2001 Vol. 9, No. 2

论文
It is pointed that large scale construction in China in the 21th century will lead to a lot of engineering geological and environmental problems inevitably; Engineering geology of the 21th century is in China. In the 21 century, the major engineering geological problems in the mountain areas of western China are: dynamic stability of rock soil mass in tectonically active region, strain energy storage and behavior of rock mass under high stress, scale effect of deformation of high steep slope and its dynamic stability, temperature and pressure of rock mass at the location of deeply buried long tunnels, rock mass structure detection and advanced geological prediction for construction of deeply buried tunnel, interaction of deformation and stability of large and complex excavation group, freeze and thaw deformation, stability of frozen earth and their treatment, karst distribution regularities and use of weak solution rock mass, treatment and utilization of thick overburden on river bed. etc. Engineering geological subjects in the eastern China and the coastal region are, deformation and stability of soft foundation and its treatment in construction of high speed traffic network, large scale deformation and its treatment of deeply mining tunnel in soft rock, foundation deformation and stability of large bridge piers in thick loose deposits, engineering geological and hydro geological problems of submarine tunnel, engineering geological problems of underground space development in urban area. Besides, major environmental problems are: water loss and soil frosion and regional desertization in northern China, suspended river in lower Yellow River and bank caving and stability in lower Yangtse River, environmental problem caused by cut off of lower Yellow River, short of water resource in dry climate region of northern China, environmental deteriortion pollution control in process of urbanization. Chinese engineering geologists should promote the theoretical research on the following aspects and develop the Chinese engineering geology: structural soil mechanics and structural mechanics of rock mass, fundamental principles of engineering geology and engineering geological dynamics, mechanism of inter action between human being and the earth and environmental engineering geology, theory, methodology,and techniques of geological engineering. It is pointed that large scale construction in China in the 21th century will lead to a lot of engineering geological and environmental problems inevitably; Engineering geology of the 21th century is in China. In the 21 century, the major engineering geological problems in the mountain areas of western China are: dynamic stability of rock soil mass in tectonically active region, strain energy storage and behavior of rock mass under high stress, scale effect of deformation of high steep slope and its dynamic stability, temperature and pressure of rock mass at the location of deeply buried long tunnels, rock mass structure detection and advanced geological prediction for construction of deeply buried tunnel, interaction of deformation and stability of large and complex excavation group, freeze and thaw deformation, stability of frozen earth and their treatment, karst distribution regularities and use of weak solution rock mass, treatment and utilization of thick overburden on river bed. etc. Engineering geological subjects in the eastern China and the coastal region are, deformation and stability of soft foundation and its treatment in construction of high speed traffic network, large scale deformation and its treatment of deeply mining tunnel in soft rock, foundation deformation and stability of large bridge piers in thick loose deposits, engineering geological and hydro geological problems of submarine tunnel, engineering geological problems of underground space development in urban area. Besides, major environmental problems are: water loss and soil frosion and regional desertization in northern China, suspended river in lower Yellow River and bank caving and stability in lower Yangtse River, environmental problem caused by cut off of lower Yellow River, short of water resource in dry climate region of northern China, environmental deteriortion pollution control in process of urbanization. Chinese engineering geologists should promote the theoretical research on the following aspects and develop the Chinese engineering geology: structural soil mechanics and structural mechanics of rock mass, fundamental principles of engineering geology and engineering geological dynamics, mechanism of inter action between human being and the earth and environmental engineering geology, theory, methodology,and techniques of geological engineering.
