Experimental Study On Old Standard Highway Guardrails' Anti-collision Ability's Promotion

Recent years,with the amount of our country's freeway service years' increasing,old freeway guardrails can not meet the requirement of the latest traffic security.The old freeway guardrails' supersession and selling can lead to tremendous economical lost,how to update the old guardrail and how to evaluate the effect of the updating are two issues that needed to be solved.Therefore,in order to solve to the existing shortage of old guardrail,the paper put forward the old guardrail updating scheme and the new type experimental test on guardrail's anti-collision ability,and did test to analyze the updating guardrail.According to the shortage of the old guardrail,the paper put forward the updating scheme,referring to which,the concrete is poured to the guardrail column and the steel reinforcement cage is placed in it.The updating scheme of waveform beam plate was put forward,in which,the cross shaped knighthead was used to reinforce the old guardrail,and the guardrail waveform beam plate's entire anti-collision ability was promoted efficiently.In this paper,the static load test was designed to evaluate the mechanical properties of guardrail column.In the test,the guardrail column was put in the foundation cube in which simulative roadbed was loaded and the cooperative bearing effect of the soil and the column was truly simulated.Considering the influencing factors of guardrail column's anti-collision ability,the electric-hydraulic servo-load system was used to give load to the column in horizontal direction,then the stress and the distortion were analyzed and the tensile strength and the distortion properties were obtained.In this paper,the dynamic load test on anti-breaking and anti-pulling was operated,the moment and the distortion of column being hit by the car can be furtherly simulated.By operating the test,the similar result was obtained and the correct of static load test was proved.In this paper,the heavy bob impact test was designed,the entire intensity and the energy-absorbing property were evaluated.The difference of heavy bob strike and car strike was analyzed and the impact energy was modified.By controlling the weight of the bob and the length of the swing rope,the strike energy absorbing process was simulated.The process of the strike test on the column and the waveform beam plate of combined median separated guardrail and the new/old standard guardrail were recorded in detail.By measuring and analyzing the data collected by i-SPEED Control Software and comparing the distortion and the energy-absorbing situation,the conclusion was obtained,which shows that,the intensity of the updated guardrail is better than the new standard guardrail and the heavy bob strike test scheme's feasibility was proved.