基于地基动力测试中电磁激振器的改进应用研究

摘要

基于对传统地基强迫振动激振法测试中激振器所产生的激振扰力不足的问题,提出采用并联双发倍增扰力电磁激振器激振来增强激振扰力的方法.为此,首先通过分析普通机械式激振器的不足之处,提出并联双发倍增扰力电磁激振器的设计和改进方法,然后结合实际工程项目测试数据对比两者之间激励效果的差别,找出不同频点驱动电流与幅频响应之间的函数关系,最后通过不同类型地基实际测试计算结果表明,采用并联双发倍增扰力电磁激振器不但可以满足天然地基土较低频的幅频曲线特性要求也可满足岩质类地基和基桩块体基础较高频的幅频曲线特性要求,其测试得到的频响曲线在较宽阈值范围内都有真实的幅频响应,同时也完善了普通机械式激振器扰力及频带宽度上限低不适于岩质类地基和基桩块体基础振动测试的问题,说明并联双发倍增扰力电磁激振器可以用于常扰力地基土强迫振动测试,进一步也验证并联双发倍增扰力电磁激振器产生的扰力用于基桩块体基础的强迫振动测试也是可行的.%Based on the problem of insufficient excitation force caused by the excitation of the exciter in the forced vibra tion excitation test of the traditional ground,a method is proposed to increase the exciting disturbing force by using the parallel double multiplying force electromagnetic excited vibration.To this end,we first analyzed the shortcomings of the common mechanical vibration exciter,puts forward the design and improvement methods of parallel double double force electromagnetic vibration exciter,and then combined with the incentive effect of the difference between the actual project test data comparison,find out the different frequency of driving function between the current and the amplitude frequency response,finally through different types of foundation the actual test results show that the parallel double double force electromagnetic vibrator can not only satisfy the curve of amplitude and frequency characteristics of natural foundation soil with low frequency requirements can meet the requirements of the rock foundation and pile foundation block based high frequency amplitude frequency characteristic curve,the test of frequency response curve the true frequency response in a wide range of threshold,but also improve the mechanical vibration force and low bandwidth limit is not suitable for rock foundation and the pile body block vibration test based problem that parallel double double force electromagnetic vibrator can be used force of foundation soil forced vibration test,further verify the forced vibration tests parallel double double force generated electromagnetic vibration exciter for double force pile block foundation is feasible.