摘要
依托中兰铁路接入中川城际铁路工点,既有路基帮宽段地基采用高压旋喷桩处理,为得出高压旋喷桩复合地基承载力,采用钻芯取样、单桩复合地基静荷载试验及理论分析进行研究.结果表明:高压旋喷桩桩身完整、均匀,桩长、桩径均满足设计要求,无侧限抗压强度均大于设计要求的3 MPa;桩顶应力和桩间土应力随荷载的增大而增大,桩土应力比在荷载为50~200 kPa时增长较快,250~310 kPa荷载作用下增长变缓,加载至310 kPa时桩土应力比为25.42~27.93;桩的最终沉降量为21.94~24.88 mm,按相对变形值确定的单桩复合地基承载力特征值为170.3~192.0 kPa,理论计算值为260.2 kPa;该复合地基成桩质量及承载力满足工程设计要求.
In this paper,based on the Zhong-Lan railway connecting Zhong-Chuan intercity railway,the foundation of the existing subgrade with wide section of high pressure jet grouting pile is treated.In order to obtain the bearing capacity of the composite foundation of high pressure jet grouting pile,core sampling,single pile composite foundation static load test and theoretical analysis are used to study.The results show that the pile body is complete and uniform,the pile length and diameter meet the design requirements,and the unconfined compressive strength is 3MPa greater than the design requirements.The pile top stress and the soil stress between piles increase with the increase of load.The pile-soil stress ratio increases rapidly when the load is 50~200 kPa,and increases slowly when the load is 250~310 kPa.The pile-soil stress ratio is 25.42~27.93 when the load is 310 kPa.The final settlement of the pile is 21.94~24.88mm.The characteristic value of the bearing capacity of the single pile composite foundation determined by the relative deformation value is 170.3~192.0 kPa,and the theoretical value is 260.2kPa.The pile quality and bearing capacity of the composite foundation meet the requirements of engineering design.
作者
石旭东
张太雄
刘斌
王定顺
SHI Xu-dong;ZHANG Tai-xiong;LIU Bin;WANG Ding-shun(School of Civil Engineering,LanzhouJiaotong University,Lanzhou 730070,China)
出处
《兰州工业学院学报》
2021年第6期13-17,共5页
Journal of Lanzhou Institute of Technology
关键词
高压旋喷桩
复合地基
承载力
现场试验
桩土应力比
high pressure rotary-jet pile
composite foundation
bearing capacity
field test
pile-soil stress ratio
