Various conditions can restrict the connection between
tunnel exits and surface roads. Moreover, under certain conditions during the
actual design of projects, the corresponding indexes given by relevant
regulations are not rational. Therefore, a case study is conducted on the rivercrossing
tunnel of the Heyi road in Quzhou, China. Based on the running speed from the
aspect of drivers, a calculation model is established for the safety distance
between the tunnel exit and the road intersection. The index requirements of
the distance between the tunnelground connection point
and the downstream road intersection in the 〖WT5BX〗Code for Design of Urban Underground Road Engineering〖WT5《TNR》〗 are
consistent with the safety distance between the tunnel exit and the road
intersection proposed in this study, which is suitable for urban tunnels with
opensection structures. For urban tunnels without an
opensection structure, the distance between the tunnel
exit and the lightcontrolled road intersection should
not be less than 1.5 times the stopping sight distance, which is larger than
that in the code(1 time). Furthermore, considering the driving comfort, the
SIANAL94 intersection
queuing length model is used to establish a model for calculating the ideal
distance between the tunnel exit and the road intersection. It is concluded
that when the queue length of a single lane is overly large, the relevant
specifications are not applicable. The actual distance required by the project
should be calculated according to various factors, such as the queue length of
the traffic volume and the number of lanes. Finally, the optimized connection
measures are proposed in the design of the rivercrossing
tunnel of the Heyi road.
LIU Jishun
,
CHEN Haijun
,
ZHANG Juwen
. Ideal Connecting Distance Between Exit of Urban Tunnel
and Road Intersection Based on Running Speed[J]. Tunnel Construction, 2023
, 43(8)
: 1387
-1395
.
DOI: 10.3973/j.issn.2096-4498.2023.08.013
