# Surface Loads tab

Used to apply uniform pressure on the faces of solid elements.

Note: Surface elements have been deprecated in STAAD.Pro CONNECT Edition. The analysis and design engine will allow them but their use is not recommended.

SettingDescription
Load Force is the magnitude of the load.
Direction The load may be applied along the local Z axis, or along one of the global X, Y or Z axes (GX, GY, GZ).

## Pressure on Full Surface

SettingDescription
Load W1 is the variable using which the pressure value is defined, in pressure units.
Direction The load may be applied along the local Z axis, or along one of the global X, Y or Z axes (GX, GY, GZ).

## Partial Surface Pressure Load

To apply a partial pressure load on a surface, provide the magnitude of the pressure load in the W1 edit box.  X1 Y1 and X2 Y2 represent the coordinates of the extremities of the loaded area. The coordinates are with respect to a local coordinate system with the origin at the first node of the surface element. Using the Direction option, specify the direction of application of the load which can be either in the local Z direction or in any of the global directions (GX, GY or GZ).

SettingDescription
Load The surface pressure (force per unit area) or concentrated load (force unit). For concentrated load, the values of X2 and Y2 must be omitted, while X1 and Y1 must be specified.
X1, Y1, X2, Y2 For surface pressure (force per unit area), these values represent the coordinates of the rectangular boundary on which the pressure is applied. If X1, Y1, X2 and Y2 are all zero,the pressure is applied over the entire element. If X1 and Y1 are specified but X2 and Y2 are omitted, then W1 is treated as a concentrated load.
Direction GX, GY, GZ represent the global X, Y, and Z directions along which the pressure may be applied. Local Z indicates that the pressure is applied normal to the surface in the local Z direction.

## Partial Surface Trapezoidal Load

Used to load a portion of a surface with a non-uniform pressure.

SettingDescription
Direction of Pressure GX, GY and GZ represent the global X, Y, and Z directions along which the pressure may be applied. Local Z indicates that the pressure is applied normal to the element in the local Z direction.
X1, Y1, X2, Y2 For element pressure (force per unit area), these values represent the coordinates of the rectangular boundary on which the pressure is applied. If X1, Y1, X2 and Y2 are all zero,the pressure is applied over the entire surface. If X1 and Y1 are specified but X2 and Y2 are omitted, then W1 is treated as a concentrated load.
Variation along element

The varying pressure values at the four corners of the loaded area.

Enter the pressure intensity F1 at the lowest local coordinate location (start) and the intensity F2 at the highest local coordinate location (End). Start and End are defined based on the positive direction of the local X-axis or local Y-axis.