The safety of engineering structures is increasingly receiving attention,and how to quickly evaluate the safety of structures has become a hot and difficult research topic in this field.The deformation displacement generat-ed by the structure is one of the intuitive variables in structural safety assessment.How to improve the accuracy of displacement monitoring based on computer vision is one of the focuses of research in this field.This article propos-es a structural dynamic displacement data processing method that combines non-contact and contact methods.The dynamic trajectory of the structural visual target is converted into pixel displacement,and then Kalman filtering is performed on the displacement converted from the accelerometer data to simulate the true displacement of the struc-ture.The feasibility of the proposed method is verified by identifying structural modal parameters.The research re-sults indicate that the method proposed in this paper obtains dynamic displacement of structures and has high moni-toring accuracy.
The article introduces long-short pile combined with reinforcement in passive zone support structure about some project in detail and analyzes mechanism of the support briefly. The influence of long-short pile and reinforcement in passive zone on deformation of support pile, overall stability of excavation, moment of support pile is analyzed by using finite element method. The results show: compared to no reinforcement, the maximum horizontal displacement of support pile is significantly reduced after reinforcement in passive zone, and overall stability safety factor of excavation has a more substantial increase; After setting a certain amount of reinforcement mass, there has a little effect on maximum horizontal displacement of support pile by using short pile, long-short pile and long pile, but it is minimal by using short pile; The setting of long pile is beneficial to improve the overall stability safety factor of excavation, but whether the passive zone reinforces or not has a greater impact on the stability of excavation; When the parameters of reinforcement mass reach a certain range, the parameters of reinforcement mass has little effect on the maximum horizontal displacement of support pile, but it has a certain role in improving the overall stability safety factor of excavation; The height of reinforcement mass has a great influence on the moment of support pile, but the form and width of reinforcement mass have little effect on the moment of support pile.
As a waste of wood processing, a large accumulation of sawdust will have an impact on the environment. In this paper, sawdust is added to concrete to explore the influence of sawdust on the performance of concrete. Experiments show that sawdust water absorption and friction are the key factors affecting the rheological properties. Through Inductively coupled plasma mass spectrometry, it can be understood that sawdust fiber can adsorb ions, so it will have an impact on early hydration. Nanoindentation shows that sawdust changes the properties of hydration products, which is related to the adsorption of ions by sawdust. Sawdust hurts the compressive strength and heat resistance of concrete. Mercury intrusion porosimetry and Ultrasonic pulse velocity results show that similar to wood chips will lead to a decline in the interfacial transition zone, resulting in increased porosity, but the adsorption of chloride ions on wood chips is beneficial to the protection of concrete, so in the appropriate dosage conditions, wood chips will not significantly affect the performance of concrete.
Based on the Jiangluling Tunnel project, we investigate the engineering design and ground temperature monitoring on the active thermal protection entity project of the heat pipe group in the shallow-buried section of the tunnel in the permafrost region. It is concluded that the application of the heat pipe group has raised the upper limit of the frozen soil at the tunnel top, and the frozen soil impermeable layer formed, which shortens the freezing time of the surrounding rock of the tunnel. The occurrence and development of the disease in the shallow-buried section of the tunnel portal are effectively prevented, providing the eference for disease prevention and treatment of similar projects in the shallow-buried section of tunnels in permafrost regions.
管廊工程开挖卸载会对下方的地铁隧道产生扰动影响,为比较不同开挖方案的影响程度,依托合肥某综合管廊工程,采用数值分析手段,建立管廊、管线、道路基坑与地铁隧道的三维有限元模型,分析整体开挖、先两边后中间、先中间后两边3种管廊开挖工况下地铁隧道位移情况.研究结论地铁隧道以竖向位移为主;管廊、管线、道路基坑开挖引起了地铁隧道较大位移,是位移控制的关键阶段;上方管廊预留土对控制地铁隧道位移有利;管廊分区开挖形式对后续管线、道路基坑施工引起的隧道位移影响很小;3种工况地铁隧道最大位移未超过控制值,结构处于安全状态.可为同类型地质条件工程提供借鉴与参考.
