基桩综合检测技术在中风化泥岩中的应用

Application of Comprehensive Testing Technique of Foundation Pile in Medium-Weathered Mudstone

高应变法具有适用性强、效率高、成本低等优点,常应用于摩擦型基桩检测,但该法在软岩地基检测中可参考的经验较少,研究资料相对缺乏,且受锤重、落距、贯入度等因素影响,CASE法阻尼系数jc参数选取具有较大主观性。论文基于CASE理论计算方法,提出中风化泥岩地基中的高应变检测贯入度及j_(c)值建议选取范围。以依托工程AZ18#、AZ35#、AZ57#桩基高应变、静载试验数据对比分析,动静误差分别为3.06%、15.74%、5.16%。结合高应变波形曲线图分析AZ35#桩侧阻与端阻,认为该桩身完整性类别为Ⅱ类桩,桩底反应明显,动静载误差虽>15%,尚属于试验可控的允许误差。

High strain variation method has the advantages of strong applicability,high efficiency and low cost,and is often applied to the foundation pile detection of friction pile.However,this method has little reference experience in the detection of soft rock foundation,and research data is relatively lacking.Influenced by factors such as hammer weight,fall distance and penetration degree,Dampling coefficient of CASE method j_(c) parameter selection is relatively subjective.Based on the calculation method of CASE theory,the recommended selection range of high strain detection penetration degree and jc value in moderately weathered mudstone foundation is proposed.Based on the comparative analysis of high strain and static load test data of AZ18#,AZ35#and AZ72#,the static and static errors are 3.06%,15.74%and 5.16%,respectively.Based on the analysis of the side resistance and end resistance of AZ35#pile based on the high-strain waveform diagram,it is considered that the pile belongs to classⅡpile,the pile bottom response is obvious,and the static and dynamic load error is greater than 15%,which is the allowable error of the controllable test.