The new feature of the program is a section relating to design for the influence of trees and removal of trees. The input allows for ys and yt, potential surface movement due to the tree, (induced suction change in addition to the normal design suction change) and optional ‘if tree is removed’. The design is in accordance with Appendix H Guide to Design of Footings for Trees and appendix CH Commentary to Guide to Design of Footings for Trees. Guidance to the design for trees using CORD is also provided in Appendix B of this manual.
The program allows for different footing types, stiffened Raft, Waffle Raft and Strip footing design for the classes of structures set out in AS2870-2011, Section 1.1.
The program is a design ''tool'' to assist the user in designing raft and waffle raft slabs and strip footings. It is intended to be used in conjunction with the design procedures and site management requirements set out in AS2870-2011. A thorough understanding of the importance of the geotechnical input data relating to the physical characteristics of the site foundation soils is considered a necessary prerequisite for the satisfactory use of the package.
The normal working limits for which CORD is recommended are:
Articulated superstructure, 20 mm ≤ ys ≤ 250 mm
Non-articulated superstructure, 20 mm ≤ ys ≤ 120 mm
CORD 8.0 includes the design calculation of footings for the influence of trees (tree drying effects) and the effects of tree removal or death. These are calculated by the program.
For ys < 50 mm the moment of resistance for centre heave (hogging) is the critical design
case. The depth of footing required is very sensitive to the percentage reinforcement for this case. Designs where the footing depths are significantly less than those given in Section 3.0 of AS2870-2011, which have a history of satisfactory field performance, should be reviewed by a Qualified Engineer.