3D geological modeling, one of the most important applications in geosciences of 3D GIS, forms the basis and is a prerequisite for visualized representation and analysis of 3D geological data. Computer modeling of geo...3D geological modeling, one of the most important applications in geosciences of 3D GIS, forms the basis and is a prerequisite for visualized representation and analysis of 3D geological data. Computer modeling of geological faults in 3D is currently a topical research area. Structural modeling techniques of complex geological entities contain- ing reverse faults are discussed and a series of approaches are proposed. The geological concepts involved in computer modeling and visualization of geological fault in 3D are explained, the type of data of geological faults based on geo- logical exploration is analyzed, and a normative database format for geological faults is designed. Two kinds of model- ing approaches for faults are compared: a modeling technique of faults based on stratum recovery and a modeling tech- nique of faults based on interpolation in subareas. A novel approach, called the Unified Modeling Technique for stratum and fault, is presented to solve the puzzling problems of reverse faults, syn-sedimentary faults and faults terminated within geological models. A case study of a fault model of bed rock in the Beijing Olympic Green District is presented in order to show the practical result of this method. The principle and the process of computer modeling of geological faults in 3D are discussed and a series of applied technical proposals established. It strengthens our profound compre- hension of geological phenomena and the modeling approach, and establishes the basic techniques of 3D geological modeling for practical applications in the field of geosciences.展开更多
One of the core developments in geomathematics in now days is the use of digital data processing in mineral prospecting and assessment. The information discovery is based on multidisciplinary geoscientific data and an...One of the core developments in geomathematics in now days is the use of digital data processing in mineral prospecting and assessment. The information discovery is based on multidisciplinary geoscientific data and an integrated management approach is crucial. The lack of a standard description hinders interoperations in database search and discovery. Metadata hierarchy aims to provide a standard view of the geoscientific data, and facilitate data description and discovery. In the research of integrated geoscientific database, the metadata hierarchy used a standardized description for each collection in the content structure and realized in semantic structure. It recorded both dataset identification and inner structures and relationships of objects, thus differed from many other applications. There were four tiers in the content structure and three levels in the semantic structure. With its help, database users could determine how applicable a dataset is to a project, and improve their queries to the database. Effectiveness of data accessing is significantly enhanced through the rich, consistent metadata.展开更多
The cause and mechanism of fly rock in geological condition of weak intercalation are analyzed.According to the features of fly rock caused by weak intercalation,the differences of fly rock caused in weak intercalatio...The cause and mechanism of fly rock in geological condition of weak intercalation are analyzed.According to the features of fly rock caused by weak intercalation,the differences of fly rock caused in weak intercalation and general condition are distinguished.Specific to complicated circumstance of weak intercalation and town,the control measures of fly rock are given.With project examples,the control measures are scientific and rational,and have important project value.展开更多
Assessing subsurface characteristics and imaging geologic features （e.g., faults, cavities, low-velocity lay- ers, etc.） are typical problems in near-surface geophysics. These questions often have adverse geotechni-...Assessing subsurface characteristics and imaging geologic features （e.g., faults, cavities, low-velocity lay- ers, etc.） are typical problems in near-surface geophysics. These questions often have adverse geotechni-cal engineering implications, and can be especially acute when associated with high-hazard structures such as large earthen flood-control dams. Dam-related issues are becoming more frequent in the United States, because a large part of this major infrastructure was designed and constructed in the early- to mid-twentieth century; these dams are thus passing into the latter stages of their design life, where minute flaws that were overlooked or thought to be insignificant in design/construction are now proving problematic. The high-hydraulic heads associated with these structures can quicken degra-dation of weak areas and compromise long-term integrity. Addressing dam-related problems solely with traditional invasive drilling techniques is often inadequate （i.e., lack of lateral resolution） and]or econom- ically exorbitant at this scale. However, strategic geotechnical drilling integrated with the broad utility of near-surface geophysics, particularly the horizontally polarized shear-wave （SH-mode） seismic-reflection technique for imaging the internal structural detail and geological foundation conditions of earthfill embankment dams can cost-effectively improve the overall subsurface definition needed for remedial engineering. Demonstrative evidence for this supposition is provided in the form of SH-wave seismic-reflection imaging of in situ and engineered as-built components of flood-control embankment dams at two example sites in the central United States.展开更多