It has been nearly 40 years since the surveying, monitoring, studying and controlling on geo hazards had been started in the Three Gorges area on Changjiang River, and it contributed more to the construction of the Three Gorge projects and the protection in ecological geo environment this region. However, it has been found that there were some shortages in previous works in such as less guidance to directly developing the socil economy and to constructing the immigration project, less consideration of ecological environment,and backward techniques. In this paper, the authors suggest a new thought of surveying and studying the geo hazards in the Three Gorges region (include 19 counties and cities),i.e.. The work must be centered at the conservation environment for human existence and settlement of residents migrated from the project area; the modern monitoring techniques and analysis methods must be applied. Basing on the comprehensive survey, we can develop a geo hazards geologic information system (GGIS), which contains digital spatial database and multiplicity of map sets. Some quantitative indexes such as development degree, risk degree and damage degree are used as a base for comprehensive assessment, classifying, monitoring and forecasting geo hazards. Then a monitoring and forecasting net work system consisting of RS, GPS, GGIS and public prevention system . Our top target is to realize the development protection of geo environment and the qsprediction and reduction of geologic hazards. It has been nearly 40 years since the surveying, monitoring, studying and controlling on geo hazards had been started in the Three Gorges area on Changjiang River, and it contributed more to the construction of the Three Gorge projects and the protection in ecological geo environment this region. However, it has been found that there were some shortages in previous works in such as less guidance to directly developing the socil economy and to constructing the immigration project, less consideration of ecological environment,and backward techniques. In this paper, the authors suggest a new thought of surveying and studying the geo hazards in the Three Gorges region (include 19 counties and cities),i.e.. The work must be centered at the conservation environment for human existence and settlement of residents migrated from the project area; the modern monitoring techniques and analysis methods must be applied. Basing on the comprehensive survey, we can develop a geo hazards geologic information system (GGIS), which contains digital spatial database and multiplicity of map sets. Some quantitative indexes such as development degree, risk degree and damage degree are used as a base for comprehensive assessment, classifying, monitoring and forecasting geo hazards. Then a monitoring and forecasting net work system consisting of RS, GPS, GGIS and public prevention system . Our top target is to realize the development protection of geo environment and the qsprediction and reduction of geologic hazards.
The forming factors is also the base to differentiate the danger slope which may be occur high speed landslide. Topography, stratum, slope structure , structure and slope metabolic actuality are selected as differentiating factors. The Golden Partition is used to confirm the value of differentiating factors which form the differentiating factor systems. Applying fuzzy mathematics to set up the danger slope model which maybe form high speed ladnslide. The forming factors is also the base to differentiate the danger slope which may be occur high speed landslide. Topography, stratum, slope structure , structure and slope metabolic actuality are selected as differentiating factors. The Golden Partition is used to confirm the value of differentiating factors which form the differentiating factor systems. Applying fuzzy mathematics to set up the danger slope model which maybe form high speed ladnslide.
In this paper the influence of atmospheric precipitation on moisture content and volume weight landslide body and hence the influence moisture content in soil on internal friction angle and cohesive force are discussed. Based on these influences, two different initiation mechanisms for landslide are presented. The models for forecasting initial velocity, pushing force, direction, and time of initiation are established based on these relationships involving factors of precipitation moisture content volume weight and internal friction angle cohesive force stability. At the same time, numerical simulation of landslide initiation mechanisms is accomplished by GIS. In this paper the influence of atmospheric precipitation on moisture content and volume weight landslide body and hence the influence moisture content in soil on internal friction angle and cohesive force are discussed. Based on these influences, two different initiation mechanisms for landslide are presented. The models for forecasting initial velocity, pushing force, direction, and time of initiation are established based on these relationships involving factors of precipitation moisture content volume weight and internal friction angle cohesive force stability. At the same time, numerical simulation of landslide initiation mechanisms is accomplished by GIS.
The Yangtze River becomes wide after it runs through the Nanjinguan Pass of theThree Gorges, then the hydraulic gradient decreases. The grains of the sediments gradually thindown from the upper reaches to the lower reaches, hence the engineering geological condition becomes bad gradually from the upper to the lower reaches of the river. With expecting to provide data of physical properties, engineering geomechanical characteristics, and basic geologic environment of the floodplain land in the modern beach of the middle and the lower reaches of the river. The Yangtze River becomes wide after it runs through the Nanjinguan Pass of theThree Gorges, then the hydraulic gradient decreases. The grains of the sediments gradually thindown from the upper reaches to the lower reaches, hence the engineering geological condition becomes bad gradually from the upper to the lower reaches of the river. With expecting to provide data of physical properties, engineering geomechanical characteristics, and basic geologic environment of the floodplain land in the modern beach of the middle and the lower reaches of the river.
The development degree and homogenity of fault structures in a rock mass are the significant factors affecting structure types of the rock mass, rock mass quality, stability and comprehensive utilization of the engineering rock mass. Thus,it is important to estimate quantitatively the development degree and grade fault structures in the engineering rock mass. The permanent shiplock slope engineering in the Three Gorges Project is taken as an example, the methods to evaluate the development degree of fault structures are discussed systematically in this paper. A grade scale and the principles to decide indices are put forward. Results show that the comprehensive fuzzy evaluation and the artificial neural network are feasible to estimate the development degree of fault structures in rockmass based on regularity and patterns of the fault structure. The development degree and homogenity of fault structures in a rock mass are the significant factors affecting structure types of the rock mass, rock mass quality, stability and comprehensive utilization of the engineering rock mass. Thus,it is important to estimate quantitatively the development degree and grade fault structures in the engineering rock mass. The permanent shiplock slope engineering in the Three Gorges Project is taken as an example, the methods to evaluate the development degree of fault structures are discussed systematically in this paper. A grade scale and the principles to decide indices are put forward. Results show that the comprehensive fuzzy evaluation and the artificial neural network are feasible to estimate the development degree of fault structures in rockmass based on regularity and patterns of the fault structure.
