Numercial Simulation For The Stability Of The Tunnel In Half-hard And Half-soft Rock

With the development of our national economy, many major cities are being constructor about to construct Subway. Because by the subway tunnel construction projectmanagement environment and the uniqueness or various uncertainties. But the tunnelexcavation often will meet half hard half a soft layer, this paper in half hard soft layer is topoint to in half tunnel excavation cross-sectional half for weathered rock, where structure iscomplete, the rock strength is greater; The other is disabled soilwith brokenandintensity.When the tunnel through half rock mass under the condition of half the land,dig surrounding rock stress and deformation will be changed. But the stability ofsurrounding rock and analysis the causes of the deformation, analysis of the tunnel, changeof stress and ground surface settlement, in order to provide theoretical guidance forengineering construction has become the task of top priority role.Based on the tunnelengineering of subway2line in ChangSha,we can use numerical simulation analysis methodto get surrounding rock stress change rule,deformation and the change of the excess porewater pressure.The useful conclusions for actual works have been gained, which can guidethe design and optimize construction, and offer reference for the future similar projects., themain completed the following work：(1) The subject of this thesis is the verification of a three-dimensional numericalmodelling approach for the prediction of stabilityof the surround rock due to tunnelling inthe half-hard and half-soft rock.Based on the tunnel engineering of subway2line inChangSha which is the tunnel of construction work, using the finite element softwareADINA for non-linear finite element analysis.By analyzing the distribution characteristicsand some effect factors of the soil-rock and a half tunnel structure’s displacement andstress,the useful conclusions for actual works have been gained, which can guide the designand optimize construction, and offer reference for the future similar projects.(2) The monitoring data and numerical simulation results were compared，resultsshowed that：there is some error between the simulation result and the monitoring results,butmonitoring data and the numerical simulation results are consistent with the change rule inthe tunnel of half rock and half soil surrounding rock.In a way, the results of numericalsimulation can guide the design and construction.