(1. Key Laboratory of Disaster Prevention and Mitigation in Civil Engineering of Gansu Province,Lanzhou University of Technology,Lanzhou,Gansu 730050,China;2. Northwest Center for Disaster Mitigation in Civil Engineering of Ministry of Education,Lanzhou University of Technology,Lanzhou,Gansu 730050,China)
Abstract:Research on the performance of pile for the weak or non-collapsible Q2 Lishi loess layer is very scarce. In order to determine the pile Q2 Lishi loess layer thickness on the large pile in loess area,the single pile static load test was carried out. Concrete strain gauges and reinforcement stress meter are arranged on test piles,and soil pressure cells were installed on pile bottom to test internal forces on-site. Results show that:(1) Distribution of axial force of pile and lateral friction along the pile is not only related to pile top load,but also related to the nature of pile side soil. (2) When the ratio of pile top load and limit value of pile top load is less than 0.80(Pt/Pu<0.80),pile top settlement is mainly caused by the elastic compression of pile;when Pt/Pu≥0.80,endpoint soil subsidence Sb should be considered when calculating the pile settlement. (3) Standardized coefficient of the simplified method of synthetic factor value slants big,it is recommended to take = 0.44 in the region of the same type as the pile of calculation parameters. A new way was put forward by using amount of pile body compression to estimate the settlement of single pile in terms of simplified method and linear method.
《工程地质手册》编写委员会. 工程地质手册[M]. 北京:中国建筑工业出版社,2007:418-420.(The Compilation Committee of Engineering Geology Handbook. Engineering geology handbook[M]. Beijing:China Architecture and Building Press,2007:418-420.(in Chinese))
[2]
华遵孟,张森安,张恩祥,等. 陇东黄土塬场地高层建筑地基基础设计方案分析[J]. 工程勘察,2010,(增1):267-277.(HUA Zunmeng,ZHANG Sen¢an,ZHANG Enxiang,et al. Ground Foundation design of high-rise building in Longdong loess plateau project analysis[J]. GeotechnicalInvestigationand Surveying,2010,(Supp.1):267-277.(in Chinese))
[3]
中华人民共和国行业标准编写组. TB10018—2003铁路工程地质原位测试规程[S]. 北京:中国铁道出版社,2003.(The Professional Standards Compilation Group of People¢s Republic of China. TB10018—2003Code for in-situ measurement of railway engineeringgeology[S]. Beijing:China Railway Publishing House,2003.(in Chinese))
[4]
中华人民共和国行业标准编写组. JGJ 94—2008建筑桩基技术规范[S]. 北京:中国建筑工业出版社,2008.(The Professional Standards Compilation Group of People¢s Republic of China. JGJ 94—2008 Technical code for building pile foundations[S]. Beijing:China Architecture and Building Press,2008.(in Chinese))
[5]
朱彦鹏,赵天时,陈长流. 桩基负摩阻力沿桩长变化的实验研究[J]. 岩土力学,2013,34(增1):265-272.(ZHU Yanpeng,ZHAO Tianshi,CHEN Changliu.Field tests on changes of pile negative friction along its length[J]. Rock and Soil Mechanics,2013,34(Supp.1):265-272.(in Chinese))
[6]
黄雪峰,陈正汉,哈 双,等. 大厚度自重湿陷性黄土中灌注承载性状与负摩阻力的试验研究[J]. 岩土工程学报,2007,29(3):338-346.(HUANG Xuefeng,CHEN Zhenghan,HA Shuang,et al. Research on bearing behaviors and negative friction force for filling piles in the site of collapsible loess with big thickness[J]. Chinese Journal of Geotechnical Engineering,2007,29(3):338-346.(in Chinese))
[7]
杨校辉,黄雪峰,朱彦鹏,等. 大厚度自重湿陷性黄土地基处理深度和湿陷性评价试验研究[J]. 岩石力学与工程学报,2014,33(5):1 063-1 074.(YANG Xiaohui,HUANG Xuefeng,ZHU Yanpeng,et al. Experimental study on site soaking and foundation treatment deepness of self-weight collapse with heavy section[J]. Chinese Journal of Rock Mechanics andEngineering,2014,33(5):1 063-1 074.(in Chinese))
[8]
中华人民共和国国家标准编写组. GB 50007—2011建筑地基基础设计规范[S]. 北京:中国建筑工业出版社,2011.(The National Standards Compilation Group of People¢s Republic of China. GB 50007—2011 Code for design of building foundation[S]. Beijing:China Architecture and Building Press,2011.(in Chinese))
[9]
MATTES N S,POULOS H G. Settlement of single compressible pile[J]. Journal of Soil Mechanics and Foundation Division,1969,95(SM1):189-207.
[10]
张 雁,刘金波. 桩基手册[M].北京:中国建筑工业出版社,2009:54-59.(ZHANG Yan,LIU Jinbo. Handbook for pile foundation[M]. Beijing:China Architecture and Building Press,2009:54-59.(in Chinese))
[11]
林天健,熊厚金,王利群. 桩基础设计指南[M]. 北京:中国建筑工业出版社,1999:410-418.(LIN Tianjian,XIONG Houjin,WANG Liqun. Pile foundation design manual[M].Beijing:China Architecture and Building Press,1999:410-418.(in Chinese))
[12]
李大展,何颐华,隋国秀.Q2黄土大面积浸水试验研究[J]. 岩土工程学报,1993,15(2):1-11.(LI Dazhan,HE Yihua,SUIGuoxiu.Study andtest on immersion of Q2Loess in large area[J]. Chinese Jounal of Geotechnical Engineering,1993,15(2):1-11.(in Chinese))
[13]
方祥位,申春妮,李春海,等. 陕西蒲城Q2黄土湿陷变形特性研究[J]. 岩土力学,2013,34(增2):115-120.(FANG Xiangwei,SHEN Chunni,LI Chunhai,et al. Collapsible deformation properties of Q2loess in Pucheng of Shaanxi province[J]. Rock and Soil Mechanics,2013,34(Supp.2):115-120.(in Chinese))
[14]
《桩基工程手册》编写委员会.桩基工程手册[M]. 北京:中国建筑工业出版社,1995:157-164.(Editorial Committee of Pile Foundation Engineering Manual.Pile foundationengineering manual[M]. Beijing:China Architecture and Building Press,1995:157-164.(in Chinese))
[15]
杨龙才,周顺华,高强. 基于单桩轴力实测的桩身压缩变形计算与分析[J]. 工程勘察,2004,(4):42-46.(YANG Longcai,ZHOU Shunhua,GAO Qiang. Calculation and analysis of pile shaft compression of single bored pile based on testing date of shaft force[J].Geotechnical Investigation and Surveying,2004,(4):42-46.(in Chinese))
[16]
中华人民共和国国家标准编写组. GB 50010—2010混凝土结构设计规范[S].北京:中国建筑工业出版社,2010.(The National Standards Compilation Group of People¢s Republic of China. GB 50010—2010 Code for design of concrete structures[S]. Beijing:China Architecture and Building Press,2010.(in Chinese))