In the construction of mountain highway bridges, doing a good job in bridge design, subgrade, tunnel, and cross-construction control is of great significance for the continuous progress of the project. Mountain highway bridge construction plays a vital role in highway construction. During the construction process, it is necessary to fully grasp bridge information, select suitable construction schemes and technological techniques, strengthen construction management, ensure that the constructed bridges meet standard requirements, and further promote the progressive development of mountain transportation.

1 The Current State of Mountain Expressway Bridges

1.1 High Construction Difficulty

The mountainous terrain features large undulations, steep slopes, and complex mountain structures, making the phased differentiation of the project intricate. Additionally, the impact of the groundwater environment further increases the construction difficulty of expressway bridges. High engineering difficulty prolongs the construction period and increases the probability of construction changes. The design schemes for mountain highway bridges typically adopt large curved longitudinal slopes and long bridges. From the perspective of high pier construction, the cross-sectional area is small, the pier height is large, and the pier body has high flexibility. In terms of bearing pressure, the design scheme should be positioned at the center of the two to ensure construction effectiveness. In practical applications, the need for continuous measurement adjustments due to topographical conditions brings greater difficulties to construction.

1.2 High Project Cost

Highway bridge projects are characterized by intensive capital investment. Construction difficulties and prolonged schedules tie up a large amount of funds, leading to high economic input and slow capital turnover. As mountain highway bridge construction is mostly carried out in phases, there is a lag in fund allocation. In the early stage of project construction, the focus is on the construction phase, which may affect the capital investment in later project quantities. If enterprises advance funds for a long time, their economic burden will increase in subsequent construction, potentially triggering a series of chain reactions that impact later mountain highway bridge construction.

1.3 Complex Construction

The route selection for mountain expressway bridges is complex, with rapid altitude changes, narrow and steep terrain, crisscrossing gullies, and diverse landforms. The geological environment is complex, with engineering routes crossing fault zones, high seismic intensity, and underdeveloped adverse geology. Moreover, the climate is harsh, with long periods of rain, snow, ice, fog, wind, and other severe weather affecting high-altitude routes, increasing construction difficulties. The project involves a large amount of bridge and tunnel construction with technical challenges, and many routes are distributed along steep cliffs, subject to numerous constraints during implementation.

2 Construction Difficulties of Mountain Expressway Bridges

2.1 Foundation Treatment Technology for Bridge Substructures in Mountain Expressway Construction

In mountain expressway bridge construction, the foundation of the substructure is the basis of the entire bridge construction. Due to the complexity of mountain terrain, the foundation of the bridge substructure needs to be treated according to different topographical features. In foundation treatment of the substructure, one approach is to use technical methods such as contact grouting and consolidation grouting for effective treatment. The second is to use concrete seepage prevention technology to treat the substructure foundation.

2.2 Bridge Pier Construction Technology in Mountain Expressway Bridge Construction

In mountain expressway bridge construction, the design structures of bridge piers vary. For bridge piers with low construction difficulty, traditional bridge pier construction techniques are usually used. For bridge piers with high construction difficulty, diversified bridge pier construction techniques should be selected to better ensure the construction quality of mountain expressway bridges.

2.3 Analysis of Bridge Module Engineering Technology in Mountain Expressway Bridge Construction

In mountain expressway bridge construction, bridge module construction is a crucial component. In highway bridges, modules play an important role in the structure of bridge piers. Typically, bridge modules are about 1.5 meters long. During module installation, it is necessary to confirm the installation position to avoid affecting bridge construction due to installation issues and to reduce construction risks to a certain extent.

3 Exploration of Construction Management for Mountain Expressway Bridges

3.1 Management of Materials and Mechanical Equipment

In highway bridge construction, materials and mechanical equipment are indispensable components, and their quality and safety are crucial to the smooth progress of bridge construction. First, ensure the quality of materials during selection by checking whether they meet standard requirements, such as concrete and steel bars, and inspecting their strength and load-bearing capacity. High-precision three-dimensional finite element analysis technology can be used for load-bearing capacity testing. At the same time, check whether the concrete mix ratio and performance meet requirements to ensure that bridge construction complies with regulations. Second, carry out quality and safety supervision of mechanical equipment, and perform daily maintenance to prevent malfunctions that could delay the construction schedule.

