How to reinforce old factory buildings

1 Introduction The West Tower of Guangzhou Zhujiang New Town is 432 m tall (Figure 1), ranking sixth in the world and second in the Chinese mainland. The project covers an area of 31,000 m2, with a total construction area of around 450,000 m2. It consists of a main tower with 4 underground floors and 103 above-ground floors, along with an annex building with 28 floors. The complex will include a super-luxury five-star hotel, top-class office spaces, an international conference center, hotel-style apartments, high-end shopping malls, fine restaurants, an underground parking garage, and VIP boarding passes, and is set to become the most elite comprehensive business complex in South China. The project will be completed by the end of 2009 and put into use as a supporting facility for the 2010 Asian Games. 2 Information management systems: Building on the successful experiences of information management in large-scale projects (such as the new CCTV headquarters project and the Shanghai World Financial Center project), advanced information management systems are promoted for use. To ensure standardized and modernized information management, guarantee the accuracy, timeliness, and traceability of information, and utilize modern information management methods to transform management approaches in order to improve work efficiency, management standards, and collaborative capabilities. The information management systems promoted and applied in this project are shown in Table 1. 3P3E/C Project Management System 3.1 Overview of the P3 Management System P3 software is short for Primavera Project Planner; its main functions are schedule, cost, and resource management. The main feature is that the software integrates advanced project management concepts and methods, enabling it to effectively combine schedule, resources, resource constraints, and resource allocation. It allows for comprehensive and dynamic management of project timelines, costs, and resource utilization, while also establishing a seamless connection between the current progress of a project and its target management objectives. Using P3 software as a management tool for project schedule control can serve the following purposes: 3.1.1 Developing and optimizing the overall project schedule as well as the schedule for individual project phases, and making timely adjustments and updates to these schedules as needed ； Generate various charts. 3.1.2 Calculate time parameters to identify the critical path and critical activities. 3.1.3 Compare the actual progress with the planned progress to determine the deviation and evaluate the actual progress. On this basis, tracking of the actual progress against the planned progress is achieved. 3.1.4 The summary includes plans for the requirements of funds, materials, labor, and specialized construction equipment, as well as their distribution over time, providing informational support for the supply of project resources. 3.1.5 On this basis, it provides convenience and a foundation for formulating medium- and short-term progress plans. 3.2 Using P3 for progress management 3.2.1 Utilizing P3 software to develop construction project schedules 3.2.1.1 Based on an analysis of the engineering drawings and contract documents, and in accordance with the technical measures required for project construction, it is possible to determine the various tasks and operations needed to achieve the different objectives of the project, as well as the logical relationships between these tasks. 3.2.1.2 Estimate the time required to complete each task based on the nature of the work, as well as the equipment and manpower allocated. 3.2.1.3 In P3, enter the project’s start date, the various tasks involved, the duration of each task, and their logical relationships. Through P3’s automatic updates or progress calculations, a series of time-related parameters can be obtained, including the earliest start date and earliest completion date for each task, as well as the latest start date and latest completion date. The float time for each task and the earliest possible completion date for the entire project can also be determined. Additionally, constraints can be set for certain milestones and the dates at which work is handed over between different sections of the project by applying appropriate restrictions. 3.2.1.4 Following the approach of P3 and using 44 panels, the total load on the roof truss after the modification is kept roughly the same as before; the brackets, columns, and foundations meet the requirements and no reinforcement is necessary. IV. Reinforcement design of steel roof trusses The steel roof trusses consist of upper chords, lower chords, intermediate web members, and end members at the supports. In this project, there are two types of connections between the steel roof trusses and the concrete columns: one type involves the steel roof trusses resting directly on the top of the columns, with hinge-type supports. Another option is to hinge the steel roof truss to brackets, with the brackets being steel-connected to the concrete columns. Since the original steel roof trusses were exposed to the air and have been in use for over 15 years, and although the manufacturer carries out regular anti-corrosion treatments on