Abstract The rational determination of an Excavation Damage Zone (EDZ) in fractured rock plays an important role in selecting an excavation method and support pattern. A quantitative analysis was carried out for an EDZ range and its mechanical properties using an optimized numerical model based on the fine measurement and characterization of the structural plane of the rock onsite. Using the excavation of a tunnel on the Jianchang-Xingcheng expressway as an example, information regarding the structural plane at the working face was collected by noncontact measurement, imported into the GeoSMA-3D system, and used to produce a 3D model approximating the actual situation. Based on this, the PFC method was adopted to determine the EDZ range, and comparative analyses of the surrounding rock stress curve, displacement curve, force chain distribution, and fracture distribution were carried out. The results show that the force chain concentration represents the degree of disturbance to the surrounding rock, while the fracture density represents the degree of damage, and the fracture connectivity implies the failure zone, by which the EDZ and the mechanical properties of the fractured rock mass can be accurately identified. The local damage during rock failure can be well simulated by the PFC method.
Abstract：
The rational determination of an Excavation Damage Zone (EDZ) in fractured rock plays an important role in selecting an excavation method and support pattern. A quantitative analysis was carried out for an EDZ range and its mechanical properties using an optimized numerical model based on the fine measurement and characterization of the structural plane of the rock onsite. Using the excavation of a tunnel on the Jianchang-Xingcheng expressway as an example, information regarding the structural plane at the working face was collected by noncontact measurement, imported into the GeoSMA-3D system, and used to produce a 3D model approximating the actual situation. Based on this, the PFC method was adopted to determine the EDZ range, and comparative analyses of the surrounding rock stress curve, displacement curve, force chain distribution, and fracture distribution were carried out. The results show that the force chain concentration represents the degree of disturbance to the surrounding rock, while the fracture density represents the degree of damage, and the fracture connectivity implies the failure zone, by which the EDZ and the mechanical properties of the fractured rock mass can be accurately identified. The local damage during rock failure can be well simulated by the PFC method.
WANG Shu-Hong,
ZAN Shi-Ming,
WANG Cun-Gen etc
.Analysis of Local Damage Induced by Tunnelling in a Fractured Rock Mass Based on Noncontact Measurement Techniques[J] MODERN TUNNELLING TECHNOLOGY, 2014,V51(3): 110-116
2014, Vol. 51 