Research on theory of catastrophe of rock burst in underground chamber (in Chinese)

Research on theory of catastrophe of rock burst in underground chamber (in Chinese)

EXCAVATIONS:DYNAMIC LOADS ridges from ground strain at values much lower than were previously expected. In shallow workings compression humps are to b...

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EXCAVATIONS:DYNAMIC LOADS ridges from ground strain at values much lower than were previously expected. In shallow workings compression humps are to be expected, and their occurrence is thought to diminish with increasing depth of extraction. However, field evidence suggests that even in deeper workings, compression ridges may be anticipated where lithological contacts outcrop. (from Authors) 962401 Risk and reward: pipes and sinkholes in east Tennessee J. A. Scarborough, in: Karat geohazards: engineering and environmental problems in karst terrrane. Prec. 5th conferenee, Gatlinburg 1995, ed B.F. Beck, (Balkema), 1995, pp 349-354. It is likely that the formation of sinkholes at three commercial sites was related to the subsurface installation of large diameter pipes for storm water storage and conveyance. Seepage from the pipes is believed to be a likely cause of subsequent sinkhole formation. Alternatives for sinkhole repair included: backfilling, excavation and the attempted plugging of a bedrock throat, and remedial compaction grouting. Additional alternatives for pipe repair included sliplining and abandonment. Replacement of at least a portion of the pipe was required at each site. (from Author) 9624O2 Land sabeidenee along the northeastern Texas Gulf coast:

effects of deep hydrocarbon production J. M. Sharp Jr & D. W. Hill, Environmental Geology, 25(3), 1995, pp 181-191. This study investigates the possibility of deep petroleum production as a cause for high regional rates of subsidence. The Big Hill and Fannett field, bottom hole pressure (BHP) and well log data are examined in detail. The hypothesis of deep petroleum production is tested in three ways. Firstly, industry BHP tests show many of the fields are depressurized to far below hydrostatic pressures. Second, analysis of BHP data over time indicates that some zones in these fields were below hydrostatic when production commenced. This indicates that depressurization from production in neighboring fields or zones within the same field is not limited to the production zone. Third, three models for subsidence using reasonable hydrogeological parameters, predict subsidence within the inferred range of data. (from Authors) 962403 Prediction of subei~oce due to coal mining in Raniganj

coalfield, West Bengal, India R. P. Singh & R. N. Yadav, Engineering Geology, 39(1-2), 1995, pp 103-111. The occurrence of a thick coal seam at shallow depth is the main reason for the subsidence and as a result collapses have occurred in many coal mines in recent years~ The paper attempts to predict the subsidence occurring in Indian coalfields in general and, in particular, in the Raniganj coalfield using a visco-elastic model. The ground subsidence has been computed for two coal mines. The computed subsidence profiles of the Ratibati and Shivadanga coal mines of the Raniganj coalfield are compared. (from Authors) 9624O4 Multiphase approach to thaw subsidence of unsaturated

frozen soils: equation development M. Y. Corapcioglu & S. Panday, Journal of Engineering Mechanics - ASCE, 121(3), 1995, pp 448-459. Construction and maintenance of engineering structures in arctic regions demands an understanding of and the ability to cope with environmental problems produced by permafrost. Where thawing of the permafrost cannot be prevented, the range, amount, and extent of degradation are factors that must be taken into account in the design of engineering structures. Predictions of these factors are faci~litated by the use of a mathematical model designed to predict the physical system under consideration. This study addresses the problem by developing a predictive model to describe permafrost thaw subsidence based upon a complete formulation of the

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problem. This problem is one of multiphase (air, ice, water, and solid) transport and deformation in a porous medium. The conservation of mass equations for liquid water, ice with phase change, and deforming soil solids are developed. (from Authors) 9624O5 Research on theory of catastrophe of rock burst In underground chamber (in Chinese) Fei Honglu, Xu Xiaohe & Tang Chunan, Journal - China Coal Society, 20(1), 1995, pp 29-33. Sections of a stress-strain curve of a complete rock failure process are regarded as a constitutive relation, based on which, the state of a circular chamber under hydrostatic pressure is analyzed. The stress zone is divided into a softened area and an elastic area. A model established on the basis of theory of catastrophe is discussed by potential function. A criterion for the occurrence of rock burst is given and compared with measured data. It is proved that this theory is effective. (English summary)

Influence of dynamic loads 9624O6 Static and seismic stability of residual soils over a bedrock cavity J. Ben-Hassine, P. E. Booth & D. R. Riggs, in: Karst geohazards: engineering and environmental problems in karst terrane. Proc. 5th conference, Gatlinburg 1995, ed B.F. Beck, (Balkema), 1995, pp 357-362. This paper describes an approximate method to assess the stability of a landfill underlain by cavitose bedrock. The static stability is assessed by plane strain finite element modeling of a section comprising a layer of compacted waste and a layer of competent residual soil overburden underlain by cavitose bedrock. Seismic stability is assessed by using an approach that combines the results of the static finite element analysis and a seismic stress profile obtained through an equivalent linear seismic response analysis (SHAKE-91). (from Authors) 9624O7 Dynamic analysis of large 3-D underground structures by the BEM A. A. Statues & D. E. Beskos, Earthquake Engineering & Structural Dynamics, 24(6), 1995, pp 917-934. An up to date literature survey on the dynamics of underground structures is presented briefly. The dynamic response of large three-dimensional underground structures to external or internal dynamic forces or to seismic waves is numerically determined by the frequency domain boundary element method. This method is used to model both the structure and the soil medium, which are assumed to behave as linear elastic or viscoelastic bodies. Various numerical examples involving lined cavities and long lined tunnels buried in the full- or the half-space subjected to harmonic or transient external forces or seismic waves are presented to illustrate the method and demonstrate its advantages. (from Authors) 962408 Surface waves of oblique incidence across deep infilled trenches J. S. Lee & E. N. Its, Journal of Engineering Mechancs ASCE, 121(3), 1995, pp 482-486. Propagation of surface waves of oblique incidence across infiUed trenches is considered. An analytical approach based on the Green's function technique is developed to estimate the reflection and transmission of surface waves across a layer inserted between two homogeneous quarter-spaces. Reflection and transmission coefficients of the Rayleigh wave across the layer are integrated by using the representation theorem. After validating the method against experimental data, influence of the material contrast and the angle of incidence on the efficiency of an in-filled trench is examined. (from Authors)