The dynamic response characteristics and cumulative
damage characteristics of the base structure under 40 t axle load had not been
considered in existing research results in China and abroad, hence, a twodimensional
numerical model of tunnelsurrounding rock coupling is
established by using software ABAQUS. Based on the cumulative damage mechanism
of the surrounding rock and the damage plasticity of the concrete structure at
the bottom of the tunnel, the main design parameters of the lining structure at
the bottom of the singletrack ballasted tunnel under
the load of heavyhaul train with the traveling speed
of 120 km/h and 40 t axle load are studied. The results show that: (1) With the
increase of train axle load, the surrounding rock at the bottom of tunnel is
gradually damaged, especially when the axle load reaches 40 t, the damage
effect of tunnel bottom structure is obvious. (2) The variations of the spantospan ratio and the thickness of the
filling layer affect the vertical displacement of the inverted arch little;
with the decrease of the spantospan ratio, the tensile stress of the inverted arch structure
continues increases, and when the spantospan ratios are less than 1∶6 and 1∶7, respectively, the tensile stress of the inverted arch structure
increases significantly. (3) With the increase of the thickness of the filling
layer, the tensile stress of the inverted arch structure of the tunnel continuously
decreases, and when the thickness of the filling layer is greater than 1.3 m,
the decreasing trend gradually slows down. (4) Under the condition of
recommended key parameters, the fatigue life of the tunnel bottom lining
structure can meet relevant requirements.
MIAO Dehai, WANG Kejin, GAO Jianguo, YU Jun, ZHOU Tao
. Study on Design Parameters of Bottom Structure of 40 t
Axle Load Singleline Ballasted Heavyhaul Railway Tunnel[J]. Tunnel Construction, 2020
, 40(S1)
: 31
-38
.
DOI: 10.3973/j.issn.2096-4498.2020.S1.005
