The Research Of Earth Pressure Calculation Theory And Reinforcement Load Reduction Of Open-cut Tunnel For High Fill Soil

30years of reform and opening up，China’s city development has gained thesuccess that attract worldwide attention，but the city process has been speeded up lotsof people flocked to the city，brought hitherto unknown challenge to the city landresources and the traffic in this city。policymakers have to take fill gap creates ideas，so high fill of open-cut tunnel appears will be not at all surprising。The problem is thatthese high fill deep tunnels due to lack of reasonable earth pressure calculationtheory，often appear disease of cracking after design and completion of construction，increasing maintenance and repair costs。 Based on this situation, through thecollection and access to a large number of deep buried tunnel earth pressure theoryand load reduction theory literature，comparative analysis indicates these theories thatrelates to calculation and reduction of open-cut tunnel in high fill soil pressure arecommon defects；not suitable for this task which is of high fill of open-cut tunnelearth pressure calculation theory and reinforcement load reduction。In this paper,aiming at the problem，calculation method of earth pressure and.the design theory ofreinforcement load reduction by using numerical simulation and theoretical derivationare obtained. The main research work and achievements are as follows：(1) First，by numerical simulation method，considering soil characteristics，boundary conditions，soil characteristics and section forms on effect of changeregulation of the vertical earth pressure of open-cut tunnel under high fill beforereinforced；then，analysising factors such as reinforcement method，boundaryconditions and soil bulk density on influence of displaying degree of the effect ofreinforcement load reduction after reinforced。(2) Proposing the calculation expression of the vertical earth pressure onopen-cut tunnel which considered the soil arching effect under the high fill，so that itis convenient for the engineering and technical personnel to master it。(3) On the premise of "artificial reinforcement bridge" as the unloadingstructure，respectively，using Geogrid as the study of "flexibility method" and fill asthe main force of object "limit equilibrium method" two methods，deducing the earthpressure calculation expression that is beared by "artificial reinforcement bridge"。(4) As the basis of the soil pressure calculation expression according to "thelimit equilibrium method" which is beared by "artificial reinforcement bridge"，proposing "artificial reinforcement bridge" design theory of load structure system，including①geogrid set height，②arrangement of reinforcement layers，③the length of reinforcement material along the width direction of the cavern，④loadshedding hole size determination in four aspects。(5) In order to prove the design theory in "artificial reinforcement bridge" as theload reduction structure system reliability，in this paper，according to LanzhouJiuzhou Development Zone Luo guo gou open-cut tunnel reducing load as anengineering example，and in-depth analysis of the original load structure system，finally,designing"artificial reinforcement bridge"load structure system that can meetthe requirements of the engineering load reduction but also to maximize to save theengineering investment。...