Static And Dynamic Study On Different Cross-sectional Tunnels

With the development of the economy,high-speed railway,subway,urbanunderground space development is in full swing in the land of China and tunnels areimportant structural forms among these projects. Therefore the static-dynamic study ondifferent cross-sectional tunnels has great practical significance.In my paper circulartunnel,square tunnel,straight wall arch tunnel,horseshoe-shaped tunnel are selected to beanalysised. The main work is as follows:1.To vertify the error of FLAC2D and SAP84in static calculationRespectively simulate a tunnel problem with static analystic solution by FLAC2D andSAP84and compare their solution with the analystic solution,then we will know thecalculation error of FLAC2D and SAP84.Finally FLAC2D is decided to be used for thefollowing static and dynamic calculations.2.The analysis of static characteristicThe static calculation of the four kind of tunnels in one plastic surrounding rock arecalculated by FLAC2D,during the calculation six working condition of different burieddepth are considered.The results are used to analysis the variation with buried depth ofdifferent tunnels and the drawing of the internal foce diagram.After that,Five kind ofelastic constitutive working conditions are also calculated and the variation with burieddepth and shear wave velocity is discussed,after which the magnitude relationshipbetween the four cross-sectional tunnels.3. The analysis of dynamic characteristicFour kind of sesmic wave is input to FLAC2D to calculate the tunnel problemsamong which five different elastic surrounding rock and six different buried depth isconsidered. Afer the calculation,the results is used to analysis the impact of the spectralcharacteristics of different sesmic waves,buried depth,surrounding rock shear wavevelocity on different kind of tunnels.In order to analysis the results scientifically,inaddition to the dynamic maximum internal force,one property is defined,namelyRelative increment，then deeply analysis is undergone. At last,some useful conclusionsare obtained.