tailieunhanh - Báo cáo lâm nghiệp: " Possibilities of using the portable falling weight deflectometer to measure the bearing capacity and compaction of forest soils"

Tham khảo luận văn - đề án 'báo cáo lâm nghiệp: " possibilities of using the portable falling weight deflectometer to measure the bearing capacity and compaction of forest soils"', luận văn - báo cáo phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | JOURNAL OF FOREST SCIENCE 56 2010 3 130-136 Possibilities of using the portable falling weight deflectometer to measure the bearing capacity and compaction of forest soils R. Klvac P. Vrána R. Jirousek Department of Forest and Forest Products Technology Faculty of Forestry and Wood Technology Mendel University in Brno Brno Czech Republic ABSTRACT The paper discusses possibilities of using the portable falling weight deflectometer to measure the bearing capacity and compaction of forest soils. Within the study measurements were made using manual penetrometer and Loadman II portable falling weight deflectometer. To eliminate the extreme values Grubbs s test was used. The results indicate that Loadman II deflectometer may be used to measure both the bearing capacity and compaction of forest soils under the canopy as well as in transport lines. A significant difference was found between deflection of water-unaffected sites and water-affected sites and mm respectively . Measurements of bearing capacity after removal of forest litter give far more precise details however the authors do not refuse the measurements without litter removal either. To determine the degrees of soil compaction it is useful to measure the soil reaction time to measure the bearing capacity it is vital to measure deflection. Keywords deflection E-module PFWD soil bearing capacity soil compaction soil reaction The moto-manual technology of wood production is often replaced by fully mechanized technologies. The degree of mechanization is gradually increasing and the timber harvesting and hauling machines do the processing of an ever-higher percentage of annual prescribed cut in the Czech Republic. The timber logging and hauling machines are mainly farm tractors harvesters and forwarders wheeled trucked and or combined in the Czech Republic. However the use of these technologies also entails soil damage hazards. The most frequently occurring reasons for damage to forest ecosystems may be .