Abstract:

The durability and long-term strength of anchor are the key factors to influence the safety of ground anchorages, therefore it is one of hot research problems in geotechnical engineering. The different scale and degree of damages and defects in jointed rock mass provide a storage space and transporting channels for groundwater in rocks. The frost heaving and accompanied by groundwater migration caused by freezing in rocks will affect the anchorage system performance. freezing and thawing cycles will result in degradation of longterm anchoring performance and durability of anchorage system. Therefore based on the freezing theory of porous media, a hydrostatic pressure model on contact surfaces among mortar, rocks, mortar-steel and mortar-rock is constructed after analyzing the freezing mechanism. The damage mechanism due to freezing and thawing and its influence factors are studied more systematically. Considering the existing relevant achievements six modes and their corresponding mathmetical models are established to describe the degradation of anchorage performance in jointed rocks under repeating freezing and thawing.

Key words: anchoring performance, cycle of freezing and thawing, rock damage, long-term strength, durability, porous media