In order to more accurately and conveniently calculate
the additional load value of the most unfavorable action position of the tunnel
undercrossing the airstrip during taxiing, the peak value of the most
unfavorable sliding load of the 22 wheels of the aircraft is taken as the
concentrated force of the static load of the aircraft. The additional stress
value of the stratum under wheel load is analyzed, and the distribution and
magnitude of the maximum additional stress under different depths are analyzed.
According to the loadstructure method and the theoretical
solution of the additional stress of the aircraft, the most unfavorable
distribution mode of the additional load in the tunnel under the airstrip and
metro is determined, and the simplified calculation formula of the additional
load of the aircraft q1 and q2 are obtained through regression analysis. Finally, the
applicability of the J. Boussinesq theoretical formula is verified by numerical
simulation. The research results show that: (1) As the burial depth of the
tunnel increase, the proportion of the maximum vertical additional stress of
the aircraft to the surrounding rock pressure of the tunnel decreases rapidly
first and then slowly; when the burial depth is greater than 50 m, the
proportion of the maximum vertical additional stress of the aircraft is
relatively small. (2) The positions of the maximum vertical additional stress
value of the aircraft under different burial depths are basically the same,
which are located on the central axis 2.1~3.3 m from the last row of wheels of
the aircraft. (3) The most unfavorable distribution mode of the aircraft additional
load is approximately symmetrical trapezoid distribution mode, and the point of
the maximum vertical additional stress value of the aircraft is directly above
the tunnel crown. (4) The simplified additional stress q1 is negatively related to the burial depth z of the tunnel, and q5 is negatively
related to the burial depth z of the tunnel and the tunnel diameter D.
TONG Jianjun
,
GUI Dengbin
,
WANG Li
,
WANG Mingnian
,
WANG Zhilong
. Calculation Method of Additional Load of Metro Tunnel
Crossing underneath Existing Airstrip[J]. Tunnel Construction, 2020
, 40(9)
: 1292
-1299
.
DOI: 10.3973/j.issn.2096-4498.2020.09.007
