Study On Damage Of Anchorage Structure Of Slope Under Confining Pressure And Freezing And Thawing Conditions

With the rapid rise of China's economy,traffic construction has developed rapidly.In the construction of mountain roads,the instability of slopes is often encountered.As a common method of slope reinforcement,anchoring structures are the most widely used in engineering.The slope anchorage structure in the seasonal frozen zone is affected by confining pressure and freeze-thaw cycles,and its stability and mechanical properties change,which affects the stability of the slope.Therefore,studying the influence of confining pressure and freeze-thaw cycles on the anchorage structure of the slope is of great significance to the geotechnical engineering construction in the seasonal frozen zone.In this paper,the effects of confining pressure and freeze-thaw cycles on the anchorage structure are studied.By consulting the literature and theoretical analysis,mortars,anchors and sandstone-bolt specimens are made from bolts of different materials to carry out confining pressure and freeze-thaw.The model test under three conditions of cyclic coupling,freezing period and repeated load,the main research contents and conclusions are as follows:(1)Through the pull-out test of the mortar-anchor specimen under confining pressure and freeze-thaw cycles,the following conclusions are drawn: in the range of 0kN~100kN,as the confining pressure increases,the anchoring force change curve rises.trend.When the confining pressure is coupled with the freeze-thaw cycle,the anchoring force increases with the increase of confining pressure,decreases with the increase of the number of freeze-thaw cycles,and the confining pressure has an inhibitory effect on the freeze-thaw cycle.When the GFRP and CFRP composite ribs are subjected to the freeze-thaw cycle and confining pressure,the anchoring force variation curves are similar and less than the anchoring force of the ordinary steel anchor specimens under the same conditions.(2)The sandstone bolt test piece was used to replace the rock slope,and the sandstone bolt test piece was tested under confining pressure and freezing and thawing conditions by the pull-out test.It was found that the anchoring structure anchorage force increased with the confining pressure.Reduce the wavy curve that decreases after increasing.(3)Under the conditions of freezing action,fatigue load and freeze-thaw cycle,the tensile test was carried out on the test pieces under different freeze-thaw cycles,repeated load times and frozen conditions.The experimental results show that with the increase of the number of repeated loadings,the anchoring force decreases overall,but the trend gradually becomes slower.When the freezing-thawing cycle is coupled with the repeated load,the anchoring force of the anchoring structure decreases more severely.During the freezing period,the anchoring force of the specimen was 1.3 times that at normal temperature.During the freezing period,the anchoring force of the anchoring structure also decreases with the increase of the number of freeze-thaw cycles,and the damage form also changes.In this paper,the factors affecting the stability of rock slope by mortar bolt specimen and sandstone bolt specimen are studied,and a large number of conclusions are drawn.The anchorage structure of rock slope is affected by factors such as freezing and thawing,confining pressure and fatigue load.Data support is provided.