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
Bridge bearing people's safety and happiness, bridge safety is a problem that can not be ignored. On July 21, under the leadership of Liu Gaojian, the leader of the practice group of "Bridge building people's livelihood, Concrete building future", according to the testing task arranged by the bridge testing center, the members of the practice group and the professional staff of the testing center went to Laizhou City, Yantai City, to test and survey the cross-channel highway bridge in Laizhou area of the Yantai section of Jiaodong Diversion water.
Through the explanation of the staff and the field investigation of the bridge, the members of the "bridge builds people's livelihood, Concrete builds the future" practical practice group had a deeper understanding of the existing types of bridge diseases and the current technology of bridge detection. Under the guidance of the staff, the members of the practice group have carried out professional bridge inspection on the decks of such Bridges as S218 cross-canal Road bridge of Chengsan Road, Laigang Road cross-canal Road Bridge, and Dongnan cross-canal Road Bridge of Beidengjia. At the same time, the bridge floor cracks, deep water whitening, honeycomb surface and concrete spalling and other bridge diseases are analyzed professionally. The team members have a deeper knowledge of bridge disease identification and classification.
Let the "minor disease" gradually develop into a "major disease", and the bridge will eventually develop into a dangerous bridge if it works with "disease" for a long time. Strengthening the inspection of highway bridge disease can provide more powerful guarantee for the safe operation of bridge. In the field investigation of the cross-district bridge in Laizhou, the members of the practice group fully understood the types of bridge diseases and the main causes of the formation of the diseases, and also realized the importance of strengthening the bridge disease detection more deeply, so as to strengthen the determination of the members of the practice group to improve the safety of the bridge.
