Residential

Wood Framed Load-bearing walls

Exterior walls that carry ceiling, roof or upper floor loads to the foundation are load bearing or "bearing" walls. Internal walls that support joists at mid span and transfer loads down to foundations are also bearing walls. Bearing walls usually have perpendicular joists or rafters crossing or resting on top of them and foundations underneath them. An exception are the end walls of a gable-roofed house; these usually run parallel to rafters and joists but must bear the weight of extensive wall framing.

Wind and seismic loads, which produce lateral stresses on a house, are managed by tightly interlocking framing members. Plywood sheathing or wood or metal cross bracing interconnect framing members, creating a sturdy triangular form and-together with foundation bolts-lock walls to foundation. The roof is protected from wind uplift by steel strapping.

MORE ABOUT:
/ Foundations / / Foundation footings / / Standard wood framing /
/ Balloon framing / / Wall framing 1 / / Wall framing 2 / / Floor & ceiling framing 1 /
/ Floor & ceiling framing 2 / / Roof framing 1 / / Roof framing 2 /
Information source: http://www.hometips.com/hyhw/structure/104detail.html

Multi Floor Buildings

Steel & Masonry Load-Bearing Walls

Bearing Walls with Core(s)

A core is little more that two, three or four bearing walls placed perpendicular to each other in order to create a "closed" geometry. Tubes, round or square, can resist torsional loading and are very stiff. A core can be added to the typically parallel alignment of the bearing walls in order to create a lateral load resistance in a direction perpendicular to the bearing walls. Otherwise, the parallel walls can collapse like dominoes.

The core is often placed in a central location. This is due to the convenience for the distribution of building services AND for an increased structural integrity. Off-center placement of a core can create torsional rotational loadings that might require additional resistance mechanisms. Bearing walls with core(s) allow for a greater free floor area and is thus more popular for office buildings than the parallel Bearing Wall systems. This is a common system for reinforced concrete structures of moderate height.

Information source: http://www.uoregon.edu/~struct/resources/pencil/systems/sys2.htm

Self Supporting Boxes

This system was developed in the late 1970s when the prefabrication of reinforced concrete structures was at the height of its popularity. Prefabricated concrete "containers" are stacked on top of each other - each layer oriented perpendicular to the one directly below it. This results in a criss-cross pattern that also gives it a degree of stability. The main difficulty with this system is the lack of a logical clarity or regularity for the building systems.

Information source: http://www.uoregon.edu/~struct/resources/pencil/systems/sys3.htm

Core with Cantilevers

Solid Core supports cantilevered floor slabs which are often post-tensioned. This has the advantage of freeing the facade and clearing the interior floor space of columns. The disadvantage is the additional thickness required as the cantilever increases.

Information source: http://www.uoregon.edu/~struct/resources/pencil/systems/sys4.htm

Flat Plate Systems

This system was initially developed at the beginning of the century by Robert Maillart in Switzerland and C.A.P. Turner in the USA. The first systems had thicker floor slabs around the columns to increase the slab's resistance to punching shear. The flat plate resists this shear by an increase in the reinforcing steel or the introduction of shear heads at the columns. This is a very common system today for moderately sized structures.

Information source: http://www.uoregon.edu/~struct/resources/pencil/systems/sys5.htm

Suspension

Utilization of hangers for the suspension of floor plates from stiff girders. Hong Kong Shanghi Bank is one example.

Information source: http://www.uoregon.edu/~struct/resources/pencil/systems/sys7.htm