Background information] a total of 12 culvert projects in a bid section of a secondary highway, including box culverts and cover culverts and other structural forms, one of which is a cover culvert design schematic diagram as shown in Figure 3, the construction unit determined the main construction process of the cover culvert as follows: measurement pay-off foundation pit excavation cast-in-place concrete foundation mortar wall (b) prefabricated cover plate in advance and hoisting entrance and exit slurry masonry (c) culvert backfill and reinforcement.
The following events occurred during construction:
Event 1: At the beginning of the project, the project manager organized personnel to investigate the hidden dangers of production safety, and required the site to do so"Construction personnel management"with"Construction site safety protection"Two met. Upon inspection,"Construction personnel management"The employment registration of front-line personnel, construction safety training records and all kinds of personnel holding certificates are in line with the regulations.
Event 2: For all kinds of culverts, some construction practices are as follows:
1) When the strength of finished concrete such as prefabricated cover plate reaches the design strength of 85, it can be handled and installed, and the prefabricated structure is prefabricated after installation.
The hoisting holes on the pieces should be filled with mortar.
2) The cast-in-place box culvert is constructed in two stages, and the pouring of the stem rib concrete is carried out first, and then the concrete pouring of the remaining part is completed.
3) The culvert platform backfill filler should be made of permeable materials, and when the permeable materials are insufficient, lime soil or cement stabilized soil can be used to backfill.
4) The backfill on both sides of the culvert body should be filled at the same time, horizontally, layeredly and symmetrically, and the degree of compaction should not be less than 90%.
Event 3: During the construction of the cover culvert, the supervising engineer checked the concrete and mortar strength, structural size, length, span, maximum height difference of adjacent plates, top elevation, cover support center deviation, culvert pavement thickness, masonry flatness and other items. After the project is qualified, the measurement of the culvert is completed according to the measurement requirements specified in the "Highway Engineering Standard Construction Bidding Documents".
Question] 1 Write the name of structure A in Figure 3, and write the names of cover culvert construction process B and C.
2 In the requirements for the investigation of potential safety hazards in event 1"Construction personnel management"What are the two other contents that need to be checked when the project meets the standard?
3. Judge whether the construction practice in event 2 is correct one by one, and write the correct practice if not.
4.What are the two main items that need to be checked in the cover culvert quality inspection in event 3?
5 In Figure 3, how many meters is the measurement quantity of the cover culvert? Explain whether the hole pavement and cap stone in Figure 3 are measured separately? (The calculation result is kept to 3 decimal places) First-class constructor