Laboratory Test Study On Silt Flow Solidified Soil In Dalianwan Lake Bottom

In order to will be a lot of dredged mud into the sustainable development of land resources,this paper takes the dalian bay sea dredged silt as the research object,with cement,fly ash and phosphogypsum composite curing materials flow on sludge solidification treatment,was studied by indoor test the flow characteristics of dredged mud solidified soil,the unconfined compression test,triaxial compression test to study the curing agent,curing condition,age and other factors on the mud flow stabilized soil,the influence of strength and deformation in service and environmental factors in the process of its influence on its durability.The main conclusions are as follows:(1)There is a decreasing relationship between the flow value of silt flow solidified soil and the amount of curing agent.The influence of fly ash on the flow value is more obvious than that of cement.There was a good exponential function relationship between flow value and intensity,and r-square was greater than 0.88.When the cement-mud ratio is 0.09~0.16 and the flyash-mud ratio is 0.35~0.80,the initial flow value of the silt flow solidified soil is 27cm-36 cm,and the flow value gradually decreases with the increase of the placement time,and the flow value after 3 hours is 18cm-24 cm.(2)When the cement-mud ratio is 0.09~0.16 and the flyash-cement ratio is 0.35~0.80,the failure strain of the silt flow solidified soil is 0.75-2.5%,and the deformation modulus has a linear relationship with the unconfined compressive strength,and r-square is greater than 0.83.With the increase of cement content,the strength value of solidified soil increases obviously,and the longer the age,the more obvious the influence of fly ash on the strength value.The damage strain of silt flow solidified soil increases with the increase of initial water content.The higher the curing temperature is,the greater the strength of silt solidified soil is and the greater the damage strain is.(3)When the cement-mud ratio is 0.11~0.16 and the flyash-cement ratio is 0.35~0.80,the strength and failure strain of the silt flow solidified soil also increase with the increase of confining pressure,while the internal friction Angle changes little,which is 10°-19°.With the increase of age and the amount of curing agent,the cohesive force of silt flow solidified soil increases gradually.When the confining pressure is 100 kPa,the principal stress difference of the silt flow solidified soil is 1.8-3.5 times that of the unconfined compressive strength.(4)When the cement-mud ratio is 0.09~0.16 and the flyash-cement ratio is 0.35~0.80,with the increase of the number of dry and wet cycles,the strength of the silt solidified soil decreases first and then increases,and finally the strength value continues to decline.The damage strain of silt flow solidified soil soaked in acid,alkali and salt solutions was 1.9%~3.2%,and the damage strain of solidified soil soaked in acid solution was 1.3 times of that in salt solutionThe freezing-thawing cycle led to the serious deterioration of the silt flow solidified soil,and obvious cracks appeared.After the fifth freezing-thawing,the solidified soil strength value lost 50%.With the increase of coupling cycles,the strength loss rate of silt flow solidified soil increases gradually,and the strength loss rate of the fourth time is 40%~45%.