埕岛粉喷桩复合地基应力比试验
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摘要
桩土应力比是反映桩体和桩间土协同工作的重要指标,也是复合地基承载力和沉降计算的重要参数,与地基土的物理力学性质密切相关,影响因素复杂。结合某大型工程,首次对埕岛软土上粉喷桩复合地基进行大型应力比试验,得到埕岛粉喷桩复合地基应力比随荷载、时间、褥垫层厚度、褥垫层刚度的变化规律,并进行有限元分析,对两种结果进行对比。结果表明:粉喷桩复合地基桩土应力比值没有时间效应;粉喷桩复合地基桩土应力比与褥垫层厚度负相关,一定厚度褥垫层可协调桩土工作,宜试验确定最佳厚度范围;应力比与褥垫层弹性模量正相关,模量达到某一值时桩土应力比不再变化,应根据桩体材料选用适当弹性模量褥垫材料;该地区粉喷桩复合地基桩土应力比主要分布在6.5～9.0。
Pile-soil stress ratio is a very important indicator to reflect the level of the together-work of the pile and soil,also a major parameter calculating bearing capacity of composite foundation and settlement,and it is interrelated with the physical and mechanical properties of the soil,whose influencing factor is also complicated.Combined with a large-scale project,the large stress ratio test to the DJM pile composite foundation in the soft clay of Chengdao was conducted.The regulations of the pile-soil stress ratio of DJM pile composite foundation with the change of load,time,thickness and stiffness of pillow in Chengdao region were obtained.The finite element analysis was carried out,and these two results were compared.The results show that there is no time effect to the pile-soil stress ratio of DJM pile composite foundation.The pile-soil stress ratio of DJM pile composite foundation is negative correlation to the thickness of pillow.The pillow with a certain thickness could coordinate the work of the pile-soil,and the best thickness range should be confirmed by experiments.The pile-soil stress ratio of DJM pile composite foundation is positive correlation to the elastic modulus of pillow.Pile-soil stress ratio would never change when the elastic modulus reaches a certain value.The pillow material with proper elastic modulus should be chosen based on the pile material.The numerical value of the pile-soil stress ratio of DJM pile composite foundation in this region mainly distributed from 6.5 to 9.0.
Pile-soil stress ratio is a very important indicator to reflect the level of the together-work of the pile and soil,also a major parameter calculating bearing capacity of composite foundation and settlement,and it is interrelated with the physical and mechanical properties of the soil,whose influencing factor is also complicated.Combined with a large-scale project,the large stress ratio test to the DJM pile composite foundation in the soft clay of Chengdao was conducted.The regulations of the pile-soil stress ratio of DJM pile composite foundation with the change of load,time,thickness and stiffness of pillow in Chengdao region were obtained.The finite element analysis was carried out,and these two results were compared.The results show that there is no time effect to the pile-soil stress ratio of DJM pile composite foundation.The pile-soil stress ratio of DJM pile composite foundation is negative correlation to the thickness of pillow.The pillow with a certain thickness could coordinate the work of the pile-soil,and the best thickness range should be confirmed by experiments.The pile-soil stress ratio of DJM pile composite foundation is positive correlation to the elastic modulus of pillow.Pile-soil stress ratio would never change when the elastic modulus reaches a certain value.The pillow material with proper elastic modulus should be chosen based on the pile material.The numerical value of the pile-soil stress ratio of DJM pile composite foundation in this region mainly distributed from 6.5 to 9.0.
引文
[1]DUNCAN J M,CHANG C Y.Nonlinear analysis of stress and strain in soils[J].Soil Mech and Found,1970,96(5):1629-1653.
[2]段继伟.复合地基桩土应力比影响因素有限元分析[C]//沈珠江,等.第二届华东地区岩土力学学术讨论会论文集.杭州:浙江大学出版社,1992:43-47.
[3]秦建庆,叶观宝.水泥土桩复合地基桩土分担荷载的试验研究[J].工程勘察,2000(1):35-37.QIN Jian-qing,YE Guan-bao.Loading test of the stress ratio between pile and earth in composite ground[J].Geotechnical Investigation&Surveying,2000(1):35-37.
[4]朱中卫,方磊.粉喷桩复合地基桩土应力比试验研究[J].岩土工程技术,2004,18(3):113-115.ZHU Zhong-wei,FANG Lei.Experimental study on stress ratio between pile and soil of DJM pile composite foundation[J].Geotechnical Engineering Technique,2004,18(3):113-115.
[5]李扬,李自力,张艳.不同类型场地对隔震储罐地震响应的影响[J].中国石油大学学报:自然科学版,2008,32(5):108-113.LI Yang,LI Zi-li,ZHANG Yan.Influence of different types of sites on seismic response of base isolated liquid storage tank[J].Journal of China University of Petroleum(Edition of Natural Science),2008,32(5):108-113.
[6]程旭东,马红,刘永红.软土地区储罐群地基沉降的三维数值模拟[J].中国石油大学学报:自然科学版,2009,33(6):100-104.CHENG Xu-dong,MA Hong,LIU Yong-hong.Three-di-mensional numerical simulation of foundation settlement of storage tank group in soft soil area[J].Journal of China University of Petroleum(Edition of Natural Science),2009,33(6):100-104.
