桩土(岩)耦合机理是一个非常复杂的力学问题。通过将桩土(岩)复合体看作由不同刚度地质材料组成的层状体,由桩土(岩)界面变形协调条件(界面分离瞬间,土(岩)、桩变形相差n倍),基于连续介质理论建立了快速确定桩基侧阻力的模型。研究结果显示:①桩基侧阻力随土(岩)、桩弹性模量比值Es/Ep增大而提高,且Es/Ep越大,侧阻力变化越明显;②挤土效应越明显,侧阻力降低越明显;③采用快速确定桩基侧阻力模型对工程试桩试验数据进行验证,结果表明,利用该模型对类似场地桩基的侧阻力进行预测是可行的、有效的。
Abstract
The stress and deformation of pile-earth/rock coupling system is a complex mechanics issue. In this paper, a model for the quick determination of pile’s side resistance is established based on continuous medium theory according to the deformation coordination condition (the deformations of soil/rock and pile differ by n times at the moment of separation between soil/rock and pile). The pile-soil/rock complex is considered as a layered material composing geologic materials with different stiffness. The research findings are as follows: (1) The side resistance of pile is manly affected by Es/Ep the ratio of soil/rock’s elastic modulus to pile’s elastic modulus; the greater Es/Ep is, the more remarkable side resistance changes. (2) Side resistance of pile declines when the soil squeezing effect gets more evident. (3) The test dafa of the engineering test piles are verified by the rapid determination model for pile foundation’s side resistance. The results show that it is feasible and effective to use the model to predict the lateral resistance of similar pile foundations.
关键词
桩基侧阻力 /
连续介质理论 /
桩土(岩)界面 /
变形协调条件 /
挤土效应
Key words
side resistance of pile foundation /
continuous medium theory /
pile-soil/rock interface /
deformation coordination condition /
soil squeezing effect
{{custom_sec.title}}
{{custom_sec.title}}
{{custom_sec.content}}
参考文献
[1] 程昌钧,胡育佳.受轴力作用的桩基在水平振动时的抗力[J].上海大学学报(自然科学版),2005,11(3):275-281.
[2] KOO K K, CHAU K T, YANG X, et al. Soil-pile-structure Interactions under SH Wave Excitation[J]. Earthquake Engineering & Structural Dynamics, 2003, 32(3): 395-415.
[3] WONG S C, POULOS H G. Approximate Pile-to-pile Interaction Factors Between Two Dissimilar Piles[J]. Computer and Geotechnics, 2005, 32(8): 613-618.
[4] 陆建飞,王建华,沈为平.考虑固结和流变的层状地基中的水平单桩的理论分析[J].岩石力学与工程学报,2001,20(3):386-390.
[5] MATLOCK H. Correlation for Design of Laterally Loaded Piles in Soft Clay[C]∥Proceedings of the 2nd Annual Offshore Technology Conference. Houston, April 22-24, 1970: 577-594.
[6] REESE L C, COX W P, KOOP F D. Field Testing and Analysis of Laterally Loaded Piles in Stiff Clay[C]∥Proceedings of the 7th Annual Offshore Technology Conference. Houston, May 5-8, 1975: 671-690.
[7] MYLONAKIS G,GAZETAS G. Lateral Vibration and Internal Forces of Grouped Piles in Layered Soil[J]. Journal of Geotechnical and Geoenvironmental Engineering, 1999, 125(1): 16-25.
[8] 黄茂松,吴志明,任 青.层状地基中群桩的水平振动特性[J].岩土工程学报,2007,29(1):32-38.
[9] ZERTSALOV M G, KONYUKHOV D S. Analysis of Piles in Rock[J]. Soil Mechanics and Foundation Engineering, 2007, 44(1): 9-14.
[10]蔡江东,夏红春.大直径嵌岩桩侧阻强化桩土界面影响因素研究[J].岩石力学与工程学报,2014,33(增刊1):3062-3067.
[11]张利新.石家庄地区后注浆灌注桩侧阻力及端阻力增强系数取值的试桩研究[J].建筑结构,2014,44(1):66-72.
[12]程昌钧,胡育佳,朱媛媛,等.桩基的数学建模、理论分析与计算方法[M].北京:科学出版社,2009.
[13]JGJ 94—2008,建筑桩基技术规范[S].北京:中国建筑工业出版社,2008.
[14]杨 乐.基于Cosserat 介质理论的层状岩体均匀化数值分析与应用研究[D].重庆:重庆大学,2009.
[15]杨春和,李银平.互层盐岩体的 Cosserat 介质扩展本构模型[J].岩石力学与工程学报,2005,24(23):4226-4232.
[16]JT/T 738—2009,基桩自平衡法静载试验技术规程[S].南京: 江苏科学技术出版社,2009.
基金
贵州省土木工程一流学科建设项目(QYNYL[2017]0013)
PDF(2085 KB)
