Variation Of Geotechnical Properties Of Weathered Granite In Southeast China

Weathering granite is distributed in most surface areas of the southeast China. They, as one constitute part of the red weathering crust in south China, are paid more attention by experts and scholars in geotechnical engineering, engineering geology and environmental geology. The main reason is that, granite without weathering is hard massive rock with favorable engineering geological properties, but its strength is sharply decreased with progressive weathering. The strength varies to a large extent in different regions and location of profiles due to weathering grades are influenced by climate, landform, biology, etc.. In one profile, residual soils without parent rock structures on the uppermost, rocks with more fissures and fracture in the mid-section and fresh rocks with few fractures are in the bottom.Previously most researches on weathering crust were carried out in different regions with aims at different projects. The researches deal with subjects of chemical components and mineral contents, microstructures, physics and mechanics. But nearly all of the researches are dispersed and independent, and the regulation of result variations in area is paid less attention. These shortages were associated with various but disagreement standards of weathering grades, with much more parameters or indices, which are artificial identified or lack of strict tests in standards. Through collecting data, filed investigation and laboratory tests on aspects such as chemical components, physical and mechanical properties, this paper was tried to solve the problems as presented above. Main aim of this research is to reveal the variation regulation of mechanical index in this region. The research works include literatures (about 300 pieces) review and collection into about 5 research bearings. They are the study on weathering granites in regions, the weathering degrees and the standards of classification, the basic engineering geological properties of weathered granites, the bearing capacity of the foundation and the stability of the slope (cut slope and nature slope), and the geological and environmental hazards. Then, a database of the weathering crust information about region and the profiles was set up using the database software with relation model-Access2000. The main function of the database is to query various index and their variations. Based on this, a brief analysis was carried out on regulation of variations in areas and profiles for the weathered granites.