3.2 Strengthen Quality Supervision and Personnel Safety Control

Construction personnel are required to follow standardized procedures, and management personnel should conduct on-site quality supervision to prohibit the use of substandard materials and cut corners. Any violations should be severely punished. Project owners and investors should maintain good communication, and all units should deeply understand that cost savings do not mean cutting corners on construction materials; instead, the focus should be on bridge construction quality, which must meet regulatory requirements to ensure the transportation function in subsequent use. In addition, improve the quality protection and detection system, inspect material quality parameters, clarify responsibilities, and ensure that bridge engineering quality meets standard requirements.

During mountain expressway construction, personnel management is also a critical factor. It is necessary to enhance the safety awareness and construction skills of workers, conduct in-depth research on potential safety hazards, and implement effective solutions. Strengthen safety measures during construction, such as safety protection during high-altitude operations and the construction of access routes to operation platforms, and clear debris to avoid threats to life safety.

3.3 Adoption of New-Style Quality Inspection Methods

Although highway construction quality is closely linked to the market economy, it is essential to avoid reversing priorities during construction, ensuring that management plans are effective and weeding out personnel who fail to meet regulations. With the improvement of the highway construction quality control system, although the supervisory authorities do not have veto power, technical and administrative units may be in opposition. Therefore, project managers should actively fulfill their responsibilities by establishing a quality management responsibility system to ensure the effectiveness of highway construction quality control. Highway construction quality emphasizes audit and evaluation. In subsequent quality meetings, all quality assurance personnel from construction teams should be required to participate, clarify the monthly project quality status, and promptly identify potential issues. On the other hand, formulate scientific and effective response plans, and emphasize the improvement of quality control experience through communication.

3.4 Expansion Joints and Drainage

To ensure the effectiveness of quality management, staff should regularly inspect bridge expansion joints and strengthen control over expansion to maintain stability between the bridge and its natural and external environments, which is core to project quality control. In terms of drainage performance, every effort should be made to extend the service life of the bridge by ensuring waterproofing during construction, coordinating the angles between the longitudinal and transverse slopes for smooth drainage, and ensuring that highway bridge construction quality meets requirements.

3.5 Reinforcement Quality Management

First, steel bars should be uniformly processed and cut in the processing shed, with straightening, bending, and cutting meeting technical specifications. Second, after processing, encode and sort the steel bars before transporting them to the site for 绑扎 (binding) and welding. During the connection of pier column main reinforcement, joints should be staggered by more than 35d, and the area of jointed steel bars should not exceed 1/2 of the total area. The installation deviation of steel bars should be controlled within 2 cm based on the center point, and standard-height spacers should be used on the sides of the pier columns to ensure the reinforcement protective layer thickness is more than 3 cm.

3.6 Maintenance Management

After the initial completion of bridge engineering and before formwork construction, measures should be taken to prevent mud leakage. In subsequent operations, strengthen maintenance management to avoid quality issues such as bridge deck cracks and pier cracks, and address problems promptly upon discovery. During the maintenance period, staff should implement maintenance measures in accordance with standard procedures, which helps extend the service life of the bridge and better promotes the development of transportation.

4 Conclusion

Mountain expressway bridge construction is characterized by complex construction, high investment, and vulnerability to external environmental influences. Therefore, it is necessary to strengthen construction quality management, improve quality management systems, implement responsibility systems, and ensure standardized construction in all aspects, including subgrades, pavements, bridges and culverts, and tunnels, to achieve ideal construction results. Conversely, substandard highway bridge quality not only affects corporate economic efficiency but also causes adverse social impacts. Therefore, highway bridge management must be comprehensive and cover the entire process.