Research On The Control Of Deformation During Construction Of Rock Tunnel Undercrossing Buildings

Rock tunnels under the influence of external force and engineering environmentmostly present a time-dependent mechanical property, and are often associated with thecreep behavior of rocks. At home and abroad have been some tunnels since thebeginning of the design did not consider the creep properties of rock, leading to stillgenerate large deformation within the operating time of a few years after the tunnelconstruction completed, cause the lining cracking, surrounding rock instability, surfacesettlement, overlying building damage. So, rock creep has important influence on thesurrounding rock deformation and long-term stability of underground engineering.Therefore, considering the influence of rock creep has important significance inengineering construction and theoretical research when study on the deformationcontrol of rock tunnel construction and the long-term stability problem.Based on Tong-Mao tunnel project，a systematic and thorough study was given onsafety control standard for deformation of the rock tunnel construction undercrossingbuildings under rock creep conditions, on the basis of comprehensive analysisengineering geological, design data, monitoring data, by using a combined method offield investigation, theoretical analysis, numerical simulation. The main researchcontents of this paper are as follows:①Based upon geological investigation data of Tong-Mao tunnel which located inyubei district of Chongqing, integrates field investigation, analysis engineering geologyand distribution of the buildings, and the formation and buildings deformation due totunnel excavation and the basic theory of rock creep is analyzed in this paper.②Analysis of deformation and failure control standard with tunnels and rockfoundation buildings. According to the tunnel and building foundation specification andthe deformation failure research of tunnel and building at home and abroad, deformationfailure control standard for tunnels and rock foundation buildings is analyzed in thispaper.③Creep parameters inversion of surrounding rock for rock tunnel. Combinedwith field monitoring data of Tong-Mao tunnel, analyze and summary about the creepdeformation law of rock tunnel. Operate displacement back analysis of surroundingrock by using finite difference method and BP neural network to obtain the rock creepparameters, and inversion results were analyzed and evaluated. ④The impact of tunnel construction on deformation of building foundationground and foundation under the formation creep conditions. Based on Tong-Maotunnel project，establish a reasonable numerical model using the finite differencesoftware to simulation the impact of large section tunnel construction on deformation ofoverlying building foundation ground and foundation under creep and non creepconditions, control standard for surrounding deformation of large section tunnelconstruction under creep conditions is put forward, which provides reference for tunneldesign and construction under creep conditions.