What are the construction methods for integral lining? The construction methods of integral lining are mainly divided into the following categories, each with its applicable scenarios and characteristics, as well as the construction precautions for integral lining.

　　I、Construction method of integral lining

　　1. Sliding mode construction method

　　The sliding formwork construction method is a relatively advanced method in the construction of integral lining. It uses a continuously rising sliding formwork to pour and form in one go, and has the advantages of fast construction speed, good integrity, and smooth surface. Suitable for long-distance and large section tunnel lining construction.

　　2. Trolley construction method

　　The trolley construction method uses movable trolleys as templates and is suitable for medium length tunnel construction. During construction, the trolley is in place, the formwork is fixed, and then concrete pouring is carried out. After the concrete reaches a certain strength, move the trolley to the next position and repeat the construction process. This method is flexible in construction and has strong adaptability.

　　3. Segmented construction method

　　For projects with complex geological conditions and significant changes in tunnel cross-sections, the segmented construction method can be adopted. According to the different geological conditions and tunnel sections, the lining is designed and constructed in sections, and the construction of the next section is carried out after each section is completed. This method has high flexibility, but relatively low construction efficiency.

　　4. Assembled integral lining

　　Prefabricated integral lining is a type of prefabricated component assembly, which involves prefabricating concrete lining sections in the factory and then assembling them inside the tunnel. This method has a fast construction speed, but requires high precision for prefabricated components and requires significant transportation and lifting space.

　　5. Spray concrete lining

　　Although shotcrete lining itself is not a typical construction method for integral lining, in some special conditions such as rapid construction or unstable geological conditions, shotcrete can be used as initial support first, and integral lining can be constructed when conditions permit.

　　II、 Construction precautions

　　1. When selecting construction methods, factors such as geological conditions, cross-sectional size, construction conditions, and schedule requirements of the tunnel should be fully considered.

　　2. Adequate preparation should be made before construction, including geological survey, design optimization, construction organization design, etc., to ensure construction quality and safety.

　　3. During the construction process, the quality of concrete should be strictly controlled to ensure the strength and durability of the lining.

　　4. Pay attention to construction safety, especially when working in environments with complex geological conditions and abundant groundwater, effective safety measures should be taken.

　　The construction method selection of integral lining should comprehensively consider multiple factors to achieve the best engineering effect and economic benefits.