Risk Assessment And Length Setting Study Of Mountain Highway Maintenance Work Area

In recent years,with the rapid development of expressways,the early construction of expressways has faced maintenance difficulties,especially mountain expressways.Although the state has been committed to expanding the territory of mountain expressways in recent years,most mountain expressways still carry a large amount of traffic in mountain areas.Mountain highway maintenance operation area leads to traffic efficiency,traffic safety reduction,coupled with mountain terrain and adverse climate and other factors,the accident rate is much higher than ordinary roads,but at present,there are very few special studies on risk assessment of mountain highway maintenance operations in China,and some provinces and cities have issued local standards for highway risk assessment technology,but the relevant national norms and standards for the layout length of the maintenance operation area are set more generally,and ordinary road maintenance operation areas are used.Therefore,it is necessary to carry out special research on maintenance operations on mountain expressways.This thesis establishes a risk assessment system for highway maintenance operations in mountainous areas,as a more systematic special risk assessment,improves the risk assessment system of highway maintenance operations to a certain extent,establishes a corresponding length setting scheme according to the risk assessment results,and refines the length setting content of highway maintenance operation layout,which has certain practicality.In this thesis,the risk assessment research of the mountain highway section with clear maintenance operation requirements is carried out,the linear conditions are used to divide the road section unit,the special evaluation index is determined,and the risk evaluation index is determined according to the mountain expressway,maintenance operation demand and relevant norms and standards in combination with traffic flow,road surface and safety facilities,natural climate factors,and the fuzzy comprehensive evaluation combined with analytic hierarchy method is used as the evaluation model.Comprehensively evaluate the risks of mountain highway maintenance operation areas,and establish a risk assessment system for mountain highway maintenance operation areas.Based on the risk assessment results,the multi-risk level layout length setting scheme is determined,and based on the hierarchical speed limit scheme,the recommended value of warning zone length setting based on traffic conflict threshold and the recommended value of upstream transition zone length setting based on vehicle merging model and acceptable clearance theory are determined for high-risk roads,and the recommended value of setting the length of multi-risk level maintenance operation area is obtained by combining the length of other areas.Taking the Wulong tunnel section of Yuxiang Expressway as the actual project,the risk assessment of the mountain highway maintenance operation area was carried out,and the evaluation result was that the low-risk level was basically consistent with the actual road section survey,because no other road section data was collected,the Wulong tunnel data was still used as the engineering example,and the high-risk level length setting scheme and the normative standard setting scheme were simulated and compared,and it was found that the service level of the high-risk level length setting scheme and the normative standard setting scheme were generally the same,but the safety level was slightly higher than that of the normative standard setting scheme.The recommendation scheme is more reasonable,which is conducive to improving the safety of the maintenance operation section of the expressway in mountainous areas.