scholarly journals Investigation on the Vibration Effect of Shock Wave in Rock Burst by In Situ Microseismic Monitoring

2018 ◽  
Vol 2018 ◽  
pp. 1-14 ◽  
Author(s):  
Mingshi Gao ◽  
Hongchao Zhao ◽  
Yichao Zhao ◽  
Xiaojun Gao ◽  
Xiangyu Wang

Rock burst is a physical explosion associated with enormous damage at a short time. Due to the complicity of mechanics of rock burst in coal mine roadway, the direct use of traditional investigation method applied in tunnel is inappropriate since the components of surrounding rock are much more complex in underground than that of tunnel. In addition, the reliability of the results obtained through these methods (i.e., physical simulation, theoretical analysis, and monitoring in filed application) is still not certain with complex geological conditions. Against this background, present experimental study was first ever conducted at initial site to evaluate the effect of shock wave during the rock burst. TDS-6 microseismic monitoring system was set up in situ to evaluate the propagation of shock wave resulting in microexplosions of roadway surrounding rock. Various parameters including the distance of epicentre and the characteristic of response have been investigated. Detailed test results revealed that(1)the shock wave attenuated exponentially with the increase of the distance to seismic source according to the equation ofE=E0e-ηl; particularly, the amplitude decreased significantly after being 20 m apart from explosive resource and then became very weak after being 30 m apart from the seismic source;(2)the response mechanics are characteristic with large scatter based on the real location of surrounding rock despite being at the same section. That is, the surrounding rock of floor experienced serious damage, followed by ribs, the roof, and the humeral angles. This in situ experimental study also demonstrated that microseismic monitoring system can be effectively used in rock burst through careful setup and data investigation. The proposed in situ monitoring method has provided a new way to predict rock burst due to its simple instalment procedure associated with direct and reasonable experimental results.

2013 ◽  
Vol 838-841 ◽  
pp. 889-893
Author(s):  
Biao Li ◽  
Feng Dai ◽  
Nu Wen Xu ◽  
Chun Sha

The right bank underground powerhouse of Houziyan hydropower station is a typical deep-buried type with high geostress and complicated geological conditions. To monitor and analyze the stability of surrounding rock mass during continuous excavation of the powerhouse excavation and locate the potential failure zones, an ESG (Engineering Seismology Group) microseismic monitoring system manufactured in Canada was installed in April, 2013. The wave velocity of the monitoring system was determined through fixed blasting tests. And the average location error is the minimum while P-wave velocity is 5700m/s, less than 10m and meeting the system request. By combining the temporal and spatial distribution regularity of microseimic events with field excavation, micro-crack clusters and potential instability zones were identified and delineated. The results will provide a reference for later excavations and supports of the underground powerhouse. Furthermore, a new monitoring method can also be supplied for the stability analysis of surrounding rock mass in deep-buried underground powerhouses.


2010 ◽  
Author(s):  
ByoungChang Kim ◽  
MinCheol Kwon ◽  
JaeBoong Ha ◽  
KangWoo Lee

2011 ◽  
Vol 90-93 ◽  
pp. 2307-2312 ◽  
Author(s):  
Wen Jiang Li ◽  
Su Min Zhang ◽  
Xian Min Han

The stability judgement of surrounding rock is one of the key jobs in tunnel engineering. Taking the Erlongdong fault bundle section of Guanjiao Tunnel as the background, the stability of surrounding rock during construction of soft rock tunnel was discussed preliminarily. Based on plastic strain catastrophe theory, and combining numerical results and in-situ data, the limit displacements for stability of surrounding rock were analyzed and obtained corresponding to the in-situ monitoring technology. It shows that the limit displacements obtained corresponds to engineering practice primarily. The plastic strain catastrophe theory under unloading condition provides new thought for ground stability of deep soft rock tunnel and can be good guidance and valuable reference to construction decision making and deformation managing of similar tunnels.


2013 ◽  
Vol 779-780 ◽  
pp. 1526-1531
Author(s):  
Kang Lin Wei ◽  
Ming Chen ◽  
Fei Wang ◽  
Qiong Fang

Total phosphorus is an much important key water quality parameter . In view of the technical defects of existing detection methods and instruments for in situ monitoring total phosphorus, a new detection method based on ultrasonic assisted sample digestion and spectrum analysis was put forward in this paper, and the automatic monitoring system prototype based on such detection method had been developed. Aiming at wastewater treatment, the spot experiment had been carried out to contrast prototype with Chinas national standard analysis method for on line measuring total phosphorus in the water, and the results of the comparative experiment showed that the automatic monitoring instrument prototypes had good repeatability (10%) and high accuracy (±10%), which met the technical qualifications of Chinas environmental protection industry standards.


2012 ◽  
Vol 204-208 ◽  
pp. 196-201 ◽  
Author(s):  
Jian Cong Xu ◽  
Yi Wei Xu

The parabolic-apex numerical back-analysis method (PNBM) was proposed to obtain such physical-mechanics parameters as Young's modulus and lateral pressure coefficient of surrounding rock by 3D FEM numerical analysis based on in-situ monitoring data. Taking Xiang-an Subsea Tunnel (located in Xiamen, Fujian Province, China) for example, adopting the PNBM using ABAQUS software, three dimensional elastic-plastic FEM-PNBM of tunnel surrounding rock was validated using in-situ monitoring data. The results show as follows: Using the PNBM, not only may high calculation precision be obtained, better meeting the demand of actual projects, but also more reasonable and reliable physical mechanics indices of surrounding rock such as Young's modulus and lateral confinement pressure coefficient, may be obtained. The applicability and the simplicity of this proposed method also support its usefulness.


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