钢渣-水泥注浆加固全强风化花岗岩试验研究

Study on strongly-fully weathered granite reinforced by steel slag cement grouting

为研究钢渣-水泥浆液对全强风化花岗岩的注浆效果,采用了不同水灰比、不同钢渣含量的浆液对全风化花岗岩进行注浆试验,测定了浆液凝结时间、浆液扩散半径,结石体单轴抗压强度,渗透系数的变化曲线,初步确定了注浆效果较好的水灰比与钢渣含量范围.后采用PFC离散元软件对实际隧道掌子面进行数值模拟,进一步评价钢渣-水泥对全风化花岗岩的注浆加固效果,分析最优水灰比与钢渣含量.结果表明:浆液扩散半径随着钢渣含量上升而减小,当浆液水灰比≥1时,浆液扩散半径减小幅度不超过6%;钢渣含量与水灰比,共同影响全风化花岗岩结石体的抗压强度,当水灰比<1时,钢渣含量上升,结石体抗压强度先上升后减小,当水灰比≥1时,钢渣含量上升,结石体抗压强度不断升高但速率减慢;结石体的渗透系数随着钢渣含量上升,先增大而后减小,且水灰比越小,下降越明显;全风化花岗岩地层隧道超前加固中,采用水灰比1:1,钢渣含量为6%钢渣-水泥浆液进行注浆,掌子面的稳定性可以得到有效保障,研究成果可为类似全风化花岗岩地层的注浆加固工程提供指导.

In order to study the grouting effect of steel slag cement slurry on completely weathered granite,grouting tests were carried out on completely weathered granite with different water cement ratio and steel slag content.The variation curves of grout setting time,slurry diffusion radius,uniaxial compressive strength and permeability coefficient were measured.The range of water cement ratio and steel slag content with better grouting effect was preliminarily determined.After that,PFC discrete element software is used to simulate the actual tunnel face,further evaluate the grouting reinforcement effect of steel slag cement on completely weathered granite,and analyze the optimal water cement ratio and steel slag content.Results show that:the slurry diffusion radius decreases with the increase of steel slag content.When the water cement ratio of slurry is greater than or equal to 1,the decrease range of slurry diffusion radius is not more than 6%;the steel slag content and water cement ratio jointly affect the compressive strength of completely weathered granite stone body.When the water cement ratio is less than 1,the steel slag content increases,and the compressive strength of the stone body increases first and then decreases With the increase of steel slag content,the permeability coefficient of stone body first increases and then decreases,and the smaller the water cement ratio,the more obvious the decrease;in the advanced reinforcement of tunnel in completely weathered granite stratum,the water cement ratio is 1:1,and the steel slag content is 6%.The stability of tunnel face can be effectively guaranteed by grouting with steel slag cement slurry.The research results can provide guidance for grouting reinforcement projects similar to completely weathered granite stratum.