| During the development of large-scale civil engineering,the interaction between the engineering body and the geological body has always been an important issue in the study of engineering stability.High-rise buildings—foundation foundations,gravity dams—dam foundations,arch dams—dam shoulders,long-buried long-tunnel lining surrounding rocks—linings,etc.,are typical rock-concrete monolithic body.And the study of damage mechanism is an inevitable requirement for engineering development.In order to study the acoustic emission characteristics of rock-concrete monolithic body,the acoustic emission test and numerical simulation test were expanded under the uniaxial compression based on the background of the surrounding rock-lining structure of the diversion tunnel in Qirehatar.Severl properties of rock-concrete monolithic body have been studied in the process of uniaxial compression,for example,the basic mechanical properties,the time domain characteristics of acoustic emission signal,and the evolution of b-values and fractal correlation dimensions of Acoustic Emission signal.The research aims to provide a theoretical basis for the safety monitoring of the engineering body in practical projects.The main contents and results of this article are as follows:(1)The basic mechanical properties and the evolution law of cracks of rock-concrete monolithic body were obtained through the uniaxial compression acoustic emission test.The results show that the rock-concrete monolithic body show the properties of continuum mechanics.(2)The acoustic emission ringing counts,energy counts,and event counts of the samples were analyzed with stress-strain changes in the process of uniaxial compression.The results show that the peak of ringing counts of a rock-concrete sample can be used as a precursor of the cracks' expanding from concrete to the rock through bonding.(3)Based on Matlab,the calculation results show that the AE b-values show a trend of the change from large to small,and the scale of the damage of rock-concrete monolithic body is limited by the stress of 70% of the peak stress.(4)Using GP algorithm,the fractal correlation dimension of acoustic emission amplitude and ring count sequence were calculated.The results show that the acoustic emission amplitude and ringing count sequence of the two bodies of rock-concretemonolithic body have obvious Fractal features.(5)The evolution of rock-concrete's cracks is reproduced during uniaxial compression failure in based on the PFC2 D numerical simulation.The accumulative parameters of the acoustic emission change with the strain are consistent and correspond to each stress phase of the sample. |
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