GGU-UNDERPIN: Earth pressure redistribution

Classical earth pressure redistribution is not appropriate for braced or tied-back walls. Earth pressure calculated according to classical theory must be redistributed. GGU-UNDERPIN includes a large number of pre-programmed redistribution figures. In addition, by defining a polygon, the user can create any redistribution figure. The figures available are given below:

• rectangle,

• 2 rectangles,

• triangle, maximum at top,

• triangle, maximum at centre,

• triangle, maximum at base,

• trapezoid,

• quadrilateral with maximum at anchor locations or at any point,

• user-defined redistribution figure by means of a polygon,

• all EAB redistribution figures.

For normal underpinning walls, earth pressure redistribution according to the EAB is probably the simplest way of finding the correct redistribution figure. If you select this option, you only need to wait for the analysis to be completed. GGU-UNDERPIN selects the most appropriate from the available EAB figures (R 71 for in-situ concrete walls). If the program is unable to find a suitable EAB figure because of abnormal anchor or strut positions, analysis is terminated, and a warning message is issued. You must then give some thought to selecting or defining your own redistribution figure.

GGU-UNDERPIN gives you the option of including or excluding area loads in redistribution. Water pressure is never redistributed.