Study On Treatment Technology Of Soft Mucky Soil In Airport Engineering

As a typical engineering soft soil,a series of engineering problems caused by improper tr-eatment of muddy soil have gradually emerged in practical engineering.The treatment and ut-ilization of muddy soil urgently need to be solved.The reasonable treatment and utilization o-f muddy soil in infrastructure such as airports,railways,and highways have both practical sig-nificance and the necessity of in-depth research.The Tianjin Binhai Airport Phase III renovat-ion and expansion project has excavated over 8 million cubic meters of soil,mainly consistin-g of silt and silty clay.This article relies on the research project of Tianjin Binhai Airport Pha-se III Reconstruction and Expansion Project to improve the undisturbed soil in the area to sol-ve the problems of waste soil backfilling,co MPaction,and bearing capacity not meeting the standards in the future Phase III project,improve design indicators,and ensure project quality.The dissertation focuses on the characteristics of muddy soil at Tianjin Binhai Airport and dra ws on the research results of muddy soil at home and abroad.It conducts relevant research on the ap-plication of soil solidification treatment methods to the filling of road foundations.The main research content is as follows:(1)Routine indoor physical and mechanical tests were conducted on natural mudd-y soil in accordance with current test specifications.Based on the actual situation and effectiv-eness of using undisturbed muddy soil directly for on-site road foundation filling,analysis and evalu ation were conducted to demonstrate the necessity of treating and reusing natural mud-dy soil.(2)Treat the undisturbed muddy soil and solidify the natural muddy soil under the condit-ions of lime,cement,and NW solidifying agent single and multiple admixtures.According to the requirements of construction design indicators,conduct unconfined compressive strength tests,CBR tests,dry wet resistance tests,freeze-thaw resistance tests,water stability tests,and electron microscope scanning microscopic tests on solidified soil samples with different amounts of solidifying agent,different co MPaction times,and different ages,Analyze and co MPar-e the strength characteristics,durability,and micro mechanisms of the four types of solidified soil mentioned above.(3)This article establishes a theoretical formula for the reaction modulus of the roadbed and extends the formula for calculating the replacement thickness.Through conducting on-sit e replacement tests on mountain stones and solidified soil,it is found that the rebound modulu-s of the undisturbed soil and replacement materials,as well as the replacement height,compr-ehensively affect the reaction modulus value of the roadbed.By using a numerical simulation model,the vertical stress corresponding to different reaction modulus values of the roadbed is analyzed.Finally,from the perspective of actual on-site engineering,Based on the formula fo r calculating the replacement thickness,data fitting was performed on the replacement height and the rebound modulus of the undisturbed soil,and a prediction model for the replacement t-hickness in the airport runway area and non runway area was regressed.(4)Based on on-site tests and current design specifications,select economically reasonab-le and meet the design and construction requirements of cement-lime-NW solidified soil.By adding cement,lime,and NW solidified agent,the undisturbed muddy soil is treated.In the on-site test section,various road performance indicators of cement-lime-NW solidified soil are tested.And strict control is carried out on the construction process and quality.After testing,th-e co MPaction degree and reaction modulus of the composite roadbed can meet the constructi-on design requirements.