Cement-soil mixing piles are often used to treat soft soil roadbeds in mountainous areas.However,weak compressive strength and deformation performance make them prone to brittle failure.Therefore,a method using basalt fibers to improve the compressive performance of cement-soil mixing piles is proposed in this study.Then,the influence of fiber content and length on the compressive performance of basalt fiber reinforced cement-soil is analyzed through a series of uniaxial compression tests.Finally,the mechanism of basalt fiber improving the compressive performance of cement-soil is revealed through several scanning electron microscope(SEM)tests.The results show that the stress-strain curves of basalt fiber reinforced cement-soil have undergone four typical stages:pore compaction,elastic deformation,elastic-plastic deformation,and failure.The addition of basalt fibers effectively improves the compressive performance of cement-soil.Its compressive strength and peak strain first increase and then decrease with the increase of fiber content,and the elastic modulus first decreases and then fluctuates slightly.As the fiber length increases,the compressive strength decreases,the peak strain first increases and then decreases,while the elastic modulus first decreases and then increases.When the fiber content is 0.6％and the length is 6 mm,the compressive strength reaches its maximum value.Basalt fibers reinforce the cement-soil through friction and anchoring force between the basalt fibers and the cement soil particles.This constrains the crack propagation inside the cement-soil and enhances the connecting force between the particles.However,the fibers will be stacking and cross overlapping when they are too much or too long in length.This phenomenon will reduce the number of effective reinforced fibers and thereby reducing the compressive performance of the sample.Therefore,when adding basalt fibers to cement-soil,the fiber content and length should be appropriate.
关键词
软弱土/玄武岩纤维/水泥土搅拌桩/单轴抗压试验/电镜扫描
Key words
Soft soil/Basalt fiber/Cement-soil mixing pile/Uniaxial compressive test/Scanning electron microscope(SEM)
维普
万方数据