基于块体基础自由振动计算地基阻尼比的新方法

提出了一种基于能量守恒原理计算地基土阻尼比的新方法。不同于对数衰减法仅依据振幅计算阻尼比，该方法考虑了体系振动的整个反应时程，克服了对数衰减法对幅值测量精度要求很高的缺陷。数值仿真和实测结果表明：与对数衰减法相比，该方法计算精度较高，抗干扰能力强，稳定性好，即便对于信号干扰比较大的情况，采用该方法也能得到较好的结果。

A new method of subsoil damping ratio identification based on free vibration of a massive concrete foundation

A new method of subsoil damping ratio identification based on law of conservation of energy is proposed. This method considers the whole time histories of vibration, differs from the traditional damping ratio identification method in the time domain which uses merely the amplitude to calculate damping ratio, and overcomes the defect of the traditional logarithmic decrement method for high accuracy requirement of amplitudes. The subsoil damping ratio of a massive concrete foundation is tested and calculated. The results of numerical simulation and actual test show that this method is of higher precision, stronger anti-noise ability and better stability compared with the traditional logarithmic decrement method. Even if the data acquisition is disturbed seriously by noise, the method proposed is effective and reliable.