Preface

In the domestic transportation industry, expressways play an important role. Because of the greater impact of some human and environmental factors, all tunnels and bridges on expressways have suffered certain damages, which has a greater impact on driving safety. In order to maintain the transportation function of the expressway and ensure driving safety, relevant departments must implement reinforcement treatment on tunnels and bridges. However, compared with developed countries, my country has greater restrictions on the reinforcement technology of tunnels and bridges. If improperly used during construction, it will have a greater impact on the overall construction quality of tunnels and bridges, and even cause some safety accidents.

1 The necessity of applying reinforcement technology in tunnel and bridge construction

1.1 Reduce waste of resources

During the construction of the expressway, many important resources are very limited. Therefore, if there is a problem with the bridge and tunnel on the expressway, the reinforcement technology must be used. Formulate a reasonable repair plan, and then effectively solve the problem, so that the highway can be reused, reduce the possibility of road rebuilding, thereby reducing waste, saving valuable resources and construction funds.

1.2 Promote the continuous development of the transportation industry

With the continuous improvement of people's overall living standards, people's travel requirements are also constantly improving, and there are higher requirements for the actual smoothness, cleanliness of the road and the greening on both sides. Therefore, in order to meet people's needs, construction workers need to continuously improve the technology to promote the highway to become more perfect. Reinforcement technology as a back-up support can let people see my country's attention to and investment in transportation construction, and then promote the continuous development of the transportation industry.

2 Specific application of reinforcement technology during tunnel and bridge construction

2.1 Paste the steel plate

During the reinforcement of tunnels and bridges on expressways, the method of pasting steel plates is widely used. The main feature of this technology is that it will not damage the original structure, and the operation of pasting steel plates is relatively simple, which can effectively shorten the construction period and improve the reinforcement effect. When applying the technology of pasting steel plates, the construction workers need to glue the concrete and steel plates together with an adhesive to make them into a whole, thereby improving the rigidity of the tunnel and bridge.

When strengthening, the construction personnel also need to place the steel plates based on actual needs. Assuming that if you want to increase the bending strength of the beam, you need to place a steel plate under the beam, and also need to reasonably optimize the shear strength. If you want the beam to have the shear strength, you need to place a steel plate on the side of the beam. If you want to improve the stability of the tunnel bridge, be prepared to ensure that the actual direction of the steel plate and the shear reinforcement in the bridge structure are consistent

2.2 Dynamic compaction method

The dynamic compaction method refers to the implementation of compaction operations on the soil in a direct and simple way through gravity. This is a reinforcement technique often used by construction workers and is generally applicable when large cracks appear in the foundation of a bridge tunnel. When dealing with soft and sticky soil, the dynamic compaction method can be used. During actual use, a heavy hammer weighing 80kN is usually lifted to reach a certain height, and then the rammer is allowed to fall freely so that it can compact the soil through its own weight and the weight of the free fall motion to achieve the purpose of reinforcement. The dynamic compaction method can narrow the gap between the foundations and improve the drainage capacity of the foundation.

2.3 Grouting method

Grouting technology is mainly a technology to strengthen and repair soft soil foundation. As the overall span of the expressway is relatively large, the soil quality will vary. When working on soft soil foundations, construction personnel can apply grouting technology to strengthen the hardened soft soil foundation and promote the gradual improvement of various properties of the foundation, such as improving bearing capacity, waterproofing capacity, and compressive resistance. A grouting technique often used by construction workers is to use concrete as a foundation, choose two special slurries, mix the concrete evenly according to a certain proportion, and then pour it into the foundation soil to complete the grouting. In this way, the soft soil foundation of the bridge and tunnel can be effectively strengthened, and the quality and safety of the expressway can be improved.

2.4 Concrete spraying technology

Generally speaking, the concrete spraying technology improves the overall load-resistant capacity of the building structure by increasing its cross-sectional area. Although the cost of this technology is relatively small, it will greatly increase the weight and volume of the tunnel and bridge, and the construction process is also very cumbersome. Concrete spraying technology can be divided into two methods: dry and wet spraying.

2.5 Glue injection repair crack technology

For tunnels and bridges, cracks in concrete are the most critical factor affecting tunnels and bridges. For cracks, construction personnel need to take corresponding measures to repair them in a timely manner to ensure the overall quality and use safety of tunnels and bridges. Assuming that the construction personnel do not deal with the cracks, the cracks will gradually increase, and then the overall structure of the tunnel and bridge will be destroyed. When reforming and strengthening cracks, there are mainly two repair methods available. One is to repair the surface, and the other is to repair the interior, but which method needs to be selected according to the crack situation. When the surface repair method is used, it can be treated by sticking the carbon fiber cloth. When applying the internal repair method, first use tools to inject structural glue into the cracks, and after the glue is cured, the cracks can be bonded. In this way, in addition to ensuring the overall performance of the tunnel and bridge, it can also prevent some internal components from being corroded by gas and moisture.

2.6 Techniques of post-reinforcement rooting

There are many technologies used to reinforce and renovate tunnels and bridges, and the post-rooting technique of steel bars is one of them, which can play a role in rebuilding and strengthening. The application of this technology is actually to implement reinforcement treatment in the bridge structure to achieve the purpose of reconstruction and reinforcement. This technique of post-reinforcement rooting is mainly applicable to the following bridge structures. First, the steel bars in the bridge structure were damaged. Second, the colloid in the structure is destroyed. Third, the structural substrate is destroyed. In view of the above problems, all of them can be dealt with using the technique of post-reinforcement rooting. At this stage, when applying this kind of technology, in order to ensure the quality of reinforcement, structural glue will be used to improve the reinforcement effect of the bridge

3 Conclusion

In summary, the reinforcement of tunnels and bridges on expressways can not only guarantee the overall performance of the expressways and guarantee driving safety, but also reduce the waste of resources and promote the continuous development of the transportation industry. When the construction personnel apply the reinforcement technology, they need to carry out specific analysis for specific problems, and improve the feasibility of the reinforcement technology through research and analysis. Only in this way can the tunnel bridge be effectively reinforced and the overall quality of the expressway can be improved.