On May 19, the Xiatong No. 2 section of Qinghai 308 Provincial Highway, which was constructed by the Second Company of China Railway Eleventh Bureau, was verified at the subgrade and the bottom of the road. The verification totaled 18 kilometers, and the indicators such as roadbed elevation, center deviation, structural size, longitudinal and horizontal slope, bending and sinking, compaction degree, and overall appearance tested by the third party all met the design requirements, and successfully passed the verification in the whole line at one time.
1. Compaction test
The subgrade of the Xiatong Ii section of Qinghai 308 Provincial Highway has a total length of 27.01 km, is built according to the secondary highway standard, the design speed is 60 km /h and 40 km/h, and the width of the subgrade is 10 meters. Since the project belongs to a high altitude area (average altitude of 3500 meters), the winter is cold and the freezing period is long, and the frozen soil depth is 1.5 meters. Considering the phenomenon of overloading and heavy load of trucks during actual operation, the requirements for cushion bending and sinking are high. Since the project resumed work in early 2021, the project department of the second company has organized personnel and machinery to set off a climax of surprise construction, racing against the clock, working overtime, stopping equipment non-stop, overcoming difficulties such as rain and snow weather on the plateau and various unfavorable factors, always keeping pace with the deployment of the owner's construction period, strictly controlling the quality of subgrade filling, closely following the owner's construction period node, completing the subgrade construction task at high speed and quality, ensuring the overall construction period requirements of the subgrade project, and laying a solid foundation for the follow-up pavement construction.
2. Bending and sinking detection
The successful verification of the subgrade and the bottom of the road surface is another important node after the construction of the water stability test section of the Provincial Highway 308 project, and the project will continue to maintain the construction trend, make overall arrangements, strengthen safety and quality control, steadily and orderly promote construction, and ensure the smooth completion of the traffic target on schedule. (Yan Changyu)