No_7_July_1968 — Page 30

PHILIPPINES

Ilocos Norte Provincial Capitol Building

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PACE structures of concrete, steel or wood are now widely used in the design of government buildings in the Philippines.

In the past the integration of these three-dimensional structures into our buildings was not possible because of a general inexperience with the com- plex design calculations, the lack of suitable materials and the difficulties of construction such as joining sever- al members at different angles.

However, with recent technological advancements these barriers have been overcome and space structures are now a common feature of govern- ment architecture.

Professor A. M. Haas said in his paper Concrete Space Structures- Relation Between Form and Structur-

al Design "This subject of space structures is born out of urgency. There is a need for it. There exists a lack of understanding between the masters of form, and of structural design: the architects and the struc-

NEW STRUCTURAL FORMS IN GOVT. BUILDING DESIGN

by F.S. Ilustre and R.A. Mallonga

tural engineers. Especially in the domain of concrete space structures are new techniques being worked, new structures created and fresh pos- sibilities as to form and shape grasp- ed."

The change-over from two-dimen- sional structures to the three-dimen- sional space system is in many ways a reaction to the column-and-beam system. Space structures, aside from giving a greater freedom of architec- tural expression, are often more economic since large spans may be covered without internal columns.

The Dome

The distribution of loads, spread- ing of forces, reduction of bending moments and the utilization of ma- terial to its limits are further ad-

Folded plate roof of the lecture hall building for Mindanao State University

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*

vantages of the space system which are now recognised by Philippine government architects and engineers.

The dome is the most common form of thin shells of double curva- ture. In contrast to the ordinary roof truss or portal frame two-dimension- al structure which can resist only loads applied in its own plane, the dome resists loads applied at any point, at any inclination to the sur- face and acting in any direction.

Spheres, ellipsoids and conoids are now common shapes in the roofs of reservoirs, storage tanks and the monumental portions of public buildings in the Philippines. Recent examples include:

1. The Philippine Atomic Research Centre at Diliman, Quezon City A conoidal dome of reinforced con- crete shell, adopted to solve the de- sign requirement of an air-tight build- ing with the minimum of door and window openings.

2. Water reservoir for the Con- gressional Employees housing project

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In place of a ring wall, a spherical dome of reinforced concrete shell supported by columns roofs the cylindrical water tank.

3. The administration office of the NDC Tenement Building spherical dome.

4. The proposed dome over the Ilocos Norte Provincial Capitol

* Mr. F. S. Ilustre is consulting architect to the Philippine Government. Mr. R.A. Mallonga is chief of the Structural Engineering Branch, Division of Archi- tecture, Bureau of Public Works.

Far East BUILDER, July 1968.

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