2003 Vol. 11, No. 4

论文
Some basic problems of environmental geology are briefly described from the authors view in the paper, They are the scientific implications of environmental geology and geologic environment, the relationship between environmental geology and the relevant disciplines, the proper position of geologic environment reservation in the whole environmental protection, the formation steps of geologic hazards, the domains of environmental geology remaining to be improved and others. Meanwhile, some problems concerning the whole environmental science are suggested. Some basic problems of environmental geology are briefly described from the authors view in the paper, They are the scientific implications of environmental geology and geologic environment, the relationship between environmental geology and the relevant disciplines, the proper position of geologic environment reservation in the whole environmental protection, the formation steps of geologic hazards, the domains of environmental geology remaining to be improved and others. Meanwhile, some problems concerning the whole environmental science are suggested.
Using the method of historical analysis, the process of Xian ground rupture from the Cenozoic era is analyzed. A sequence of the ground fissure events is set up. During the study, geophysical survey, thermolumiescence dating, and inspection of old buildings were conducted . The ground fissures are discussed from geologic history, historical records of earthquakes and present time. Based on seismic effect in the ground fissure field, the risk from ground fissure event is predicted for future fifty years.The result is useful for Xian city planning and provides a basis for prevention of buildings in ground fissure zone. Using the method of historical analysis, the process of Xian ground rupture from the Cenozoic era is analyzed. A sequence of the ground fissure events is set up. During the study, geophysical survey, thermolumiescence dating, and inspection of old buildings were conducted . The ground fissures are discussed from geologic history, historical records of earthquakes and present time. Based on seismic effect in the ground fissure field, the risk from ground fissure event is predicted for future fifty years.The result is useful for Xian city planning and provides a basis for prevention of buildings in ground fissure zone.
Previous study shows that there exit structural planes in rockmass and soilmass and deformation and failure of rockmass and soilmass around engineering projects are controlled by the structural planes. Based on quantitative comparison of integrated preferred index value (R i) of structural planes(faults), we find out the influence degree of structural planes(faults) on tunnel stability.Thus, different measures can be taken for treating the different structural planes(faults). The study result reveals that water hazard, gas outburst and rockmass quality are closely related with the structural planes. Previous study shows that there exit structural planes in rockmass and soilmass and deformation and failure of rockmass and soilmass around engineering projects are controlled by the structural planes. Based on quantitative comparison of integrated preferred index value (R i) of structural planes(faults), we find out the influence degree of structural planes(faults) on tunnel stability.Thus, different measures can be taken for treating the different structural planes(faults). The study result reveals that water hazard, gas outburst and rockmass quality are closely related with the structural planes.
How to determine the properties of soil sliding zone and the location of sliding plane accurately in the course of landslides investigation is a difficult problem. The structural features of landslide body and soil properties in sliding zone of Xietan landslide on Three-Gorges Reservoir are introduced in this paper. Stria, mirrors and casts of gravels can be clearly bound in soil of sliding zone of Xietan landslide, and even mylonitic and re-cementation of soil can be also found in the sliding zone. Furthermore, landslide-influenced zone was observed under the sliding zone of Xietan landslide. The soil properties in sliding zone of Xietan landslide are very typical, so it is helpful for identifying sliding plane in practice. How to determine the properties of soil sliding zone and the location of sliding plane accurately in the course of landslides investigation is a difficult problem. The structural features of landslide body and soil properties in sliding zone of Xietan landslide on Three-Gorges Reservoir are introduced in this paper. Stria, mirrors and casts of gravels can be clearly bound in soil of sliding zone of Xietan landslide, and even mylonitic and re-cementation of soil can be also found in the sliding zone. Furthermore, landslide-influenced zone was observed under the sliding zone of Xietan landslide. The soil properties in sliding zone of Xietan landslide are very typical, so it is helpful for identifying sliding plane in practice.
Jinan city is famous for its history and culture as the capital of Shandong provience. With the rapid urbanization, the engineering-geological and environmental problems become more and more acute. It is important to make classification and evaluation of engineering-geological-environmental quality of rock-soil foundation for the city construction. This paper analyzes the engineering-geological environmental conditions and sets up a model and determines its preferred indices for the classification and evaluation of engineering-geological-environmental quality of rock-soil foundation in Jinan area by using a BP neural network. Jinan city is famous for its history and culture as the capital of Shandong provience. With the rapid urbanization, the engineering-geological and environmental problems become more and more acute. It is important to make classification and evaluation of engineering-geological-environmental quality of rock-soil foundation for the city construction. This paper analyzes the engineering-geological environmental conditions and sets up a model and determines its preferred indices for the classification and evaluation of engineering-geological-environmental quality of rock-soil foundation in Jinan area by using a BP neural network.
