1994 Vol. 2, No. 4

论文
The paper discusses constitutive models of geologic discontinuities(e.g.joint and fault etc.)in engineering geology within the theoretical framework of the elastoplastic damge.These models can reflect the behaviours of damage softening,elastic stiffness degradation and shear dilatancy.In the models,the plastic deformation increment is non-normal to the yield surface,but the obtained constitutive matrix is symmetrical.The former is consistent with experimental data and the latter is extremely important in the numerical analysis and theoritical research. The paper discusses constitutive models of geologic discontinuities(e.g.joint and fault etc.)in engineering geology within the theoretical framework of the elastoplastic damge.These models can reflect the behaviours of damage softening,elastic stiffness degradation and shear dilatancy.In the models,the plastic deformation increment is non-normal to the yield surface,but the obtained constitutive matrix is symmetrical.The former is consistent with experimental data and the latter is extremely important in the numerical analysis and theoritical research.
Engineering geology is getting in the period of forecasting and controlling.Geo-engineering,a new branch of engineering geology,is a technique for evaluating,remaking and controlling on moutain mass and region crustal stability.The entity of geo-engineering is complex geomass that is in the state of evolution.The rockmass structure control,engineering geologic mass control and engineering geologic processing control are the three basic theories of geo-engineering.The geological survey, design and construction are combined togather in the geo-engineering,and thedesign such as a bridge for connect the geological survey and construction.A computer-based geo-engineering design supportsystem will be developed to help the geo-engineering. Engineering geology is getting in the period of forecasting and controlling.Geo-engineering,a new branch of engineering geology,is a technique for evaluating,remaking and controlling on moutain mass and region crustal stability.The entity of geo-engineering is complex geomass that is in the state of evolution.The rockmass structure control,engineering geologic mass control and engineering geologic processing control are the three basic theories of geo-engineering.The geological survey, design and construction are combined togather in the geo-engineering,and thedesign such as a bridge for connect the geological survey and construction.A computer-based geo-engineering design supportsystem will be developed to help the geo-engineering.
The Jilintai Hydropower Station in located in a region with strong modern tectonic activity.The recent faulting has an important influence on the safety of the station.During the field investigation,a series of fault rock samples were collected along the faults in the station area,and analyses of deformation microstructures and quartz surface textures,as well as isotopic dating techniques have been used in lab for comprehensive research.The results show that the lower and upper limits of time of the last strong faulting are 130-200 and 90-150ka,respectively.The results of structural model experiments indicate that under the action of modern tectonic stress field,the engineering site area will uplift as a whole,but new fault system and stress concentration zone will not occur in future.Therefore,the sellected station site is a relatively stable place in this tectonically active region. The Jilintai Hydropower Station in located in a region with strong modern tectonic activity.The recent faulting has an important influence on the safety of the station.During the field investigation,a series of fault rock samples were collected along the faults in the station area,and analyses of deformation microstructures and quartz surface textures,as well as isotopic dating techniques have been used in lab for comprehensive research.The results show that the lower and upper limits of time of the last strong faulting are 130-200 and 90-150ka,respectively.The results of structural model experiments indicate that under the action of modern tectonic stress field,the engineering site area will uplift as a whole,but new fault system and stress concentration zone will not occur in future.Therefore,the sellected station site is a relatively stable place in this tectonically active region.
In this paper,Sanshandao Gold Mine,being mining,is stutied object.Rockmass structure,the relationship between mechanic characterisitics of ore pillars,top-supporting ore pillars,and fault gouge in mine-controlled fault F1 and its covering rockmass,were discussed.After experiment,material composition.mechanical characteristics of the fault gouge,and their relationship to mud thickness and water content were determined.Then-some reinforcement measures are proposed:1)to anchor middle-inclination structural plane forimprovement of rockmass slide resistance;2)to raise the stiffness level of ore pillars with high inclination;3)to anchor top-supporting ore pillars in advance and to mine ore at different stages i 4) to discharge water from fissure-dense zones for strenthening fault gouge. In this paper,Sanshandao Gold Mine,being mining,is stutied object.Rockmass structure,the relationship between mechanic characterisitics of ore pillars,top-supporting ore pillars,and fault gouge in mine-controlled fault F1 and its covering rockmass,were discussed.After experiment,material composition.mechanical characteristics of the fault gouge,and their relationship to mud thickness and water content were determined.Then-some reinforcement measures are proposed:1)to anchor middle-inclination structural plane forimprovement of rockmass slide resistance;2)to raise the stiffness level of ore pillars with high inclination;3)to anchor top-supporting ore pillars in advance and to mine ore at different stages i 4) to discharge water from fissure-dense zones for strenthening fault gouge.
