Influence of temperature changes on the CP Ⅲ plane measurements
The mileage of constructed high-speed railways in China has reached over 30,000 kilometers,that ranking the first in the world.Before the production of ballastless track bed,the track control net-work(CP Ⅲ)measuring is an essential task.It is found in the construction of a high-speed railway CPⅢ network that the coordinate difference between the two measurements at the lap area is large and field remeasuring is needed.By analyzing these data,it is concluded that the significant temperature dif-ference betweenthe two measurements could be one of the reasons for the unsuccessful overlap,tem-perature changes can have an impact on the measurement results of CP Ⅲ.The calculated width varia-tion of the beam based on the concrete expansion coefficient shows minimal deviation from the mea-surements,none of them exceeds 0.7 mm,thereby validating the mentioned perspectives.Finally,it con-eluded that if the threshold of bridge beam width variation is set to±2 mm,the temperature difference between two measurements should not exceed-21.6 ℃～21.6 ℃ and-16.4 ℃～16.4 ℃ when the bridge beam width is 9.25 m and 12.20 m respectivelly.
万方数据