The effect of cross-section shape of roadway of distance of working face,sequence of excavation on the stability of surrounding rock, and displacement of many sites in deep part of surrounding rock are simulated with FLAC3D in some engineering practice . The result shows that there are different mechanical effect with different cross-section shape of roadway under the same condition of surrounding rock, different deformation of different surrounding rocks, appeared on the same cross-section and the curve of horizontal displacement of surrounding rock is s-shaped with distance from working face. A maximum horizontal displacement of surrounding rock mainly occurs in a range of double diameters of the roadway in the rear of working face. The range of displacement of deep part of Ⅲ-grade surrounding rock is about 2.6~4.3m and that of Ⅳ-grade surrounding rock is 6.9~ 7.8 m. For larger cross-section of roadway in-steps an excavation is beneficial to control on surrounding rock. The effect of cross-section shape of roadway of distance of working face,sequence of excavation on the stability of surrounding rock, and displacement of many sites in deep part of surrounding rock are simulated with FLAC3D in some engineering practice . The result shows that there are different mechanical effect with different cross-section shape of roadway under the same condition of surrounding rock, different deformation of different surrounding rocks, appeared on the same cross-section and the curve of horizontal displacement of surrounding rock is s-shaped with distance from working face. A maximum horizontal displacement of surrounding rock mainly occurs in a range of double diameters of the roadway in the rear of working face. The range of displacement of deep part of Ⅲ-grade surrounding rock is about 2.6~4.3m and that of Ⅳ-grade surrounding rock is 6.9~ 7.8 m. For larger cross-section of roadway in-steps an excavation is beneficial to control on surrounding rock.
The combined key stratum is regarded as a crucial factor for the motion of overlying rock strata. The stress of the combined key stratum is discussed on the basis of elastic thin slab theory and the laminated slab theory of compound material mechanics. The study result provides an approach to calculate the overall strength of the combined key stratum. In the actual engineering practice of mining subsidence controlling, the maximum load for instability of the combined key stratum is calculated by using the structural plastic limit analysis theory and the expression of the plastic limit load of the key stratum was obtained on the condition of sufficient mining. On this basis, a new method for judgment of the key stratum position is also found from another point of view. The result provides a reference for grouting and reducing subsidence. The combined key stratum is regarded as a crucial factor for the motion of overlying rock strata. The stress of the combined key stratum is discussed on the basis of elastic thin slab theory and the laminated slab theory of compound material mechanics. The study result provides an approach to calculate the overall strength of the combined key stratum. In the actual engineering practice of mining subsidence controlling, the maximum load for instability of the combined key stratum is calculated by using the structural plastic limit analysis theory and the expression of the plastic limit load of the key stratum was obtained on the condition of sufficient mining. On this basis, a new method for judgment of the key stratum position is also found from another point of view. The result provides a reference for grouting and reducing subsidence.
The durability of shotcrete and rockbolt support system has direct influence on structure stability and operating life in tunnel and underground engineering projects with composite lining. Anchor system, which is mainly made of steel elements, is readily subjected to corroding. Based on the structural features of the tunnel and underground engineering project with composite lining, it can be deduced that the erosion of a bolt can be mainly attributed to the interaction between the anchor system and erosive underground water from wall rocks. In this paper, the dominant factors, influencing the erosion of anchor system of underground structure in sulfide-bearing wall rocks are discussed, especially the formation of erosive underground water in wall rocks and the physico-chemical mechanism for the erosion of a bolt under this condition are described. Based on this mechanism, and a method for estimating the operating life of an anchor system in sulfide-bearing wall rocks is proposed. The durability of shotcrete and rockbolt support system has direct influence on structure stability and operating life in tunnel and underground engineering projects with composite lining. Anchor system, which is mainly made of steel elements, is readily subjected to corroding. Based on the structural features of the tunnel and underground engineering project with composite lining, it can be deduced that the erosion of a bolt can be mainly attributed to the interaction between the anchor system and erosive underground water from wall rocks. In this paper, the dominant factors, influencing the erosion of anchor system of underground structure in sulfide-bearing wall rocks are discussed, especially the formation of erosive underground water in wall rocks and the physico-chemical mechanism for the erosion of a bolt under this condition are described. Based on this mechanism, and a method for estimating the operating life of an anchor system in sulfide-bearing wall rocks is proposed.
