Study on simple estimate method of soil parameters and applicability of simplified equation of attenuation with distance in prediction of ground vibration

点击翻译按钮获取中文摘要

This research is performed on the following five items ; 1)the manufacture of simple exciting equipment, 2)the establishment of estimate system, 3)the improvement of estimate system, 4)the applicability of simplified equation of attenuation with distance, 5)the measurement of predominant frequency.In the item 1, the exciting equipment with the total mass of about 30 kg is manufactured by combining a falling weight and a spring. It is examined through the field measurement that the equipment generates exciting force about equal to expected force.In the item 2, a neural network system is built to estimate soil parameters in which the ground is modeled as a visco-elastic half-space and the waveform of exciting force obtained in the item I is used. It is confirmed that this estimate system is possibly applied to practical use.In the item 3, the improvement of neural network is treated.. It is examined whether the estimate system is improved by using horizontal displacements instead of time lags. From results for several soil profiles, it is found that it doesn't lead to improvement of the system to exclude the time lags from input parameters.In the item 4, it is examined to relate coefficients in Bronitz equation to soil parameters estimated in the item 3. It is found that Bornitz equation with the coefficients obtained from estimated soil parameters may be applicable to prediction of the attenuation with distance of ground vibration.In the item 5, it is performed to find out whether it is possible to pick out predominant frequency at a site from ground vibrations measured in the daytime and to use the predominant, frequency for the prediction of ground vibration from the viewpoint of simple prediction method.