詹云刚.CFG桩复合地基加固深厚软基沉降计算研究[D].南京工业大学硕士学位论文,2005
    张爱军,谢定义.复合地基三维数值分析[M].北京:科学出版社,2004
    张定.复合地基中桩体变形模量的分析与计算[J].岩土工程学报,1999,21(2):205-208
    张定.散体材料桩复合地基的沉降分析与计算[J].铁道学报,1998,20(6):98-104
    张土乔.水泥土的应力应变关系及搅拌桩破坏特性研究[D].浙江大学博士学位论文,1992
    张小敏,郑俊杰.刚性桩复合地基应力及沉降计算[J].岩土工程技术,2002,5:184-188
    张小平,俞仲泉.用Mindlin解推求复合地基中附加应力的计算公式[J].河海大学学报,1999,27(2):35-38
    张忠坤,殷宗泽等.复合地基临界桩长的研究[J].岩土工程学报,1999,21(3):205-208
    张忠苗,陈洪,吴慧明.柔性承台下复合地基应力和沉降计算研究[J].岩土力学,2004,25(3):451-454
    张世尧,陈涛等.以沉降控制的掺粉煤灰水泥粉喷桩优化设计方法[J].结构工程师,2003,1:29-34
    赵明,赵明华,陈昌富.确定碎石桩复合地基桩土应力比的一种新方法[J].湖南大学学报(自然科学版),2002,29(2):112-116
    郑俊杰,彭小荣.桩土共同作用设计理论研究[J].岩土力学,2003,24(2):242-245
    郑俊杰.复合地基承载特性分析及设计方法研究[D].浙江大学博士学位论文,2001
    周建.复合地基加固区沉降计算的一种新方法[J].浙江大学学报,2000,134(1):83-87
    周建安,杨淑碧.碎石桩复合地基承载力性状有限元分析[J].地质灾害与环境保护,1996,7(1):104-107
    朱百里,沈珠江等.计算土力学[M].上海:上海科技出版社,1990
    邹坚.深搅桩复合地基的计算理论及其应用研究[D].河海大学硕学位论文,2001

© 2004-2018 中国地质图书馆版权所有 京ICP备05064691号 京公网安备11010802017129号

地址:北京市海淀区学院路29号 邮编:100083

电话:办公室:(+86 10)66554848;文献借阅、咨询服务、科技查新:66554700