Study on the Influence Pattern of Seepage Field on Temperature Field in the Construction of the Metro Cross Passage by Freezing Method in Water-Rich Strata
(1 College of Mining Engineering, Taiyuan University of Technology, Taiyuan 030024; 2 The 2nd Engineering Co., Ltd. of China Railway 12th Bureau Group, Taiyuan 030032)
Abstract:
Based on the hydro-thermal coupling theory, this paper establishes a numerical model for single-row freezing pipes to study the influence pattern of the seepage field on the temperature field under different water head differences in the freezing process, as well as a numerical model for multi-row freezing pipes to optimize the freezing effect because of the deficiency of freezing effect of single-row freezing pipes. Finally the numerical simulation results are applied and verified in the construction of a cross passage of Taiyuan subway project. The results show that the influence of groundwater seepage on the temperature field has a hysteresis effect along the seepage direction; during the freezing process the seepage field has the most significant effect on the upstream freezing effect, and using the single-row freezing pipes it cannot effectively reinforce the strata in a timely manner; under the same freezing conditions, arranging freezing pipes densely around the cross passage can advance the closing time of freezing wall by 43 d and increase the thickness of the upstream freezing wall by 0.7 m. The application effect in the actual engineering shows that using the multi-row-pipe freezing method no water inflow or sand gushing phenomenon is observed, thus achieving the purpose of ground freezing and reinforcement.
PAN Xudong1 BAI Yunlong1 BAI Yunfei2 ZHANG Zhiqiang2 LIAO Lin1
.Study on the Influence Pattern of Seepage Field on Temperature Field in the Construction of the Metro Cross Passage by Freezing Method in Water-Rich Strata[J] MODERN TUNNELLING TECHNOLOGY, 2021,V58(5): 122-128