Research On Micro-tremor Characteristics Of Loess Slope In Baoji

Since earthquake happens suddenly, it is extremely easy to make a destructive impact on human activities. Particularly, the secondary disasters caused by earthquake sometimes make a more destructive impact than the earthquake itself can cause. The loess slopes tend to fail easily because of their own characteristics. The occurrence of destructive earthquake will certainly cause huge losses of lives and properties as well as social economic development.The loess areas where the city of Baoji locates belong to the seismic landslide hazard prone areas, so a reasonable evaluation must be made on the seismic slope stability of the Baoji area. This paper takes the Panlongyuan loess slope in Baoji as the object of analysis and researches the influence law of the free vibration characteristic of the loess slope. Focusing the researching object of this paper, the following work has been mainly developed:1. the site micro-tremor measurement of the Panlongyuan loess slope;2. Building up initial numerical model of the slope based on reconnaisance data;3. Numerical simulation of micro-vibration of the Panlongyuan loess slope, analysis of vibration mode to the dynamic response of the loess slope;The site micro-tremor measurement is an important mean to study the dynamic characteristic of the loess slope, which can provide restriction to the dynamic characteristic analysis of the slope. The predominant mode of vibration of this slope is achieved during the micro-vibration numerical simulation. The mode of vibration basically agrees with the site micro-tremor measurement. The free vibration frequency of the Panlongyuan loess slope is about2.5Hz. By simulating the conditions of the Panlongyuan loess slope under inciting forces of different directions, different frequencies and different durations, the magnitude distribution of dynamic stress in different parts of rock and soil mass of the slope has been achieved. The reliable numerical model basis is provided for the following modeling of the destruction of the slope, and the controlling factors of the slope stability have been preliminary explored.The results of the site micro-tremor measurement combined with FLAC3D numerical simulation can be viewed as references for the slope stability study of the loess slope in Baoji. At the same time, FLAC3D numerical simulation method can be proved to be a useful tool in the field of geotechnical engineering.