偏心荷载下双层饱和黏土地基承载特性

詹云刚; 袁凡凡; 栾茂田

doi:10.13204/j.gyjz200709018

偏心荷载下双层饱和黏土地基承载特性

doi: 10.13204/j.gyjz200709018

1.
1. 中国科学院武汉岩土力学研究所武汉 430071;
2.
2. 大连理工大学土木水利学院岩土工程研究所海岸和近海工程国家重点实验室大连 116024

基金项目:

国家自然科学基金资助项目(50509023、50579006)

详细信息

作者简介:
詹云刚男 1971年5月出生博士研究生

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- 被引次数: 0
出版历程
- 收稿日期: 2007-03-12
- 刊出日期: 2007-09-20

BEARING BEHAVIOUR OF STRIP FOUNDATIONS ON UNDRAINED TWO-LAYERED SUBSOIL SUBJECTED TO ECCENTRICAL LOADING

1.
1. Institute of Rock and Soil Mechanics,The Chinese Academy of Science Wuhan 430071;
2.
2. Institute of Geotechnical Engineering,School of Civil and Hydraulic Engineering The State Key Laboratory of Coastal and Offshore Engineering,Dalian University of Technology Dalian 116024

摘要

摘要: 在海洋与近海工程中,海洋建筑物地基受到水平荷载、竖向荷载和弯矩荷载的共同作用,地基土体非均质成层分布。因而,复合加载模式下层状地基的极限承载力与破坏机理研究是海洋工程设计的关键问题。针对竖向荷载(V)和弯矩荷载(M)共同作用下双层饱和黏土地基的极限承载力与破坏机理进行有限元分析。土体采用理想弹塑性模型,屈服准则为Mohr-Coulomb准则;基础与地基间假定切向完全黏结、竖向可分离。通过有限元计算,得到双层地基在V-M荷载空间的破坏(极限)荷载包络线,归纳得出地基的破坏模式。计算结果表明,双层地基的破坏包络线随着上层土体的厚度与基础宽度比值、上下土层的抗剪强度指标比值的增大而不断扩大,最终达到一个稳定值;在V-M复合加载条件下,地基可能发生深层整体剪切破坏或浅层局部剪切破坏。
- 有限元分析 /
- 地基 /
- 极限承载力 /
- 破坏包络线
Abstract: Two -dimensional finite element analysis of strip surface foundations resting on undrained two -layered subsoilunder the effect of combined vertical(V)and moment(M)loading has been applied to investigate the ultimate bearingcapacity and failure mechanism of the subsoil. In this analysis, the material response of the soil is represented with elasticperfectly plastic constitutive law yielding according to Mohr -Coulomb failure criterion. The surface foundation is assumed tohave no uplift capacity, and the footing may detach from subsoil under a V -M load combination, which is significantlydifferent from the fully attached footing. The ultimate bearing capacity of the foundation on layered subsoil is presented interms of the failure envelope in vertical and moment loading space. The effects of the thickness of upper soil, the width offooting and the shear strength of soilson the shape of the failure envelope are examined in details. It is found that the shapeof failure envelope ismainly depended onthe thickness of upper soil and the undrained shear strength ratio of two layers, andthe failure mechanism has two forms according to the combination of V -M loads.
- finite element analysis /
- foundation /
- ultimate bearing capacity /
- failure envelope

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参考文献(14)

.Hansen B. A Revised and Extended Formula for Bearing Capacity.Bulletin of the Danish Geotechnical Institute. Copenhagen, 1970, 28:5-11

.Vesic A S. Bearing Capacity of Shallow Foundations Winterkorn H F,Fang H Y.Foundation Engineering Handbook. New York:VanNostrand, 1975: 121-147

.Meyerhof G G.Limit Equilibrium Plasticity in Soil Mechanics Proc.Application of Plasticity and Generalised Stress -Strain in GeotechnicalEngineering. ASCE, 1980: 7-24

.Ukritchon B, Whittle A J, Sloan S.Undrained Limit Analysis forCombined Loading of Strip Footings on Clay. Journal of Geotechnicaland Geoenvironmental Engineering, 1998,124(3): 265-276

.Martin C M, Randolph M F. Applications of the Lower and UpperBound Theorems of Plasticity to Collapse of Circular Foundations Proc.10th IACMAG Conf. 2001: 1 417-1 428

.Tan F S. Centrifuge and Theoretical Modeling of Conical Footings onSand. London: Cambridge University, 1990

.Dean E H, James R G, Schofield A S, et al. The Bearing Capacity ofConical Footings on Sand in Relation to the Behaviour of SpudcanFootings of Jack -Ups Proc. Wroth Memorial Symp. Predictive SoilMechanics. Oxford, UK: Thomas Telford, 1992: 230-253

.Martin C M. Physical and Numerical Modelling of Offshore FoundationsUnderCombined Loads. London: University of Oxford, 1994

.Bransby M F, RandolphM F. Shallow Foundations Subject to CombinedLoadings Computer Methods and Advances in Geomechanics.Balkema, Rotterdam: 1997: 1 947-1 952

. Gourvenec S, RandolphM F. Effect of Strength Non -Homogeneity on theBearing Capacity of Circular Skirted Foundations Subjected to CombinedLoading Proc. 11th ISOPE. Kyushu, Japan: 2002: 693-698

.Gourvenec S, Randolph M F.Effect of Strength Non -Homogeneity onthe Shape of Failure Envelopes Combined Loading of Strip and CircularFoundations on Clay. Geotechnique, 2003, 53 (6): 575-586

.Murff J D. Limit Analysis of Multi-Footing Foundation Systems Proc ofthe 8th Int.Conf. on Computer Methods and Advances inGeomechanics. Morgantown: 1994: 223-244

.栾茂田, 赵少飞, 袁凡凡, 等. 复合加载模式作用下地基承载性能数值分析. 海洋工程, 2006, 24 (1): 34-40

.Butterfield R, Houlsby G T, GottardiG. StandardSign Conventions andNotation for Generally Loaded Foundations.Geotechnique, 1997, 47(5): 1 051-1 054

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