The reduced coefficient in formula for designing for bearing capacity of cement-soil mixedpile composite foundation was determined by the experiences and the range of is wide. So, it is difficult to accurately calculate bearing capacity of composite foundation. Based on the interaction of pile and soil, this paper discusses various factors influencing the reduced coefficient . By comparing the field static load test results of some typical engineering projects, the reduced parameter is analyzedand suggested its reasonable value. The reduced coefficient in formula for designing for bearing capacity of cement-soil mixedpile composite foundation was determined by the experiences and the range of is wide. So, it is difficult to accurately calculate bearing capacity of composite foundation. Based on the interaction of pile and soil, this paper discusses various factors influencing the reduced coefficient . By comparing the field static load test results of some typical engineering projects, the reduced parameter is analyzedand suggested its reasonable value.
The slip of the landslide 102 frequently broke the Chuanzang Highway. Detailed field investigation of the landslide 102 and analysis of the factors causing the water-rock interaction in the landslide suggested that the water-rock interaction is intense and diverse in the area. Based on this result, the author studied the effect of water-rock interaction on the development and evolution of the landslide 102 on the Chuanzang Highway and then suggested that in prevention of the landslide a stress should be placed on the water-rock interaction. The slip of the landslide 102 frequently broke the Chuanzang Highway. Detailed field investigation of the landslide 102 and analysis of the factors causing the water-rock interaction in the landslide suggested that the water-rock interaction is intense and diverse in the area. Based on this result, the author studied the effect of water-rock interaction on the development and evolution of the landslide 102 on the Chuanzang Highway and then suggested that in prevention of the landslide a stress should be placed on the water-rock interaction.
Engineering-hydrogeological problems are arisen from the interaction between engineering activities and geological environment, in which rock and soil mass and groundwater are the especially important constituents. Howerer, today research on them is relatively dispersive and simple due to their complexity and lack of comprehensive and systematic study methods starting from geological analysis of mechanism to geological model based on geological regularities, then to prediction of the tendency of geological evolvement and taking proper measures for solving the problems. In this paper, according to existence of water-sensitive structure in hydroelectric power project region and based on the comprehensive study of types and characteristics of the interaction between groundwater and rock and soil mass, and groundwater and engineering construction, the possible engineering Hydrogeological problems are reservoir in duced earthquakes leakage from reservoir bottom in karst, stability of high slope at reservoir banks, sliding of dam foundation and dam abutment, and confined water at key positions which are introduced and determined byusing water-sensitive factors (or structure) and according to special hydrogeological conditions . Engineering-hydrogeological problems are arisen from the interaction between engineering activities and geological environment, in which rock and soil mass and groundwater are the especially important constituents. Howerer, today research on them is relatively dispersive and simple due to their complexity and lack of comprehensive and systematic study methods starting from geological analysis of mechanism to geological model based on geological regularities, then to prediction of the tendency of geological evolvement and taking proper measures for solving the problems. In this paper, according to existence of water-sensitive structure in hydroelectric power project region and based on the comprehensive study of types and characteristics of the interaction between groundwater and rock and soil mass, and groundwater and engineering construction, the possible engineering Hydrogeological problems are reservoir in duced earthquakes leakage from reservoir bottom in karst, stability of high slope at reservoir banks, sliding of dam foundation and dam abutment, and confined water at key positions which are introduced and determined byusing water-sensitive factors (or structure) and according to special hydrogeological conditions .
The tunnel of main line of the Project of Diverting Water from Yellow River at Wanjiazhai, Shanxi, passes largely through subsiding loess, which is mainly upper Pleistocene eolian loess. Field geological inverstigation and laboratory geotechnical test permitted us to understand the physical and mechanical properties and deformation of the subsiding loess. Analyzing the characteristics and regularities of the wet subsidence of loess, we discuss the causes for defects in construction of the tunnel and suggest a scheme of reasonable engineering treatment for ensure the unimpeded water flow. The tunnel of main line of the Project of Diverting Water from Yellow River at Wanjiazhai, Shanxi, passes largely through subsiding loess, which is mainly upper Pleistocene eolian loess. Field geological inverstigation and laboratory geotechnical test permitted us to understand the physical and mechanical properties and deformation of the subsiding loess. Analyzing the characteristics and regularities of the wet subsidence of loess, we discuss the causes for defects in construction of the tunnel and suggest a scheme of reasonable engineering treatment for ensure the unimpeded water flow.
Juyutuo landslide, about 238 104 m3 in volume, is located in Wanzhou district, Chongqing city. This paper describes the characteristics of pattern distribution, structure and deformation of th landslide. The causes for formation the, stability and comprehensive treatment of the landslide are also discussed. Useful experiences in investigation and treatment of landslides in the Three-Gorges Reservoir area are presented in the paper. Juyutuo landslide, about 238 104 m3 in volume, is located in Wanzhou district, Chongqing city. This paper describes the characteristics of pattern distribution, structure and deformation of th landslide. The causes for formation the, stability and comprehensive treatment of the landslide are also discussed. Useful experiences in investigation and treatment of landslides in the Three-Gorges Reservoir area are presented in the paper.
