<正>In some cases coal measures, goaf, big caves, and huge faults, as well as high initial stress cannot be avoided in road tunnel excavation. These geological features may make it more difficul practical tunnel construction. So it is necessary to take strong precautious measures against gas outburst, water bursting and roof fall in a tunnel across coal measures with risk of gas outburst. The techniques, such as advance drilling exploration, multiple-cycle shallow depth hole controlled blasting, reinforced supporting, which include concrete grouting and twice supporting, and monitoring measures are often applied in the construction of tunnels and satisfied results are achieved. Results in this paper can help others to get experiences in road tunnel construction with similar geological features. 相似文献
Objective: The aim of this study is to evaluate, through a systematic review of hospital-based studies, the proportion of road traffic injuries and fatalities in sub-Saharan Africa (SSA).
Methods: In accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) and Meta-analysis of Observational Studies in Epidemiology guidelines, we searched the following electronic databases: PubMed, Embase, Africa-Wide Information, Global Health, and Web of Science. Articles were eligible if they measured proportion of road traffic injuries (RTIs) in SSA by using hospital-based studies. In addition, a reference and citation analysis was conducted as well as a data quality assessment.
Results: Up to 2015, there were a total of 83 hospital-based epidemiologic studies, including 310,660 trauma patients and 99,751 RTI cases, in 13 SSA countries. The median proportion of RTIs among trauma patients was 32% (4 to 91%), of which the median proportion of death for the included articles was 5% (0.3 to 41%).
Conclusion: The number of studies evaluating RTI proportions and fatalities in SSA countries is increasing but without the exponential rise expected from World Health Organization calls for research during the Decade of Action for Road Traffic Injuries. Further research infrastructure including standardization of taxonomy, definitions, and data reporting measures, as well as funding, would allow for improved cross-country comparisons. 相似文献