Study Of Injuring Degree Of Second Lining After Highway Tunnel Fire

As the important part of force structure in tunnel,the injuring degree of lining in transportation vehicle fire decides the normal operation or not.A large number of highway tunnel fire case data demonstrate the importance of the fireproof of lining.Thus,establishing the extent of damage evaluation of tunnel lining in different traffic highway vehicle fires has guiding significance for fireproof of lining while a large number of highway tunnel construction.This paper based on the left lane of Zhongliangshan tunnel of Chengdu-Chongqing highway,and its main research content includes:(1)Confirming the key parameters of simulation about different vehicle tunnel fire.(2)Simulating different transport vehicles fire scenarios with FDS about the ZK5+159.5 ~ ZK5+279.5 interval in left lane of Zhongliangshan tunnel of Chengdu-Chongqing highway.(3)Analyzing temperature distribution in lining structure with ANSYS based on the temperature curve fitting.(4)Mechanical behavior of lining in different transport vehicles fire.(5)Damage evaluation of lining in the temperature of different transport vehicles fire.In a large number of highway tunnel fire cases and on the basis of the results of experiments,this paper has made the following main results:(1)Determining transport vehicles fire key parameter cars,buses and trucks are three types of post,established six fire conditions fire scene;obtained temperature distribution tunnel different sections,and the maximum temperature vaults,spandrel wall;and in accordance with temperature changes with time data curve fitting a heating tunnel wall six fire conditions the maximum temperature point.(2)The tunnel secondary lining in the thickness direction of the heat conduction simplified one-dimensional transient heat conduction problem,with heating curve as load in the second liner surface,got six fire conditions the temperature distribution inside the concrete secondary lining;not provided Firewood under conditions and vault GK05 secondary lining concrete conditions under 1cm deep temperature was 252.65 ℃,spandrel secondary lining concrete surface temperature is 232.4 ℃;vault under two conditions GK06 concrete lining 1cm deep temperature of 363 ℃,temperature spandrel concrete lining at depths of 3cm to 292.9 ℃.(3)In tunnel secondary lining inside the concrete temperature field for the load,calculate the stress changes in secondary lining concrete and structural deformation.Firewood is not set conditions,under tensile stress conditions GK05 dome secondary lining concrete surface is 2.587 MPa,secondary lining concrete dome tensile stress at a depth of 1cm to 1.698 MPa,tensile stress spandrel concrete surface for the secondary lining 1.384MPa;under tensile stress conditions GK06 dome secondary lining concrete surface is 1.62 MPa,spandrel secondary lining concrete surface tensile stress 2.419 MPa,tensile stress spandrel concrete secondary lining 1cm depth of 1.71 MPa.(4)The establishment of a secondary lining concrete lining with two burst temperature and stress distribution evaluation system of indicators,to the extent of damage to the structure when the second lining cars,buses and trucks fire inside the tunnel were analyzed and evaluated.Zhongliangshan in Chengdu-Chongqing Expressway Tunnel in new left tunnel ZK5+159.5~ZK5+279.5 mid-range in the absence of a tunnel fire board insulation measures,the development of a fire truck in 30 min tunnel centerline position,the fire source downstream 4.2m sectional arch top secondary lining concrete damage 1cm;truck in the left tunnel road centerline position of 30 min fire development,fire source downstream 3.6m sectional dome secondary lining concrete damage 1cm,downstream 4.8m sectional secondary lining concrete spandrel damage 3cm;when set 10 mm fire board insulation measures,the burning truck and will not damage the secondary lining concrete in the fire development in 30min;cars,buses and burning fire in 30 min development process,regardless of whether the tunnel fire board fire insulation and other measures,There was no damage to secondary lining structure.