| There are a large amount of soft soil in the Wabu Lake area of Shou Co unty,Huainan City,which is mainly silt clay and contains a certain amount of organic matter.It have the characteristics of large natural water content,low bearing capacity,and large settlement deformation,which is not conducive to t he city in the area Construction.In order to improve the strength of soft soil,it should be cured.At present,cement is commonly used in engineering to soli dify soft soil,but a large amount of toxic gases and the greenhouse effect will be generated during the cement production process,causing serious pollution t o the environment.However,ground granulated blast furnace slag(GGBS)is a kind of industrial waste slag discharged during blast furnace iron smelting.Th e composition of blast furnace slag and cement is similar.You can use blast f urnace slag to replace cement as a soft soil curing agent Large amounts of sla g are piled up and polluted,bringing great economic and social benefits to soc iety.In this paper,the muddy soft soil of Wabu Lake in Shou City,Huainan is taken as the research object,blast furnace slag is used as the curing agent,a nd calcium oxide and gypsum are used as the stimulant to excite the soft soil.And use the Central-Composite Design method to optimize the three mix ratio s,and obtain the test results and conclusions as follows:(1)Based on the characteristics of high organic matter content and high w ater content of Wabu Lake soft soil,granulated blast furnace slag powder(GG BS)is used as the main curing agent,and calcium oxide and gypsum are used as the activators to prepare a composite curing agent,called CA06 compound curing agent.(2)Based on the central combination method,the optimal ratio of three a dditives are studied.Through the interaction and variance analysis of the three additives,the optimal ratio of the three additives is obtained: the granulated bl ast furnace slag powder is 9.78%,calcium oxide is 4.8%,sodium sulfate is3%.Under the optimal ratio,the unconfined compressive intensity at the curing age of 7d is 1029.85 kPa,and the intensity value at the curing age of 28 d ca n reach 1378.12 kPa.(3)Through the unconfined compressive strength test of the soft soil withthe same initial water content and different proportions of curing agents,it w as found that the reduction of the water content of the samples in the 0 group is very significant,mostly between 6%-11%.The most significant reaction m ix ratio is when the granulated blast furnace slag,calcium oxide and gypsum a re 14%,5% and 4%,respectively,the minimum moisture content of the sampl e after curing for 28 days is 13.59%,and the maximum drop is 11.01%.(4)Under the optimal ratio of the three additives,add 4% to 19% of org anic matter to the solidified soil to conduct the unconfined compressive strengt h test.The results show that under the optimal ratio of 7d and 28 d,with the addition of organic matter,the strength of the solidified soil showed a trend of rapid decline and then a slow decline.When the organic matter content was 19%,the strength of the solidified soil decreased the most,only 80% at optimal intensity.(5)Under the optimal ratio of the three additives content,the cement soli dified soil and GGBS composite solidified soil are compared with the strength curve of the two.The results show that the strength of the slag solidified soil is relatively large in the early stage,which is similar to the strength when th e cement mixing ratio is 16%,and the later strength is higher than that of the other cement solidified soil.Figure: 32;Table: 11;Reference: 69... |
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