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Mean and Non-Mean Models for the Safety Evaluation of Surrounding Rock Based on Shield Driving under a Flyover Structure
(1 School of Civil Engineering, Central South University, Changsha 410075; 2 Institute of Architecture and Engineering, Huanghuai University, Zhumadian 463000; 3 Shenyang Urban and Rural Construction Committee, Shengyang 110013)
Abstract Evaluation of the stability of a tunnel′s surrounding rock is one of the most important issues in the con? struction and maintenance of underground works. Based on this, a mean and non-mean numerical model are established from the perspective of material behavior, and the safety and stability of surrounding rock are evaluated aiming at the lot one shield tunnel of Shenyang Metro Line 2 under a flyover structure. The mean model focuses on analyzing the deformation of the surrounding rock, stress variation and distribution features of the plastic zone, and verifies the rationality of the calculation with the measured data. The non-mean model focuses on the micro-failure process of the surrounding rock, and the plastic-elastic damage constitutive model with the residual strength and degradation method characterized by failure element material are adopted to simulate the progressive failure process and the sound-emission law under the reduced strength of the tunnel surrounding rock. The overall structure safety fac? tor is calculated. Using the acoustic emission (AE) law, the failure mode of surrounding rock in similar cases is discussed.
Abstract：
Evaluation of the stability of a tunnel′s surrounding rock is one of the most important issues in the con? struction and maintenance of underground works. Based on this, a mean and non-mean numerical model are established from the perspective of material behavior, and the safety and stability of surrounding rock are evaluated aiming at the lot one shield tunnel of Shenyang Metro Line 2 under a flyover structure. The mean model focuses on analyzing the deformation of the surrounding rock, stress variation and distribution features of the plastic zone, and verifies the rationality of the calculation with the measured data. The non-mean model focuses on the micro-failure process of the surrounding rock, and the plastic-elastic damage constitutive model with the residual strength and degradation method characterized by failure element material are adopted to simulate the progressive failure process and the sound-emission law under the reduced strength of the tunnel surrounding rock. The overall structure safety fac? tor is calculated. Using the acoustic emission (AE) law, the failure mode of surrounding rock in similar cases is discussed.
.Mean and Non-Mean Models for the Safety Evaluation of Surrounding Rock Based on Shield Driving under a Flyover Structure[J] MODERN TUNNELLING TECHNOLOGY, 2017,V54(2): 121-128
2017, Vol. 54 