基金Project 2001AA135170 supported by the National High-Tech Research and Development (863) Program of China and 06ZR14031 by the Natural ScienceFoundation of Shanghai Municipality
文摘3D geological modeling, one of the most important applications in geosciences of 3D GIS, forms the basis and is a prerequisite for visualized representation and analysis of 3D geological data. Computer modeling of geological faults in 3D is currently a topical research area. Structural modeling techniques of complex geological entities contain- ing reverse faults are discussed and a series of approaches are proposed. The geological concepts involved in computer modeling and visualization of geological fault in 3D are explained, the type of data of geological faults based on geo- logical exploration is analyzed, and a normative database format for geological faults is designed. Two kinds of model- ing approaches for faults are compared: a modeling technique of faults based on stratum recovery and a modeling tech- nique of faults based on interpolation in subareas. A novel approach, called the Unified Modeling Technique for stratum and fault, is presented to solve the puzzling problems of reverse faults, syn-sedimentary faults and faults terminated within geological models. A case study of a fault model of bed rock in the Beijing Olympic Green District is presented in order to show the practical result of this method. The principle and the process of computer modeling of geological faults in 3D are discussed and a series of applied technical proposals established. It strengthens our profound compre- hension of geological phenomena and the modeling approach, and establishes the basic techniques of 3D geological modeling for practical applications in the field of geosciences.
基金Funded by the National 863 Program of China (No.2002AA130406)the Key Project of China Geological Survey (No.200218310077).
文摘One of the core developments in geomathematics in now days is the use of digital data processing in mineral prospecting and assessment. The information discovery is based on multidisciplinary geoscientific data and an integrated management approach is crucial. The lack of a standard description hinders interoperations in database search and discovery. Metadata hierarchy aims to provide a standard view of the geoscientific data, and facilitate data description and discovery. In the research of integrated geoscientific database, the metadata hierarchy used a standardized description for each collection in the content structure and realized in semantic structure. It recorded both dataset identification and inner structures and relationships of objects, thus differed from many other applications. There were four tiers in the content structure and three levels in the semantic structure. With its help, database users could determine how applicable a dataset is to a project, and improve their queries to the database. Effectiveness of data accessing is significantly enhanced through the rich, consistent metadata.
文摘The cause and mechanism of fly rock in geological condition of weak intercalation are analyzed.According to the features of fly rock caused by weak intercalation,the differences of fly rock caused in weak intercalation and general condition are distinguished.Specific to complicated circumstance of weak intercalation and town,the control measures of fly rock are given.With project examples,the control measures are scientific and rational,and have important project value.
文摘Assessing subsurface characteristics and imaging geologic features （e.g., faults, cavities, low-velocity lay- ers, etc.） are typical problems in near-surface geophysics. These questions often have adverse geotechni-cal engineering implications, and can be especially acute when associated with high-hazard structures such as large earthen flood-control dams. Dam-related issues are becoming more frequent in the United States, because a large part of this major infrastructure was designed and constructed in the early- to mid-twentieth century; these dams are thus passing into the latter stages of their design life, where minute flaws that were overlooked or thought to be insignificant in design/construction are now proving problematic. The high-hydraulic heads associated with these structures can quicken degra-dation of weak areas and compromise long-term integrity. Addressing dam-related problems solely with traditional invasive drilling techniques is often inadequate （i.e., lack of lateral resolution） and]or econom- ically exorbitant at this scale. However, strategic geotechnical drilling integrated with the broad utility of near-surface geophysics, particularly the horizontally polarized shear-wave （SH-mode） seismic-reflection technique for imaging the internal structural detail and geological foundation conditions of earthfill embankment dams can cost-effectively improve the overall subsurface definition needed for remedial engineering. Demonstrative evidence for this supposition is provided in the form of SH-wave seismic-reflection imaging of in situ and engineered as-built components of flood-control embankment dams at two example sites in the central United States.
