树根桩的反射波法低应变测试

从树根桩特性入手，分析了树根桩反射法低应变测试过程中存在波速难确定、龄期短强度低、土层变化等因素对测试的影响，以及直径小敲击点控制难等方面的难点，结合自己的经验，提出了根据地区特点综合确定波速、提高敲击力度解决砂浆强度低的问题、根据地质勘测报告。结合反射波理论综合分析，采取在桩头处理时增大敲击面积解决敲击点难控制等方法，从而顺利地进行树根桩低应变测试，并得出较精确的结果。综合工程图形实例，对以上问题进行比较，验证各种方法的可行性及准确性。

A Brief Talk on Back Wave Low Strain Testing Root Pile

Focusing on the characteristics of root pile, this essay gives analyses to difficulties existing in root pile reflecting low strains testing, such as uncertainty of wave speed, short age weak strength, influence of different soillayers, elusive knocking piont because of small diameter, and etc. Based on the practice of the author, this essay put forth ways to measure wave speed comprehensively with consideration of locality, to enhance knocking force and mortar intensity, to comprehensively reckon the influence of soillayer on tesring results on the basis of geologic prospecting reports in the lights of back wave theory, and to facilitate knocking point control by improvement on stake but that enlarges knocking area. With the help of these methods, root pile low strain testing can be carried out.