Building
Spherical dome with lan-
tern to serve as promenade for visitors. 5. Convention hall of the proposed Camarines Sur Capitol Building spherical dome.
Single curvature shells
Basically a shell is a thin curved surface, the thickness of which is small in comparison with the dimen- sions of the surface. Within this de- finition there is a large number of pos- sible forms.
Most common of shells curved in one direction is the barrel shell
as
a single unit or in a series lying side by side to give a cross-barrel or multi- barrel roof.
The cylindrical or barrel shells have found the widest use because of the simplicity of the required formwork which may be re-used several times. They are both practical and econo- mical in material.
Recent examples of multi-barrel roofs include: The office of the Secretary DANR, Manila Internation- al Airport. Reparations Commercial Building, and the proposed Iriga Supermarket.
Warped surfaces
Of the shells with a warped sur- face, the hyperbolic paraboloid is most common. Again efficient use of materials is made by relying on form or shape for strength rather than on mass. Due to its geometrical make-up of straight lines, this shell allows the use of straight reinforcing bars.
Hyperbolic paraboloid shells are used on the entrance to the Zambales Provincial Capitol Building, the en- trance to the proposed Cotabato Pro- vincial Capitol, the entrance to the proposed Romblon High School, and the proposed waiting shed for the Legislative Building.
Folded plates
The folded plate system is an ex- ample of a skin structure, in which the external loading is resolved into components acting in the planes of the
Malayan and Moslem architecture influence the design of the Lanao Provincial Capitol which has gabled roofs using rigid frames with fixed bases
plate forming the structure. These components or skin forces are resist- ed as they act in the direction of greatest stiffness of the plate,
The idea of making roofs of thin reinforced concrete slabs placed at angles to each other is similar to the principle of corrugating sheet metal in order to give it a greater strength as a beam. Being composed of flat plate-like members, the formwork is simple.
Used for long spans such as audi- toriums, grandstands, cantilevered canopies, and roofs of factories, this type of construction is to be seen on the Cotabato Provincial Capitol, Mindanao State University science building and laboratory,
Davao Medical Centre entrance, and Villesis municipal auditorium.
A combination of these shells with some other rigid frame structures is often resorted to in order that the desired form can be achieved. For example in the design of the National Convention Hall at Baguio as well as the Zambales Provincial Capitol, the combination of thin shell and arch ribs results in buildings of impressive design.
Of the many gabled roofs using rigid frames with fixed bases, the pro- posed National Prisons Hospital at Muntinglupa can be mentioned. The bandstand at Virac Catanduanes was designed using a gabled frame with two hinge supports.
One distinguishing mark of Philip- pine government buildings nowadays is the integration of the triangular frame roof with some Malayan de- corative carvings at the exposed por- tion of the ridge. This feature can be seen on the Cotabato Provincial Capitol Building. Lanao Del Sur Capitol, the proposed Embassy Build- ing at Honolulu, Hawaii and the Princes Urduya Governor's Residence, Lingayen, Pangasinan.
Another government building with a new structural form is the proposed Wildlife and Nature Centre Building to be erected at Quezon City. This building will display a wide variety of forms in laminated wood including high V-arch frames with a pitch greater than 45 degrees, curved tapered beams, A-frames and two- hinge arches.
Stair designs
A feature of some modern govern- ment buildings is the prominence given to the position and design of the main stairs. Helicoidal от free-standing stairs are not uncommon.
concrete
These are not used simply for architectural display. The reinforced free-standing staircase for instance with its cantilevered flights and unsupported intermediate land- ings provides more freedom as well as giving structural and aesthetic ad- vantages.
The same can be said of
(baba, kas pama DO B
Proposed Cotabato Provincial Capitol Building will have a folded plate roof and hyperbolic paraboloids over the main entrance
Far East BUILDER, July 1968.
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