Live load

Foundation Loads and Pressures. Foundations should be designed to support the weight of the structure, the live load, and the load effect on the structure and its foundation due to such other loads as v. ind. In general, for foundation designs, a safety factor of 3 is used for dead loads or live loads independently. A safety factor of 2 is used for combination loads including transient loads [38,40]. 

It is intended that a spread foundation be designed for a concentric load of 300,000 lb (dead load plus live load). This foundation is to be placed on the surface (brown silty sand and gravel) of the soil and bedrock column shown in Figure 2-61. If a square foundation can be made to support the 300,000-lb load, what should be the dimensions of this foundation ... 

Wind and Dynamic Stresses (Induced by Floating Hull Motion). Allowable unit stresses may be increased one-third over basic allowable stresses when produced by wind or dynamic loading, acting alone, or in combination with the design dead load and live loads, provided the required section computed on this basis is not less than required for the design dead and live loads and impact (if any), computed without the one-third increase. 

Care must also be taken where large live loading are concerned such as gantry cranes, hoists, materials handling, etc. to ensure that structural and safety implications are properly addressed during both design and construction stages. 

This value is the basic standard that AWWA M-II specifies for steel conduit and pipe, as do the ASTM and ASME. As is obvious, there are a number of factors that contribute to pipe deflection. These are the external loads that will be imposed on the pipe, both the dead load of the overburden as well as the live loads of such things as wheel and rail traffic. The factors affecting RTR pipe deflection can be summarized as follows ... 

Live load-wheel load, spacing surcharge... 

Hydraulic load 600 N/m2 live load on the plate, plus 3000 N/m2 over the downcomer seal area. 

Live Loads. These loads include the weight of the medium transported or the medium used for test. Snow and ice loads due to both environmental and operating conditions shall be considered. 

Conventional loads, such as wind and live loads, arc applied relatively slowly to a structure and remain constant for a relatively long period of time compared to the response time of the structure. Blast loaded structures experience a very rapid application of the load and a corresponding rapid rise in member stresses. This load... 

Live loads which would be blown away by a blast wave or which would not increase the inertia of a supporting member should not be included in the mass calculation. Additionally, some judgment is needed to estimate the portion of a design live loads which is normally present. For example, snow loads in cold climates may be present for relatively long durations and a portion of this live load should be included in the mass calculation. Another example is a floor live load representing personnel and furnishings which should not be included in the mass calculation. 

All or part of the live load may not be used, refer to Section 6.2.4. Unit load factors are based on the presumption that the accidental blast loading condition is an extremely rare occurrence. 

Conventional Loads - Load normally considered in structural design such as dead loads, live loads, wind loads, ana seismic loads. 

Preloads are sometimes considered in developing resistance functions. Preloads are any dead or live loads which cause a deformation in the member and thereby use up some of the available strain energy. Effects of preload on equivalent SDOF system analyses are sometimes handled by reducing the calculated available resistance by the amount of the preload. Another approach is to simply superimpose the preload on top of the blast load. 

Weight Effects Weight considerations include (1) live loads (contents, ice, and snow), (2) dead loads (pipe, valves, insulation, etc.), and (3) test loads (test fluid). 

TankRoof. The roof of a vertical cylindrical tank is treated like a building structure and uses the same basic rules as the building codes. For example, the API codes require a roof to be designed for the dead load plus a 122-kg/m2 (25-lb/ft2) live load. The minimum fabrication thickness of roof plates is 3/16 in. (4.8 mm). 

Live and dead loads generate hoop forces in the area of the roof-to-shell junction for a tank having a cone roof. For dead loads plus live loads, the roof-to-shell junction is assumed to carry most of the tensile forces generated. The minimum area required is computed assuming that the membrane force transmitted to the roof-to-shell junction varies with the sine of the angle of the roof ... 

LOUVER AHC-t F — GROSS LOUVERED AREA.- — FAK DECK LIVE LOAD. 

In the counterflow design, where eliminators are subject to live loads, the racks shall be capable of supporting the weight of a man or 25 lb/ft2. The minimum thickness of wood slats shall be -j inch. 

Fan and water distribution decks are to be of precast concrete and designed for a live load of 60 lb/ft2 plus any concentrated or distributed dead loads, such as fans, motors and maintenance equipment. 

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