Study On Wet Characteristics Of Filler Of Salamander Subbed Filler

When roads are built in areas where sericite schist is distributed,in order to solve the problem of scarcity of roadbed fillers and meet the requirements of on-site use and environmental protection,they are often used as roadbed fillers.However,the sericite schist is easily broken,has low strength,and is not easily compacted.It is prone to road subsidence and surface cracking when encountering water.In order to make it better applied to the project construction,a series of indoor tests such as disintegration resistance test,anti-powdering test,and large-scale triaxial test were carried out using sericite schist as a research object,the water wettability of sericite schist was studied.The specific work is as follows:1.The disintegration resistance test and anti-powdering test were carried out.The results showed that the sericite schist belongs to moderately durable rock and its water stability is poor;Electron microscopy scanning and X-ray diffraction experiments were carried out.The results show that the sericite schist is a layered structure with a certain amount of montmorillonite and kaolinite.The experimental results reveal the mechanism of the hydrogel softening of the sericite schist from the microstructure and composition.2.Several groups of point load tests were conducted to analyze the main factors affecting the load strength at the point of impact.The reasonable geometrical dimensions of the point load test were recommended,and the strength characteristics of the air-dried state and water immersion for 24 hours were compared and analyzed.The analysis results show that the sericite schist meets the strength requirements as a subgrade filler.3.Using the "two-wire method",a large number of indoor large-scale triaxial tests were carried out to study the stress-strain characteristics,wet deformation characteristics of sericite schists at different densities,and the effect of water on the shear strength of sericite schist.The experimental results show that the larger the packing density,the smaller the wet deformation;the larger the confining pressure,the greater the wet deformation;the strength of the filler is significantly reduced after immersion in water,and the shear strength of the filler in the air-dry state is higher than that in the saturated state.4.Based on the triaxial test results,an empirical formula deducing the relationship between the amount of wetted deformation and the axial deviatoric stress（σ₁-σ₃） of sericite schist filler was deduced.According to the curve between the axial deviation stress（σ₁-σ₃） and the strain △ε₁^w caused by humidification,the curve between△ε₁^w/（σ₁-σ₃） and △ε₁^w under different ambient pressure conditions can be obtained.After fitting,it is found that the two are approximately linear,and their slope a₁,intercept b₁,and confining pressure σ₃ are linear in logarithmic coordinates.Based on a part of experimental data,the formula parameters can be further determined and the empirical formula can be deduced.Comparing the calculation results of the formula with the experimental data,it is found that the empirical formula is well consistent.5.The particle breakage characteristics of the samples after triaxial tests were studied,and the main factors affecting the particle crushing of sericite schist were analyzed.The analysis results show that the larger the particle size,the greater theparticle breakage rate;the greater the initial dry density,the greater the particle breakage rate;the higher the stress level,the greater the particle breakage rate.