| 山地和岩溶地区端承桩质量检测与加固技术研究 |
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| 引用本文： | 胡新发,柳建新.山地和岩溶地区端承桩质量检测与加固技术研究[J].岩土力学,2011,32(Z2):686-692. |
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| 作者姓名： | 胡新发 柳建新 |
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| 作者单位： | 中南大学 地球科学与信息物理工程学院，长沙 410083 |
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| 基金项目： | 国家科技支撑计划项目(No.2011BAB04B08); 有色资源与地质灾害湖南省重点实验室和矿产资源与灾害探查湖南省高校科技创新团队项目(No.[2008]244) |
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| 摘 要： | 针对嵌岩桩桩底存在沉渣时，采用常规的低应变反射波法可能观测不到其同相反射信号，桩底软弱夹层（或溶洞）的顶面倾角接近或不小于45º时，反射法检测不到桩底软弱夹层（或溶洞）的反射信号。为弥补以上不足，提出了用低应变反射波法、频率-初速度法和钻芯法对端承桩质量及缺陷桩的加固效果进行组合检测。当反射波波形曲线异常或动刚度明显偏低时，可认为桩底沉渣较厚或桩端持力层性状异常，再用钻芯法验证；建立了桩身下部缺陷段的平均波速计算公式，有助于判断缺陷的严重程度；通过对比缺陷桩加固前后的反射波曲线和动刚度值，并将它们与其他同条件下正常桩对比，检验缺陷桩的加固效果
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| 关 键 词： | 桩基础 端承桩 基桩检测 沉渣 加固 岩溶 |
| 收稿时间： | 2011-05-23 |
Study of testing of end-bearing piles and reinforcement technology in mountain and karst area |
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| HU Xin-fa,LIU Jian-xin.Study of testing of end-bearing piles and reinforcement technology in mountain and karst area[J].Rock and Soil Mechanics,2011,32(Z2):686-692. |
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| Authors: | HU Xin-fa LIU Jian-xin |
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| Institution: | School of Geosciences and Info-Physics, Central South University, Changsha 410083, China |
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| Abstract: | The reflected signal caused by bottom sediment beneath a socketed pile may not be observed with the conventional low-strain reflected wave method, and the reflected signal caused by soft interlayer (or cave) would be undetected if its dip angle of the top surface close to 45º or not less than 45o. In order to make up these insufficiencies, the combination of low-strain reflected wave method, frequency-initial velocity method and core drilling method should be used to do the end-bearing piles and reinforcement effect testing so that they can verify mutually and the reliability of the testing can be enhanced. The abnormalities of the reflected curve of pile bottom or of obvious low dynamic stiffness would be considered too thick bottom sediment or abnormal characters of pile bearing stratum; and then it would be validated with core drilling method. Besides, a formula for the average velocity of defects in the lower section of the pile is set up; and the severity of the defect can be estimated according to the velocity. Through deeply investigating the reflected curves and the dynamic stiffness before and after reinforcement and comparing with those of the perfect piles under the same conditions, the reinforcement effect can be inspected. |
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| Keywords: | pile foundation end-bearing piles pile testing bottom sediment reinforcement karst |
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