Coal bed joints are a widespread structure in coal beds. They are important objective in study of shaft structure and also a very important engineering geological factor . Coal bed joints affect the fabric ,structure and physical properties of coal beds,and hence affect coal bed digging and stripping,engineering character of roof,gas migration and the engineering geological conditions of coal bed methane pooling,migration,and exploitation. Studying and understanding the geometric and mechanical properties of coal bed joints make us to reasonably lay out tunnel engineering,select digging technology and to take adoption of safe measures and formulate option of coal bed methane exploitation. Coal bed joints are a widespread structure in coal beds. They are important objective in study of shaft structure and also a very important engineering geological factor . Coal bed joints affect the fabric ,structure and physical properties of coal beds,and hence affect coal bed digging and stripping,engineering character of roof,gas migration and the engineering geological conditions of coal bed methane pooling,migration,and exploitation. Studying and understanding the geometric and mechanical properties of coal bed joints make us to reasonably lay out tunnel engineering,select digging technology and to take adoption of safe measures and formulate option of coal bed methane exploitation.
By using the theory of quantification (Model(Ⅱ)),this paper mainly deals with the problem on rish assessment for mine water inrush and puts forward a useful assessment model,which finds a new way for mines safety assessment. By using the theory of quantification (Model(Ⅱ)),this paper mainly deals with the problem on rish assessment for mine water inrush and puts forward a useful assessment model,which finds a new way for mines safety assessment.
The slope large distance sliding modeling is always a difficult point in the landslide study. In this paper, two methods are proposed respectively for the ductile slope sliding and the fragile slope sliding. The slope large distance sliding modeling is always a difficult point in the landslide study. In this paper, two methods are proposed respectively for the ductile slope sliding and the fragile slope sliding.
The properties of soil deformation under vacuum drainage preloading are analyzed through the stress path in the paper , then the influences of the stress path change on the settlement is induced when the soil foundation is used after its consolidation by vacuum preloading. It also calculated the value of the residual settlement compared to the consolidation settlement. Finally, a formula for evaluating the final settlement is given. The properties of soil deformation under vacuum drainage preloading are analyzed through the stress path in the paper , then the influences of the stress path change on the settlement is induced when the soil foundation is used after its consolidation by vacuum preloading. It also calculated the value of the residual settlement compared to the consolidation settlement. Finally, a formula for evaluating the final settlement is given.
The properties of rock mass, unloading failure characteristics and its mechanism of engineering rock mass are summarized in this paper. The current status of research on unloading failure mechanism engineering rock mass is reviewed. The main problems and prospects of further development in study of the failure of engineering rock mass are presented. The properties of rock mass, unloading failure characteristics and its mechanism of engineering rock mass are summarized in this paper. The current status of research on unloading failure mechanism engineering rock mass is reviewed. The main problems and prospects of further development in study of the failure of engineering rock mass are presented.
This paper inquires into application of random fuzzy method to statistic analysis of mechanical parameters of rock samples and quantitative dividing them into groups of rock mass. The stochastic uncertainty of mechanical parameters of rock samples is discussed. A presented random fuzzy method for processing of experimental data of the mechanical parameters of rock samples is improved. The authors place emphasis on discussion of choice of subjection function of rock samples in this paper. The result indicates that the values obtained with the random fuzzy method is more realistic and better than the conventional methods. Finally, the authors present analytic process: qualitative division of mechanical parameters of rock samples into groups of rock mass statistic computation of them by the random fuzzy method quantitative division of them into groups of rock mass. This paper inquires into application of random fuzzy method to statistic analysis of mechanical parameters of rock samples and quantitative dividing them into groups of rock mass. The stochastic uncertainty of mechanical parameters of rock samples is discussed. A presented random fuzzy method for processing of experimental data of the mechanical parameters of rock samples is improved. The authors place emphasis on discussion of choice of subjection function of rock samples in this paper. The result indicates that the values obtained with the random fuzzy method is more realistic and better than the conventional methods. Finally, the authors present analytic process: qualitative division of mechanical parameters of rock samples into groups of rock mass statistic computation of them by the random fuzzy method quantitative division of them into groups of rock mass.
