ARCHING IN GRANULAR SOILS

摘要

Arching is characterized by a stress distribution where the load is transferred from softer to stiffer regions of a structure forming a stable configuration. Since it is a stable arrangement, arching is not a typical limit state problem. However, it can be formulated in a manner that allows using the static theorem of limit analysis to assess the likelihood of arching. Radial stress fields within piles of sand are constructed to search for stress distributions that promote arching. Governing equations are derived for radial stress distributions with regions varying from the yielding stress state to the elastic stress state. The stress fields with an elastic core promote arching, whereas the field where all material is in the active limit state does not support arching. However, if a passive limit state is induced in a sand heap, arching over the central part of the pile base becomes a distinct feature of the fully plastic stress field. Considerations are limited here to wedge-shaped sand heaps, though many of the conclusions are applicable to conical (axi-symmetrical) sand piles.