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Loading
The following types of external loading can be applied to a Phase2 finite element model:
Distributed load applied to ground surface, deformations magnified
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Loading: Distributed Loads
A distributed load represents a surface load or pressure (force) / (unit area) when considering the out-of-plane dimension of the model. There are 3 different options for applying distributed loads: Uniform, Triangular and Ponded Water loading.
Uniform Distributed Load
The Add Triangular Load option allows you to define a distributed load which varies linearly between two points along a boundary. The load can be triangular (zero at one end) or trapezoidal (different non-zero values at each end).
Trapezoidal Distributed Load
Loads can be applied at any orientation: normal to boundaries, vertical, horizontal or at any angle. The load magnitude can be increased or decreased at different stages by selecting the Stage Load checkbox and entering multiplication factors in the Stage Factors dialog.
Add Distributed Load dialog
Stage Factors dialog for load magnitude
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Loading: Ponded Water
To define the distributed loading due to Ponded Water (e.g. impounded water against a slope or dam), a specialized option is provided, the Add Ponded Water Load option. This allows you to easily define hydrostatic loading due to Ponded Water by specifying total head boundary conditions on user-selected boundary segments.
Ponded Water (blue hatch pattern)
Weight of ponded water modeled as an equivalent distributed load
Phase2 will automatically determine the distributed loading on each selected boundary segment, which is equivalent to the hydrostatic force of the ponded water. The unit weight of water entered in Project Settings is used to determine the final load magnitude. Ponded Water loads are always normal to the boundary.
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Loading: Line Loads
Concentrated loads can be modeled with the Line Load option. A line load magnitude represents a force per unit length (e.g. kN/m) when considering the out-of-plane dimension of the model.
Vertical line load added to external boundary
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Loading: Seismic Load
The Seismic Load option allows you to define a pseudo-static seismic (earthquake) load, by entering Horizontal and/or Vertical seismic coefficients in the Seismic Loading dialog.
The Seismic Coefficients are dimensionless coefficients which represent the (maximum) earthquake acceleration as a fraction of the acceleration due to gravity. Typical values are in the range of 0.1 to 0.3. When a seismic coefficient is defined, an additional Body Force will be applied to each finite element in the mesh, as follows:
Seismic Force = Seismic Coefficient * Area of element * Unit Weight of element
material
The Seismic body force is vectorially added to the (downward) Body Force which exists due to gravity, to obtain the total body force acting on an element.
Seismic Load dialog
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Loading: Springs
Springs can be added to any node of the finite element mesh using the Add Springs option. Springs can be used to model the effect of struts or similar support elements.
Spring properties are defined by entering values of stiffness in the X and Y directions. An initial spring force may also be included in the X and/or Y directions.
Display of spring applied to node
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Loading: Liner Moment
The Liner Moment options in the Loading menu allow you to define moment boundary conditions for Liners.
The Add Liner Moment option allows you to apply an active (non-zero) moment load to a Liner.
Moment (green circular arrow symbol) applied to liner
The Add Liner Hinge option allows you to specify a zero bending moment condition for a Liner (i.e. the location of a "hinge" which allows the liner to freely rotate at that point).
Liner with two Hinges (green circles with dot)
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