Effect Of Volatile Organic Compounds (Vocs) On Engineering Properties Of Cement Soil

With the continuous development of China's economic construction,the urbanization process has been accelerating,and many chemical plants are facing relocation.Most of the old sites left over from the relocation of chemical plants have various pollution problems,and volatile organic compounds(VOCs)are one of the main types of pollution.Volatile organic compounds are not only volatile,but also have high irritancy and toxicity,which will cause great troubles for the later development and utilization of chemical plant sites.The former site of a chemical plant in Zhenjiang is facing development.Due to pollution problems,ectopic soil restoration is required.The soil remediation process uses cement soil technology.Due to its process characteristics,cement soil is greatly affected by the environment,taking into account the main types of pollution.It is a volatile organic pollution,and the current research results on the influence of special environment on cement soil mainly focus on inorganic compounds such as acid,alkali,salt and heavy metals.The research results on the influence of volatile organic compounds on cement soil characteristics are still limited.For engineering safety considerations,this paper mainly analyzes the effects of volatile organic compounds(VOCs)on the engineering properties of cemented soil.The main research work and conclusions of this paper are as follows:(1)Through the comparative test to test the unconfined compressive strength and failure strain of cement soil under different VOCs pollutant content,the influence of VOCs pollutant content on the strength and deformation of cement soil is studied.The test results show that:VOCs pollutants can be reduced.Unconfined compressive strength of cement soil.Under the same age,the higher the content of VOCs pollutants,the lower the strength of cement soil.Based on ordinary cement soil with the same mix ratio,the content of VOCs in cement soil is When the weight is increased by 1g/kg,the strength of the cement soil will decrease by 3.47%.The VOCs pollutants will have a greater impact on the failure strain of cement soil.The strain of ordinary cement soil with the same mix ratio will decrease with the increase of age,and the relationship is close to the hyperbolic curve.The deformation strain of VOCs contaminated cement soil decreases with the increase of age,and the relationship is relatively close to linear shape;the deformation coefficient E50 of cement soil is basically linear with the strength qu,and the deformation coefficient and strength of cement soil under different VOCs pollution content.The relationship is similar.By fitting,the relationship is E50=(61.1-75.4)qu.(2)The unconfined compressive strength and failure strain of VOCs contaminated cement soil under different cement mixing ratios were tested by contrast test.The influence of cement blending ratio on the strength and deformation of VOCs contaminated cement soil was studied.The test results showed that:cement The blending ratio can increase the strength of VOCs contaminated cement soil.The higher the cement blending ratio,the higher the strength of VOCs contaminated cement soil at the same age,but the cement blending ratio has little effect on the strength growth trend of VOCs contaminated cement soil.The relationship between the strength of VOCs contaminated cement soil and age t,cement admixture ratio aw and VOCs pollutant content r was obtained by data fitting:q_u=1.26(0.283-0.21×0.965~t)(a_w-10.53)(1-0.0347r).(3)Analyze the influence of VOCs pollutants on the actual project by simulating the construction of foundation pit of gravity cement retaining wall.The analysis results show that VOCs can delay the excavation time of the foundation pit.The main solution is to improve the strength method.The cross-section method is increased,and the method for increasing the strength can be subdivided into VOCs elimination method(particle adsorption method and fiber adsorption method),VOCs conversion method,cement incorporation ratio method,and early strength method.