水泥砂浆固化粉质黏土分离式Hopkinson压杆试验与分析

Analysis of silty clay stabilized by cement mortar based on split Hopkinson pressure bar experiment

为研究掺砂量(与干土的质量比)对水泥粉质黏土冲击压缩强度及能量吸收特征的影响,采用Φ50mm分离式Hopkinson压杆(Split Hopkinson pressure bar,SHPB)试验装置对不同掺砂量的水泥粉质黏土进行了0.4 MPa冲击气压下的冲击压缩试验。结果表明:普通水泥粉质黏土(未掺砂)动态应力-应变曲线大致分为弹性阶段、屈服硬化阶段及破坏阶段,而随着掺砂量的逐渐增加,水泥砂浆固化粉质黏土动态应力-应变曲线中屈服阶段愈加不明显,出现了理想的塑性阶段;水泥砂浆固化粉质黏土的冲击压缩强度随掺砂量的增大而先增大后减小,在掺砂量为10%时达到最大平均动强度9.56 MPa,较普通水泥土强度提高9.79%;水泥砂浆固化粉质黏土的吸收能随冲击压缩强度的增大而增大,两者具有较好的指数关系。

To study the effects of sand content on dynamic compression strength and energy absorption characteristics of cemented silty clay,dynamic compression tests on cemented silty clay with different sand contents were conducted usingΦ50 mm split Hopkinson pressure bar（SHPB）apparatus under 0.4 MPa impact pressure.The results show that the dynamic stress-strain curve of plain cemented silty clay（without sand）can be divided into three stages of elastic deformation,yield-hardening and failure.With the increase of sand content,there is an ideal plastic stage occurring on dynamic stress-strain curve but not obvious for yield stage gradually.In addition,the dynamic compression strength of silty clay stabilized by cement mortar increases firstly and then decreases with the increasing of sand content.The maximum of dynamic compression strength of silty clay stabilized by cement mortar is 9.56 MPa at sand content of 10%,which results in 9.79%increase compared with plain cement-soil.The absorbed energy of silty clay stabilized by cement mortar increases with the increase of dynamic compression strength,which shows an approximate exponential relation.