After the separation of the highway and railway in an
underwater tunnel, varying spacing underpass disturbance and detachment between
soilstructure occurred during a metro tunnel parallelly crossing an
existing opencut tunnel. In this study, a case study
is conducted on the metro tunnel on the north bank section of the Yellow rivercrossing tunnel in Jinan, China, and a refined threedimensional simulation model considering the detachable stratastructure interface and structural deformation joint is established
to investigate the influence of shield tunneling on 〖HJ2.7mm〗stratumstructure detachment and the
existing structure under various reinforcement schemes. The results reveal the
following: (1) The maximum ground settlement is reduced by 52% and the peak
superposition effect of the settlement curve is effectively controlled after
the column pile reinforcement is adopted. (2) The maximum lateral differential
settlement and the maximum settlement of the existing structure floor are
reduced by 43.4% and 47.0%, respectively, during shield tunneling after using
reinforcement of column pile and threeaxis mixing
pile. (3) The maximum detachment between the tunnel floor and the soil due to
shield tunneling is 1.44 mm without reinforcement. Compared with the
reinforcement of threeaxis mixing pile, the
reinforcement of column pile is more effective in reducing the detachment
between the tunnel floor and the soil. (4) The maximum tensile stress increment
of the existing structure without reinforcement measures exceeds the control
limit, and the reinforcement of threeaxis mixing pile
tends to increase the tensile stress increment within the grouting range of the
existing structure, while the use of column pile combined with threeaxis mixing pile reinforcement can effectively reduce the tensile
stress increment of the existing structure by 50%. When shield tunneling
parallelly under existing structure, it is safer and more effective to take the
ground displacement control (antidetachment) and
structural stress control into consideration than to strengthen the single
reinforcement measure.
FU Jinyang, ZHANG Hongyu, SUN Qianhui, ZHANG Liangliang, YANG Junsheng, LI Yanan
.
Reinforcement Scheme for OpenCut
Highway Tunnel Parallelly-Crossed by Metro Shield Tunnel on North Bank Section of Yellow River-Crossing
Tunnel in Jinan, China
[J]. Tunnel Construction, 2023
, 43(S2)
: 418
-427
.
DOI: 10.3973/j.issn.2096-4498.2023.S2.046
