Research on Construction Technology of Metal Corrugated Culvert (Part 3)

3. Construction technology

The construction process of metal corrugated culvert pipe can be divided into direct filling method and reverse slotting backfill method. Does not affect the overall progress of subgrade construction, generally the latter is used. Although there is a certain difference in external force, the construction process is not much different. Each is described below.

1. Direct fill method

The process flow of the direct filling method is: preparation before construction → construction lofting → setting up cofferdam → drainage and dredging → leveling the site → backfilling of the foundation layering → detection of compaction, water content, etc. → leveling → leveling the site → construction lofting → Assembling pipe joints → detecting the dense water condition and the longitudinal slope at the bottom of the pipe → detecting and remediating the anticorrosive coating → positioning of the culvert pipe → backfilling in layers on both sides → detecting the degree of compaction and moisture content → layering backfilling in the top of the pipe → detecting the degree of compaction , Water content, etc. → Import and export processing.

2. Reverse slotted backfill method

The process flow of the reverse slotting backfill method is: preparation before construction → construction lofting → excavation of culvert and construction site → leveling site → foundation layered backfilling → detection of compaction, water content, etc. → leveling → leveling site → construction lofting → Assembling pipe joints → detecting the dense water condition and the longitudinal slope at the bottom of the pipe → detecting and remediating the anticorrosive coating → positioning of the culvert pipe → backfilling in layers on both sides → detecting the degree of compaction and moisture content → layering backfilling in the top of the pipe → detecting the degree of compaction , Water content, etc. → Import and export processing.

Among them, the preparation before construction mainly includes the following:

(1) Before the construction of the culvert, one pipeline installation commander should be set up to direct the lifting and construction operations of the construction personnel; one or two technical personnel should be set up to control the key technologies such as line release and culvert placement; and appropriate auxiliary personnel should be configured;

(2) The required mechanical equipment and related tools should be prepared before the construction of the culvert, such as: bulldozer, road roller, sprinkler, level, theodolite, lifting equipment, socket wrench, etc .;

(3) Prepare the necessary materials before the construction of the culvert, such as: backfilling gravel materials, screws, asbestos (or rubber) mats, etc .; at the same time, prepare the test and testing instruments and equipment during the construction of the culvert, and implement the test personnel;

(4) Before the construction of the culvert, the culvert and its accessories must be tested on the site.On the one hand, the structural size is checked, and on the other hand, whether the surface corrosion resistance meets the requirements; if necessary, additional coating should be added on the galvanized coating surface. Asphalt or other anti-corrosion materials;

(5) Prior to the construction of the culvert, construction roads of corresponding length should be constructed according to specific conditions, and passing vehicles should be reasonably organized.

The assembly process of corrugated culvert pipe is as follows: check the culvert pipe joint → hoist the culvert pipe → transport to the construction site → proofread the import and export order of the culvert pipe → align the flange and flange hole → preliminary bolts and nuts → filled rubber Or rubber asbestos pad → tighten the bolts symmetrically → apply asphalt evenly on the inside and outside of the culvert pipe → hoist the culvert pipe in place.

4. Construction control technology

The key construction technologies of corrugated culvert pipe china are as follows:

1. The construction season should be strictly controlled to prevent construction in the freezing season from affecting the project quality;

2. The cold and frozen areas have higher requirements for basic replacement materials, especially the content of powder and clay particles should be strictly controlled to prevent the damage of the culvert caused by ice expansion;

3. The filling of the foundation and the side and top of the culvert should be layered and compacted, and the degree of compaction should meet the requirements, otherwise it will easily cause stress concentration of the culvert, deformation of the culvert and jump on both sides of the culvert;

4. The culvert pipe assembly should strictly control the longitudinal slope of the culvert, and strengthen the anticorrosion measures of the pipe joint to ensure that the performance and service life of the culvert meet the requirements. According to the design requirements or engineering experience, a certain amount of pre-arching should be reserved in the longitudinal direction of the culvert for different areas when setting up the foundation. For example, the pre-arching in soft soil area can be controlled at about 0.3% to 1% of the total length of the structure.