基桩反射波法三维干扰成因与最佳采样方法研究

发布时间：2018-07-10 03:58

本文选题：基桩 + 反射波法　；参考：《岩土工程学报》2017年09期

【摘要】：研究了基桩反射波法三维干扰信号的成因和消除三维干扰的最佳采样方法。通过模态叠加法,发现三维干扰主要来源于使桩顶表面产生非均匀轴向运动的轴对称径向振动模态,桩顶表面的模态位移零点即为三维干扰最小点。通过参数分析,提出了三维干扰最小点位置的函数表达式,从而修正了现有基桩检测规范推荐的采样位置。基于上述模态在桩顶面位移零点两侧位移反向的特点,提出了双速度平均法,该方法利用双通道仪的两个探头在干扰最小点两侧采样并平均以达到消除三维干扰的目的。与干扰最小点采样法相比,该方法测点选择范围更大,信号质量更优。工程实测数据和数值模拟结果证明了上述结论的正确性。
[Abstract]:The causes of 3D interference signal and the optimal sampling method for eliminating 3D interference are studied. Through the modal superposition method, it is found that the three-dimensional interference mainly comes from the axisymmetric radial vibration mode which causes the non-uniform axial motion on the top surface of the pile, and the zero point of the modal displacement of the top surface of the pile is the minimum three-dimensional interference point. Based on the parameter analysis, the function expression of the minimum position of 3D interference is proposed, and the sampling position recommended by the existing pile detection code is modified. Based on the reverse characteristics of the displacement of the above modes on the top surface of the pile, a two-velocity averaging method is proposed. The two probes of the dual-channel instrument are used to sample and average the two sides of the minimum interference point in order to eliminate the three-dimensional interference. Compared with the interference minimum sampling method, this method has a larger selection range and better signal quality. The engineering measured data and numerical simulation results prove the correctness of the above conclusions.
【作者单位】：汕头大学土木工程系;广东省高等学校结构与风洞重点实验室;
【分类号】：TU473.16

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