| The soil material generated during the excavation process of the mud-water balance shield is mixed with the newly injected mud and water to form mud,which is transported to the ground through the drainage pump and pipeline,and needs to be processed and processed to realize recycling.With the rapid development of underground engineering in my country in recent years,the requirements for environmental protection in the construction process are getting higher and higher.If the waste mud is not properly treated scientifically,it will not only seriously affect the progress of the project,but also have a serious impact on the ecological environment around the project.This paper mainly conducts a detailed study on the efficient separation and comprehensive treatment of the waste mud from the mud-water balance shield through a combination of literature research,theoretical analysis,laboratory tests and on-site system analysis.The mechanism and effect of the separation of mud and water,the system summed up a set of mud-water balance shield waste treatment system,to provide reference and reference for similar projects.The main research contents and results are as follows:(1)Relying on the shield section of the Jiangyin Jingjiang Yangtze River Tunnel,the performance evaluation and analysis of the waste mud generated in the actual excavation process of the project,including the particle size of the waste mud,mineral analysis and Zeta potential measurement,are used for laboratory test mud preparation provide reference;compare and analyze the mud treatment system summarized in this paper and the treatment system to be used on site,and propose optimization suggestions.(2)Based on the definition of flocculants and the mechanism of dehydration and precipitation of flocculants,two inorganic polymer flocculants and organic polymer flocculants,polyaluminum chloride were selected to explore the influence of different types,concentrations and additions of flocculants on the results of flocculation and precipitation.,through the evaluation of sediment height,sediment moisture content,supernatant p H value and supernatant turbidity,etc.The test results show that the flocculation effect is the best under the combination of anionic polyacrylamide with a molecular weight of 16 million and a concentration of 0.15% and polyaluminum chloride with a molecular weight of 28% and a concentration of 10 g/l.(3)Based on the theory of high-speed centrifugal dehydration and vacuum negative pressure,improve the existing vacuum filtration dehydration device,and explore the influence of different rotational speeds,time,vacuum negative pressure and dehydration time on the dehydration of waste mud.The centrifugal effect is the best when the rotation speed is1600r/min and the centrifugation time is 20 min.When the vacuum suction filtration is used for dehydration,the vacuum negative pressure is 60 k Pa and the suction filtration time is 20 min to achieve the best dehydration effect.The phenomenon shows that the geotextile as a filter medium is slower to block than the filter paper,and the relative effect is better.(4)Based on the research on the recycling method of waste mud and sediment,the existing projects and researches were investigated,and three processes were proposed,including the non-burning brick process,the grouting process after recycling the wall,and the foam concrete process,and the requirements,advantages and disadvantages of different processes were analyzed.In this paper,based on the properties of engineering waste mud and the results of indoor test treatment,non-burning bricks are selected as the utilization method,and the performance of non-burning bricks with different curing agent systems is explored through indoor tests,and the non-burning bricks of cement system,lime system and cementlime mixed system are compared.Uniaxial compressive strength,from the test results,it can be seen that the cement system > cement-lime mixed system > lime system,and the uniaxial compressive strength of unburned bricks under the cement system and cement-lime system can meet the requirements of the specification "JC/T 422-2007 Non-sintered garbage tailings bricks " MU15 requirements combined with laboratory tests to study the performance of nonburning bricks. |
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