Study on different mechanical properties of structural joints in loess and their regional,systematical features made us to suggest that two sets of their torsion-fracture planes are representative of orientations of maximum shear stress of neotectonic stress field.The loess structural joints systems and controlled by them gully and ravine network on soil layer can be used in reconstruction of relevant Q2-3tectonic stress field.It indicates that the structural joints are the main channels and locus for the groundwater migration in loess region and the structural basis for geologic hazards,such as ground fissuring,landslide,collapse,and water loss in the loess region.The structural joints are the weak surfaces in loess strata,and at them the weathering process and stress erosion start.and hence the erosional landforms,such as ground pan,cave.hole,ridge,pillar,wall.gully,can be gradually formed.Study on structural joints in loess has its practical significance in reconstruction of neotectonic stress field,in prediction of ground fissure and seismic activity, in control on water loss and landslide hazard, in engineering evaluation of regional stability,in understanding regularities of erosional landforms,as well as in searching ground water in arid and semiarid loess regions. Study on different mechanical properties of structural joints in loess and their regional,systematical features made us to suggest that two sets of their torsion-fracture planes are representative of orientations of maximum shear stress of neotectonic stress field.The loess structural joints systems and controlled by them gully and ravine network on soil layer can be used in reconstruction of relevant Q2-3tectonic stress field.It indicates that the structural joints are the main channels and locus for the groundwater migration in loess region and the structural basis for geologic hazards,such as ground fissuring,landslide,collapse,and water loss in the loess region.The structural joints are the weak surfaces in loess strata,and at them the weathering process and stress erosion start.and hence the erosional landforms,such as ground pan,cave.hole,ridge,pillar,wall.gully,can be gradually formed.Study on structural joints in loess has its practical significance in reconstruction of neotectonic stress field,in prediction of ground fissure and seismic activity, in control on water loss and landslide hazard, in engineering evaluation of regional stability,in understanding regularities of erosional landforms,as well as in searching ground water in arid and semiarid loess regions.
Because the granite body exposed on the ground surface and the environment change of physical and chemical conditions,the weathering crust on the granite varies in its weathering degree with depth.It is very important for engineering geological study and stability evaluation of constrution site and for analysis of different zones of the weathering crust.The outhor on this paper,basing on systematical collecting the geological data Guilin geotechanical data,thin section analysis and grain size analysis,gives a zoning of the weathering crust on the basis of geologic characters,drill data and dyamic experiment,soil geotechnical and shear experiment on the weathering crust on granite in Wuzhou city. Because the granite body exposed on the ground surface and the environment change of physical and chemical conditions,the weathering crust on the granite varies in its weathering degree with depth.It is very important for engineering geological study and stability evaluation of constrution site and for analysis of different zones of the weathering crust.The outhor on this paper,basing on systematical collecting the geological data Guilin geotechanical data,thin section analysis and grain size analysis,gives a zoning of the weathering crust on the basis of geologic characters,drill data and dyamic experiment,soil geotechnical and shear experiment on the weathering crust on granite in Wuzhou city.
It is found that the physical,mechanical and acoustic properties of rock mediumfor underground nuclear explosion vary in preshot and postshot times by the testing these proterties indoors.In the article the mechanism for the varriation is also analysed and discussed. It is found that the physical,mechanical and acoustic properties of rock mediumfor underground nuclear explosion vary in preshot and postshot times by the testing these proterties indoors.In the article the mechanism for the varriation is also analysed and discussed.
Analysis of the principles of the speckle analysis method,its mathematical description and observed examples proved that laser speckle method is a new nondestructive detecting technique for study the deformation state of analog model of underground structure of coal mine.When using the white light as a light source,this method can be used in on-the-spot test of the two-dimensional deformation field. Analysis of the principles of the speckle analysis method,its mathematical description and observed examples proved that laser speckle method is a new nondestructive detecting technique for study the deformation state of analog model of underground structure of coal mine.When using the white light as a light source,this method can be used in on-the-spot test of the two-dimensional deformation field.
Catastrophe theory is introduced to analysis of two damage ways of soil slope:catastrophie and gradual damages.Meanwhile,the corresponding catastrophic models are set up,Which theoretically explain the source of high-speed and low-speed landslide.The determining of landslids caused by water condition are proposed.Thses results have important theoretical and practical significances. Catastrophe theory is introduced to analysis of two damage ways of soil slope:catastrophie and gradual damages.Meanwhile,the corresponding catastrophic models are set up,Which theoretically explain the source of high-speed and low-speed landslide.The determining of landslids caused by water condition are proposed.Thses results have important theoretical and practical significances.
Considering the location charactor of railway direction,from geological aspect the system summarizes and generaliaed major problems(landslide ,mud-rock flow,desert,karst)affecting the location of railway direction,and set up a knowledge-base and inference scheme.This system may provide information on location of a railway direction,so as to reduce the blunders,save the cost and accomplish punctually the railway construction.In this paper the authors centre on introducing the composition of this system and concrete design method and design technique of every compositing part. Considering the location charactor of railway direction,from geological aspect the system summarizes and generaliaed major problems(landslide ,mud-rock flow,desert,karst)affecting the location of railway direction,and set up a knowledge-base and inference scheme.This system may provide information on location of a railway direction,so as to reduce the blunders,save the cost and accomplish punctually the railway construction.In this paper the authors centre on introducing the composition of this system and concrete design method and design technique of every compositing part.
After analysis of the cause of formation of cracks on outer slope of the Sanyuan Reservoir dam,reduction and dedution of physiscal parameters by using rock and soil mechanics theory and method,the author suggests that the cracks were formed by creep sliding deformation of local shallow dam-body earth under the influence of water instead of deep dam-body-earth sliding.Hence a series of corresponding crack treatment measures have been susggested for consolidating the cracks and stablizing the dam. After analysis of the cause of formation of cracks on outer slope of the Sanyuan Reservoir dam,reduction and dedution of physiscal parameters by using rock and soil mechanics theory and method,the author suggests that the cracks were formed by creep sliding deformation of local shallow dam-body earth under the influence of water instead of deep dam-body-earth sliding.Hence a series of corresponding crack treatment measures have been susggested for consolidating the cracks and stablizing the dam.