the steel structures, rusting of the steel is inevitable due to the air, water vapor in the workshop, and corrosive gases generated during production. On-site inspections of the workshop revealed that, due to their long period of use, there was varying degrees of dust accumulation on the upper and lower chords as well as the web members of the trusses. After removing the dust, the degree of rusting on the steel was found to be roughly as expected: the upper chords were the least affected by rusting, the web members were in fair condition, while the lower chords were in the worst condition. Based on this level of rusting, it was necessary to consider the reduction in the cross-sectional area of the steel (with calculations assuming a reduction of one grade in wall thickness compared to the original value; for example, what was originally L125X8 was now calculated as L125X6). After re-calculating the steel roof trusses, it was determined that all three trusses needed to be reinforced in order to meet the required standards. For the upper chord: due to the presence of significant concentrated loads, it is in a compressed state; moreover, the roof panels within the building area have been removed. The out-of-plane calculated length must be ensured by adding additional transverse horizontal supports, and joint plates are also required for the connection between these transverse supports and the upper chord. Therefore, a steel plate with a thickness of t=10 is installed along the entire length of the upper chord. Regarding the lower chord: Since all these reinforcement works are carried out at heights, and the lower chord of the roof truss still experiences tensile stresses due to its own weight as well as the construction loads after the removal of the large roof panels, using overhead welding increases the difficulty for workers during the welding process, raises the level of risk, and makes it difficult to ensure the quality of the work. If high-strength bolts are used for reinforcement, the reduction in the cross-sectional area leads to a decrease in the safety margin after reinforcement. After comparison, it was decided to use t=12 steel plates attached to the bottom within 2 sections on each side of the mid-span along the length direction; these plates are connected to the lower chord by welding along the length of the angle steel. The connection between the end web members and the middle vertical members is made using small angle steel plates. Specific reinforcement data and methods are detailed in Appendix 1. Furthermore, since the reinforcement work took place in the summer, there was a higher likelihood of heavy rain and strong winds in the area, leaving little time for the construction. The factory building required that the reinforcement of the steel roof trusses and the installation of the roof be completed within 25 days, so the feasibility of such construction operations also had to be taken into account. V. Construction of steel roof truss reinforcement: The construction process takes into account the sequence of operations, which is different from the method where the components are manufactured in a factory and then transported to the site for assembly. All of these reinforcement works involve working at heights, and the construction period is short; moreover, the roof trusses are under stress. Therefore, the sequence of operations was determined after taking into account these stress conditions during the design phase: First, the large roof panels were removed, temporary supports were added to ensure stability in the area being modified, and the steel roof trusses were treated to remove rust and prevent corrosion. II: Reinforce the steel roof truss according to the drawings. III: Installation of the horizontal bracings on the top and bottom chords of the roof truss, as well as the vertical bracings of the roof truss. IV: Installation of the elephant house and dust collection pipes. The elephant house and dust collection pipes are both additional components that can be manufactured in the factory. The elephant house is designed as a square shape, forming a geometrically stable structure through the supports between the columns; it is secured to the roof frame by 8 tie rods at each of the four corners. 6. Design Summary: Due to the tight deadline for producing the drawings required for this roof frame reinforcement, the design process was quite challenging, and the work had to be carried out while the factory was not completely shut down. Therefore, appropriate safety margins were taken into account during the design calculations. The design for renovation and reinforcement must take into account: 1: Changes to the original structural support system and variations in loads. II: During the design phase, construction factors must be taken into account; while ensuring quality, every effort should be made to facilitate construction. According to calculations, for this renovation, the amount of steel used for the reinforcement sections is 2.56 tons, while the amount of steel used for the roof section is 38.4 tons. After the construction was completed, feedback from the site indicated that the schedule, quality, and amount of steel used were all met, and the client was quite satisfied. Last edited by Lailai on 2009-3-24 18:57]

