In order to actively respond to the call of the national rural revitalization strategy, the practice group of "bridge building people's livelihood, concrete building the future" arrived in Yucheng, Dezhou on July 22, and cooperated with the staff of Shandong Highway and Bridge Testing Center Co., Ltd. to carry out bridge testing work, accurately understand the use of the target bridge, to carry out summer social practice research activities.
After the members of the practice group arrived at the practice site, the team leader first held a small meeting on the specific work arrangement. The meeting mentioned that personal safety should be ensured first, including site safety and food safety. Secondly, the work content was introduced, that is, the test experiment of bridge foundation in the third section of the North Ring section of the second Ring Road of Jinan Ring Highway. The content of the experiment is divided into cement mixing pile coring experiment and dynamic compaction foundation bearing capacity experiment.
In this experiment, a drilling machine is required to take a cement core with a diameter of 0.5m and a length of 10m from the cement mixing pile. After taking out the cement core, the core sample is placed in a row of 2m. Team members need to accurately record the time and length of taking out each piece of core sample, and make a preliminary evaluation of the overall condition of the core sample based on it. Finally, core samples are randomly selected and sent to the laboratory for detailed evaluation and comparison of various data. Because of the difficulty of the work, the core can be up to 10 pieces a day in good weather, such as rain and other bad weather, only 7 pieces a day. In addition, the core-taking process should be carried out in the open air throughout the whole process, with high temperature exposure and extremely difficult conditions. Especially after rainy days, the site roads were muddy and it was extremely difficult for equipment personnel to enter the site, but the staff still completed the work as scheduled, which is worthy of admiration.
Secondly, the bearing capacity experiment of the largest and heaviest dynamic tamped foundation, the experiment first needs to level out a 5m×5m ground on the dynamic tamped foundation, the maximum bearing capacity of 100 tons of jack is placed under an I-beam, on the flat foundation above two 2m×1m×1m concrete test blocks, in which four steel beams are placed. About 20 concrete test blocks, weighing a total of about 100 tons, are placed on the steel beam. After the assembly is completed, the oil pressure pump is connected and the dial indicator is attached. When the initial pressure is completed, it can be read according to the specification. After the reading is finished, record the experimental data, input computer when the internal business, form a curve. Due to the limitations of the site conditions, this work needs to be carried manually about 160 kilograms of jacks, there is still some difficulty in the work.
After two weeks of work, the members of the practice group cooperated with the staff of Shandong Highway and Bridge Testing Center Co., LTD., and basically completed the testing of the bridge foundation, forming a special database, which laid the foundation for the subsequent bridge maintenance work, and also made further complement and perfect the research project of the practice group.
Written by: Qi Xinru
Photo: Liu Gaojian, Liang Zheng
