水泥土拉压强度变化规律
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摘要
以扬州地区典型的砂土、粉土和黏土为对象,利用自制的试验装置进行水泥土抗拉强度试验,研究不同土质水泥土拉压强度变化规律,分析了影响因素,提出典型水泥土拉压强度的经验换算公式.试验结果表明:随着水泥掺入比的增加,水泥土的抗拉强度显著提高;水泥土抗拉强度随龄期变化规律与抗压强度基本一致,即随龄期增长而增大,早期砂土水泥土强度增长速率最快,其次是粉土和黏土水泥土,且砂土水泥土抗拉强度在不同阶段均显著高于粉土水泥土和黏土水泥土;砂土和粉土水泥土的最小拉压强度比值约为0.12,黏土水泥土最小拉压强度比值达0.16,远大于建筑基坑支护技术规程中的0.06,表明扬州地区水泥土拉压强度换算比值相对于规范限值可适当提高.
The tensile strength of cement-stabilized soil is used in design of cement-soil retaining wall,which is calculated by compressive strength.However,the relationship between compressive strength and tensile strength is changed due to different soils.In this paper,the tensile strength and compressive strength tests are made in the laboratory by using the soils of Yangzhou.The results show that the relationship between strength and cement mixing ratio is generally linear.Compared with three cement stabilized soils,the early strength growth of silty clay cement stabilized soil is relatively faster than the other.Compared compressive strength with tensile strength,the minimum tension-compression strength ratio of silt and silty sand cement stabilized soil is 0.12,and the ratio of silty caly cement stabilized soil may reach 0.16,which is much larger than that in the technical regulations(0.06).
The tensile strength of cement-stabilized soil is used in design of cement-soil retaining wall,which is calculated by compressive strength.However,the relationship between compressive strength and tensile strength is changed due to different soils.In this paper,the tensile strength and compressive strength tests are made in the laboratory by using the soils of Yangzhou.The results show that the relationship between strength and cement mixing ratio is generally linear.Compared with three cement stabilized soils,the early strength growth of silty clay cement stabilized soil is relatively faster than the other.Compared compressive strength with tensile strength,the minimum tension-compression strength ratio of silt and silty sand cement stabilized soil is 0.12,and the ratio of silty caly cement stabilized soil may reach 0.16,which is much larger than that in the technical regulations(0.06).
引文
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[10]CONSOLI N C,da FONSECA A V,CRUZ R C,et al.Voids/cement ratio controlling tensile strength of cement-treated soils[J].J Geotech Geoenviron Engin,2011,137(11):1126-1131.
[11]FESTUGATO L,MENGER E,BENEZRA F,et al.Fibre-reinforced cemented soils compressive and tensile strength assessment as a function of filament length[J].Geotext Geomembrane,2017,45(1):77-82.
[2]刘松玉,钱国超,章定文.粉喷桩复合地基理论与工程应用[M].北京:中国建筑工业出版社.
[3]严红霞.水泥土的拉、压强度性能试验研究及其数值模拟[D].扬州:扬州大学,2009.
[4]PORBAHA A,SHIBUYA S,KISHIDA T.State of the art in deep mixing technology.Part III:Geomaterial characterization[J].Proc Inst Civil Eng-Ground Improv,2000,4(3):91-110.
[5]NAMIKAWA T,KOSEKI J.Evaluation of tensile strength of cement-treated sand based on several types of laboratory tests[J].Soils Found,2007,47(4):657-674.
[6]马军庆,王有熙,李红梅,等.水泥土参数的估算[J].建筑科学,2009,25(3):65-67.
[7]陈峰.玄武岩纤维水泥土抗拉性能试验研究[J].深圳大学学报(理工版),2016,33(2):188-193.
[8]CONSOLI N C,CRUZ R C,FLOSS M F,et al.Parameters controlling tensile and compressive strength of artificially cemented sand[J].J Geotech Geoenviron Engin,2010,136(5):759-763.
[9]CONSOLI N C,CORTE M B,FESTUGATO L.Key parameter for tensile and compressive strength of fibre-reinforced soil-lime mixtures[J].Geosynth Int,2012,19(5):409-414.
[10]CONSOLI N C,da FONSECA A V,CRUZ R C,et al.Voids/cement ratio controlling tensile strength of cement-treated soils[J].J Geotech Geoenviron Engin,2011,137(11):1126-1131.
[11]FESTUGATO L,MENGER E,BENEZRA F,et al.Fibre-reinforced cemented soils compressive and tensile strength assessment as a function of filament length[J].Geotext Geomembrane,2017,45(1):77-82.