高层建筑基础桩的工程地球物理检测试验研究

Research on engineering geophysical testing of foundation pile of high rise building

对昆明某高层建筑直径1 m的混凝土灌注桩试桩进行了桩基缺陷检测试验研究,得到了3个超声波透射探测剖面的波速-深度曲线图和透射波波列曲线图,其中每个超声波探测剖面的波列图由73条透射波曲线组成.对每个剖面的透射波波列曲线和波速-深度曲线的对比分析和研究表明,所测基桩的桩身存在3处缺陷,其位置分别为距桩顶12.10~12.85 m处、14.10~15.85 m处和17.35~18.10 m处.通过钻孔取样,不但验证了上述缺陷位置的检测结果完全符合实际情况,而且确定了所测基桩上述3处缺陷的性质:缺陷(1)为局部混凝土离析,程度较轻微.缺陷(2)为严重夹沙离析和夹泥,属于层状缺陷或断桩,程度最严重.缺陷(3)为较严重的离析夹砂,属于中等程度缺陷.

The test studies of defect detection on a concrete perfusion pile foundation with 1 m diameter of a high-rise building in Kunming were carried out.The velocity-depth curves and transmission wave train curves of three ultrasonic sounding profiles were obtained.Each ultrasonic sounding profile was composed of 73 transmission wave train curves.The comparison and analysis of the above curves showed that there are three defects in the tested pile body.Their locations of the three defects were 12.10 to 12.85 m 14.10 to 15.85 m and 17.35 to 18.10 m from the top of the pile.Through the drilling sampling,not only the test results of the above-mentioned defect positions were verified being completely in line with the actual situation but also the properties of the above three defects were determined.The defect(1) was local concrete segregation with slight degree.The defect(2) was serious sand inclusion and mud inclusion which belongs to layered defect or broken pile with worst degree.The defect(3)was serious segregation and sand inclusion belonging to medium defect.