[7]颜庆智,付长波,饶江,等.东营软土工程特性及参数相关方程[J].中国石油大学学报:自然科学版,2010,34(3):130-133,139.YAN Qing-zhi,FU Chang-bo,RAO Jiang,et al.Engi-neering property of Dongying soft clay and correlation e-quation of parameters[J].Journal of China University of Petroleum(Edition of Natural Science),2010,34(3):130-133,139.
[8]中国建筑科学研究院.JGJ106-2003.建筑基桩检测技术规范[S].北京:中国建筑工业出版社,2003:7-9.
[9]中国建筑科学研究院.GB50007-2002.建筑地基基础设计规范[S].北京:中国建筑工业出版社,2002:100-102.
[10]中国建筑科学研究院.JGJ79-2002.建筑地基处理技术规范[S].北京:中国建筑工业出版社,2002:80-81.
[11]马时冬.水泥搅拌桩复合地基桩土应力比测试[J].土木工程学报,2002,35(2):48-51.MA Shi-dong.Test on pile-soil stress ratio of composite foundation with cement-soil pile[J].China Civil Engi-neering Journal,2002,35(2):48-51.
[12]段继伟,龚晓南.水泥搅拌桩的荷载传递规律[J].岩土工程学报,1994,16(4):1-7.DUAN Ji-wei,GONG Xiao-nan.Load transfer behavior of cement treated soil column[J].Chinese Journal of Geotechnical Engineering,1994,16(4):1-7.
[13]宋修广,王松根.水泥粉喷桩荷载传递规律的试验研究[J].岩土力学,1999,20(4):81-85.SONG Xiu-guang,WANG Song-gen.Field study of load transfer behavior of DJMP[J].Rock and Soil Mechan-ics,1999,20(4):81-85.
[2]段继伟.复合地基桩土应力比影响因素有限元分析[C]//沈珠江,等.第二届华东地区岩土力学学术讨论会论文集.杭州:浙江大学出版社,1992:43-47.
[3]秦建庆,叶观宝.水泥土桩复合地基桩土分担荷载的试验研究[J].工程勘察,2000(1):35-37.QIN Jian-qing,YE Guan-bao.Loading test of the stress ratio between pile and earth in composite ground[J].Geotechnical Investigation&Surveying,2000(1):35-37.
[4]朱中卫,方磊.粉喷桩复合地基桩土应力比试验研究[J].岩土工程技术,2004,18(3):113-115.ZHU Zhong-wei,FANG Lei.Experimental study on stress ratio between pile and soil of DJM pile composite foundation[J].Geotechnical Engineering Technique,2004,18(3):113-115.
[5]李扬,李自力,张艳.不同类型场地对隔震储罐地震响应的影响[J].中国石油大学学报:自然科学版,2008,32(5):108-113.LI Yang,LI Zi-li,ZHANG Yan.Influence of different types of sites on seismic response of base isolated liquid storage tank[J].Journal of China University of Petroleum(Edition of Natural Science),2008,32(5):108-113.
[6]程旭东,马红,刘永红.软土地区储罐群地基沉降的三维数值模拟[J].中国石油大学学报:自然科学版,2009,33(6):100-104.CHENG Xu-dong,MA Hong,LIU Yong-hong.Three-di-mensional numerical simulation of foundation settlement of storage tank group in soft soil area[J].Journal of China University of Petroleum(Edition of Natural Science),2009,33(6):100-104.
[7]颜庆智,付长波,饶江,等.东营软土工程特性及参数相关方程[J].中国石油大学学报:自然科学版,2010,34(3):130-133,139.YAN Qing-zhi,FU Chang-bo,RAO Jiang,et al.Engi-neering property of Dongying soft clay and correlation e-quation of parameters[J].Journal of China University of Petroleum(Edition of Natural Science),2010,34(3):130-133,139.
[8]中国建筑科学研究院.JGJ106-2003.建筑基桩检测技术规范[S].北京:中国建筑工业出版社,2003:7-9.
[9]中国建筑科学研究院.GB50007-2002.建筑地基基础设计规范[S].北京:中国建筑工业出版社,2002:100-102.
[10]中国建筑科学研究院.JGJ79-2002.建筑地基处理技术规范[S].北京:中国建筑工业出版社,2002:80-81.
[11]马时冬.水泥搅拌桩复合地基桩土应力比测试[J].土木工程学报,2002,35(2):48-51.MA Shi-dong.Test on pile-soil stress ratio of composite foundation with cement-soil pile[J].China Civil Engi-neering Journal,2002,35(2):48-51.
[12]段继伟,龚晓南.水泥搅拌桩的荷载传递规律[J].岩土工程学报,1994,16(4):1-7.DUAN Ji-wei,GONG Xiao-nan.Load transfer behavior of cement treated soil column[J].Chinese Journal of Geotechnical Engineering,1994,16(4):1-7.
[13]宋修广,王松根.水泥粉喷桩荷载传递规律的试验研究[J].岩土力学,1999,20(4):81-85.SONG Xiu-guang,WANG Song-gen.Field study of load transfer behavior of DJMP[J].Rock and Soil Mechan-ics,1999,20(4):81-85.
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