Repairing can hardly solve the problem at its root; to address both the symptoms and the cause, it’s better to tear down and rebuild.

It is possible to reinforce by installing concrete columns; especially for load-bearing beams, considering the option of rebuilding columns could be a solution! ! !

For wooden houses, simply reinforcing them is not a good solution; it’s better to hire a professional renovation company or construction firm to handle the task, so as to ensure safety.

Considering the problems encountered in the design and construction of the reinforcement of old factories, and combining specific project realities with theoretical principles to analyze the bearing capacity of beams, slabs, and columns in such old factories, an economical and feasible reinforcement method that is easy to implement is ultimately determined

At present, for factory buildings that have only suffered minor damage, we reinforce them on their original structure by adding two metal supports under the main beams; these supports are used primarily to ensure that there is a place for operators to go in case the roof sinks

The reinforcement of the factory building has been completed, but there is still one major issue: it relates to the reinforcement of the smaller beams, other than the main beams, as well as the replacement of the stirrups. Given that the main beams have been in use for a long time, it is difficult to reinforce the smaller beams directly on them. Currently, we are considering wrapping copper wire around the main beams as a kind of clamp; we’re not sure whether this will work, how long it will last, what the load-bearing capacity will be, and whether the copper wire might deform over time

A new project has started now. As a chemical plant, steel corrosion is a serious issue here. The steel roofs that were blown off by strong winds are set to be replaced entirely with wood, specifically sandwood, which is quite durable; its interior has already dried out. It was quite expensive – 1200 per piece of wood. However, wood also poses corrosion problems. Initially, it is planned to apply several coats of asphalt paint; it’s not clear how long this will hold up

Originally, wooden materials were used, but they are no longer employed in the construction of buildings. It is recommended to consider using modern materials such as steel structures or others in combination with the original structure. An assessment should be carried out first, followed by the development of a repair plan. Structural engineers will calculate the load-bearing capacity of the structure and conduct inspections, after which experts will give their final approval before the work is carried out. This can also be treated as part of a technical upgrade or improvement initiative. Please correct me! !

I don’t know which factory it is It’s better to use reinforced concrete structures; after all, the cost isn’t higher than that of wooden structures these days Please correct me!

It depends on whether there are large, heavy equipment in the factory building; from a safety perspective, it’s better to tear it down and build it again!

The factory building was constructed in 1999, so it’s quite old; it has columns and a wooden roof, and its value isn’t high. What’s important are the equipment – since their depreciation period has expired, only some of the equipment needs to be replaced. Producing even one more day yields higher profits than operating a new production line (our company built another production line last year, one with a concrete structure as mentioned above). The main focus now is on reinforcement

At present, our company uses both new and old types of materials. For example, the old facilities have wooden buildings, but our shelled corn storage sheds, coal storage sheds, large warehouses, and zirconium stabilization plants are constructed using steel structures – yet these structures do not perform well. The large warehouses and zirconium stabilization plants, in particular, have been damaged due to both acidic and alkaline environments in our company. Additionally, the PVC tiles used on the better-quality shelled corn storage sheds and coal storage sheds were severely damaged by the strong winds this time; in contrast, structures made of wood with cement tiles perform much better

There is progress where there is communication; it’s normal for one person to lack experience, but together, people’s combined efforts can move even the biggest mountains. Thank you to all our friends for their support; we will keep working hard! ! !

These past few days I’ve been applying asphalt with the employees, and it hasn’t been very effective. At first we used brushes, then switched to rollers, but there are still gaps in the wood and at some joints that aren’t covered; moreover, there are areas on the surface that haven’t been painted either. It seems that it would be much better if we painted first and then assembled everything

Personal suggestion: Strictly implement the five-design principles of \"integrated factory layout, open-air placement of production equipment, lightweight construction, socialization of utility systems, and localization of technical equipment.\" If it can be done outdoors, do it outdoors.

Personal suggestion: Strictly implement the five-design principles of \"integrated factory layout, open-air placement of production equipment, lightweight construction, socialization of utility systems, and localization of technical equipment.\" If it can be done outdoors, do it outdoors. -------------Why are production facilities built outdoors? What benefits will this bring? I always thought that working outdoors would be bad for the equipment, or not very good either for the operation. Could you explain it to me?