摘要
为研究静压桩在贯入过程中受力特性及后期的残余应力分布特征,通过刻槽法在模型桩身安装光纤光栅(fiber Bragg grating,简称FBG)传感器,及安装于桩端的微型硅压阻式土压力传感器,测得了桩端阻力和桩侧摩阻力等随贯入深度的变化规律,通过试验明确了均质黏性土中静压桩的贯入特性。试验结果表明:光纤光栅传感技术能够较好的满足黏性土中静压沉桩特性的测试需求,成功测得沉桩阻力的分布及变化规律;在均质黏性土中沉桩时,桩侧阻力与桩端阻力的所占比例是变化的。在沉桩初期,桩侧阻力所占比例较小,而在沉桩中后期,侧摩阻力所占比例不断增大,但桩端阻力所占比例仍高于桩侧阻力所占比例;桩侧摩阻力存在退化现象,且退化程度和退化速率随贯入深度的增加逐渐减小;桩身施工残余应力随深度的增加先增大后减小,其中性点约在距桩顶9D处,而桩侧残余摩阻力随深度的增加呈先增大后减小的趋势,由负摩阻力逐步转变为正摩阻力。研究结果可为黏性土地基静压桩的工程实践提供借鉴与参考。
For the study of static pressure pile mechanical characteristics in the process of penetration and the residual stress distribution characteristics of late,by grooving method in the model pile installation of fiber Bragg grating(fiber Bragg grating,FBG)sensor,and installed on the pile end of micro silicon piezoresistive type soil pressure sensors,have pile end and pile side friction resistance changing with the depth of penetration,through the test has been clear about the homogeneous characteristic of static pressure pile penetration in clayey soil.The experimental results show that the fiber Bragg grating sensing technology can better meet the test requirements of static pressure pile sinking characteristics in viscous soil,and the distribution and change rule of pile driving resistance can be measured successfully.When sinking a pile in homogeneous clay,the proportion of lateral resistance and tip resistance is variable.In the early stage of pile sinking,the proportion of lateral resistance is small,while in the middle and late stage of pile sinking,the proportion of lateral friction is increasing,but the proportion of pile tip resistance is still higher than that of lateral resistance.There exists degradation phenomenon of pile lateral friction,and the degradation degree and degradation rate decrease with the increase of penetration depth.The residual stress of pile construction first increases and then decreases with the increase of depth,and its neutral point is about 9 D away from the pile top,while the residual friction resistance of pile side increases first and then decreases with the increase of depth,and gradually changes from negative friction resistance to positive friction resistance.The results can be used for reference in the engineering practice of static pressure pile on clay foundation.
作者
刘士伟
刘雪颖
王永洪
任亮
王彬
LIU Shi-wei;LIU Xue-ying;WANG Yong-hong;REN Liang;WANG Bin(Qingdao Construction Engineering Quality Inspection Center Co.,Ltd.,Qingdao 266033,China;Cooperative Innovation Center of Engineering Construction and Safety in Shandong Blue Economic Zone,Qingdao 266033,China;School of Civil Engineering,Qingdao University of Technology,Qingdao 266033,China;Dalian University of Technology,Liaoning Province,Dalian 116024;lang Shi Jianhua Building Materials(Shandong)Co.,Ltd.,Zibo 256401,China)
出处
《光电子．激光》
EI
CAS
CSCD
北大核心
2020年第8期806-813,共8页
Journal of Optoelectronics·Laser
基金
国家自然科学基金(51708316,51778312)
山东省重点研发计划项目(2017GF16107)
山东省自然科学青年基金项目(ZR2016EEQ08)
山东省高等学校科技计划项目(J16LG02)
青岛市应用基础研究计划项目(16-5-1-39-jch)资助项目。
关键词
静压桩
桩身轴力
桩端阻力
桩侧摩阻力
残余应力
static pressure pile
pile axial force
pile end resistance
pile side friction
residual stress
