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一、序言河南登封铁路施工环境处于山区,受地质条件限制,铁路桥梁需施工桩基满足上部荷载要求。桩基的质量直接关系到铁路的运行安全。根据以往经验,需在基桩的施工过程中预先埋管做超声波检测或基桩施工完后取芯检验桩身混凝土的质量。使用上述方法,前期投入和检测费用均较大,且周期较长。由于基桩的直径远小于基桩的长度,因此,可以把基桩看做是一维杆件,同时由于弹性波(纵波)在混凝土中的传播速度远大大于波在桩周土的传播速度。因此,可以把弹性波
I. Preface The construction environment of Dengfeng Railway in Henan is in the mountainous area. Due to the geological conditions, the pile foundation for railway bridges needs to meet the requirements of the upper load. The quality of pile foundation is directly related to the safety of railway operation. According to past experience, the need to pre-buried tube in the process of construction of the pile to do ultrasonic testing or foundation pile construction after the core to check the quality of pile concrete. Using the above method, pre-investment and testing costs are large, and the cycle is longer. Because the diameter of the pile is much smaller than the length of the pile, the pile can be regarded as a one-dimensional bar. At the same time, the propagation velocity of elastic wave (P-wave) in concrete is far greater than the wave propagation speed in the soil surrounding the pile. Therefore, you can put the elastic wave