1、翻译部分英文原文Simulation of the relationship between roadway dynamic destruction and hypocenter parametersGAO Ming-shi,DOU Lin-ming,ZHANG Nong,XIE Yao-she,ZHENG Bai-shengState Key Laboratory of Coal Resources and Mine Safety,Xuzhou, Jiangsu 221008,ChinaSchool of Mining and Safety Engineering,China univers
2、ity of Mining&Technology,Xuzhou, Jiangsu 221008, ChinaAbstract:Many factors can induce rock burst. Shock energy and shock distance are two key f actors affecting rock burst. The 32101 roadway of the Xingcun coal mine, which has a tendency for rock burst, was used as an example. The dynamic module of
3、 Itascas FLAC (Fast Lagrangian Analysis of Continua) 2D explicit finite-difference software was used to simulate the roadways destruction. The vibration velocity and displacements of the rock surrounding the roadway were modeled for different shock energies and hypo- center distances. The simulation
4、 results indicate that the vibration velocity and displacement of rock surrounding the roadway have a quadratic relationship to the shock energy and a power law relationship to the distance of the hypocenter from the roadway. A dynamic view of the process was obtained from a series of “snapshots” co
5、llected at 100 different time steps. This shows an isolating “river” is first formed at the hypocenter. The region above the “river” is a low stress zone while below the “river” a high stress zone exists. This high stress zone surrounds the ribs of the roadway in a “double ear” pattern. Continuous a
6、nd repeated action of the high stress in the “double ear” shaped zone destroys the roadway.Key words: rock burst; roadway supporting; destruction process; shock energy; shockdistance; double ear effect1 IntroductionTransient rock burst occurs suddenly. During the physical explosion freed rock or coa
7、l masses are bouncing, the roadway section is rapidly reduced and immediate collapse occurs. This process usually takes between a few milliseconds to a few seconds. What is the real process? And how has the rock been effected by the shock wave created by this process? Why are some rock bursts very s
8、erious, but others not? What are the main factors affecting the roadway destruction in a rock burst? What is the rock medium shock wave interaction mechanism? What is the process of dynamic destruction to a roadway subjected to rock burst? These basic theoretical problems are worthy of indepth study
9、 but before now no reports in the literature address them.The study of process is scientific theme of work in rock mechanics. The process of dyna-mic destruction when roadway is subjected to rock burst is the key. Only when this problem is clearly understood,and the mechanism of roadway damage and d
10、estruction mastered, will it be possible to find some method to control rock burst, keep the roadway stable and minimize destruction. Application of the dynamic module of the FLAC2D numerical stimulation software to the Xingcun colliery 32101 roadway provided further insight to this problem. This ro
11、adway is representative of one where there is a high propensity for rock burst. Variations in the rock bursting velocity, and displacement of the surrounding roadway, were considered under different shock energies and different distances to the immediate roof. The dynamic destruction processes were
12、also studied. Understanding these mechanisms provides a basic reference for developing preventive measures.2 Basic conditions and simulation scheme2.1 Roadway conditionsThe roadway lies at a depth of 638892 m. Fig. 1 shows the conditions of the rock surrounding the 32101 roadway of the Xingcun Coal
13、Mine.Fig. 1 Coal seam histogram2.2 Establishing a modelA Mohr-Coulomb, plane-strain model with fixed horizontal displacement on both sides of the border was adopted. Vertical displacement of the lower boundary, and loading upon the boundary, was included. The model height is 244 m and the width is 1
14、88 m. A rectangular roadway 3 m in height and 4 m in width is excavated from the model. The grid ratio is 1:1 near the roadway but 1:2 in other areas. To sim- plify the model without losing authenticity some ad- justments for thin rock layers were made. The nu- merical simulation model grid was esta
15、blished as shown in Fig. 2 in accordance with the rock condi- tions surrounding the roadway.Fig. 2 Simulation model of roadway subjected to rock burstStrata parameters were set using actual deforma- tion data and estimates from calculations, see Table 1.2.3 Simulation scheme and proceduresTable 1 St
16、rata parameters for the numerical simulationLocationStrataThickness(m)Bulk modulus(GPa)Shear modulus(GPa)Density(kg/m3)Friction(o)Cohesion(MPa)Thick roofMud-siliceous sandstone80115524003510Roof 3Middle sandstone8115525003510Roof coal 2Peat21051800265Main roof Fine sandstone16115525003510Immediate roofMud-siliceous siltstone8208240030