According to the struture and profile of Yaan Xiakou Landslide, the applied stress pattern and state are analyzed in this paper, and the disastar model are predicted. Due to the strcture of the clayey slope and the canyons topography, the movement velocity and distance are limited, its movement pattern is slide stop wash slide. According to the struture and profile of Yaan Xiakou Landslide, the applied stress pattern and state are analyzed in this paper, and the disastar model are predicted. Due to the strcture of the clayey slope and the canyons topography, the movement velocity and distance are limited, its movement pattern is slide stop wash slide.
A new ship building paltform will be constructed on the slope with thick soft layer in Wuhu Jiangdong ship building factory. We used the FEM method and rigid limit equilibrium theory to analyze the stability of this slope. The minimum safety factor and corresponding potential sliding surface were given to each stage of ship building. The results had been verified in the construction. A new ship building paltform will be constructed on the slope with thick soft layer in Wuhu Jiangdong ship building factory. We used the FEM method and rigid limit equilibrium theory to analyze the stability of this slope. The minimum safety factor and corresponding potential sliding surface were given to each stage of ship building. The results had been verified in the construction.
The genetic types, distribution regularities and protection methods of the karstic collapse in Guilin City are analyzed, from a large amount of drilling data. The obtained results are of some reference value for the engineering constructions in Guilin City. The genetic types, distribution regularities and protection methods of the karstic collapse in Guilin City are analyzed, from a large amount of drilling data. The obtained results are of some reference value for the engineering constructions in Guilin City.
Hard clay is a kind of medium between soft rock and hard soil. It contains regularly distributed cracks and has obvious anisotropic behaviours. In this paper, a damage mechanical model suitable to the cracked hard clay is presented for on engineering application. This model was used for numerical simulation of canal slope engineering in Nanyang basin. . Hard clay is a kind of medium between soft rock and hard soil. It contains regularly distributed cracks and has obvious anisotropic behaviours. In this paper, a damage mechanical model suitable to the cracked hard clay is presented for on engineering application. This model was used for numerical simulation of canal slope engineering in Nanyang basin. .
From the data of many factors such as earthquake magnitude, stress ratio, SPT value, peak ground surface acceleration, and water table, a fuzzy neural network model was constructed and verified for classifying sand liquefaction potential in the paper. The result obtained is superior to those derived by conventional fuzzy clustering means. It indicates that this methodology is a potentially useful tool in objectively evaluating and predicting liquefaction potential of sand. From the data of many factors such as earthquake magnitude, stress ratio, SPT value, peak ground surface acceleration, and water table, a fuzzy neural network model was constructed and verified for classifying sand liquefaction potential in the paper. The result obtained is superior to those derived by conventional fuzzy clustering means. It indicates that this methodology is a potentially useful tool in objectively evaluating and predicting liquefaction potential of sand.
This paper presents the principle and procedure of Monte Carlo simulation for assessment of sand liquefaction. Also the probability distribution function and the flowchart of probability simulation are proposed. The practical examples have shown that result of this method is consistent with those of probability analysis and specification evaluation. This paper presents the principle and procedure of Monte Carlo simulation for assessment of sand liquefaction. Also the probability distribution function and the flowchart of probability simulation are proposed. The practical examples have shown that result of this method is consistent with those of probability analysis and specification evaluation.
Linfen City is one of the most serious ground fissure hazard areas in addition to Xian and Datong. It has constricts the sustainable economic development severely. Some researches demonstrate that groundwater over pumping is the second factor influencing the ground fissure hazards and assisting ground fissure formation and development via subsidence. By numerical simulation, we found the subsidence regularity, and the position prone to ground fissures is probable the seep gradient zone of subsidence. Finally, the spatio temporal regularity of subsidence and ground fissure was analyzed. Linfen City is one of the most serious ground fissure hazard areas in addition to Xian and Datong. It has constricts the sustainable economic development severely. Some researches demonstrate that groundwater over pumping is the second factor influencing the ground fissure hazards and assisting ground fissure formation and development via subsidence. By numerical simulation, we found the subsidence regularity, and the position prone to ground fissures is probable the seep gradient zone of subsidence. Finally, the spatio temporal regularity of subsidence and ground fissure was analyzed.
Influential factors on the buried depth of shallow foundation in cold regions are stated by a practical project. Then, the detailed calculation technique for the buried depth of shallow foundation is proposed in this paper. Influential factors on the buried depth of shallow foundation in cold regions are stated by a practical project. Then, the detailed calculation technique for the buried depth of shallow foundation is proposed in this paper.