Study On The Effect Of Soil Stabilizer On Sediment Stabilization Of Alluvial Fan In Collapsing Gully

At present,engineering measures and biological measures are the main measures for the management of collapsing gully.Its construction is time-consuming,laborious and difficult to promote in areas with inconvenient traffic.At the same time,a large amount of sediment will be released from the erosion of collapsing gully.Whether the eroded sediment can be used to solidify and build a sand retaining dam has become the key to the comprehensive promotion of the treatment measures of the collapsing gully.This experiment takes the sediment of the alluvial fan of collapsing gully as the research object.Through mechanical tests,durability tests and electron microscope scanning tests,the effects of different concentrations and curing ages of two soil stabilizers(ST-1,SV-LSS)on the mechanical properties and durability of alluvial fans was studied.The optimal curing agent and its corresponding concentration and curing age were obtained,which provided a scientific basis for the construction of sand retaining dams using local materials for collapsing gully control.The results show:(1)The unconfined compression test showed that the compressive strength(2273 k Pa)of the 0.03% ST-1 solidified soil sample after curing for 28 days was greater than the 0.042% SV-LSS solidified soil sample(2134 k Pa).The triaxial shear test showed that the shear strength of the cured soil increased with the increase of confining pressure,and the shear strength of ST-1 cured soil(3707 k Pa)was higher than that of SV-LSS cured soil sample(3358 k Pa)under the confining pressure of 200 k Pa.The cohesive forces of the two solidified soil samples increased with the increase of the curing age,and reached a peak at 14 d of the curing age,and then gradually became stable.The internal friction angle increased with the increase of the maintenance age.(2)The stress-strain curves of the three solidified soil samples in the dry-wet alternation and water stability tests are still strain-softening.The compressive strength of the three kinds of solidified soil samples still showed an upward trend after alternating drying and wetting and immersion in water.The unconfined compression strengths of the two kinds of tests were finally measured in descending order: ST-1 solidified soil sample > cement solidified soil Sample(control group)> SV-LSS solidified soil sample.(3)Using scanning electron microscopy,it was found that after adding the curing agent,a large amount of calcium vanadium,C-S-H(calcium silicate hydrate)gel and some calcium hydroxide crystals will be formed between the soil particles,resulting in the reduction of the pore area of ??the cured soil sample and the fractal dimension.number increases.However,after the endurance test,the unconfined compression strength was still increased due to the formation of C-S-H gel between soil particles.In summary,the mechanical and durability properties of ST-1 curing agent are better than SV-LSS curing agent,and the optimum concentration of ST-1 curing agent is 0.03%,and the optimum concentration of SV-LSS curing agent is 0.042%.The age range is 7-14 days.