Anti-liquefaction And Measures Of Gravel Steel Slag

China is in an earthquake-prone zone,and liquefaction of gravel soil is a common earthquake disaster.Due to the increasing shortage of gravel materials,it is necessary and urgent to seek for a new type of backfill material with good liquefaction resistance.Aged steel slag can be used for geotechnical backfilling,but due to the different types and thickness of steel slag,it is more complex and similar to soil types.In this paper,the anti-liquefaction characteristics of the two kinds of gravel steel slag(GSS-C and GSS-F)were studied,and two kinds of anti-liquefaction measures of rubber-gravel steel slag mixed with used tire particles and basalt fiber geogrid reinforced gravel steel slag were studied by dynamic triaxial tests.The specific research contents are as follows:The internal structure and loading principle of the DSZ-2-type dynamic triaxial apparatus were introduced,and the control factors and failure criteria of the liquefaction strength test were described.The test types of discarded steel slag,waste tire rubber particles and geogrid were determined.The two types of sample preparation methods of the dynamic triaxial apparatus were introduced.The preparation and installation of specimens for dynamic triaxial tests were briefly described.For GSS-C gravel steel slag,the stress,strain,and dynamic pore water pressure characteristics of the gravel steel slag were tested by considering factors such as consolidation stress ratio,vibration frequency,relative compactness,confining pressure and gravel content,etc..The relationship between dynamic strength and vibration frequency,dynamic strain and vibration frequency,pore water pressure and number of vibrations,dynamic stress and dynamic strain of gravel steel slag samples were analyzed and compared with anti-liquefaction characteristics of traditional gravel soils.It was concluded that GSS-C gravel steel slag had good liquefaction resistance.In the project,GSS-C gravel steel slag can be used as backfill material instead of traditional sand,gravel soil,sand-gravel material and sand pebbles to solve the current shortage of gravel resources.Waste tire rubber particles were mixed to improve GSS-F gravel steel slag with a heavy texture,forming rubber-gravel steel slag,which was compared with the density of traditional rubber-sands.The anti-liquefaction characteristics of the rubber-gravel steel slag were determined by considering the incorporation ratio of rubber particle,confining pressure,frequency,and consolidation stress ratio,and the relationship between dynamic strength and number of vibrations,dynamic strain and number of vibrations,pore water pressure and number of vibrations,dynamic stress and dynamic strain of rubber-gravel steel slag were analyzed and compared with anti-liquefaction characteristics of traditional gravel soils.It was concluded that the anti-liquefaction performance of GSS-F pure gravel steel slag was basically better than that of all traditional soils,and gravel steel slag incorporated with 10% rubber particles still had a certain degree of anti-liquefaction performance.The basalt fiber geogrid reinforced gravel steel slag was selected to improve the overall stability of the GSS-F gravel steel slag,and the liquefaction resistance of the reinforced gravel steel slag with different reinforcement layers was studied.The relationships between dynamic strength and vibration number,dynamic strain and number of vibrations,pore water pressure and number of vibrations,dynamic stress and dynamic strain of reinforced gravel steel slag samples were analyzed.It was concluded that reinforced gravel steel slag with two reinforcement layers had better anti-liquefaction performance.Comparing with the anti-liquefaction characteristics of traditional sand-gravel material,it was obtained that.