Base on the slope survey on the roadcuts of Chongqing-Qijiang and Qijiang-Wansheng super-highways in red beds, the paper presents a concept of M-shaped roadcut slopes and their features, briefly analyzes the composition and characteristics of rock and residual soil in red beds, and discusses the types of hazards and the causes for forming M-shaped slope. It provides a basis for evaluation of slop stability taking measures for reasonable reinforcement of the slope. Base on the slope survey on the roadcuts of Chongqing-Qijiang and Qijiang-Wansheng super-highways in red beds, the paper presents a concept of M-shaped roadcut slopes and their features, briefly analyzes the composition and characteristics of rock and residual soil in red beds, and discusses the types of hazards and the causes for forming M-shaped slope. It provides a basis for evaluation of slop stability taking measures for reasonable reinforcement of the slope.
Selection of the location and axis for underground plant building is an important geological work,In this paper,according to the analysis of engineering geological conditions, the optimized selection if its location and axis is researched. Selection of the location and axis for underground plant building is an important geological work,In this paper,according to the analysis of engineering geological conditions, the optimized selection if its location and axis is researched.
The variability in orientation and inclination of drill for seepage control (reinforcement)engineering is determined by the anisotropy of permeability of jointed rockmass and random of permeability ratio,which also indicates that the assumption that the permeability of rockmass is isotropic is not actual in the design of seepage control.The vector of drill for seepage control should be determined from the joint width and orientation along which the permeability and its ratio are larger. The variability in orientation and inclination of drill for seepage control (reinforcement)engineering is determined by the anisotropy of permeability of jointed rockmass and random of permeability ratio,which also indicates that the assumption that the permeability of rockmass is isotropic is not actual in the design of seepage control.The vector of drill for seepage control should be determined from the joint width and orientation along which the permeability and its ratio are larger.
A quantitative analysis of microstructure of weathered granite under optical microscope by using Qwins image processing system is done in the paper and quantitative indexes, such as content, grain size, orientrf porosity, shape factor etc. are listed. According to the analysis result, the granite in Kwun Tong is moderately weathered fine-grained granite, and the granite in Shek Kip Mei is highly weathered coarse-medium-grained granite. A quantitative analysis of microstructure of weathered granite under optical microscope by using Qwins image processing system is done in the paper and quantitative indexes, such as content, grain size, orientrf porosity, shape factor etc. are listed. According to the analysis result, the granite in Kwun Tong is moderately weathered fine-grained granite, and the granite in Shek Kip Mei is highly weathered coarse-medium-grained granite.
Qingdao port is an important port in northen China. But there exists hidden peril in its service as it has long been out of repair. Compared with several reinforcement schemes,the scheme of vertical grouting was adopted finally. In order to detect the reinforcement effectiveness of the port by underwater high-pressure grouting,the elastic wave CT technique, and detection of wave velocity and point loading strength of the rock core specimens are adopted. In this article,the principle of detection and the elastic wave computer-aided tomography (CT) are introduced and the application of elastic wave CT to examining the effect of grouting is discussed. It is confirmed that elastic wave CT technique is uniquely effective in detecting the effect of grouting at high pressure under water. Qingdao port is an important port in northen China. But there exists hidden peril in its service as it has long been out of repair. Compared with several reinforcement schemes,the scheme of vertical grouting was adopted finally. In order to detect the reinforcement effectiveness of the port by underwater high-pressure grouting,the elastic wave CT technique, and detection of wave velocity and point loading strength of the rock core specimens are adopted. In this article,the principle of detection and the elastic wave computer-aided tomography (CT) are introduced and the application of elastic wave CT to examining the effect of grouting is discussed. It is confirmed that elastic wave CT technique is uniquely effective in detecting the effect of grouting at high pressure under water.
Seismic computer-aided tomography(CT) is a new geophysical technique. This method has advantages of high resolution,high reliability and visual image features. It can be widely used in engineering-geological investigation and hazard research of highway,site, tunnel and slope. Its application to geological hazard diagnosis in Bajiaoqing tunnel of Yuanmo thruway has yidlded a good result. Seismic computer-aided tomography(CT) is a new geophysical technique. This method has advantages of high resolution,high reliability and visual image features. It can be widely used in engineering-geological investigation and hazard research of highway,site, tunnel and slope. Its application to geological hazard diagnosis in Bajiaoqing tunnel of Yuanmo thruway has yidlded a good result.