In order to solve the problems of single factor and
shortterm prediction in the existing calculation methods of shield tunnel
settlement, a simplified calculation method of tunnel settlement under the
combined action of consolidation and rheology of soft soil is proposed, which
is verified by a practical engineering case. Firstly, the consolidationrheological coupling model is established based on the Merchant
rheological model and TerzaghiRendulic theory of twodimensional consolidation. The longterm
settlement of shield tunnel is divided into two parts by the model, i.e. the
main consolidation settlement caused by excess pore water pressure dissipation
and the secondary consolidation settlement caused by soil rheology. And then,
the longterm settlement analytical formula of the
tunnel is solved by considering the influences of surface load, soil
characteristics, structure selfweight and train load.
Lastly, three typical sections of the new shield tunnel are selected to predict
the longterm settlement of the tunnel, and the
dissipation time of excess pore water pressure, settlement rate and final
settlement are compared and analyzed. The results show that: (1) In the initial
stage of operation, the dissipation speed of the excess pore water pressure of
the soil around the tunnel is faster, especially in the first 2 years. With the
passage of time, the dissipation speed of each section tends to be stable
gradually. (2) The longterm settlement of the shield
tunnel is related to the character of the underlying soil; the greater the
thickness, the worse the character of the underlying soil layer, and the larger
the settlement. The final settlement prediction values of sections 1, 2 and 3
are 146.8 mm, 97.6 mm and 46.1 mm, respectively.
LIU Jianmei
. Longterm Settlement Calculation of
Shield Tunnel in Section of Deep Soft Ground in Nansha
District, Guangzhou[J]. Tunnel Construction, 2020
, 40(S1)
: 138
-144
.
DOI: 10.3973/j.issn.2096-4498.2020.S1.017
