天然地基强迫振动测试与分析

DYNAMIC TESTING AND ANALYSIS OF SUBSOIL

在试验块体分别为明置与埋置情形时,利用激振器对某工程场地天然地基分别进行竖向、水平回转及扭转稳态强迫振动试验。试验结果表明,埋置情形试验的动力特性参数值均大于明置情形试验相应值;同种试验情形下,地基第一振型共振频率竖向最大,水平回转向其次,扭转向最小;土的参振质量均远大于基础本身质量。

On the texts of the vertical,horizontal rotary and torsional harmonic forced vibration by exciter,dynamic property of subsoil for petrochemical engineering project are measured under open and embedded conditions of concrete testing block.On the basis of testing data,the dynamic parameters of subsoil such as dynamic stiffness,dynamic stiffness coefficient,damping ratio of 1st vibration mode and mass of vibration soil are calculated.The experimental results show that the dynamic parameters under embedded condition are bigger than those under open condition.For resonance frequency of 1st vibration mode,the vertical is biggest,horizontal rotary is bigger and the torsional is smallest.It shouldn’t be ignored that the mass of vibration soil is more than total mass of testing concrete block and exciter.In the course of forced vibration,the vibration frequency of concrete testing block is not consistent with the running frequency of exciter.