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

In recent years, Tunnel Engineering has been more and more valued in themountainous area and hilly area of highway, railway construction. Due to an increase inTunnel Engineering and the increasingly complex of the topography and geologicalconditions, thus the requirements of the design and construction are very strict. Thesefactors lead to a higher demand for the construction of the tunnel engineering. The tunnelexcavation often will meet half hard half a soft layer, this paper in half hard soft layer is toin half tunnel excavation cross-sectional half for rock, the other is soil(half-hard andhalf-soft rock). Based on the synthesis and analysis of domestic and international basicresearch on the status of the the surrounding rock stability in tunnel excavation. Using thefinite element software ADINA for non-linear finite element analysis based on the tunnelengineering of highway reconstruction of the209State Line Road to Dragon community.The monitoring data and numerical simulation results were compared. Also the influence ofvarious factors on half-hard and half-soft rock tunnel structural stress and displacementdistribution were analysised. The useful conclusions for actual works have been obtained,which can guide the design and optimize construction, and offer reference for the futuresimilar projects, the main completed the following work:(1) The subject of this thesis is the verification of a three-dimensional numericalmodelling approach for the prediction of stability of the surround rock due to tunneling inthe half-hard and half-soft rock. Describing the failure mode of surrounding rock and disc-using its stress and strain state before and after excavated.(2) By analyzing the influence factors on the surrounding rock stability, such as Therelative depth of the tunnel, soil and rock tunnel face boundary line at different heights,with or without support and anchor, the strength of concrete, concrete thickness, which canguide the design, optimize construction, and offer reference for the future similar projects.(3) The monitoring data and numerical simulation results were compared，resultsshowed that：there is some error between the simulation result and the monitoring results,but monitoring data and the numerical simulation results are basically the same. In a way,the results of numerical simulation can guide the design and construction.