Abstract: This paper describes the Hangzhou Bay Bridge, the sea platform renovation project in the shaped double-wall aluminum and magnesium manganese metal roof structure characteristic shape, structure, location, function theory, the node structure design, corrosion design.
Key words: shaped double magnesium manganese metal roofing, structural position, magnesium manganese upright lock border water system, adjustable angle aluminum veneer panel system.

4. Magnesium manganese metal panel roof system design node

According to the requirements of owners and design institutes, magnesium manganese metal panel roof system and exterior decoration both have good water, thermal insulation properties, but also has a smooth appearance. The project design has created a unique double-layer aluminum-magnesium manganese metal roofing system, the bottom with aluminum-magnesium manganese plate standing seam roof systems, construction completed after the use of special aluminum jig bite clamping plate edge as magnesium manganese bearing, Install aluminum veneer panel, aluminum veneer panel is slotted structure, the gap between adjacent panels do not fight sealant, and aluminum decorative cover for shelter. This use of magnesium manganese standing seam roof system with a good waterproof polyurethane aluminum panels smooth the appearance of a good solution to a magnesium manganese metal panel roof system design (Figure 4.1).

4.1 magnesium manganese standing seam roof system design
Magnesium manganese standing seam roof system surface layer of the overall structure is as follows: 1mm thick zinc-magnesium manganese alloy plate, 80mm thick rock wool insulation, PVC membrane liner, 50mm thick centrifugal glass wool sound-absorbing layer, 0. 6mm thick plated Pressed aluminum perforated zinc plate (on the non-woven lining). Supporting structure 3. 0mm thick galvanized steel liner brush support (spacing not greater than 1000mm), high-strength aluminum alloy bearing (sub-arranged intervals of about 400mm). (Figure 4.2)

The project magnesium manganese standing seam roof system's main advantages are as follows:
a. the overall structure of water, drainage, to prevent the screw caused by the leakage risks, manganese and magnesium roof panel ribs specially designed anti-capillary groove, that is in the small rib side to set up a groove, so that large rib and a small cavity between the ribs, reducing the surface tension of water, which prevents the upward movement of capillary water penetrate indoors. (Figure 4.3)

b.. plate in one direction through the long installation, regardless of how the building shape, can fully engaged joints, changes in temperature can be free to stretch, to avoid temperature stress.
c. breathable, keeping the overall structure of long-term natural one thousand dry, extended building life. The design of the lap rib plate can prevent rain and capillary water immersion, without hindering the natural flow of air, so air can flow end roof, the roof ventilation system, just as you can breathe the same, will not wet steam stuffy board. (Figure 4.4)
4.2 adjustable angle aluminum veneer panel system design
Magnesium manganese metal roofing systems use the outermost 3mm thick aluminum panel veneer. Because magnesium manganese standing seam roof system already has a good waterproof, thermal insulation properties, so only 3mm thick aluminum veneer panel as decorative stone coated metal roofing system to meet the needs of the outer surface smooth.
Magnesium manganese metal roofing systems magnificent shape, and ultimately through the outermost layer of aluminum veneer panel stitching to achieve. According to the Institute to provide three-dimensional model building, lofting found by computer modeling, aluminum veneer surface plate and the angle between adjacent plates are not all the same, deputy general aluminum frame fixed angle adjustment means can not meet the needs of . To this end point of our design with adjustable aluminum veneer system, has solved this problem.

Adjustable angle aluminum veneer system is the traditional aluminum frame has been improved, vice design, aluminum frame at the bottom of the design for the vice-length of the cylindrical tank, then with the top of cylindrical aluminum connector plug tie, is free to rotate to adjust the angle of connection. (Figure 4.5)

Adjustable angle aluminum veneer panel system installed when the first special fixture base fixed on the aluminum standing seam roofing systems bite the edge, and then installed vice frame, aluminum connectors, aluminum connecting aluminum veneer Corner panel installed in the fixture base, this time according to need and use of sub box connection Corner angle and height adjustment panel. After adjustment tighten the bolts installed. (Eg, 4.6)
4.3 magnesium manganese metal roofing system component stress analysis of key nodes
The project is located among the sea, without any building plans around 4 .. 6 adjustable angle aluminum single system node detail] blocked, often by strong wind impact, according to the Institute to provide wind tunnel test report, the maximum negative pressure of local roofing standard is wk = 5. 55kN/m2, the largest negative pressure design is w = 1.4 x 5. 55 = 7. 77kN / 2,, this design our finite element analysis software ANSYS, all roof systems components were calculated and analyzed, both to meet the force requirements. Are excerpts from some of the calculation results are as follows:
a computational analysis of aluminum veneer panel
b the use of finite element analysis software ANSYS modeling of aluminum veneer panel calculation results are as follows:

c. special fixtures aluminum base calculation and analysis
Finite element analysis software ANSYS modeling of aluminum alloy special fixture base calculation results are as follows:

5. Magnesium manganese corrosion of metal roof system design

Perennial sea breeze of this project to accept baptism, air humidity, high salinity, corrosion resistance, so manganese for magnesium corrosion of metal roofing systems require special design considerations.
5.1 Project magnesium manganese metal roofing system corrosion protection of steel structures
a. the surface of steel components using sandblasting (pill) rust, rust grade 5a2. 5 level, should be carefully remove grease before rust, burrs, drug skin, and iron oxide and other flying objects.
b. Surface treatment were sprayed aluminum and zinc a thickness of not less than 120um, epoxy paint a cloud of iron closed, dry film thickness of 40um, coated with thick non-intumescent fire retardant coating, fire-resistant coating surface should be smooth handling. Interior surface of the sprayed aluminum and zinc a thickness of not less than 80um. , Epoxy paint a cloud of iron closed, dry film thickness of 40 um, coated with intumescent fire retardant coating, the outermost layer of spray acrylic polysiloxane finish, dry film thickness of 80 um.
5.2 Project magnesium manganese metal roofing system panels treated with preservatives
a. magnesium manganese standing seam metal roof with super anti-corrosive magnesium manganese alloy grassroots, covered by YEGAL made of zinc coating process, zinc surface in the natural environment to generate a thin dense base zinc carbonate film can prevent further oxidation, has strong corrosion resistance, even if the zinc carbonate layer is damaged, the aluminum alloy substrate itself has a strong anti-acid rain and salt conditions of capacity, excellent durability .
b. 3mm thick aluminum veneer surface fluorocarbon spraying, three-coat three baking, the average film thickness should be greater than 40um


6. Conclusion

The project is located in the sea among the magnificent style, its shape is shaped by a number of three-dimensional geometric shapes stitched together to design and construction caused great difficulty. In the design of the project in our magnesium manganese shaped according to the characteristics of double-layer metal roof, the integrated use of a variety of the latest technology, and design and development of the adjustable angle aluminum veneer panel system, a good solution to a variety of difficult between the problems. Currently, the engineering design work has been completed, is in a tight construction work, I believe the near future, an architectural masterpiece will stand in the beautiful Hangzhou Bay, in order to increase people's journey a beautiful landscape.
----edited by stone coated steel roofing