The Subway Vibration Under The Action Of The Dynamic Characteristics Of Saturated Sandy Pebble Soil Around The Tunnel Is Studied

Compared to other soils, saturated sandy pebble soil has its unique properties. It has a complicated engineering properties and is widely used in engineering field. At present, the researches from foreign and domestic scholars on saturated sandy pebble soil dynamic characteristics of the study are less. This paper summarizes the research develpoments of dynamic properties of coarse grained soil, vibration response of surrounding rock under subway loads. In numerical model of saturated sandy pebble soil for research object, using the finite element numerical software, the numerical model of dynamic triaxial test sample of saturated sandy pebble soil is established.The dynamic response of the numerical model under different consolidation pressures, different consolidation stress ratio, and different vibration frequencies is simulate. Following conclusions are obtained:Under dynamic loads, dynamic strain increases with dynamic stress, and the dynamic stress-strain curve increases with the consolidation stress towards stress axis; the dynamic stress-strain curve becomes steeper with consolidation stress ratio. Greater consolidation stress ratio towards stress axis; The larger the consolidation stress ratio, the larger the dynamic stress required; Vibration frequency has very little effects on dynamic stress-strain curve. Dynamic stress-strain curves at different vibration frequencies are dense in the same distribution belt, and have good agreement. The simulated results are compared and analyzed with dynamic triaxial test results by other scholars.The growth trends of the pore pressure with the number of vibrations under different consolidation pressures and the dynamic stresses are simulated. The pore pressure-vibration weeks curve is obtained. The pore pressure increases with the increase of the number of vibrations under dynamic loading; the larger dynamic stress, the faster the pore pressure increase, and the less vibration weeks is required. Dynamic pore pressure ratio at the end of the vibration is basically close to one. It explains that saturated sandy pebble soil can be liquefied normally. Finally, based on numerical results, the mathematical expression of pore pressure is provided.The subway loads are applied to numerical models as exciting force function. The the dynamic response of numerical model is simulated under the subway loading. The dynamic response of the subway model at different speeds is obtained.