Abstract It is critical for the construction safety of a new metro tunnel underneath existing operating railway with? out pre-reinforcement measure. Based on the shield tunnel which is located at east depature and arrival line of Yuanhua depot of phase 1 project of Chengdu rail transit line 9 and approaching existing Chengdu-Kunming railway, it simulates the engineering safety in most unfavorable condition, the feasibility of realizing groundstress compensation through active underpinning by grouting and the sensitivities of track deformation to physical and mechanical parameters changes of soil and rock by FEM software. The research results show that it can compensate stratum stress loss through active underpinning and restrain plastic zone development of surrounding rock, meeting the requirement that vector value of vertical deviation of rail track with 10 m chord should be less or equal to ±0.5 mm during construction of a shield tunnel approaching existing Chengdu-Kunming railway in conditions of argillite stratum,no prereinforcement, train load effect and grouting pressure being 0.30 MPa or more.
Abstract：
It is critical for the construction safety of a new metro tunnel underneath existing operating railway with? out pre-reinforcement measure. Based on the shield tunnel which is located at east depature and arrival line of Yuanhua depot of phase 1 project of Chengdu rail transit line 9 and approaching existing Chengdu-Kunming railway, it simulates the engineering safety in most unfavorable condition, the feasibility of realizing groundstress compensation through active underpinning by grouting and the sensitivities of track deformation to physical and mechanical parameters changes of soil and rock by FEM software. The research results show that it can compensate stratum stress loss through active underpinning and restrain plastic zone development of surrounding rock, meeting the requirement that vector value of vertical deviation of rail track with 10 m chord should be less or equal to ±0.5 mm during construction of a shield tunnel approaching existing Chengdu-Kunming railway in conditions of argillite stratum,no prereinforcement, train load effect and grouting pressure being 0.30 MPa or more.
ZHAO Taidong
.Analysis on Construction Safety of a Shield Tunnel beneath Existing ChengduKunming Railway without Pre-reinforcement in Argillite[J] MODERN TUNNELLING TECHNOLOGY, 2020,V57(3): 122-127
2020, Vol. 57 