Subgrade construction steps
1. Low-lying areas and potholes on subbase should be carefully filled and compacted. The washboard on the grass-roots level should be scraped off; Loose place, should rake loose sprinkler and re-rolling.
2. Check whether the elevation of the lower bearing layer meets the design requirements one by one. The error of the elevation of the lower bearing layer shall conform to the specifications and meet the design requirements.
3. The newly completed subbase or soil foundation must be accepted according to the specifications. Where the unqualified sections are accepted, measures must be taken to make them conform to the standards before paving the base or subbase.
4. In the road section with trough section, the drainage ditch or gravel blind ditch shall be alternately excavated at regular intervals (5 ~ 10m) on the shoulders on both sides.
5. Subgrade cleaning, shaping, cleaning, watering and rolling; Scroll. Then the subgrade is comprehensively tested, especially the compactness, deflection value and elevation of subgrade. Seriously deal with the place that does not meet the design requirements until it meets the requirements.
6. Re-measure the width, height, longitudinal slope, transverse slope and ultra-high transverse slope of subgrade.
7. Deal with the place where there are loose soft bullets on the subgrade surface, especially soft bullets, dig out the soft bullets and backfill them with lime soil or gravel soil.
8. In the road trough section, drainage ditches or gravel blind ditches shall be alternately excavated at regular intervals (5 ~ 10m) on the shoulders on both sides to prevent water accumulation in the road trough.
Second, the subgrade construction organization design
Before construction, the supervisor shall first review the contractor's pavement construction organization design, focusing on the time limit for a project arrangement, material supply (yard location, crushing technology and supply plan), mixing site, mixing equipment configuration, mixture transportation, paving equipment and rolling machinery configuration, as well as the quality control system and guarantee measures, technical force arrangement and self-inspection system operation of each process. Once the construction organization design is approved, the supervisor shall strengthen contract management according to the construction organization design and bidding commitment, supervise the contractor to realize the trinity management of equipment, manpower and quality, and guide and help the contractor to prepare construction instructions.
Three subgrade construction materials quality supervision and self-inspection system
Material quality control should be the focus of pavement construction supervision. For purchased finished products: materials, their technical indicators should be strictly sampled in batches. For local materials; 1, and its material quality control should start from controlling the material source, starting from the mining and crushing processes. All incoming materials must be sampled according to regulations (size, flat needle shape, silt content, crushing value, polishing value, water absorption, PH value, etc. ). Unqualified materials should be returned and cleared within a time limit and will not be tolerated.
Supervision of key procedures in subgrade construction
The key processes such as mixing, paving and rolling of pavement mixture must implement the system of working procedure standing by, that is, people should be in place, records should be detailed, and problems should be handled in time. In the process of mixing and rolling, the key points of supervision are: batching and weighing of mixture, mixing time, temperature control of asphalt mixture (mixing temperature, transportation insulation measures and paving and rolling temperature), paving uniformity (particle size and thickness), flatness and rolling compactness. After the completion of each level of rolling work in each construction period, the contractor shall be supervised to carry out quality self-inspection and inspection, and the supervisor shall conduct random inspection in time according to regulations. Only when the quality of this process meets the quality requirements can the supervisor approve the next process and resolutely put an end to the unqualified products of the previous process.
The above is the construction-related knowledge about "Roadbed Construction Organization Design" collected by Zhong Da Consulting for architects. For more information, please visit Zhong Da Architectural Design Consulting Company.
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