The Study On The Security Technology In Construction Area Of Overpass

The overpass is a node for converting traffic in highway. Its construction technical isdifficult and organization of traffic flow is complex. Construction accidents and trafficaccidents happened frequently. This brought enormous economic losses to the countrayand individuals，while resulting in advers social impact.In this paper，overpass construction area was regarded as the research object toanalyze. Through the analysis to work zone and its impact area and affiliated regional，thescope of the construction area is determined and the concept of construction area basedon driving characteristics is clearly defined. Through the collection and analysis to datasof traffic accidents，we found that the traffic flow is super-saturated in the constructionarea，load degree in one lane is1.67times than normal road. Trough the analysis to datasof safety incidents，we found that there are five types of accidents during the constructionof overpass: against objects，falls，mechanical injury，vehicle damage and electricalshock，fire，and the reason resulting in the five types accidents，and the dangerous levelsthey belonged.Trough the analysis to safety hazards in the construction method， naturalenvironment，the operating environment，the traffic environment，22kinds of safetyhazards were summarized，safety hazards model of overpass construction zone was built.We use the rough set theory to calculate22index weights，combined with the dangerlevels of indicators，filter out the regulatory to safety facilities from managers，groundconditions for mechanical walking，parked position，conditions for material storage，standard deviation of speed in the upstream transition lanes as safety evalustions ofconstruction zone. Through the analysis to accident datas of construction zones，we usedSPSS to regression model about the relation between standard deviation of speed andeconomic losses，about the relation that reporting time，slope，requirements of materialsmanagement with economic losses.Through the analysis to the characteristics of the construction area and the laws of the accidents，we design a safety protection facility，which is portable，adjustable.Considering the characteristics of traffic flow and the rules of traffic organization，we usevissim to simulate different styles of combination that the circular curve with thetransition curve under various connection of ramp. Finally，we got the best combinationof circular curve and transition curve under different connections and design speeds.Wedesigned and simulated different combinations of speed limit signs，by comparing thedelay with the standard deviation of speed，we got the optimal combination of speed limitsigns.The application of the results will be reduce accidents and injuries in constructionzone of overpass，improve the safety of the construction area，reflecting the concept ofsafety，prevention first.This work supported by the communications department of Hebei province.