Research on Route Selection Model of Road Network Emergency Evacuation under Ice and Snow

Abstract

Abstract:The route selection of road network emergency evacuation is of great practical significance for possible emergencies in future. Based on analyzing the principles of emergency path selection, the paper takes the traffic capacity, intersection density and vehicle delays in the intersection into consideration, and establishes the route selection model of road network emergency evacuation under ice and snow. IntroductionUrban road network is one of the Infrastructures exposed to the natural conditions, the influence of adverse weather conditions or disaster weather on the urban road network is generally serious[1], northern cities in winter suffer more snow and ice, the traffic in Beijing and Shenyang have been disordered and even paused caused by snow storm. Some southern cities have also suffered the freezing rain and snow weather. In order to effectively resist the influence of snow and ice on the urban road traffic, reduce the impact on urban emergency evacuation, it is necessary to study In-depth on the route selection problem of emergency evacuation under ice and snow [2].When an emergency takes place in cities, it is necessary to evacuate and transfer persons in large scale [3], due to the sharp increasing of traffic flow and the change of traffic operating conditions in the short time, the running balance of the road network must be broken, the road network traffic in entire city will be re-allocated, therefore, it is of great significance for guiding future possible emergency to establish the route selection module based on the emergency evacuation conditions [4]. The Initial Selection of emergency evacuation routeEvacuation route would depend on the existing road network, but not the full use, therefore, for the route selection, it is necessary to conduct route initial selection for the final optimal results [5]. When the route is selected, the safety and efficiency of emergency evacuation routes should be fully considered, to conduct initial selection on candidate routes. The main selected parameters include: Road condition. The basic condition of the road influence comfort of drivers and evacuees directly, and better conditions could ensure the safety of vehicles. In addition, from the evacuation demand and the road design, the urban roads on high level have better performance in road capacity and road stability [6], and meet the evacuation needs better avoid traffic congestion in large scale caused by the evacuation.

Design of a Wideband Tonpilz Transducer Comprising Non-Uniform Piezoceramic Stacks with Equivalent Circuits

“…Rodrigo proposed a wideband transducer design that installs three compliant rods and an additional head mass to combine two resonant modes [8]. Butler [9] and Zhang et al [10] both proposed multi-resonance structures with additional head masses and compliant layers. Saijyou and Okuyama proposed installing a bending piezoelectric disk in the head mass to widen the bandwidth [11].…”