The Study On The Disturbed Liquefaction Law Of Saturated Weakly Cemented Fine Sand

Based Taking the Lanmao Railway Humaling Tunnel as the engineering background,the Upper Tertiary weakly cemented saturated fine sandstone is poor in lithology,weak in clay and weak in structure,and it is easy to cause structural damage due to water infiltration or prolonged exposure.In the process of tunnel construction,under the continuous disturbance of artificial dynamic loads such as mechanical equipment vibration and construction personnel disturbance,the surrounding rock disturbance liquefaction specific situation and treatment measures.Using the analogy analysis method,the generation mechanism,basic characteristics(waveform,frequency,amplitude,etc.)and propagation laws(wave velocity,attenuation characteristics,etc.)of the disturbance wave are analyzed by comparing with the seismic wave,and the appropriate disturbance wave is selected as the disturbance of this paper.Load.Based on the principle of energy transfer theorem and effective stress,using the theory of saturated soil mechanics and dynamics,taking the 3# inclined well of Humaling Tunnel as an example,the concept of disturbance liquefaction,liquefaction mechanism and cause,main factors affecting liquefaction,disturbance liquefaction site The method of liquefaction and liquefaction hazard is determined by systematic research.Using the FLAC3 D three-dimensional finite element software with advanced tunnel engineering direction,the Finn liquefaction model is used to simulate the liquefaction process of surrounding rock under disturbance during tunnel excavation,in static excavation(gravity field)and groundwater seepage(seepage field).Under the three field forces of dynamic action(dynamic field),the liquefaction of the bottom of the tunnel and the liquefaction of the tunnel was first studied,and then the liquefaction condition after the precipitation measures and the pre-disturbed grouting reinforcement technology of the pre-vibration cannula was studied.The table is compared with the pore water pressure,effective stress and liquefaction depth of the three working conditions.Finally,the specific data is used to analyze the principle of precipitation and the pre-disturbing grouting resistance to disturbance liquefaction.Combined with the specific construction situation of Humaling Tunnel,the comprehensive treatment technology of disturbance liquefaction is summarized,and the construction points of different treatment measures are sorted out,which provides reference for the industry to understand and deal with disturbance liquefaction.