[Background information].
A construction unit undertakes the construction of a span embankment bridge project, the bridge is a three-span prestressed concrete continuous beam bridge, the span layout is 48m + 80m + 48m, the superstructure is a prestressed concrete box girder, and the top width of the box girder is 145m, bottom width 70m, the height of the box girder is 60m gradient to 25m。The construction unit set up a project management department, and the following events occurred during the construction process:
Event 1: After a detailed survey of the site, the project management department prepared an implementation construction organization design, requiring the labor subcontractor of the superstructure to prepare a special construction plan for the hanging basket, and the project management department submitted it for approval in accordance with the regulations.
Event 2: After analysis and comparison, the project management department determines that the cantilever pouring hanging basket of the superstructure adopts a diamond-shaped hanging basket, and the hanging basket is shown in Figure 3, emphasizing that the weight ratio of the hanging basket and the concrete of the cantilever pouring beam section is not greater than A, and the total weight of the hanging basket should be controlled within the weight limit specified in the design, and special requirements are made for the quality of the components B, C and D in the hanging basket.
Event 3: The chief engineer of the project made a detailed safety technical disclosure before the construction of the hanging basket, emphasizing that the strength of the concrete should not be lower than the e of the design strength grade value, and the elastic modulus should not be lower than the f of the 28d elastic modulus of concrete, and when the concrete age is used instead of the elastic modulus control, it should not be less than g days, and when the two ends are stretched, the allowable error of the synchronous tensile force between the jacks should be h.
Event four: hanging basket construction to 5 beam section, pouring concrete to remove the inner template found that there is uneven thickness defect in the position of the web part, the project management department after careful analysis, found out the possible causes of the defect, including the template design is unreasonable, the box girder template displacement (the template is not fixed firmly, so that the relative horizontal position of the inner and outer template deviation) and other reasons for the template itself and construction.
Question] 1Correct the wrong practice in incident 1 and explain what approval process the special construction plan for hanging baskets must go through before it can be implemented
2 What is the value of a in event two?Write out the names of components b, c, d.
3.Write the values of e, f, g, and h in event three.
4.There may also be the formwork itself and the reasons for the construction in the supplementary event 4 (only three are required to be written). A build exam