Saddle roof

The hyperbolic paraboloid, also known as HP- shell or Hyparschale, is a system developed by Herbert Müller of Halle an der Saale Shell structure in the shape of a hyperbolic paraboloid and thus a saddle surface. It is carried out of a composite concrete slab of steel and concrete.

With the development of this particular form of construction, which is curved in opposite directions at each point, it was possible to build extremely durable roofs and bridges with a very wide chip space.

Examples

A 45 -meter long pedestrian bridge from one piece is still in Halle / Saale, which offers the low cost of materials. Examples of the application are also the Ausflugsgaststätte at Petersberg near Halle, the Baltic Hall in Binz, the Friedrich- Ebert-Halle in Ludwigshafen am Rhein, the Church of St. Hildegard in Limburg an der Lahn, the Alsterschwimmhalle in Hamburg and the Hyparschale, a multi-purpose hall in Magdeburg, which was built according to the plans of the civil engineer Ulrich Müther 1969, who also wrote a thesis on hyperbolic paraboloids. Striking are the corrugated concrete panels that make the overarching principle advantage and were used for many gyms and swimming pools especially on the territory of the GDR.

Roof structures

In modern architecture, the hyperbolic paraboloid is often used as roof area. To construct just imagine a square base with posts at each of the four corners, the diagonally opposite pole are the same. If one connects the four posts peaks along the sides of the square together, you get four straight lines which span the backbone of the paraboloid. Well you always connects equivalent points on two opposite these routes with each other ( ie, the middle of each side, and the two points in the middle between the middles and ends, etc.) and thus obtains a family of distances that define the surface of the hyperbolic paraboloid.

In this roof shape wear is not about the First and the rafters like other roofs, but the load is carried by the shell itself - the roof carries himself is referred to as a shell structure. If the two low points still clamped together (eg by a steel cable ), so the roof gets higher strength again. Even the rain water no longer flows into a long eaves, but accumulates at the low points of the roof, there only needs to be thought of a drain.

Weblink

• Baulexikon online: hyperbolic paraboloid

• Structural