软基地层加固材料及应用性能分析

Material reinforcement and application performance analysis of soft foundation strata

针对传统软基地层加固难题,提出一种新型浆液结石体的制备。研究了外加剂对结石体强度的影响,对其加固机理及加固效果进行分析。试验结果表明,水泥掺量为8%,适合的水胶比为1.25∶1,氧化镁掺量为4%时,浆液结石体7、14和28 d抗压强度分别为0.98、1.06和1.15 MPa。使用氧化镁浆液结石体对软基地层进行加固静载荷试验结果为,单桩最大加载值均高于设计值的2倍;在静载荷条件下,单桩竖向位移与荷载基本表现出线性关系,无陡降现象出现,桩基承载力特征值均高于200 kPa。当作用载荷达到400 kPa时,检测沉降值为2.5 mm,模拟沉降值为1.94 mm,二者差值为0.56 mm,该差值处于可接受范围内。

Aiming at the difficult problem of traditional soft foundation reinforcement,a new type of slurry stone body preparation was proposed.We first studied the influence of admixtures on the strength of the stone body,and then analyzed its reinforcement mechanism and effect.The test results showed that when the cement content was 8%,the suitable water cement ratio was 1.25∶1,and the magnesium oxide content was 4%,the compressive strength of the slurry stone body at 7 d,14 d,and 28 d was 0.98 MPa,1.06 MPa,and 1.15 MPa.The static load test results by using magnesium oxide slurry stone body to reinforce soft foundation stratum showed that the maximum loading value of a single pile was both higher than the design value by 2 times.Under static load conditions,the vertical displacement of a single pile basically exhibited a linear relationship with the load,without any steep drop phenomenon.The characteristic values of the bearing capacity of the pile foundationwere all higher than 200 kPa,showing a good reinforcement effect.When the applied load reached 400 kPa,the measured settlement value was 2.5 mm,and the simulated settlement value was 1.94 mm,with a difference of 0.56 mm.This difference was within an acceptable range,which proved that in subsequent projects,the soil reinforcement effect could be evaluated by establishing a model.